Orthopedic Board Review: OITE & AAOS MCQs Part 224

About This Board Review Set

This is Part 224 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

This set has been strictly audited and contains 100 100% verified, high-yield multiple-choice questions (MCQs) modelled on the exact format of the Orthopaedic In-Training Examination (OITE) and the American Academy of Orthopaedic Surgeons (AAOS) board examinations.

How to Use the Interactive Quiz

Two distinct learning modes are available:

Study Mode — After selecting an answer, you immediately see whether you are correct or incorrect, together with a full clinical explanation and literature references.
Exam Mode — All feedback is hidden until you click Submit & See Results. A live timer tracks elapsed time. A percentage score and detailed breakdown are displayed upon submission.

Pro Tip: Use keyboard shortcuts A–E to select options, F to flag a question for review, and Enter to jump to the next unanswered question.

Topics Covered in Part 224

This module focuses heavily on: Arthroplasty, Foot, Fracture, Hip, Knee, Revision, Scoliosis.

Sample Questions from This Set

Sample Question 1: What is the most consistent finding regarding glenohumeral kinematics in patients with symptomatic tears of the rotator cuff?...

Sample Question 2: A 17-year-old high school track athlete has had progressive midfoot pain for the past 3 weeks that prevents him from running. Examination reveals pain over the tarsal navicular. Radiographs are normal, but a CT scan reveals a nondisplaced s...

Sample Question 3: A non-communicative 16-year-old girl with spastic quadriplegic cerebral palsy and a 75-degree thoracolumbar scoliosis undergoes a successful posterior spinal fusion with instrumentation. What is the most predictable outcome of the surgical ...

Sample Question 4: A 45-year-old distance runner has a hyaluronic acid injection to his knee because of degenerative arthritis. He immediately develops a severe rash and a systemic hypersensitivity reaction. This patient most likely is also allergic to which ...

Sample Question 5: belowshowtheradiographsobtainedfromayearoldmanwithprogressivelyworseningrightsidehippainoverthelast8months.Heis6feettall,withaBMIof51kg/m2andreportsthathisindex totalhiparthroplastywasperformed8yearsago.Thepreoperativework-upincludesnegativ...

Why Active MCQ Practice Works

Evidence consistently demonstrates that active recall through spaced MCQ practice yields substantially greater long-term retention than passive reading alone (Roediger & Karpicke, 2006). All questions in this specific module have been algorithmically verified for clinical integrity and complete explanations.

Comprehensive 100-Question Exam

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Question 1

What is the most consistent finding regarding glenohumeral kinematics in patients with symptomatic tears of the rotator cuff?

Explanation

DISCUSSION: Normal glenohumeral kinematics are represented by ball-and-socket modeling when the rotator cuff is intact. This is true for motion that involves more than 30 degrees of abduction. In patients with shoulder pain and symptomatic rotator cuff tears, superior translation occurs with abduction beyond 30 degrees. This is quite evident in massive tears but is seen consistently to a lesser degree with smaller tears.
REFERENCES: Yamaguchi K, Sher JS, Anderson WK, et al: Glenohumeral motion in patients with rotator cuff tears: A comparison of asymptomatic and symptomatic shoulders. J Shoulder Elbow Surg 2000;9:6-11.
Poppen NK, Walker PS: Normal and abnormal motion of the shoulder. J Bone Joint Surg Am 1976;58:195-201.

Question 2

A 17-year-old high school track athlete has had progressive midfoot pain for the past 3 weeks that prevents him from running. Examination reveals pain over the tarsal navicular. Radiographs are normal, but a CT scan reveals a nondisplaced sagittally oriented fracture line. Management should consist of

Explanation

DISCUSSION: The patient has a nondisplaced stress fracture of the tarsal navicular. Weight bearing is associated with a high rate of nonunion; therefore, management should consist of immobilization and no weight bearing for 8 weeks. Delayed union or nonunion is treated by excision of sclerotic fracture margins and bone grafting, with or without internal fixation. Generally, CT should be repeated to document healing before permitting a return to sports.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 597-612.
Torg J, Pavlov H, Cooley LH, et al: Stress fractures of the tarsal navicular: A retrospective review of twenty-one cases. J Bone Joint Surg Am 1982;64:700-712.

Question 3

A non-communicative 16-year-old girl with spastic quadriplegic cerebral palsy and a 75-degree thoracolumbar scoliosis undergoes a successful posterior spinal fusion with instrumentation. What is the most predictable outcome of the surgical procedure?

Explanation

DISCUSSION: Surgical treatment of spinal deformity in a totally involved child with cerebral palsy has been shown on outcomes instruments to significantly improve the caregiver’s perception of the child’s comfort. The other parameters mentioned are difficult to measure and unpredictable.
REFERENCES: Tsirikos Al, Lipton G, Chang WN, et al: Surgical correction of scoliosis in pediatric patients with cerebral palsy using the unit rod instrumentation. Spine 2008;33:1133-1140.
Cassidy C, Craig CL, Perry A, et al: A reassessment of spinal stabilization in severe cerebral palsy. J Pediatr Orthop 1994;14:731-739.

Question 4

A 45-year-old distance runner has a hyaluronic acid injection to his knee because of degenerative arthritis. He immediately develops a severe rash and a systemic hypersensitivity reaction. This patient most likely is also allergic to which of the following?

Explanation

DISCUSSION: Preparations of hyaluronic acid can be divided into low and high molecular weight compounds. Contraindications to intra-articular hyaluronic acid include joint or skin infection, overlying skin disease, and allergies to chicken or egg products if using a preparation derived from rooster comb.
REFERENCES: Gloyscen DN, Gillespie MJ, Schenek RC: The effects of medication in sports injuries, in DeLee JC, Drez D Jr, Miller MD (eds): Orthopedic Sports Medicine: Principles and Practice, ed 2.
Philadelphia, PA, WB Saunders, 2003, vol 1, pp 121-124.
Schenck RC Jr: New approaches to the treatment of osteoarthritis: Oral glucosamine and chondroitin sulfate. Instr Course Lect 2000;49:491-494.

Question 5

below show the radiographs obtained from a year old man with progressively worsening right side hip pain over the last 8 months. He is 6 feet tall, with a BMI of 51 kg/m 2 and reports that his index total hip arthroplasty was performed 8 years ago. The preoperative work-up includes negative infectious laboratory results. What is the most appropriate surgical plan for revision of the femoral component in this patient?

Explanation

DISCUSSION:
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The patient’s radiographs demonstrate varus femoral remodeling around a broken cylindrical, distally fixed femoral stem. Proximal femoral remodeling around loose or fractured stems occurs in 21% to 42% of femoral revisions, based on the definitions outlined by Foran and associates. In definition 1, varus femoral remodeling occurs when the template falls within 2 mm of the endosteal cortex of the metaphysis on templating with a diaphyseal engaging stem. In definition 2, varus femoral remodeling = when the template crosses the lateral femoral cortex proximally. Based on the templating or drawing a line from the isthmus proximally along the lateral cortex, implantation of a straight stem would perforate the cortex proximally, indicating varus femoral remodeling. An extended trochanteric osteotomy would aid in the removal of the well-fixed distal segment and enable the safe insertion of the new femoral component. The approach is not the concern in this case, because extended trochanteric osteotomies have been described from the posterior and direct lateral approaches with excellent outcomes and union rates. The key is that the extended osteotomy is necessary and not a trochanteric slide or standard (shorter or incomplete trochanteric) osteotomy. These types would not provide access to the well-fixed distal stem, nor would they afford a straight tube in which to insert a new femoral component.

Question 6

A 25-year-old construction worker lands on his outstretched hand in a fall. The position of his wrist at the time of impact causes a force that leads to hyperextension, ulnar deviation, and intercarpal supination. Radiographs are shown in Figures 48a and 48b. What type of injury pattern is shown?

Explanation

DISCUSSION: The patient has a transscaphoid dorsal perilunate dislocation. The radiographs clearly define a dorsal dislocation of the capitolunate joint, and the scaphoid fracture component is easily visible on the AP view. A scaphoid fracture alone is an unlikely diagnosis because of the midcarpal dislocation component. The radiocarpal joint is not dislocated because the lunate is sitting in the lunate fossa of the radius. Isolated radiocarpal dislocations are not associated with a midcarpal disruption. While a midcarpal dislocation is a component of a dorsal perilunate dislocation, this diagnosis does not address the scaphoid fracture. A volar lunate dislocation is not seen because the lunate is reduced in the lunate fossa of the distal radius. Volar lunate dislocations are in the spectrum of injury of perilunate dislocations and fracture-dislocations; however, the radiographs show a transscaphoid dorsal perilunate dislocation.
REFERENCES: Mayfield JK, Johnson RP, Kilcoyne RK: Carpal dislocations: Pathomechanics and progressive perilunar instability. J Hand Surg Am 1980;5:226-241.
Herzberg G, Comtet JJ, Linscheid RL, Amadio PC, Cooney WP, Stalder J: Perilunate dislocations and fracture-dislocations: A multicenter study. J Hand Surg Am 1993;18:768-779.

Question 7

5 standard deviations below young normals (< -2.5). The Z-score represents a comparison to age-matched normals.

Explanation

You are planning on performing a study to determine if there is a difference in healing rates for distal femur fractures by placing patients on Vitamin D after injury. With regards to your study, the statistician mentions a power analysis. What is the purpose of power analysis and when should it be performed?
This patient has an impending subtrochanteric femur fracture and should be stabilized with cephalomedullary nailing.
Bisphosphonates have been shown to prevent osteoporotic fractures. They suppress osteoclastic recruitment and activity and induce apoptosis of osteoclasts. However, they have also been associated with subtrochanteric femur fractures. Cortical stress reactions in the form of lateral cortical thickening have been documented when radiographs were performed during the prodromal period preceding these fractures. If radiographs are obtained and demonstrate lateral cortical thickening in the presence of thigh pain, the entire femur should be stabilized with prophylactic cephalomedullary nailing to prevent fracture.
Shane et al. performed a review of atypical subtrochanteric and diaphyseal
femoral fractures. They report that long-term bisphosphonate use is associated with these injuries. Bisphosphonates localize in areas that are developing stress fractures and suppress intracortical remodeling. When bisphosphonate use has stopped, the risk of fracture decreases over time. They conclude that teriparatide may advance the healing of atypical femur fractures after surgical treatment.
Koh et al. studied the natural history of femoral stress lesions associated with bisphosphonate therapy. They determined certain features that predispose to complete stress fractures. They found all patients had thigh pain before fracture. They conclude that cortical stress reactions associated with prolonged antiresorptive therapy and the "dreaded black line" should be prophylactically stabilized to avoid a complete fracture.
Figure A is a radiograph of the proximal femur demonstrating lateral cortical thickening with the "dreaded black line." Illustration A is the same image with an arrow indicating the "dreaded black line."
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Which of the following statements regarding bone mineral density (BMD) is true?
The 2017 American College of Rheumatology/American Association of Hip and Knee Surgeons Guideline for the Perioperative Management of Antirheumatic Medication states that hydroxychloroquine can be continued and etanercept
should be held for 2 weeks prior to undergoing total hip arthroplasty.
Patients with rheumatoid arthritis (RA) report high satisfaction following hip or knee replacement despite the higher rates of infection, dislocation, and readmission rates. Patients with RA may present on a variety of different biologic and nonbiologic medications used to control their systemic RA.
Optimal preoperative management of these immunosuppressant medications may help mitigate some of the risks of postoperative complications in RA patients.
Singh et al. reviewed the evidence surrounding the benefits and harms of various antirheumatic medications. They found evidence for traditional DMARDs, biologic agents, and nonbiologic agents in acute and established RA totaling 74 recommendations. They concluded that these recommendations are not prescriptions and that ultimate decision making should be patient- specific in a shared-decision
making process between the patient and physician.
Goodman et al. performed a multistep literature review on optimal antirheumatic medication management prior to joint replacement surgery. They were able to provide recommendations on when to continue, when to withhold, and when to restart these medications, and the optimal perioperative dosing of glucocorticoids. They concluded that these guidelines will help physicians manage antirheumatic medications at the time of elective THA or TKA.
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An 83-year-old woman presents complaining of thigh pain. The pain has been progressing over the last few months. She denies any night chills or recent weight loss. She has smoked 1 pack per day for the last 40 years. Her current medications are alendronate and citalopram. Her current imaging is shown in Figure A. What is the next best step in treatment?
The patient is presenting with complex regional pain syndrome (CRPS) type 1 after a distal 1/3 tibial shaft fracture. The best diagnostic test for this is a thorough history and physical exam.
CRPS is a disorder of increased sympathetic activity in a region of prior trauma. Cases can be classified as type 1, where there is no demonstrable nerve damage, or type 2, where a specific nerve is affected. Patients will typically present with cool and mottled skin that atrophic and absent of hair. Many times the affected limb will be noticeably cooler than the contralateral side. In advanced stages, there will be joint contractures and extensive osteopenia on radiographs. Several diagnostic aids have been developed, but remain inadequate to diagnostic sensitivity compared to a thorough history and physical.
Shah et al. reviewed the diagnosis and treatment of CRPS. The authors reported that sweat quantification testing, skin thermography, and electromyography may be useful aids in diagnosis, but there is a lack of diagnostic sensitivity to make these tests reliable. The authors concluded that evidence suggests gabapentin, prazosin, propranolol, nifedipine, and mexiletine are the best medications for treatment.
Hogan et al. reviewed the diagnosis and treatment of CRPS. The authors reported that the most sensitive means for diagnosis is a good history and physical exam as there is no single test to confirm the diagnosis. The authors recommended a multidisciplinary team approach including pain specialists, physical therapists, and orthopedic surgeons as syndrome response to medications is variable.
Figures A and B demonstrate an AP and lateral radiograph of the right tibia and fibula with a distal 1/3 tibia fracture. Illustration A depicts that Lankford and Evans classification for CRPS.
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A 72-year-old female with rheumatoid arthritis is scheduled to undergo total hip arthroplasty. She presents for her preoperative visit and asks about dosing of her antirheumatic medications. She currently takes etanercept weekly and hydroxychloroquine daily. Which of the following is the best dosing recommendation for her antirheumatic medications prior to surgery?
the entire right lower extremity, with sensitivity to cold temperatures. Physical exam demonstrates hyperesthesia of the extremity, thin and shiny appearing skin, cyanotic appearing with skin cool to the touch. What is the likely diagnosis and what is the best diagnostic test?
In a 5-year-old female without a history of trauma or rashes and with persistent oligoarthritis that improves during the day, the most likely diagnosis is juvenile idiopathic arthritis (JIA). Early-onset JIA is associated with chronic uveitis.
JIA is defined by the American College of Rheumatology as persistent arthritis and swelling in one or more joints for 6 weeks or longer in a patient younger than 16 years of age. It is a diagnosis of exclusion, usually entailing pattern recognition after a thorough history and physical exam. Serologic studies, including rheumatoid factor (RF), antinuclear antibody (ANA), and HLA-B27, may be helpful to rule out other etiologies (septic arthritis, systemic lupus erythematosus, rheumatic fever); however, these are neither sensitive nor specific. In patients with JIA, evaluation for possible uveitis by an ophthalmologist should be considered. Although this patient could have Lyme disease given the likely recent exposure to ticks during her camping trip, the lack of a rash, unresponsiveness to antibiotics, and polyarthritic nature make it less likely.
Arvikar et al. compared clinical features of systemic autoimmune arthritides to those of Lyme arthritis. They found that patients with Lyme arthritis usually had a clinical picture of monoarticular knee arthritis, whereas patients with systemic autoimmune arthritis manifested with polyarthritis. They concluded that systemic autoimmune arthritis with or without a history of Lyme disease should be treated with disease-modifying antirheumatic drugs (DMARDs).
Punaro et al. reviewed common rheumatologic conditions in children who may present to orthopaedic surgeons. For JIA, they reported a typical history of oligoarthritis for 6 weeks or more in a white female patient, with a peak onset between ages 1 and 3 years. Uveitis was typically chronic, bilateral, and asymptomatic. They concluded that while serologic tests were useful in
excluding other diagnoses, they were less useful in confirming JIA.
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A 40-year-old patient sustains the injury in Figures A and B six months ago and underwent the appropriate fixation method. The patient is continuing to experience a tremendous amount of pain in
returning from summer camp. She denies any antecedent trauma, fevers, or rashes. Antibiotics prescribed by her primary care doctor have provided no significant relief, but she reports feeling better at
the end of the day. Labs reveal a negative rheumatoid factor. Which of the following is most commonly associated with her diagnosis?
The hardware shown in Figure A is a tension band plate. It is able to perform its function due to the Hueter-Volkmann Law.
Bones undergo continuous remodeling and turnover which are sensitive to the surrounding mechanical environment. Bone remodeling is governed by Wolff’s law, while the mechanical influence on longitudinal bone growth is controlled by the Hueter– Volkmann law. Wolff’s law relates to the adaptation of bone to its mechanical environment, and involves bone apposition stimulated by intermittent increased stress and bone resorption following reduced intermittent stress. The Hueter–Volkmann law relates to immature bone growth suppression through sustained compressive loading and growth acceleration by reduced loading or distraction.
Villemure et al. performed a review of growth plate mechanics and mechanobiology. They report that growth plates are sensitive to the surrounding mechanical environment. There are a number of clinical conditions of the skeleton that are thought to result from abnormal mechanical loading conditions influencing longitudinal growth prior to skeletal maturity, such as clubfoot (associated with limb position in utero), slipped capital femoral epiphysis, tibia vara, spondylolisthesis, and scoliosis.
Shabtai et al. performed a review of the limits of growth modulation using tension band plates in the lower extremities. Tension band plates have been found to be safe and effective at correcting pediatric frontal plane angular deformities. They found that the success rate for idiopathic cases nears 100%. The success rate for pathologic cases is lower and they have a higher complication rate. They conclude that tension band plates are a reasonable option for all but the most extreme frontal and sagittal plane deformities.
Figure A is a bilateral knee radiograph of a pediatric patient with tension band plates on the right tibia. Illustration A is a bilateral knee radiograph of the same pediatric patient.
The physis appears to have partially closed down and the angle of the screws has changed. One of the screws has broken which happens frequently.
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A 5-year-old girl presents with an 8-week history of pain and swelling in the right knee, right shoulder, and left elbow after
Limb buds develop at 4 weeks and are first able to be visualized by transvaginal ultrasound at 8 weeks.
In a developing fetus, limb buds form at 26 days. The development of the limb is guided by a complex interaction of gene transcription factors and regulatory loops. The most important genes in limb development are sonic hedgehog (SHH), HOX genes, and WNT genes. Ultrasound evaluation is increasingly
being utilized to diagnose and guide treatment for developmental anomalies of a fetus. The limb buds of the fetus can be first seen at 8 weeks of gestation.
Krakow et al. reported on the prenatal diagnosis of fetal developmental dysplasias. They found that differentiating these disorders in the prenatal period can be challenging because they are rare and because many of the ultrasound findings are not necessarily pathognomic for a specific disorder.
Oetgen et al. authored a review on prenatal diagnosis of musculoskeletal conditions. They note that ultrasonography is a safe and cost-effective tool used to prenatally detect common musculoskeletal conditions such as clubfoot, skeletal dysplasias, limb-length discrepancies, spinal abnormalities, and hand and other upper extremity deformities.
Illustration A is a pictorial representation of limb bud formation Incorrect Answers:
The hardware shown in Figure A relies on which of the following principles to achieve its function?
Both Hemophilia A and B are inherited by X-linked recessive patterns. Hemophilia A is caused by factor VIII deficiency, whereas hemophilia B is caused by factor IX deficiency.
Factor VIII deficiency, also known as Hemophilia A, most commonly affects males due to the X-linked recessive inheritance pattern and occurs with a frequency of 1:5000 males. Factor IX deficiency, also known as hemophilia B, also only affects males due to X-linked recessive inheritance, with a frequency of 1:30000 males. Both disorders commonly present with recurrent spontaneous hemarthroses that affect large joints, typically the knee, leading to chronic synovitis and eventually joint destruction. Initial treatment involves factor replacement to within 60% normal, joint aspiration, and immobilization until the physical exam is normal. Treatment for chronic synovitis involves radiosynovectomy, open synovectomy, or arthroscopic synovectomy. End- stage joint destruction requires reconstructive surgery with aggressive factor replacement pre- and postoperatively.
Luck et al. performed a review on hemophilic arthropathy and recommended treatment options for hemophilic arthropathy. The authors recommend that infants get
primary prophylaxis with factor replacement prior to developing a "target" joint. In patients that experience a hemarthrosis, factor replacement with joint aspiration and immobilization until a normal physical exam are paramount for reducing chronic synovitis. Synovectomy, either arthroscopic or open, is recommended for chronic synovitis to reduce the progression of arthropathy. Then arthroplasty is reserved for end-stage joint destruction characteristic of recurrent synovitis.
Zingg et al. performed a retrospective review of 43 consecutive TKA in patients with hemophilic arthropathy. At 9.5 years follow-up there were two hematogenous infections, three revisions, 94% good-to-excellent patient- reported outcomes, and significantly increased ROM compared to preoperative examination. The authors concluded that TKA remains a successful option for end-stage arthropathy for hemophiliacs, but outcomes do not reach the level of non-hemophiliacs.
Journeycake et al. performed a retrospective review on 28 arthroscopic synovectomies performed on pediatric hemophiliac patients with chronic synovitis. At 5-years follow-up 76% of affected joints had stable or improved levels of function. The authors concluded that arthroscopic synovectomy provides a reliable means for limiting current hemorrhage in the affected joint and improving ROM.
Illustration A depicts a pedigree with an X-linked recessive inheritance pattern. Notice how only males are affected, but women can be carriers. Illustration B depicts the process by which recurrent hemarthroses leading to chronic synovitis and then arthropathy.
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deficiency of von Willibrand factor; which assists in platelet adhesion. It is inherited in autosomal recessive pattern with the gene locus found on chromosome 12.
In terms of fetal limb bud development, which of the following is true?
Fluoroquinolones such as levofloxacin act by block DNA replication by inhibiting DNA gyrase.
Fluoroquinolone antibiotics are bactericidal, and their mechanism of action works through the inhibition of DNA gyrase. Side effects of fluoroquinolones include inhibition
of early fracture healing through toxic effects on chondrocytes and increased rates of tendinitis, with a special predilection for the Achilles tendon.
Levine et al. published a review on fluoroquinolones. They report that fluoroquinolones act by inhibiting DNA topoisomerases such as DNA gyrase (topoisomerase II). Due to increasing antibiotic resistance, their use is limited to specific clinical scenarios.
Additionally, their use in children is restricted due to a potential for growth disturbance and cartilage damage.
Perry et al. performed an experimental study on the inhibition of fracture healing by levofloxacin and trovafloxacin in rats. They found that experimental fractures systemically exposed to levofloxacin or trovafloxacin have diminished healing during the early stages of fracture repair. They, therefore, concluded that the administration of quinolones during early fracture repair may compromise fracture healing in humans.
Illustration A is an image illustrating the targets of the various antibiotic classes. Incorrect Answers:
Which of the following bleeding disorders is caused by an X- linked recessive mutation?
An isotonic muscle contraction is a muscle contraction with constant tension such as the upwards and downwards motions of a biceps curl.
The word “isotonic” is derived from two Greek words: “iso”, meaning “same”, and “tonikos” meaning “tension”. An isotonic muscle contraction is one during which the muscle maintains the same tension as it shortens. There are two types of isotonic contractions: concentric and eccentric. In a concentric isotonic contraction, the muscle shortens while contracting. In an eccentric isotonic contraction, the muscle lengthens during contraction.
Ashe et al. review exercise programs used in physical therapy. They report that muscle strengthening can be classified into isotonic, isometric, and isokinetic contractions.
Isotonic exercises involve the development of muscular force through range of motion or movement. Isokinetic exercises involve the force generation at a constant speed.
Isometric exercises involve the development of force without movement, as in tensing and holding a muscle
at a certain part of the range.
Illustration A is an image which illustrates the difference between isotonic and isometric contractions.
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Which of the following correctly describes a class of antibiotics and its mechanism of action?
The third step in applying EBM is to appraise the evidence.
Evidence-based medicine (EBM) refers to an explicit process of using and evaluating information to make medical decisions. When applying EBM in practice, there are 5 steps that should be followed: 1) formulate an answerable question, 2) gather evidence, 3) appraise the evidence, 4)
implement the evidence, and 5) evaluate the process to determine the efficacy of the proposed treatment.
Bernstein published a review on EBM. He advocates for the use of a five-step process for sound decision making: formulate answerable questions, gather evidence, appraise the evidence, implement the valid evidence, and evaluate the process.
Spindler et al. published a review on reading and reviewing the orthopaedic literature. They focus on the third step of EBM: appraising the evidence. They report that systematic review assists the orthopaedic surgeon in interpreting study results and in understanding the relative validity of these results in the hierarchy of evidence.
Illustration A is a table listing the 5 steps of EBM.
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4: Gathering evidence is the second step of EBM.
Which of the following activities describes an isotonic muscle contraction?
On average, physicians interrupt patients within 23 seconds of their interview.
The patient-physician interaction often begins with an initial "survey of problems" through an open-ended question designed to give the patient the freedom to speak and explain
their reason for seeking care. This is followed by a set of focused or closed-ended questions designed to elicit additional details and clarification. Unfortunately, physicians are often quick to interrupt or redirect patients prior to the completion of their reason for seeking care. This practice may lead to missed information, poor communication, and poor
patient satisfaction. Time constraints on physicians may contribute to this behavior. Marvel et al. looked at 264 patient-physician interviews by board-certified family practice physicians. They found patients' initial statement of concern were only complete 28% of the time with an average physician redirection
time of 23.1 seconds. They found patients only needed an additional 6 seconds to complete their statement of concern compared to those who were
redirected by the physician. They conclude that obtaining a complete patient agenda takes little time and can improve interview efficacy and increase data collection.
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When applying evidence-based medicine (EBM) in practice, there are 5 steps that should be followed. Which of the following describes the third step?
For upper extremity surgery, the majority of narcotic pills prescribed by hand surgeons are not consumed by patients.
Patients in the United States are treated very aggressively for pain control. This is due, in part, to The Joint Commission, which has controversially identified pain as the "5th vital sign." An opioid epidemic has ensued which has been linked to a decreased the life expectancy in the United States for three consecutive years beginning in 2014. As a result, unused prescription pain medication following upper extremity surgery represents a liability for patients and surgeons. Following simple soft tissue surgeries (trigger finger, carpal tunnel, mass removal) patients typically only require pain
medication for 2-3 days, and there is no difference in pain control between narcotic or anti-inflammatory medication.
Stanek et al. implemented a standardized postoperative opioid prescription protocol for a group of academic hand surgeons. They found that the protocol decreased the opioid prescription size by 15%, prescription variability, and decreased refills. The authors recommend the development of specific prescription guidelines.
Rodgers et al. interviewed 250 patients after upper extremity surgery about opioid consumption. They reported that patients most frequently received 30 narcotic pills, which provided relief in 92% of cases. The authors found that patients undergoing bone procedures used on average 14 pills, most patients took medication for less than two days post-operatively, and the number of pills consumed on average was 10, with 19 pills unused. As a result, the authors advocated for more limited narcotic prescriptions post-operatively.
Weinheimer et al. randomized patients undergoing hand surgery to receive either Norco or acetaminophen/ibuprofen. They found no difference in time until patients were pain- free, average VAS scores, or the absolute number of those patients who were pain-free. They did find that the narcotic group experienced more adverse side effects (23% vs 3%), ultimately recommending for limiting narcotics post-operatively.
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During a new patient office visit, a physician asks an initial open- ended question to the patient. On average, how much time elapses before the physician redirects the patient's initial statement of concern?
The patient’s laboratory workup is likely to reveal hypovitaminosis D. Metabolic and endocrine abnormalities should be considered in patients who exhibit poor fracture healing, especially in those who lack history and exam findings suggestive of infection.
In addition to ruling out infection, a nonunion workup should include tests to identify metabolic and endocrine abnormalities. 25-hydroxyvitamin D3, synthesized from cholecalciferol in the liver, is the laboratory study of choice to determine vitamin D deficiency. Low vitamin D is a common, and easily treated, form of malnourishment in orthopedic trauma patients. Other important factors that can negatively impact fracture healing include protein malnourishment, diabetes mellitus, nicotine use, and HIV.
Warner et al. showed perioperative vitamin D deficiency correlated with
inferior clinical outcomes in patients who underwent operative fixation of ankle fractures. Of the 98 patients studied, 36 (37%) were found to be deficient in vitamin D (<20 ng/ml) and 31 (32%) were found to have a vitamin D insufficiency (> 20 ng/ml, <30 ng/ml). They concluded insufficient vitamin D may result in worse outcomes in orthopedic trauma patients recovering from fracture fixation.
Brinker et al. reviewed metabolic and endocrine abnormalities in 37 patients with nonunions. Inclusion criteria were: 1) an unexplained nonunion that occurred despite adequate reduction and stabilization; 2) history of multiple low-energy fractures with at
least one nonunion; or 3) a nonunion of a nondisplaced pubic rami or sacral ala fracture. Of the 37 patients who met screening criteria, 31 (84%) had metabolic or endocrine abnormalities. Vitamin D deficiency, discovered in 25 of 37 patients (68%), was the most common newly diagnosed abnormality. The authors conclude all patients with nonunion who meet their screening criteria should be referred to an endocrinologist.
Bishop et al. reviewed the assessment of compromised fracture healing and advocate for a metabolic and endocrine workup in the presence of nonunion. If an endocrinology consultation is unavailable, the initial laboratory screening should include 25- hydroxyvitamin D, calcium, thyroid-stimulation hormone, phosphorus, and alkaline phosphatase levels. They also emphasize that the presence of normal inflammatory markers does not exclude the possibility of infection, which should remain in consideration until fracture union and resolution of symptoms.
Incorrect Answers
However, the rate of infection is lower than hypovitaminosis D and both can occur simultaneously.
A hand surgeon plans on performing a carpal tunnel release on a healthy 45- year-old female. Which of the following is true regarding pain management for this case in the post-operative setting?
The ideal scenario to use the ANOVA test is when comparing parametric continuous data (i.e. BMI) for three or more groups.
In statistical analyses, data can be described as discrete (categorical, ordinal) or continuous. Discrete data are observations that can be expressed as categories such as gender, race, or disease status. Continuous data, such as age, are observations for which the difference between the numbers have meaning on a numerical scale. The ANOVA test is used to compare differences in mean values (i.e. continuous data) when there are more than two independent sample groups. When discrete data is compared in the setting of two or more independent sample groups, the chi-squared (parametric) or Fischer's exact test (non-parametric) may be utilized.
Kuhn et al. reviewed statistical tests when discrete data are analyzed. They reported that data may be either discrete (i.e. categorical) or continuous (i.e. age, BMI, height). They presented examples of tests used for discrete data including the chi-square test and Fischer's exact test. They emphasized the importance of scrutinizing the data presented prior to selecting a statistical test.
Greenfield et al. reviewed statistical tests when continuous data are analyzed. They reported that statistical tests for continuous data must be used if the outcome of interest is a comparison of sample means for data that are continuous (i.e. the height of populations). They discuss one-sample t-tests, independent two-sample t-tests, paired t- tests, and ANOVA.
Illustration A demonstrates an algorithm that is helpful in selecting the correct statistical test.
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A 40-year-old Hispanic male presents with persistent pain seven months after open reduction internal fixation of a closed distal tibial fracture. His postoperative course was unremarkable and weight- bearing was resumed at six weeks. Exam reveals a well-healed incision with tenderness at the fracture site. There is no swelling or erythema. Radiographs demonstrate intact hardware and an oligotrophic nonunion. Laboratory workup is most likely to support which of the following interventions:
General anesthesia carries an increased risk of thromboembolism compared to spinal anesthesia. The remaining statements are false.
There have been multiple factors that demonstrate an increased risk of venous thromboembolism (VTE). Some of these risk factors include a previous VTE, obesity (BMI
> 30), surgery type (i.e. total joint arthroplasty),
hypercoagulable states (i.e. cancer, inheritable traits), myocardial infarction (MI), congestive heart failure, family history of VTE, hormone replacement therapy, elevated hormone conditions, varicose veins, and general anesthesia (increased risk compared to epidural/spinal anesthesia). Current AAOS guidelines recommend mechanical prophylaxis in all total hip and knee arthroplasty patients and chemoprophylaxis is recommended, but no optimal regimen is recommended. Chemical prophylaxis should be individualized for each patient and their risk factors.
Geerts et al. put forth their recommendations on the prevention of VTE from the American College of Chest Physicians in 2008. Some of the important points include aspirin not being recommended as a monotherapy (this recommendation was changed in 2012 and is now accepted as monotherapy), recommendation for mechanical prophylaxis, and recommendation for routine chemoprophylaxis for elective hip and knee arthroplasty for a minimum of 10 days.
Caprini et al. retrospectively reviewed 939 patients with either a DVT, PE, or PE and DVT and their treatment. They found that there was lower than anticipated use of low molecular weight heparin, insufficient bridging of patients to warfarin, and insufficient continuation of anticoagulation following hospitalization. They concluded that hospitals need to re-evaluate adherence to VTE treatment guidelines and develop strategies to optimize therapy.
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An orthopedic surgery intern is preparing to perform statistical analyses for his research project. He presents to the department statistician inquiring about the Analysis of Variance (ANOVA) test. Which of the following below is the ideal scenario to use the ANOVA test?
While almost all patients undergoing major orthopaedic procedures receive VTE prophylaxis, this is often not within the ACCP post-operative VTE prophylaxis guidelines.
VTE events typically occur following hospital discharge, within the first 2 to 6 weeks following surgery. Risk is increased with major orthopaedic surgery due to greater soft tissue disruption, venous stasis from limb manipulation, and post-operative immobility. VTE following major orthopaedic hip and knee surgery represents not only a significant cause of postoperative morbidity and mortality but contributes a substantial economic burden. Prophylaxis is the single-most-important factor mitigating the risk of VTE. Therefore adherence to the AAOS and ACCP guidelines is recommended.
Friedman et al. evaluated compliance of physicians with American College of Chest Physicians (ACCP) post-operative VTE prophylaxis guidelines following TKA and THA. The authors found moderate compliance overall, with 47% of THA and 61% of TKA patients receiving appropriate prophylaxis in terms of type, duration, start time, and dose. Compliance with Warfarin use was the lowest, while that with low-molecular-weight heparin was significantly higher. They concluded that while almost all patients received prophylaxis, this was often not within the guidelines.
Oster et al. investigated the economic consequences of VTE following major orthopaedic hip or knee surgery. The authors found that 2.2% of patients developed clinically significant VTE, 62% after hospital discharge and that patients who developed in-hospital VTE had a significantly longer length of hospital stay and associated costs than those that did out-of-hospital and were later readmitted. They concluded that the economic impact of VTE was
substantial regardless of setting.
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Which of the following statements is true as it relates to the risk of thromboembolism?
Those utilizing opioids prior to elective hip and knee arthroplasty are at elevated risk of complications. Weaning opioids preoperatively has been shown to improve postoperative outcomes.
Nonoperative management of osteoarthritis (OA) is focused on reducing pain and limiting functional impairment with medications, physical therapy, activity modification, weight
loss, and intra-articular corticosteroid injections.
Pharmacologic management of OA includes NSAIDs and tramadol (per the AAOS CPGs). Opioids have been increasingly used for OA despite the lack of evidence behind their usage. Chronic opioid usage may improve OA-related pain but it has been associated with numerous adverse effects and worse musculoskeletal treatment outcomes.
Gaffney et al. in their review of perioperative pain management for hip and knee arthroplasty, describe the role of opioids, cryotherapy, acetaminophen, NSAIDs, tramadol, anticonvulsants, spinal analgesia, epidural analgesia, peripheral nerve blocks, and periarticular injections. They recommend IV dexamethasone on POD1, scheduled Tylenol, scheduled NSAIDs (Celebrex vs naproxen vs ketorolac), and PRN tramadol, oxycodone, or hydromorphone for breakthrough pain.
Nguyen et al. performed a retrospective matched cohort comparing patients undergoing hip or knee arthroplasty who were either opioid-naive, chronic opioid users, or chronic opioid users weaned of opioids preoperatively. They found that chronic opioid users who were able to reduce their preoperative opioid use by half prior to arthroplasty had outcomes (SF12 physical component and WOMAC) superior to those who were unable to decrease preoperative opioid use.
Sing et al. performed a retrospective review including 1263 patients undergoing primary THA or TKA, finding that patients who utilized opioids preoperatively had elevated postoperative pain, consumed a greater amount of morphine equivalents, walked fewer meters, had a longer postoperative length of stay, were more likely to be discharged to a care facility, and had 4-
5x greater 90d complications. They conclude that opioid users are a high-risk group.
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Which of the following is true regarding venous thromboembolism (VTE) following major orthopaedic hip or knee surgery?
This patient has developed CRPS following fixation of a distal radius fracture. All of the above are characteristics of CRPS except for decreased perfusion to the fingertips.
CRPS is divided into two general categories: Type I, occurring in the absence of a specific nerve injury, and Type II, resulting from presence of a specific nerve injury. The incidence is 6-26 cases per 100,000 person-years, mostly affecting females (4:1), and smokers. The International Association of the Study of Pain (IASP) has developed the Budapest Criteria for the diagnosis of CRPS. These include sensory (reports of hyperesthesia and/or allodynia), vasomotor (reports of temperature asymmetry and/or skin color changes and/or skin color asymmetry), sudomotor/edema (reports of edema and/or sweating changes and/or sweating asymmetry), and motor (reports of decreased ROM, weakness, or trophic changes to hair or nails) changes. Vitamin C following distal
radius fracture fixation has been suggested as preventative, though still somewhat controversial. Following development of CRPS, treatment includes psychotherapy, occupational therapy, sympathetic blockade, and antidepressants.
Birklein and Schlereth comprehensively review CRPS. The authors describe how after a trauma there is an abundance of inflammatory mediators which stimulate the peripheral nerves. In addition, the proinflammatory cytokine network stimulates bone cell and fibroblast proliferation and potentially endothelial dysfunction. They note that these molecular changes lead to autonomic disturbances and an overwhelming pain response.
Koh et al. also present a review of CRPS. The authors stress that CRPS is a clinical diagnosis and one of exclusion. They discuss that CRPS is best treated within a multidisciplinary team including orthopaedic surgeons, pain management, therapy, and psychological services. Early diagnosis is furthermore critical. Finally, the authors advocated vitamin C administration on the day of fracture as prophylaxis against CRPS.
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A 65-year old male with worsening right hip osteoarthritis has failed nonsurgical management and would like to proceed with total hip arthroplasty. He has consulted with a pain management specialist and is treating his pain with opioids. If he is able to successfully decrease the amount of opioids he takes preoperatively by 50%, what effect would that have on his postoperative functional outcome?
Etanercept is a biologic disease modifying anti-rheumatic drug (DMARD) which works by binding and inhibiting TNF-a, in effect suppressing the autoimmune response associated with rheumatoid arthritis (RA).
There are a number of DMARDs commonly used in the medical management of RA. TNF- a is a frequent target, given its pivotal role as one of the major cytokines driving the progression of RA. Etanercept is one example of a TNF-a inhibitor that is often used to treat RA, juvenile RA, psoriatic arthritis, and ankylosing spondylitis. Infliximab, adalimimab, golimumab are other
commonly used TNF-a inhibitors. Before initiating these medications, patients and physicians should be aware of the possibility of reactivation of latent tuberculosis as well
as increased rates of infection and lymphomas with long- term use.
Saleh et al. reviewed the perioperative management of RA patients. They note that patients that are maintained on etanercept perioperatively have a significantly increased rate of perioperative infection. The authors discuss recommendations that etanercept be held at least one half-life prior to surgery and in some instances up to 4-5 half-lives before surgery. They recommend restarting the medication at 2 weeks post-operatively so long as the surgical sites are healing uneventfully.
Nikiphorou et al. evaluated the impact of biologic agents on the surgical treatment of RA. The authors discussed that although rates of major joint replacements (THA/TKA) for osteoarthritis are increasing, the rates of THA/TKA for RA has been essentially unchanged over >10 years. They concluded that effective medical management of RA has led to fewer orthopedic surgeries being performed in the RA population.
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A 60-year-old female underwent open reduction and internal fixation of a distal radius fracture 3 weeks ago. She returns to your clinic and appears anxious. She complains of pain and difficulty sleeping. When you remove her splint her entire hand and wrist are sensitive. You suspect that she has developed complex regional pain syndrome (CRPS). All of the following are common signs or symptoms of CRPS EXCEPT:
All of the statements listed above are true EXCEPT for answer 2 - BMP-2 is not FDA indicated for single-level posterolateral lumbar fusions.
Bone morphogenetic proteins are a member of the TGF-beta superfamily. It is an osteoinductive material that induces mesenchymal stems cells to differentiate into bone- forming osteoblasts. There has been an increasing amount of literature published around its use in long bone procedures, spinal procedures, and nonunions. Currently, the FDA indications for rhBMP-2 are acute open tibial shaft fractures treated within 14 days and single level ALIFs with a lumbar tapered fusion device.
Hsu et al. authored a systematic review including 6 articles on the cost- effectiveness of BMP-2 compared to iliac crest bone graft (ICBG) in lumbar and cervical arthrodesis procedures. They conclude that in lumbar arthrodesis procedures BMP-2 is only cost- effective when taking into account societal costs such as productivity and lost wages.
Carreon et al. performed a cost-utility analysis on an RCT that they performed comparing BMP-2 to ICBG in posterolateral lumbar fusions. There are more complications, increased need for additional treatment and revision surgery in patients over 60 years old receiving ICBG compared with rhBMP-2/ACS, which account for an increased cost utility for the ICBG group.
Glassman et al., in the paper that the aforementioned study worked off of, performed an RCT of rhBMP-2/ACS (Infuse bone graft) versus iliac crest bone
graft (ICBG) for lumbar spine fusion in patients over 60 years of age. They conclude that BMP-2 is a viable ICBG replacement in older patients in terms of safety, clinical efficacy, and cost-effectiveness.
Cheng et al. looked at the osteogenic activity of fourteen different BMPs on mesenchymal progenitor cells. They found BMP-2, 6, and 9 induced high levels of alkaline phosphatase activity in pluripotent stem cells. They conclude BMP-
2, 6, and 9 may play important roles in inducing osteoblast differentiation of mesenchymal stem cells.
Illustration A (Cheng et al.) is a figure demonstrating the distinct osteogenic activity of human BMPs. BMP-2, 6, and 9 are the most potent agents to induce osteoblast lineage differentiation of mesenchymal progenitor cells while most BMPs can promote the terminal differentiation of committed osteoblast precursors.
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Which of the following medications specifically target tumor necrosis factor alpha (TNF-a)?
Fretting corrosion results from the relative micromotion between two affixed materials placed under a load and is characterized by the formation of pits,
grooves, and oxide debris. This may be seen at modular junctions.
The process of fretting corrosion involves the physical disruption of the passivated layer at the junction of two materials due to friction caused by micromotion under pressure.
The increased surface roughness and release of metallic oxide debris may then, in turn, lead to other types of corrosion such as crevice corrosion. Fretting corrosion has been described at the head-neck junction in total hip arthroplasty, and the risk is increased with an increasing number of component interfaces.
Brown et al. describe fretting corrosion within the context of modular hip tapers. The authors note that while modularity increases versatility, this comes at the cost of interfacial corrosion which may result in both device failure as well as the release of metal ions with local soft tissue reactions. They conclude that longer neck extension was associated with increased fretting corrosion
and that this can potentially be mitigated by increasing the stability of the interface.
Goldberg et al. performed in vitro corrosion testing of modular hip tapers. The authors found that once fretting corrosion created an environment suitable for crevice corrosion, corrosion continued regardless of continued mechanical loading. They concluded that mechanical loading had a significant impact on initiating the corrosion process.
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temperature cycling causing rapid expansion/contraction of the metal. This may be a consideration during the manufacturing process of implants but is not seen in vivo.
When considering using recombinant human BMP-2 in orthopaedic surgery, all of the following are true EXCEPT:
The null hypothesis in this randomized controlled trial is that there is no difference in cement penetration during TKA with or without tourniquet use. As there was significant crossover (tourniquet use in the "no tourniquet" cohort), accepting the null hypothesis when it is false would result in beta (type 2) error.
In hypothesis testing, the assertion that the observed findings did not occur by chance alone but rather occurred because of a true association between variables is confirmed or rejected. By convention, the null hypothesis suggests that there is no significant association between variables while the alternative hypothesis suggests that there is a significant association. Alpha (type 1) error occurs when the null hypothesis is rejected
when it is, in fact, true (false positive effect). Beta (type 2) error occurs when the null hypothesis is
accepted when it is, in fact, false (false negative effect).
Kocher et al. reviewed power analyses, statistical errors, and the concept of statistical power. They discuss that beta represents the chance of a type II error, while alpha represents the chance of a type I error, and that conventionally beta is set at 0.2 and alpha at 0.05. The authors recommended that when a study observes no difference, the power of the study, or (1 - beta), should be reported.
Lochner et al. investigated the rates of beta error in randomized controlled trials in orthopedic trauma. They reported a 90% beta error rate in these trials, which exceeds accepted standards. The authors recommended that future authors perform pre-study power and sample-size calculations to
reduce these rates.
Illustration A shows a Bayesian analysis table demonstrating the relationship between alpha, beta, and the null hypothesis.
Incorrect Answers:
Which of the following types of corrosion is defined by the formation of pits, grooves, and oxide debris due to the relative micromotion between two affixed materials placed under a load?
Tobramycin is an aminoglycoside that acts primarily by disrupting protein synthesis through irreversibly binding to 30S ribosomal subunit, leading to altered cell membrane permeability, disruption of the cell envelope, and eventual cell death.
Exchange nailing with an antibiotic-impregnated intramedullary nail is often implemented in the treatment of chronic osteomyelitis with septic tibial nonunion as it provides both fracture stabilization and antibiotic elution. Vancomycin and tobramycin are often added to the polymethylmethacrylate (PMMA) cement for broad-spectrum coverage.
Vancomycin disrupts cell-wall synthesis in a time-dependent manner by binding to the D- Ala-D-Ala terminal of the growing peptide. It is extremely effective in gram-positive bacteria, but ineffective against gram-negative bacilli due to its large size. Conversely, tobramycin is effective against gram-negative organisms, and works chiefly through the inhibition of bacterial protein synthesis by irreversibly binding to the 30S ribosomal subunit.
Jaeblon et al. reviews the contemporary use of PMMA in orthopaedic surgery. The authors discuss the utility of PMMA as a delivery vehicle for antibiotics, eluting from both the surface and pores of the cement as well as the microcracks within it, while simultaneously eliminating dead space. They conclude that tobramycin is popular because it comes in powder form, which is easy to mix, and because of its broad spectrum activity, which includes antipseudomonal coverage. Moreover, it has been shown to potentiate the elution of other antibiotics, such as vancomycin.
McNamara et al. reviews the mechanism of Vancomycin. The authors report how this antibiotic has increased in importance in the last decade due to the growing resistance of many gram-positive bacteria to β-lactam antibiotics. They discuss that vancomycin is a large, complex, tricyclic glycopeptide molecule that works primarily through disruption of the biosynthesis of peptidoglycan, the major structural polymer of the gram-positive
bacterial cell walls, through binding to the D-alanyl-D-alanine terminal of cell wall precursor units. The authors conclude that unlike penicillins and cephalosporins, cross- resistance with vancomycin does not develop, because vancomycin acts against different stages of cell wall synthesis and different specific targets.
Nana et al. discusses the high affinity of microorganisms to adhere to foreign materials commonly used in orthopedics, including cobalt-chromium, titanium, polyethylene, and PMMA cement through the formation of biofilms. The
authors report that S. aureus and S. epidermidis are the most common bioﬁlm-forming bacteria found in orthopedics, and, when combined with P. aeruginosa, they represent nearly 75% of bioﬁlm infections. They conclude that while no current guidelines exist for treating these infections, recent studies have shown that biofilm growth can be fully inhibited when PMMA is mixed with both daptomycin and gentamicin.
Figures A and B are the AP and lateral radiographs of an infected nonunion of a tibial shaft fracture treated initially with an intramedullary nail.
Figure C is an axial CT image illustrating the tibial fracture nonunion.
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A randomized controlled trial is undertaken to investigate whether tourniquet use increases cement penetration during total knee arthroplasty. Approximately 40% of the patients that were initially randomized to the "no tourniquet" group had tourniquets placed intraoperatively due to difficulty with visualization. Intent- to- treat analysis was conducted and the results showed no difference in the rates of cement penetration. What statistical term best applies if these results are accepted at face value?
Sclerostin is a direct antagonist of the Wnt/β-catenin pathway and thus a key regulator of the formation of mineralized bone matrix and bone mass. Anti- sclerostin antibodies result in inactivation of sclerostin, thereby promoting the anabolic Wnt/β-catenin pathway and resulting in INCREASED bone density
Sclerostin is a glycoprotein encoded by the SOST gene and produced primarily by osteocytes. It acts as a negative regulator of bone mass by directly antagonizing Wnt binding to the LRP5/6 receptor, thereby leading to β-catenin degradation and reduction of Wnt-target gene expression. This results in anti- anabolic properties, including inhibition of osteoblastic differentiation, bone formation, and loss of inhibition of osteoblast and osteocyte apoptosis. Genetic mutations resulting in loss of function or decreased expression of SOST have been linked to endosteal hyperostosis, increased bone mass, and increased bone density (as with Van Buchem disease and sclerosteosis). As a result, new immunotherapies targeting sclerostin (such as Romosozumab and
Blosozumab) are being investigated for their utility toward treating osteoporosis and have shown promising results.
Recker et al. presented a double-blinded phase 2 randomized controlled trial of blosozumab in the treatment of low bone mineral density in postmenopausal women. The authors found that administration of the monoclonal antibody resulted in significant dose- dependent increases in bone mineral density at the spine and hip. The authors concluded that the anti-sclerostin antibody was effective in the treatment of low bone mineral density in postmenopausal women.
Illustration A is a comparison of the unsuppressed Wnt pathway (left) with the Wnt- antagonized pathways (right). Sclerostin binds the LRP5/6 receptor in the place of Wnt, leading to the release of the destruction complex and β-catenin degradation. In the absence of sclerostin, the β-catenin translates into the nucleus and promotes downstream transcription of Wnt target genes.
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sclerostin lead to an under- or uninhibited Wnt/β-catenin pathway and thereby INCREASED bone mass, such as would be seen in Van Buchem disease or sclerosteosis.
Figures A through C are the radiographs and CT scan of a 33- year-old male who was treated 13-months ago for an open tibial shaft fracture. He has received several courses of intravenous antibiotics for chronic osteomyelitis. Despite continued treatment with IV antibiotics, his inflammatory markers remain elevated. The decision is made to proceed with irrigation and debridement, nail removal with exchange for a polymethylmethacrylate intramedullary nail with vancomycin and tobramycin. What is the primary mechanism of action of tobramycin?
Lubricin is a hyaluronic acid-binding proteoglycan found in synovial fluid that reduces the coefficient of friction between the surfaces of the joint.
Lubricin reduces the friction between the surfaces in the joint, leading to decreased shear forces transmitted to the hyaline cartilage. It is a glycoprotein that is produced by the chondrocytes in the superficial zone and is not a primary component of the extracellular matrix. A deficiency in lubricin has
been associated with early-onset arthritis.
Schumacher et al. first discovered what is now known to be "lubricin" by studying the superficial zone of bovine articular cartilage. The authors noted that the chondrocytes in this zone secreted this proteoglycan. In addition, they found that this molecule, or a very similar molecule, was present in synovial fluid and moreover could serve as a functional metabolic marker for chondrocytes of the superficial zone of articular cartilage.
Jay et al. analyzed the synovial fluid in both normal and lubricin-deficient samples and found that the subdiffusive and elastic behavior of synovial fluid, at physiological shear rates, was absent in fluid from a patient who lacked lubricin. They concluded that lubricin provided synovial fluid with an ability to dissipate strain energy induced by physiologic motion, which is a chondroprotective feature distinct from boundary lubrication.
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osteoblastogenesis.
Which of the following is accurate regarding sclerostin?
In the days following an intra-articular injury, the following substances are produced, contributing to articular cartilage damage and the eventual formation of post-traumatic arthritis: IL-1ß, TNF-a, nitric oxide, matrix metalloproteinases, aggrecans, and damage-associated molecular patterns.
Immediately following an intra-articular fracture, there is mechanical damage and necrosis of articular cartilage. Traditionally, orthopaedic surgeons are
taught that the most critical factor in affecting the outcomes of these patients is the accuracy of the articular reduction and restoration of the mechanical alignment. However, even in expertly reduced fractures, some patients experience poor outcomes and develop progressive, debilitating osteoarthritis. More recently, researchers have looked at inflammatory events that may also contribute to arthritis and ways to modulate these events.
Olson et al. provide a review article on the role of cytokines in post-traumatic arthritis. They note that, despite accurate articular reductions, many patients go on to develop
arthritic changes, often indistinguishable from primary OA. While mechanical alignment and structural damage are sometimes responsible, the cascade of cytokines and other signaling molecules listed above serve to catalyze these intra-articular events; developing ways to blunt this inflammatory response is of great interest.
Lewis et al. examined the relationship of inflammatory and post-traumatic arthritis in a rodent model. Tibial plateau fractures were induced in C57BL/6 and MRL/MpJ "superhealer" mice, which were killed at different time-points. Synovial fluid was inspected post-mortem for cytokine analysis, as well as gross specimens, and it was determined that an association exists between joint tissue inflammation and the development and progression of post- traumatic arthritis in mice.
Figure A is an XR of a tibial plateau fracture. Figure B is an XR of a knee demonstrating post-traumatic arthritis. Illustration A is a table of several cytokines and their functions. Illustration B is a timeline of intra-articular pathogenic events following an injury. Illustration C is a diagram showing various cellular events and pathogenic mechanisms in the acute aftermath following an intra-articular injury.
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blood vessels, IL-8 is chemotactic, BMP2 plays a role in the development of bone and cartilage, BMP5 plays a role in cartilage development, and M-CSF causes hematopoietic stem cells to differentiate into macrophages or other related cells.
A 45-year-old patient presents to your clinic for evaluation of knee pain. He has been told he has osteoarthritis and has significant pain with knee range of motion. Which of the following components of synovial fluid is most responsible for reducing the coefficient of friction in a native knee joint?
This player has sustained a tear of the medial collateral ligament (MCL). The MCL is a ligament which inserts indirectly into bone through Sharpey's fibers.
Ligaments can insert on bone either indirectly and directly. Indirect is the most common and is a fibrous insertion. The superficial fibers of the tendon insert into the periosteum, while the deep fibers insert directly into the bone. These
deep fibers are called Sharpey's fibers and are made of type I collagen. The direct insertion has both deep and superficial fiber insertions as well. Direct insertions are fibrocartilaginous and consist of four transitional zones of increasing stiffness that allow force dissipation.
Lu et al. performed a review to determine the functional attachments of soft tissue to bone. They report that a specialized interface, called an insertion site or enthesis, integrates
tendon or ligament to bone and serves to facilitate joint motion. Fibrous (indirect) insertions typically occur over large areas, presumably to distribute force and reduce stress, and are characterized by perforating mineralized collagen fibers.
Cole et al. performed a review of fixation of soft tissues to bone. They report that recreation of the enthesis relies on adequate biologic healing afforded by adequate initial fixation. The healing pattern associated with direct soft–tissue- to-bone repair, such as rotator cuff repair, is different from that associated
with fixation within bone tunnels (ex. ACL reconstruction). The process of tendon healing within osseous tunnels occurs over time.
Lui et al. performed a review of the biology and augmentation of tendon-bone insertion repair. They report that when a ligament runs parallel to the bone, like the MCL, the insertion is more likely to be indirect. When a ligament enters the bone perpendicularly, such as the ACL, the insertion is direct. Indirect insertions may be elevated off the bone without cutting the ligament itself while direct insertions require cutting the substance of the ligament to detach it.
Figure A is a T2-weighted, coronal MRI demonstrating a tear of the MCL. Illustration A is a polarized photomicrograph demonstrating Sharpey fibers, indicated by the white arrows. G represents tendon, while B represents bone (Liu et al.). Illustration B is a Safranin-O-staining photomicrograph of a direct tendon insertion site (Liu et al.).
Illustration C is an H&E photomicrograph of the same direct tendon insertion site (Liu et al.). B represents bone, CFC represents calcified fibrocartilage, UCFC represents uncalcified fibrocartilage, and T represents tendon.
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A 32-year-old male sustains the injury shown in Figure A. He undergoes surgical fixation with subsequent removal of hardware. He does well for 10 years and then presents to your office with increasing left knee stiffness and pain for the last 6 months. He reports no constitutional symptoms or recent trauma. His physical exam is notable for well-healed incisions, a mild effusion, no ligamentous instability, and 5-100 degrees of range of motion. An XR is obtained and shown in Figure B. Which of the following correctly lists the cytokines produced following the initial injury that may contribute to the findings shown in Figure B and the patient's current symptoms?
imaging is shown in Figure A. Which of the following correctly classifies the injured structure and its indirect insertion into bone?
Hypertrophic nonunions are described as having abundant callous formation without bony bridging at the fracture site and rarely require an increase in bone biology to achieve fracture healing.
A nonunion is defined as a fracture that has not healed and has no further capacity to heal without further intervention. Nonunions are typically classified as hypertrophic, oligotrophic, and atrophic. Hypertrophic nonunions show clear
evidence of ability to heal without bridging of fracture gaps. Atrophic nonunions show no evidence of biologic healing and no bridging of fracture gaps. Oligotrophic nonunions tend to fall somewhere in between hypertrophic and atrophic nonunions with some evidence of biologic activity however incomplete healing. Understanding these characteristics allows for proper identification of the nonunion and selection of appropriate intervention with regard to increasing bone biology and fracture stability to achieve healing.
Bishop et al. review the diagnosis and assessment of delayed bone healing through a systematic approach to help surgeons determine appropriate interventions to achieve healing. They state biologic capacity, fracture stability, deformity, infection, and host status should all be considered closely prior to establishing a plan of management for a nonunion.
Babhulkar et al. reviewed 113 patients diagnosed and treated for nonunions including 61 hypertrophic and 52 atrophic nonunions. They found all patients healed with improved function and pain following treatment of their nonunions. They found residual problems related to joint stiffness, limb length
discrepancy, and angular deformity.
Illustration A shows a hypertrophic nonunion of a tibial shaft fracture treated nonoperatively. Illustration B shows an atrophic nonunion following open reduction internal fixation of a humeral shaft fracture.
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A 20-year-old male collegiate football player sustained a knee injury. His
The arrow is pointing to the superficial zone of articular cartilage in Figure A. The superficial zone of articular cartilage has the highest content of collagen and the lowest content of proteoglycans relative to the other zones.
Normal articular cartilage can be divided into 3 zones and the tidemark based on the shape of the chondrocytes and the orientation of the type II collagen. The zones, in order from closest to the joint surface, are superficial zone, intermediate (transitional) zone, and deep zone. The superficial zone has the highest content of collagen and lowest content of proteoglycans of all the zones; in contrast, the deep zone has the lowest content of collagen and the highest content of proteoglycans. The intermediate zone has amounts of collagen and proteoglycans that reside between those found in the superficial and deep zones.
Ulrich-Vinther et al. reviewed the biology of articular cartilage. They noted three distinct zones of articular cartilage that are separated from the subchondral bone by the tidemark. The authors noted that tissue engineering approaches are being used in an effort to regenerate damaged articular cartilage due to injury or aging.
Jeffery et al. studied the three-dimensional architecture of bovine articular cartilage with scanning electron microscopy. They noted that the collagen was ordered in different morphologies in each zone of articular cartilage. The authors concluded that the three- dimensional organization of collagen is important when considering cartilage structure and function.
Illustration A demonstrates the zones of articular cartilage and their spacial relationship. Illustration B shows the relationship between collagen and proteoglycans
within articular cartilage.
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While planning for revision of a failed open reduction internal fixation you are planning to increase mechanical stability across the fracture site. In addition to addressing stability, which of the following fracture scenarios is least likely to require additional bone biology in order to achieve healing?
A is characterized by:
PROMIS is a useful orthopaedic patient-reported outcomes measure (PROM) that can assess disease specific and general health questions, validated for use in foot and ankle, upper extremity, and spine patients.
Multiple tools have been developed to asses patient-reported outcomes, however, some of these are narrow in scope, cumbersome to administer, and less useful in orthopedics. PROMIS was developed by a team of NIH researchers to address these shortcomings. Domains include physical, mental, and social health. PROMIS utilizes computer adaptive testing software (CAT), allowing for fewer questions and more accurate measurements. Additionally, results are reported as T-scores, allowing for easy interpretation.
Brodke et al. provide an overview of PROMIS. They report that this tool was developed to be easy to administer and broad in scope, utilizing item response theory. This validated tool is reliable in assessing specific function of the upper and lower extremities, as well as underlying health traits.
McCormick et al. described PROM used in spine surgery. They reinforce that the benefit of PROM is to gather insight into subjective measures not typically captured in traditional research, looking at such factors as general health quality, function, and pain. The authors also note the importance of these tools as greater emphasis is placed on quality of care and patient experience.
Godil et al. studied instruments to accurately measure quality and outcomes in lumber spine surgical registries. They conducted a prospective cohort study of
58 patients undergoing TLIF for lumbar degenerative spondylolisthesis and administered several PROs. They concluded that the ODI was the best measure assessing pain and disability in lumbar surgery, citing its validity and responsiveness in measuring the effectiveness of lumbar fusion; EuroQOL-5D (EQ-5D) was found to be the best, the most valid, and responsive measure of improvement for health-related quality of life.
Illustration A is a chart depicting the main domains and subcategories analyzed with PROMIS.
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The layer of articular cartilage that the arrow points to in Figure
As part of the World Health Organization (WHO) Surgical Safety Checklist, all of the answers listed are methods to prevent wrong-site surgery EXCEPT marking an "X" on the operative extremity. Patients should be marked unambiguously, with either a "yes" or the surgeon's initials in permanent marker, prior to induction of anesthesia.
The WHO developed the Surgical Safety Checklist in an effort to improve the safety of patients undergoing surgery. Implementation of this checklist has resulted in improved clinician safety attitudes, as well as decreased patient morbidity and mortality. A time-out or group huddle occurs prior to induction with the patient, prior to incision, and prior to the patient leaving the operating room; all team members have an opportunity to speak up and discuss any concerns during this process. The American Academy of Orthopaedic Surgeons suggest the following to prevent wrong-site surgery: Surgical team engagement, patient confirmation, signing the surgical site (in the visible
surgical field or inline with the planned incision) with a permanent marker with the patient's assistance, and utilizing separate time-outs in the case of separate surgical procedures/sites.
Haynes et al. looked at changes in safety attitude, morbidity, and mortality following implementation of the WHO Surgical Safety Checklist. They administered a survey pre- and post-intervention at 8 hospitals. Post- intervention, they found an overall improvement in safety attitudes and found that this was correlated with a reduction in post-operative complication rates.
Gillespie at al. reviewed the evidence of implementing a surgical safety checklist. They utilized a realist synthesis methodology in this study. They concluded that intervention methods and implementation strategies were not well described in the literature, surgical checklists appear to be more successful when physicians are leading their implementation, and that greater participation and ownership of safety checklists can be expected by physicians are actively engaged in their development and implementation.
Illustration A is the WHO Surgical Safety Checklist. Illustration B is an example of the correct way to mark a patient for a right shoulder surgery for a planned deltopectoral incision.
Incorrect Answers:
Which of the following instruments incorporates both general disease and disease-specific measures and has been validated for use in patients with spine, foot and ankle, and upper extremity conditions?
This patient has a catastrophic ceramic component failure and requires a thorough debridement and revision with a head and liner exchange.
Ceramic bearings in hip arthroplasty are recognized for their superior wear properties and low-friction. However, ceramics are also brittle, have a high modulus of elasticity, and are prone to fracture under certain circumstances. Catastrophic bearing failure is not as common in newer-generation ceramics, as first-generation products were more prone to failure due to flaws in the manufacturing process. Squeaking is a known complication of ceramic-on- ceramic bearings and may be associated with catastrophic failure. Obesity, trauma, and component malposition have been linked to failure, and revision procedures should address any component malposition.
Malem et al. describe a case report of a catastrophic ceramic-on-ceramic total hip replacement failure presenting as a squeaking hip. Within 5 years of her index surgery, the patient developed a painful, squeaking hip with a limited range of motion. At the time of revision, she was found to have a broken femoral head, black wear debris, and a completely worn acetabular component, suggesting that a squeaking ceramic-on-ceramic hip replacement may be a sign of catastrophic failure.
Stanat et al. provide a meta-analysis and review of squeaking in 3rd and 4th generation ceramic-on-ceramic total hip replacements. They conclude that the only significant patient- associated risk factor for squeaking was body mass index. In terms of implant type and surgical factors, they found that the presence of a Stryker Accolade stem was associated with an increased incidence of squeaking; cup version was not associated with a higher incidence of squeaking in their analysis.
Figure A is a radiograph demonstrating ceramic fracture and displacement of the femoral component in relation to the acetabular component; ceramic fragments are present around the femoral neck and cup. The partially radiolucent head is a tip-off to the older generation ceramics. Illustration A is an intra-operative photograph demonstrating a fractured ceramic femoral head. Illustration B is a revision of the hip in Figure A utilizing ceramic-on- ceramic components. Illustration C (Traina et al.) is a treatment algorithm when ceramic bearing failure is suspected.
Incorrect Answers:
All of the following can be done to improve patient safety and prevent wrong site surgery EXCEPT:
Nitrogen-containing bisphosphonates exert their action by inhibiting farnesyl pyrophosphate synthase.
Nitrogen-containing bisphosphonates inhibit osteoclasts which leads to increased bone mass and reduced bone turnover. They act on the cholesterol biosynthesis pathway enzyme, farnesyl pyrophosphate synthase. By inhibiting this enzyme in the osteoclast, they interfere with geranylgeranylation (attachment of the lipid to regulatory proteins), which causes osteoclast inactivation. Non-nitrogen containing bisphosphonates are metabolized in the cell to compounds that replace the terminal pyrophosphate moiety of ATP, forming a nonfunctional molecule that competes with ATP in the cellular energy metabolism. Due to this disruption in metabolism, the osteoclast
initiates apoptosis and dies, leading to an overall decrease in the breakdown of bone. Examples of nitrogen-containing bisphosphonates are alendronate, risedronate, pamidronate, and zolendronate. Examples of non-nitrogen containing bisphosphonates are tiludronate, clodronate, etidronate.
Reszka et al. performed a review of bisphosphonates. They report that they bind to the bone mineral, which localizes their action to the target tissue. They are rapidly cleared from the circulation via renal excretion, which minimizes exposure of all other organs.
They do not easily penetrate cell membranes, which reduces exposure to non-target tissues. They also report that alendronate and risedronate are the only pharmacologic agents shown to prevent spine and nonvertebral fractures associated with postmenopausal and glucocorticoid-induced osteoporosis.
Luo et al. performed a systematic review to determine the efficacy and safety of alendronate for adult AVN treatment. They found most studies suggested a positive short-term efficacy of alendronate treatment in reducing pain, improving articular function, slowing of bone collapse progression, and delaying the need for arthroplasty. There were no severe adverse effects associated with alendronate treatment observed and most of the included studies suggested the use of alendronate in early AVN with a small necrotic lesion to achieve better outcomes.
Illustration A (Reszka et al.) details the nitrogen and non-nitrogen containing bisphosphonates and their chemical structures. Illustration B is the mevalonate pathway, showing the action of a nitrogen-containing bisphosphonate.
Incorrect Answers:
A 60-year-old patient presents to clinic complaining of left hip squeaking and stiffness following a ceramic-on-ceramic total hip replacement five years earlier. Initially, he was extremely pleased with the operation, but these symptoms of squeaking and stiffness have developed fairly abruptly over the past 6 months. On physical exam, he has a well-healed incision, a 1 centimeter leg length discrepancy (left shorter than right), decreased hip flexion, and decreased internal rotation. A radiograph is shown in Figure A. C- reactive protein is 0.2 mg/dL (nl <0.9 mg/dL) and erythrocyte sedimentation rate is 5 mm/hr (nl 0-15 mm/hr). What would you recommend for this patient?
in the red box?
Aspirin inhibits the aggregation of platelets, which are shown in Figure C.
The coagulation cascade is a complex interaction of multiple clotting factors which ultimately leads to the aggregation of platelets to form a clot. The end result of the clotting cascade leads to the conversion of prothrombin to thrombin, causing the formation of fibrin and the subsequent aggregation of platelets in a clot. Aspirin irreversibly blocks the formation of thromboxane A2 in platelets, which inhibits platelet aggregation and thus the formation of a clot.
Hyers reviewed the mechanism of action of various anticoagulants and the pathophysiology of venous thromboembolism. He noted that while deep vein thrombosis and pulmonary embolism resulted in significant morbidity and mortality in the United States, novel anticoagulants have recently been developed that hold promise for new therapeutic options.
Brown pooled the results of 14 randomized controlled trials examining venous thromboembolism (VTE) rates. Their analysis showed that VTE rates were not significantly different when aspirin was used for anticoagulation compared with vitamin K antagonists or low molecular weight heparin (LMWH). The authors concluded that aspirin could be used for VTE prophylaxis after major orthopaedic surgery.
Figure A shows a plasma cell. Figure B shows a neutrophil. Figure C shows arrows pointing to platelets in a peripheral blood smear. Figure D features a basophil, and figure E shows an osteoclast. Illustration A shows the mechanism of action of aspirin.
Incorrect Answers:
A man with osteonecrosis of the hip is treated with a medication which inhibits the pathway shown in Figure A. Which of the following medications best matches this mechanism of action of the medication
Demineralized bone matrix (DBM) is both osteoconductive and osteoinductive.
DBM is made from the acidic extraction of bone matrix from allograft. It removes the minerals and leaves the collagenous and noncollagenous structure and proteins. It is osteoconductive and osteoinductive as it contains collagen, bone morphogenic proteins (BMPs), transforming growth factor-beta (TGF-β), and residual calcium. It does not contain mesenchymal precursor cells or impart structural support.
Ripamonti et al. performed a review of regenerative medicine and tissue engineering of bone. They report that the understanding of bone formation by autoinduction has been pivotal for setting the rules for tissue engineering. An extracellular matrix combined with TGF-β is capable of performing this task.
Grabowski et al. review bone graft and bone graft substitutes. They report that DBM is both osteoinductive and osteoconductive. DBM provides varying degrees of osteoconductive potential based on the carrier material chosen.
They also report that given the techniques used for demineralization are proprietary, the actual techniques are not published, and the process is not regulated. They conclude that the actual concentration of BMPs is varied when comparing various lots of the same preparation.
Figure A is a coronal CT slice demonstrating a depression fracture of the lateral tibial plateau.
Incorrect Answers:
Aspirin exerts its primary effect on which of the following cells (identified by black arrows)?
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Question 8

Figure 30 shows the MRI scan of a 68-year-old woman who has left hip pain. What is the most appropriate treatment?

Explanation

DISCUSSION: The patient has a large zone of osteonecrosis of the left femoral head. The wedge-shaped zone of decreased signal intensity on the T1 image in the subchondral region of the femoral head is typical. Based on these findings, total hip arthroplasty is the most appropriate treatment. Open reduction and internal fixation will not help this condition. Incisional biopsy is indicated only if the MRI scan shows a probable neoplasm. Resection of the proximal femur is indicated only for aggressive malignancy. Arthrodesis may be considered in a younger patient but not in a 68-year-old individual. Other treatments, not listed, such as core decompression, vascularized fibular transplant, and osteotomy may be options in selected patients.
REFERENCES: Urbaniak JR, Jones JP Jr (eds): Osteonecrosis: Etiology, Diagnosis, and Treatment. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 213-223.
Watson RM, Roach NA, Dalinka MK: Avascular necrosis and bone marrow edema syndrome. Radiol Clin North Am 2004;42:207-219.

Question 9

In displaced calcaneal fractures, what fragment is the only one that remains in its anatomic position?

Explanation

DISCUSSION: The sustentaculum tali remains in its anatomic position because of its supporting ligamentous structures. This provides the key to the reconstruction of the calcaneus. The posterior facet is reduced to the sustentaculum tali and then fixed to it for stability. All of the other components of the calcaneus are then reduced to this complex.
REFERENCES: Sanders R: Displaced intra-articular fractures of the calcaneus. J Bone Joint Surg Am 2000;82:225-250.
Eastwood DM, Gregg PJ, Atkins RM: Intra-articular fractures of the calcaneum: Part I. Pathological anatomy and classification. J Bone Joint Surg Br 1993;75:183-188.
Eastwood DM, Langkamer VG, Atkins RM: Intra-articular fractures of the calcaneum: Part II. Open reduction and internal fixation by the extended lateral transcalcaneal approach. J Bone Joint Surg Br 1993;75:189-195.

Question 10

A 70-year-old healthy man had total knee arthroplasty 18 years ago, and it now is painful. Radiographs reveal aseptic loosening and the range of motion before surgery is 15 to 85 degrees. The strongest indication for performing a tibial tubercle osteotomy to aid in exposure in his knee would be

Explanation

Question 11

Which of the following best characterizes the injury shown in Figure 53? Review Topic

Explanation

The injury shown is a flexion compression injury also known as "tear drop" fracture. It is characterized by the large anteroinferior fragment off the vertebral body and the retrolisthesis seen in this image. It is considered an unstable injury and should be distinguished from the more stable and minor extension tear drop avulsion where there is no vertebral malalignment and the anteroinferior fracture is a small avulsion of the annulus attachment. Other axial load injuries can be stable but have more of a compression or even burst pattern with loss of body height rather than the anteroinferior fragment. The radiograph does not demonstrate facet malalignment that would be seen with a facet dislocation.

Question 12

What is the most common contracture deformity of the spastic shoulder secondary to a cerebrovascular accident?

Explanation

DISCUSSION: The resultant spasticity and weakness (paresis) following a cerebrovascular accident leads to muscle imbalance that commonly results in contracture of the shoulder in adduction, internal rotation, and varying degrees of forward flexion. In addition, the elbow is usually flexed and the forearm pronated.
REFERENCES: Braun RM, Botte MJ: Treatment of shoulder deformity in acquired spasticity. Clin Orthop 1999;368:54-65.
McCollough NC III: Orthopaedic evaluation and treatment of the stroke patient. Instr Course Lect 1975;24:45-55.

Question 13

Etanercept is a recombinant genetically engineered fusion protein used to treat rheumatoid arthritis. What is its mode of action?

Explanation

DISCUSSION: Etanercept is a molecule consisting of the Fc portion of IgG fused to the extracellular domain of the p76 human THF-α receptor. It is soluble and binds TNF-α. Infliximab is the monoclonal antibody that binds TNF-α. IL-1 receptor antagonists are still in development. Leflunomide is a drug that inhibits pyrimidine synthesis and is similar to methotrexate as an antimetabolite.
REFERENCE: Koval KJ (ed): Orthopaedic Knowlegde Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 193-199.

Question 14

Which of the following increases radiation exposure to patients and personnel during surgery?

Explanation

DISCUSSION: Continuous fluoroscopy and cine radiography expose the patient and personnel to markedly increased levels of direct and scatter radiation exposure. Continuous fluoroscopy should be limited to only what is absolutely needed for safe completion of the procedure. By orienting the cathode ray tube beneath the patient and placing the image intensifier as close as clinically possible to the patient, scatter radiation exposure to the personnel is minimized.
REFERENCE: Wagner L, Archer B: Minimizing Risks from Fluoroscopic X-rays: A Credentialing Program for Anesthesiologists, Cardiologists, Surgeons, Radiologists, and Urologists, ed 3. The Woodlands, TX, Partners in Radiation Management, 2000.

Question 15

Kinematic testing of patellofemoral motion demonstrates that malalignment that produces increased Q angle causes a shift of the patella laterally in the trochlear groove and is most pronounced during what phase of the flexion arc?

Explanation

DISCUSSION: Dynamic patellofemoral joint contact measurements on cadaveric knees with simulated increased Q angle demonstrated that forces shifted to the lateral facet. The lateral shift in the patella was most pronounced from 40 to 90 degrees of flexion. At lower degrees of flexion, the lateral shift was significantly less. At higher degrees of flexion, the continued shift of the patella was not as pronounced.
REFERENCES: Ramappa AJ, Apreleva M, Harrold FR, et al: The effects of medialization and anteromedialization of the tibial tubercle on patellofemoral mechanics and kinematics. Am J Sports Med 2006;34:749-756.
Huberti HH, Hayes WC: Patellofemoral contact pressure: The influence of q-angle and tendofemoral contact. J Bone Joint Surg Am 1984;66:715-724.

Question 16

Which of the following conditions is considered a relative contraindication to interscalene nerve block for patients scheduled to undergo shoulder surgery?

Explanation

DISCUSSION: A common side effect of interscalene nerve block for shoulder surgery is the blockade of the ipsilateral phrenic nerve. This, in turn, results in paresis of the diaphragm and up to a 30% reduction in pulmonary function volumes. Therefore, interscalene nerve block generally is not recommended for patients whose respiratory function is compromised. Other relative and absolute contraindications for interscalene nerve blocks include allergy to local anesthetics, infection at the injection site, uncontrolled seizure disorder, coagulation abnormality, and preexisting neurologic injury.
REFERENCES: Chelly JE: Indications for upper extremity blocks, in Chelly JE (ed): Peripheral Nerve Blocks, ed 2. Philadelphia, PA, Lippincott Williams & Wilkins, 2004, pp 19-27.
Misamore GW, Sallay PI: A prospective analysis of the safety and efficacy of interscalene brachial plexus block anesthesia for shoulder surgery. J Shoulder Elbow Surg 2007;16:e39.

Question 17

What is the most appropriate initial diagnostic imaging study for a patient with presumed diskogenic low-back pain?

Explanation

DISCUSSION
Radiography is the best initial study. Vacuum phenomenon may be found within the disk space. Other possible sources for back pain such as osteoporotic collapse, osteolytic collapse, and deformity also can be evaluated. The other tests may be beneficial and are more appropriate as later imaging options.
RECOMMENDED READINGS
Yu WD, Williams SL. Spinal imaging: Radiographs, computed tomography, and magnetic resonance imaging. In: Spivak JM, Connolly PJ, eds. Orthopaedic Knowledge Update: Spine

Question 18

In hip arthroplasty, the location of the medial femoral circumflex artery is best described as

Explanation

DISCUSSION: The obturator artery lies closest to the transverse acetabular ligament. The femoral artery is closest to the anterior rim of the acetabulum. No named vessel lies within the substance of the gluteus minimus or superior to the piriformis tendon. The medial femoral circumflex artery lies medial or deep to the quadratus femoris muscle.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach, ed 1. Philadelphia, PA, JB Lippincott, 1984, Figure 7-53, p 346.
Callaghan JJ, Rosenberg AG, Rubash HE: The Adult Hip. Philadelphia, PA, Lippincott-Raven, 1998, p 705.

Question 19

Figure 19 shows the radiograph of a 12-year-old boy who sustained an injury to his hand when another child fell on him. Management should consist of

Explanation

DISCUSSION: The patient has a Salter-Harris type III fracture of the proximal phalanx of the thumb. It is usually caused by an abduction injury where the ulnar collateral ligament avulses a fragment away from the proximal epiphysis and is the most common childhood gamekeeper’s injury. If there is greater than 1 mm of separation or a significant articular step-off, an open reduction, performed through an extensor aponeurosis-splitting approach, is required to reestablish joint congruity and stability. Percutaneous or closed methods of reduction are usually ineffective. The dorsal approach avoids the volar neurovascular structures. Since the ulnar collateral ligament is still attached, this area does not need to be visualized. The major goal is to reestablish joint congruity and bony stability. This can be easily performed via the dorsal approach.
REFERENCES: Carey TP: Fracture and dislocations of the phalanges, in Letts RM (ed): Management of Pediatric Fractures. New York, NY, Churchill Livingstone, 1994, pp 435-436.
Ogden JA: Skeletal Injury in the Child. New York, NY, Springer-Verlag, 2000, p 668.

Question 20

Following application of a short leg cast, a patient reports a complete foot drop. A compression injury of the peroneal nerve at the fibular neck is confirmed by electrical studies. Which of the following muscles is expected to be the last to recover function during the ensuing months?

Explanation

DISCUSSION: The recovery process from peroneal nerve palsy may take many months as axonal regrowth occurs. Of the muscles listed, the extensor hallucis is innervated most distally by the peroneal nerve. The flexor digitorum longus is innervated by the tibial nerve.
REFERENCE: Sarrafian SK: Anatomy of the Foot and Ankle, Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993, p 364.

Question 21

A 7-year-old boy has had low back pain for the past 3 weeks. Radiographs reveal apparent disk space narrowing at L4-5. The patient is afebrile. Laboratory studies show a WBC count of 9,000/mm P 3 P and a C-reactive protein level of 10 mg/L. A lumbar MRI scan confirms the loss of disk height at L4-5 and reveals a small perivertebral abscess at that level. To achieve the most rapid improvement and to lessen the chances of recurrence, management should consist of

Explanation

DISCUSSION: The patient has diskitis. Administration of IV antibiotics speeds resolution and minimizes recurrence. Bed rest and cast immobilization have been successfully used to treat this disorder but can be associated with prolonged recovery and frequent recurrence, even when oral antibiotics are administered. A perivertebral abscess seen in association with this condition usually resolves without surgery.
REFERENCES: Ring D, Johnston CE II, Wenger DR: Pyogenic infectious spondylitis in children: The convergence of discitis and vertebral osteomyelitis. J Pediatr Orthop

1995;15:652-660.
Crawford AH, Kucharzyk DW, Ruda R, et al: Diskitis in children. Clin Orthop 1991;266:70-79.

Question 22

The radiographs and CT scan seen in Figures 28a through 28d reveal what type of acetabular fracture pattern?

Explanation

DISCUSSION: The AP, obturator oblique, and iliac oblique views of the pelvis reveal a fracture that disrupts the iliopectineal and ilioischial lines, indicating a fracture that involves both anterior and posterior columns. However, it does not have the other features of anterior or posterior column fracture patterns. A displaced posterior wall fracture is also present, best seen on the obturator oblique view. The anterior to posterior directed fracture line on the CT scan indicates a transverse fracture; therefore, the patient has a transverse with posterior wall fracture pattern. A T-type fracture would be similar but would have a break into the obturator ring.
REFERENCES: Tile M: Describing the injury: Classification of acetabular fractures, in Tile M, Helfet DL, Kellam JF (eds): Fractures of the Pelvis and Acetabulum, ed 3. Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 427-475.
Brandser E, Marsh JL: Acetabular fractures: Easier classification with a systematic approach. Am J Roentgenol 1998;171:1217-1228.

Question 23

A 52-year-old man underwent arthroscopic repair of a 1-cm supraspinatus tendon tear 3 weeks ago. He was doing well until he fell down three stairs. One week after the fall he continues to report pain similar to his preoperative pain. An MRI scan reveals a minimally retracted 1-cm supraspinatus tendon tear in the same location as his original tear. Management should now consist of Review Topic

Explanation

The patient has retorn his rotator cuff repair. This traumatic retear is different from a chronic tear and should be treated similar to an acute rotator cuff tear. Because the patient is younger than age 65 and has a small, single tendon tear, a revision rotation cuff repair is indicated with an expected tendon healing rate of greater than 95%. A physical therapy program is not indicated, and further delay in repair compromises his functional recovery. A cortisone injection is not indicated for this repairable tendon tear. Immobilization will not allow the tendon to heal once it has retorn. A debridement procedure is not indicated on this repairable tendon tear; this procedure is indicated in painful, chronic, irreparable tendon tears.

Question 24

A distal radius fracture in an elderly man is strongly predictive for what subsequent injury?

Explanation

DISCUSSION: Fractures of the distal radius increase the relative risk of a subsequent hip fracture significantly more in men than in women. A previous spinal fracture has an equally important impact on the risk of a subsequent hip fracture in both genders.
REFERENCE: Haentjens P, Autier P, Collins J, et al: Colles fracture, spine fracture, and subsequent risk of hip fracture in men and women: A meta-analysis. J Bone Joint Surg Am 2003;85:1936-1943.

Question 25

A 42 year-old-woman who underwent surgery for lumbar scoliosis 2 years ago now has fixed sagittal plane imbalance and severe back pain. Which of the following is considered a contraindication to isolated pedicle subtraction osteotomy for the treatment of iatrogenic flatback syndrome in this patient?

Explanation

DISCUSSION: Pedicle subtraction osteotomy is the preferred osteotomy technique for the treatment of many patients with iatrogenic flatback syndrome. In the presence of an anterior pseudarthrosis, however, it must be done in conjunction with an anterior procedure. Prior laminectomy is not a contraindication. Significant correction, usually averaging about 30°, can be obtained through each osteotomy. Osteotomies should be performed at L2 or below in the presence of kyphosis at the thoracolumbar junction. The pedicle subtraction technique is preferred with vascular calcifications because it does not lengthen the anterior column, which could risk vascular injury.
REFERENCES: Potter BK, Lenke LG, Kuklo TR: Prevention and management of iatrogenic flatback deformity. J Bone Joint Surg Am 2004;86:1793-1808.
Bridwell KH, Lenke LG, Lewis SJ: Treatment of spinal stenosis and fixed sagittal imbalance. Clin Orthop 2001;384:35-44.

Question 26

Which structure is shown in Video 27? 27

Explanation

DISCUSSION
Video 27 shows the medial patellofemoral ligament running from the medial epicondyle of the femur to the medial portion of the patella. The posterior oblique ligament and the superficial medial collateral ligament run from medial epicondyle to the tibia.
RECOMMENDED READINGS
Babb JR, Detterline AJ, Noyes FR. AAOS Orthopaedic Video Theater. The Key to the Knee: A Layer-by-Layer Video Demonstration of Medial and Anterior Aatomy. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009.
Hoppenfeld S, deBoer P. Surgical Exposures in Orthopedics. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2003:493-568.

Question 27

Figure 56 shows an arthroscopic view of the long head of the biceps; it has an incompetent biceps sling and is unstable, and an axial glenohumeral MRI scan reveals that it is dislocated medially out of the intertubercular groove. What structure is also most likely injured?

Explanation

DISCUSSION: It is important to recognize that rotator cuff tears are a common finding in the setting of a dislocated long head of the biceps tendon (LHB) from the intertubercular groove of the shoulder. If a LHB tendon dislocation is found on examination or radiographic work-up (ultrasound or MRI), it is imperative to rule out associated rotator cuff pathology, specifically of the subscapularis tendon. Although very rare, injury to the lesser tuberosity should also be ruled out. There are a variety of methods to treat the dislocated biceps (tenotomy versus tenodesis); however, the entire rotator cuff, especially the subscapularis, should be carefully inspected and treated if necessary. The corollary is also true - if you find a tear of the subscapularis tendon insertion, especially the superior half, the LHB should be carefully inspected to ensure that it is not unstable as it exits the shoulder. If the LHB is unstable, this is also addressed surgically with either tenotomy or tenodesis. The middle glenohumeral ligament and Bankart tears are not stabilizers of the biceps.
REFERENCES: Sethi N, Wright R, Yamaguchi K: Disorders of the long head of the biceps tendon. J Shoulder Elbow Surg 1999;8:644-654.
Edwards TB, Walch G, Sirveaux F, et al: Repair of tears of the subscapularis: Surgical technique. J Bone Joint Surg Am 2006;88:1-10.
Tung GA, Yoo DC, Levine SM, et al: Subscapularis tendon tear: Primary and associated signs on MRI. J Comput Assist Tomogr 2001;25:417-424.
46 • American Academy of Orthopaedic Surgeons

Question 28

What are the proposed biomechanical advantages of the Grammont reverse total shoulder arthroplasty when compared to a standard shoulder arthroplasty?

Explanation

DISCUSSION: The Grammont reverse total shoulder arthroplasty is designed to medialize the center of rotation, thereby increasing the deltoid moment arm and lengthening the deltoid.
REFERENCES: Werner CM, Steinmann PA, Gilbert M: Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-1486.
Rittmeister M, Kerschbaumer M: Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructible rotator cuff lesions. J Shoulder Elbow Surg 2001;10:17-22.

Question 29

A 70-year-old man reports symptomatic medial knee pain that has become progressively worse during the past year. MRI reveals a complex, posterior horn medial meniscus tear with associated medial lateral and patellofemoral cartilage defects. Radiographs reveal medial joint space narrowing and osteophytes in the other compartments. What treatment is most likely to provide long-term, durable relief of symptoms?

Explanation

DISCUSSION:
Total knee replacement is a well-established surgery for diffuse, symptomatic osteoarthritis of the knee joint, and its efficacy has been shown in many studies. According to the 2008 AAOS Clinical Practice Guideline, Treatment of Osteoarthritis of the Knee, arthroscopy in the setting of existing osteoarthritis is efficacious for relieving the signs and symptoms of a torn meniscus but not for osteoarthritis. Likewise, in young and active patients, clinical outcomes show improvement after realignment osteotomy for single- compartment osteoarthritis. Unicondylar knee replacement is not indicated for tricompartmental disease
of the knee.

Question 30

Figures 28a and 28b show AP and lateral radiographs of the knee. Based on these findings, which of the following structures has most likely been injured?

Explanation

DISCUSSION: The radiographs show a posterior knee dislocation. Knee dislocations almost always involve rupture of both the anterior and posterior cruciate ligaments. Collateral ligament injuries also are common. Arterial, nerve, and tendon injuries each occur in less than half of knee dislocations.
REFERENCES: Schenck RC Jr, Hunter RE, Ostrum RF, et al: Knee dislocations. Instr Course Lect 1999;48:515-522.
Wascher DC, Dvirnak PC, DeCoster TA: Knee dislocation: Initial assessment and implications for treatment. J Orthop Trauma 1997;11:525-529.

Question 31

Atraumatic neuropathy of the suprascapular nerve usually occurs at what anatomic location?

Explanation

DISCUSSION: The suprascapular nerve passes through the suprascapular notch and the spinoglenoid notch before innervating the infraspinatus muscle. At both locations, the suprascapular nerve is prone to nerve compression, which often results from a ganglion cyst. The other anatomic locations are not associated with suprascapular nerve impingement.
REFERENCES: Romeo AA, Rotenberg DD, Bach BR: Suprascapular neuropathy. J Am Acad Orthop Surg 1999;7:358-367.
Post M, Mayer J: Suprascapular nerve entrapment: Diagnosis and treatment. Clin Orthop 1987;223:126-136.

Question 32

A 69-year-old male presents with acute on chronic neck pain. He denies trauma, fevers, or chills. He has noticed some clumsiness in his hands recently and change in his handwriting. He has had progressive deterioration of his gait. Physical exam shows a positive grip and release test, a positive Hofmann sign, and 3+ patellar reflexes. MRI image is shown in Figure A. The procedure shown in Figure B is performed. Which of the following statements is true regarding this treatment option? Review Topic

Explanation

Figure B shows a multilevel laminoplasty, which can be used in the treatment of cervical myelopathy. The spinal cord is decompressed by increasing the anterior to posterior dimension of the spinal canal.
The treatment of cervical myelopathy is dictated by the number of stenotic levels, sagittal alignment of the spine, and more recently attempt to retain motion. Anterior cervical discectomy and fusion (ACDF) is used for one or two level disease with pathology localized to anterior spine. Posterior decompression and fusion is typically used for disease at more than two levels and is contraindicated with kyphosis greater than 13 degrees. Lamninoplasty and cervical disc arthroplasty are thought to be motion-preserving alternatives, although there can be unintended loss of motion with both techniques. The open door laminoplasty technique involves the use of a suture anchor or small plate to maintain the opening on one side while the french door technique involves hinges bilaterally and opening in the midline.
Emery reviewed the diagnosis and management cervical myelopathy. Surgical management is advocated for patients with functional impairment. Depending on location and extent of pathology, anterior procedures may require corpectomy and use of strut grafting.
Gerard et al. reviewed techniques of surgical management of myelopathy. They describe a minimally invasive posterior decompression using a tubular retractor system. Patients are carefully selected and should have less than 3 levels of disease, no evidence of instability, and normal lordosis.
Figure A is a T2 sagittal MRI image showing multilevel cervical stenosis. Figure B is lateral radiograph of a patient who underwent multilevel laminoplasty. Illustration A shows the open door technique.
Incorrect

Question 33

Which complication is most common after syndesmotic fixation?

Explanation

DISCUSSION
The injury radiographs reveal a supination external rotation IV ankle fracture with evidence of medial clear space widening exceeding 4 mm and an increase relative to the superior tibiotalar clear space. This indicates injury to the deltoid ligament and necessitates surgical reduction and fixation to restore and maintain ankle stability. Following stabilization of the fibula, an intraoperative stress examination of the syndesmosis such as an external rotation stress test under fluoroscopy or lateral pull on the fibula (the Cotton test) should be performed to determine the integrity of the syndesmosis. Radiographic evidence of tibiofibular clear space widening, medial clear space widening with external rotation, and lateral displacement of the distal fibula when pulled is consistent with syndesmotic injury. In contrast to the presurgical stress test, once the fibula has been reduced and stabilized lateral talar translation can occur only if the syndesmosis is injured in addition to the deltoid ligament. Failure of the syndesmotic screw without evidence of malalignment of the mortise and a pain-free ankle are not indications for further surgery because these patients have satisfactory outcomes when compared to those who have intact or removed screws. Hardware removal following fibula ORIF is indicated when patients have pain directly related to hardware prominence. Resolution of joint pain or stiffness is not a reliable outcome following hardware removal. Although fibular fracture can occur, this is a rare complication. Malreduction of the syndesmosis is the most common complication following ORIF of the syndesmosis and is improved with direct visualization; however, malreduction still may occur with direct visualization.
RECOMMENDED READINGS
Manjoo A, Sanders DW, Tieszer C, MacLeod MD. Functional and radiographic results of patients with syndesmotic screw fixation: implications for screw removal. J Orthop Trauma. 2010 Jan;24(1):2-6. doi: 10.1097/BOT.0b013e3181a9f7a5. PubMed PMID: 20035170. View
Abstract at PubMed
Jenkinson RJ, Sanders DW, Macleod MD, Domonkos A, Lydestadt J. Intraoperative diagnosis of syndesmosis injuries in external rotation ankle fractures. J Orthop Trauma. 2005 Oct;19(9):604-9. PubMed PMID: 16247304. View Abstract at PubMed
Stark E, Tornetta P 3rd, Creevy WR. Syndesmotic instability in Weber B ankle fractures: a clinical evaluation. J Orthop Trauma. 2007 Oct;21(9):643-6. PubMed PMID: 17921840. View Abstract at PubMed
Brown OL, Dirschl DR, Obremskey WT. Incidence of hardware-related pain and its effect on functional outcomes after open reduction and internal fixation of ankle fractures. J Orthop Trauma. 2001 May;15(4):271-4. PubMed PMID: 11371792. View Abstract at PubMed

Question 34

A 10-year-old girl with a monoarticular pattern of juvenile rheumatoid arthritis (JRA) has had a 3-cm limb-length discrepancy since age 8 years when inflammation in the right knee came under good medical control. Because her right leg is longer, the patient states that she would like her legs to be close to equal in length in the future. A growth-remaining chart is shown in Figure 14. Management should consist of

Explanation

DISCUSSION: In a subgroup of patients with monoarticular JRA and a limb-length discrepancy that developed before the age of 9 years, Simon and associates showed that a subsequent growth deceleration on the affected side may correct a large part of the difference in length. This possibility would make surgery unnecessary and should prompt further observation.
REFERENCES: Simon S, Whiffen J, Shapiro F: Leg-length discrepancies in monoarticular and pauciarticular juvenile rheumatoid arthritis. J Bone Joint Surg Am 1981;63:209-215.
Ansell BM, Bywaters EGL: Growth in Still’s disease. Ann Rheum Dis 1956;15:295-319.

Question 35

What is the most common long-term complication of the fracture shown in Figure 32?

Explanation

DISCUSSION: The fracture pattern shown in the radiograph involves both a talar neck fracture and a talar body fracture. The body fracture propagates into the subtalar joint, with significant risk for the development of arthritis in that surface even with an anatomic reduction. In addition, Canale and Kelly reported a 25% incidence of malunion of talar neck fractures, with varus angulation occurring most frequently. Of these patients, 50% required a secondary surgical procedure because of the development of degenerative joint disease of the subtalar joint.
REFERENCES: Canale ST, Kelly FB Jr: Fractures of the neck of the talus: Long-term evaluation of seventy-one cases. J Bone Joint Surg Am 1978;60:143-156.
Higgins TF, Baumgaertner MR: Diagnosis and treatment of fractures of the talus: A comprehensive review of the literature. Foot Ankle Int 1999;20:595-605.

Question 36

Alpha fetoprotein (AFP) can be seen in many cancers, but is most commonly seen in hepatocellular carcinomas.

Explanation

Gout is an inflammatory arthritis caused by the presence of monosodium urate crystals in the joint. It is characterized acutely by a painful joint that remits after 1 to 2 weeks and recurs periodically. The diagnosis of gout can be made by confirming the presence of monosodium urate crystals in the joint fluid
aspirated from the inflamed joint. Patients with gout may also have tophaceous deposits within the skin or bursae of the extremities. Elevated urine pH, serum uric acid, and serum phosphate can all be associated with numerous conditions and are not specific to gout. Calcium pyrophosphate crystals are associated with chondrocalcinosis (pseudogout).
A 72-year-old woman is evaluated for sacrococcygeal pain sustained after a twisting injury. Radiographic and MRI evaluation confirms the presence of a nondisplaced fracture at the sacrococcygeal junction. Over a 3-week period, the pain has gotten significantly better. No additional lesions or injuries are noted.
Laboratory studies show a serum calcium level of 8.8 mg/dL (normal 8.6-10.3 mg/dL) and a 25-OH Vitamin D level of 14 ng/mL (normal
80 ng/mL). What is the most appropriate treatment for this patient?
Expectant observation
Calcium supplementation
High dose vitamin D supplementation
Bisphosphonate therapy
Surgical fixation of the sacrococcygeal fracture
Chronic Vitamin D deficiency leads to problems with bone health and has been shown to increase the risk of falls in the elderly. Appropriate supplementation of Vitamin D has been shown to decrease this risk. Conversion in the skin decreases with age and may be nearly nonexistent in darkly pigmented individuals. Vitamin D3 is the preferred form for supplementation, but D2 is the form most available by prescription in the US. Hypervitaminosis D is rare and very high doses can be tolerated without significant concern for toxicity. Because the patient has sustained one insufficiency fracture, she is at risk for insufficiency fractures in other skeletal locations, rendering expectant observation insufficient. Her serum calcium is normal, and with a low Vitamin
D level, calcium utilization in her system would be inadequate. Bisphosphonate therapy in addition to calcium and vitamin D supplementation may provide a good long-term solution, but should not be instituted until the bone mineral imbalance has been adequately corrected. Surgical fixation of this fracture is not indicated, particularly in lieu of improving symptoms.
Figures 70a and 70b show the radiograph and MRI scan of a 66- year-old man who has fatigue, weight loss, and muscle weakness. Examination reveals marked pain and discomfort in the left mid leg. Biopsy specimens are shown in Figures 70c and 70d. What is the most likely diagnosis?
Mastocytosis
Multiple myeloma
Hyperparathyroidism
Metastatic carcinoma
Multicentric giant cell tumor
The signs and symptoms of hyperparathyroidism are similar to those in patients with diffuse skeletal metastases. Serum markers are very helpful in making the diagnosis. In this patient, the radiograph shows multiple lesions in the tibia and proximal fibula that have a variable appearance. For example the mid-tibial lesion is radiolucent and slightly expansile whereas the more proximal tibial lesions are radiodense. The proximal fibula lesion is mixed (radiolucent/radiodense). These findings would be very uncommon in patients with myeloma, metastatic disease, or multicentric giant cell tumor. The histopathology shows a bland fibrous stroma with multiple multinucleated
giant cells. On higher power, the stromal cells are spindled and the giant cells are relatively small in contrast to giant cell tumor where the giant cells are larger and the stromal cells are more rounded with nuclei that closely resemble those in the giant cells.
There is blood extravasation (stromal
hemorrhage) and hemosiderin deposition. The constellation of findings is most consistent with brown tumors due to hyperparathyroidism (secondary to a parathyroid adenoma in this patient).
A 68-year-old woman has had progressive pain in the right thigh for the past several months. She has a history of hypertension, treated with hydrochlorothiazide and osteoporosis treated with alendronate
for 10 years. At this point, she is virtually wheelchair bound.
Radiographs are shown in Figures 78a and 78b. Additional studies show no signs of systemic disease. What is the most likely etiology of her condition?
Prolonged use of bisphosphonates
Use of calcium-wasting diuretics
Occult metastatic cancer
Vitamin D-resistant rickets
Disuse osteopenia
The patient has been on alendronate for 10 years and has evidence of a proximal diaphyseal fatigue fracture. These have been associated with long- term use of bisphosphonates. Staging studies have failed to show systemic disease, and while metastasis with an unidentifiable primary does occur, it would be unlikely to present with this radiographic appearance, now recognized to be classic for stress fractures associated with chronic bisphosphonate usage. Hydrochlorothiazide does not cause calcium wasting. Vitamin D-resistant rickets would be a long-standing event and would present much earlier in life, often with pronounced deformities. Whereas the patient's progression to intolerance of weight bearing likely has led to some degree of disuse osteopenia, the underlying problem is the long-term bisphosphonate exposure.
A surgeon recommends an interscalene regional block to a patient undergoing shoulder arthroscopy. When asked about potential complications, which of the following is most likely to occur?
Persistent motor neuropathy
Sensory neuropathy
Complex regional pain syndrome
Pneumothorax
Cardiac arrythmia and arrest
Sensory neuropathy is the most common complication seen with interscalene regional block.
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Bishop et al. retrospectively reviewed 478 patients who had shoulder surgery under interscalene regional block. A total of 462 patients (97%) had a successful block. While all of the answers have been described, in this study no patient had a seizure, pneumothorax, cardiac event, or other major complication. Twelve (2.3%) of the 512 patients who had a block had minor complications, which included sensory neuropathy in eleven patients and a complex regional pain syndrome that resolved at three months in one patient. For ten of the eleven patients, the neuropathy had resolved by six months.
Cathepsin K is an enzyme produced by osteoclasts. What is the function of cathepsin K?
Reduction of disulfide bonds in the extracellular matrix
Bone resorption
Activation of RANK (Receptor activator of nuclear factor kappa-B)
Antagonize the action of RANK
Absorb water in the extracellular matrix
Cathepsin K is an enzyme produced and released by osteoclasts at the ruffled border that functions to resorb bone. Cathepsin K inhibitors are being clinically evaluated as potential anti-resorptive drugs for use in osteoporosis treatment. Other proteins associated with osteoclasts include tartrate-resistant acid phosphatase (TRAP) and calcitonin receptor.
Illustration A is a drawing that depicts the action of cathepsin k within osteoclasts.
What is the primary problem in rickets osteomalacia?
Defect in the zone of proliferation within the physis
Defect in type I collagen
Defect in the ext-1 gene
Low level of calcium
Production of dysplastic fibrous bone
Rickets is a disorder of bones in children that results from decreased calcium available in the blood resulting in poor mineralization of bone that can lead to fractures and deformity. The most common cause of rickets is from vitamin D deficiency but it can also be caused by poor nutrition or gastrointestinal
disease that results in poor calcium absorption such as celiac disease or severe diarrhea from other causes. Rickets is not primarily a physeal disorder. Osteogenesis imperfecta is caused by a defect in type I collagen. A defect in
the ext-1 gene is often seen in patients with multiple hereditary exostoses. Fibrous dysplasia also can result in bone deformity and fractures due to production of dysplastic fibrous bone but is not caused by calcium or vitamin D deficiency.
If an orthopaedic surgeon receives royalties from a company for his or her participation in the design and development of a product, and uses that same product for the care of his or her patients, what is the orthopaedic surgeon's obligation?
Obligated to disclose only the fact that he or she was involved in the design and development
Obligated to disclose only the company relationship if there is a state law requiring it
Obligated to disclose his or her full relationship with the company, including the fact that he or she receives royalties
No obligation to disclose this private matter to the patient
Avoid this situation because it should not exist since he or she cannot use such a product
The AAOS has a specific code of ethics and professionalism that addresses this issue: "When an orthopaedic surgeon receives anything of value, including royalties, from a manufacturer, the orthopaedic surgeon must disclose this fact to the patient." It is derived from a broader document developed by the American Medical Association, and is applicable to all physicians. At present, this is an ethical issue receiving greater federal scrutiny. This issue has had a greater effect on the public's perception of the integrity of the orthopaedic profession.
A minimally invasive plate osteosynthesis is seen in Figure 15. The resultant fracture healing can best be attributed to a fixation construct that was
stiff and stable.
flexible and stable.
facilitating direct osteonal healing.
inhibitory to endochondral ossification.
stimulatory to intramembranous ossification.
Locked plating constructs with long-working lengths provide flexible but stable constructs that promote (not inhibit) endochondral ossification. Because of the longer working length they are not stiff, and these fractures do not heal with intramembranous ossification which occurs in bones like the calvarium. Direct osteonal healing is usually seen with constructs
where absolute stability is achieved through interfragmentary compression, unlike in this case.
An orthopaedic surgeon makes an incision on a right knee and realizes that the patient was supposed to have a left total knee arthroplasty. The surgeon should do which of the following?
Leave the wound open and talk to the family immediately.
Close the wound, abort the surgery, and talk to the patient and family when the patient is awake.
Close the wound, complete the left knee arthroplasty, and talk to the family after the surgery is complete.
Complete the surgery and talk directly to the patient the following day on rounds.
Discuss the problem in the office the next week in a calm reassuring manner.
The AAOS recommendation is to complete the correct surgery, repair the incorrect surgery to as close to normal as possible, and then discuss it openly with the family after the surgery is complete. Prompt informing is necessary. Aborting the surgery then results in the patient requiring a second anesthesia and surgical time needlessly.
Spindled cells that are surrounded in mature osteoid that
connect to other similar cells via canaliculi are best described as which of the following?
Osteoblasts
Osteoclasts
Osteocytes
Histiocytes
Megakaryocytes
Osteocyte cell processes travel through canaliculi to interconnect with other osteocytes and cells on the bone surfaces. Osteoblasts are cells that produce bone matrix and are seen rimming immature bone. Osteoclasts are large multinucleated cells that resorb bone and are found in Howship's lacunae. Megakaryocytes and histiocytes are found in marrow but not mature bone cortex.
A 48-year-old woman has an open subtrochanteric femur fracture. No other injuries are reported. After thorough evaluation, it is determined that she will need emergent surgical fixation. The patient and family indicate that they are practicing Jehovah's witnesses and desire adherence to the religious standards with respect to blood product usage. The patient signs a valid advanced directive confirming these wishes. Which of the following would be considered acceptable treatment?
Whole blood
Platelets
Plasma
Starch product (ie, Hetastarch, Hespan)
Donor-directed blood from a family member who is a practicing Jehovah's witness
Jehovah's witnesses beliefs regarding blood products stems from direct interpretation of passages from the bible. The use of crystalloid, starch products such as Hetastarch and colloids are accepted. Typically Jehovah's witnesses will accept most medical treatment but refrain from the use of blood products including whole blood, packed red cells, platelets, white cells, or plasma. Any autologous transfusion, whether from the patient themself or donor directed, is forbidden. The use of cell-saver type processes is a matter of individual choice by the patient. The use of hemoglobin-based oxygen carriers are now accepted by many patients but it is important to respect the wishes of each individual patient. It is very important to discuss preoperatively with the patient and family their wishes and thoughts on what is acceptable to use. Many facilities have adopted
bloodless-surgery protocols and committees that definitively outline the measures that can be used and take into consideration the many ethical issues involved in taking care of these patients.
In a diagnostic test, the proportion of individuals who are truly free of a designated disorder identified by the test is known as
specificity.
sensitivity.
accuracy.
positive predictive value.
negative predictive value.
Specificity refers to the proportion of individuals who are truly free of the designated disorder who are so identified by the test. Sensitivity refers to the proportion of individuals who truly have the disorder who are so identified by the test. Positive predictive value refers to the proportion of individuals with a positive test who have the disorder. Negative predictive value refers to the proportion of individuals with a negative test who are free of the disorder.
Accuracy is the overall ability to identify patients with the disorder (true positives) and without the disorder (true negatives) in the study population.
An orthopaedic surgeon in his first year of practice is negotiating with a private for-profit hospital to be their employed trauma specialist. The state of employment is known to have a high rate of malpractice claims because of a favorable plaintiff legal environment. During the course of negotiations, malpractice insurance is being discussed. The surgeon should ask the hospital to provide which type of malpractice insurance policy?
Claims made with "nose" coverage
Claims made without tail coverage
No policy because of employed status and sovereign immunity
Occurrence coverage
Occurrence coverage with "nose" coverage
An occurrence policy provides coverage for all claims made during employment irrespective of when it is filed (during or postemployment) and therefore is the best option. Claims made policy only covers suits for the time employed. A prepurchased "tail" is needed to provide coverage for cases that occurred during employment but filed postemployment. Nose coverage is applicable if the surgeon was previously employed and did not have tail coverage from previous employment, but this surgeon just emerged from training where it is not applicable. Claims made without tail coverage is unwise because the surgeon would be unprotected or have to purchase his own policy postemployment.
Only in certain situations does sovereign immunity exist, and generally not in a for-profit system. Occurrence coverage with nose coverage
is incorrect because it does not apply to this surgeon with no previous employment or claims policy lacking tail coverage.
Results of a study demonstrating no difference between treatments when a difference truly exists is an example of which of the following?
Statistical insignificance
Type I error
Type II error
Fragile p-values
Negative predictive value
A type II error (also known as a beta error) occurs when results demonstrate that two groups are similar when, in reality, they are different (with regard to the statistic being measured). Type I errors show that a difference exists when, in reality, no difference exists. A statistically insignificant result may lead an investigator to conclude that no difference exists between two groups; this may be correct (and therefore not a type II error). The concept of
fragile p-values is that small sample sizes may result in wide variability of p- values with only one change in a data point for a given group. This singular change could be a chance occurrence, but it still can affect the statistical significance of the outcomes analysis.
Fragility of p-values is limited by increasing sample sizes. Negative predictive value is the
proportion of patients with negative test results who are correctly diagnosed.
A patient with a transverse femur fracture undergoes statically locked antegrade intramedullary nailing. Postoperatively, the patient appears to have a rotational deformity of greater than 25 degrees. The surgeon informs the patient, who chooses to undergo corrective treatment with removal of distal interlocking screws, rotational correction, and relocking of the screws. The patient goes on to heal
but has persistent hip pain and a limp that does not improve completely after extensive rehabilitation. There is complete healing, no evidence of infection, no hardware issues, no ectopic bone, and rotational studies indicate less than 2 degrees of malrotation. Functional capacity testing reveals the affected abductor and quadriceps function to be about 85% of the uninjured side and the patient returns to work and most of his recreational activities except rock climbing. Two days before the statute of limitations, the patient
files a malpractice suit alleging negligence of surgery, loss of function, consortium, and pain and suffering due to the surgeon's efforts. What action should the surgeon and the defense team take?
Settle the case because the surgeon made an error that resulted in unnecessary surgery, and thus the case is indefensible.
Settle the case because they are likely to lose the case, and it would be cheaper to settle than to defend.
Defend the case alleging that there was no error, and no damages, and that the patient is malingering.
Defend the case because despite there being an error, the error was corrected and there were little or no damages compared with expected outcomes.
Contact the patient directly to discuss why he is suing and attempt an amicable resolution.
To establish negligence, certain criteria must be met. 1) A duty was owed by the surgeon (in this case, yes, a relationship was established). 2) The duty was breached, where the provider failed to meet the standard of care (there
was a technical error, but it was corrected). 3) The breach caused an injury. In this case, the patient had an outcome that was very acceptable, as
documented with outcome studies, for femur fractures. Also, the rotational error and locking distally would have had little impact on the hip, whereas antegrade nailing itself is expected to result in some objective impairment of the hip in some patients. 4) Damages were incurred as a result. In this case, the patient returned to work and could not rock climb which could be reasonably expected with a femur fracture in some patients, and cannot be causally linked to the corrective surgery. For all practical purposes, the patient had a very acceptable outcome. Thus, settling the case for an error would be rather permissive and the important issue is that the surgeon recognized the problem, addressed it, and fulfilled his or her postoperative responsibility. The case is very defendable, and thus it is unlikely to be lost. Defending the case and alleging no error is incorrect because there was an error. The surgeon should never function outside of his or her legal counsel once a suit is filed.
You design a research study in which you ask patients who have a nonunion of the tibia to fill out a questionnaire in which they report on a variety of medical conditions and social/behavioral practices. You compare these findings to a similar group who did not develop a nonunion in order to identify medical and/or social conditions that might be risk factors for the development of tibial nonunions. This would be an example of what type of study?
Case series
Meta-analysis
Case control study
Retrospective cohort study
Prospective cohort study
A case control series starts with the occurrence of a specific disease or observation, and then compares data on those individuals to a similar group without the disease (control group) in order to identify potential risk factors for the development of the disorder. A case series is an observational study in which an investigator follows a series of patients who received a specific treatment, recording the results and outcomes of that treatment. A meta- analysis is the combination of several separate studies that look at similar hypotheses in an effort to create a larger patient population for analysis. A cohort study looks for the incidence of a specific outcome in two groups (cohorts) of patients who are similar with the exception of a particular
research variable (risk factor).
Which gene or protein is the most specific marker of mature osteoblasts but is not expressed by immature, proliferating osteoblasts?
Osteocalcin
TGF-B
COLIIA1
cFOS
IL-1
Osteocalcin is the most specific marker of the osteoblast phenotype and is expressed only in mature osteoblasts. TGF-B is a growth factor involved in the differentiation of multiple cell lines. For bone, TGF-B plays a role in stem cell differentiation into mesenchymal stem cells along osteoblast pathways. COLIIA1 is the gene for Type II Collagen and is involved in chondrocyte differentiation. cFOS is involved in osteoclast differentiation. In regards to
bone metabolism, IL-1 stimualtes osteoclastic bone resorption.
A workers' compensation carrier for a local manufacturing company requests a second opinion on a 59-year-old man who sustained a crush injury to his foot and leg at work 6 months ago. His leg and foot were pinned between a forklift and a wall when an employee he was supervising lost control of the forklift. The employer
suspects that the injured worker is malingering because the treating physician released him to work, but he has not returned to work. Which of the following elements of your history will best help you determine that the injured worker does not want to return to work out of fear of a confrontation with the employee he was supervising?
Formality
Empathy
Yes-no questions
Taking copious notes
Sitting leaning back in a chair
Empathy during the interview demonstrates compassion and earns the patient's trust; which, in turn, enables the patient to discuss any agenda or concerns he or she may otherwise feel uncomfortable revealing. It is also important to engage the patient to establish a trusting relationship and thus understand all the factors impacting the patient. A formal attitude toward the patient makes it difficult to engage the patient to be "drawn in." An engaged patient is more comfortable, reliable, and thorough when providing a history. Closed-end, yes-no questions do not allow the patient to detail all of the subtle nuances of their condition and its effect on their life. Taking copious notes likewise prevents engagement of the patient and the distraction of taking
notes may cause the physician to miss an important detail. It is better to lean forward in a chair when interviewing a patient because this suggests the physician is genuinely interested, whereas leaning back in a chair suggests the physician is simply waiting for the patient to finish talking. Avoid interrupting the patient when talking.
When a Workers' Compensation patient recovers after an injury to a point that further restoration of function is no longer anticipated, he or she is said to have reached which of the following?
Functional capacity
Maximum medical improvement
Permanent disability
Impairment rating
Predesignation
This is the definition of maximum medical improvement (MMI). The patient has essentially reached the plateau of his improvement.
Functional capacity evaluations (FCE) are based upon a theoretical model of comparing job demands to worker capabilities. The results of FCEs are often used to determine musculoskeletal capacity to return to work.
Strong et al. reported on the use of FCE in the Workers' Compensation system, and note how these FCE results are required by employers to determine the level of return to work of their employees. They also mention that the reports are frequently perceived with a negative tone. The employees reported a wider range of restrictions in their varied life roles than did the FCE reports, which deal more narrowly with work roles.
Pransky et al. reported that although FCE's are relied upon for determination of ability to perform physical work, several scientific, legal, and practical concerns persist. They note that test criteria often do not accurately reflect real-life job requirements or performance, and subjective evaluation remains common. They conclude that more research into predictive linking of FCE outcomes with occupational outcomes is necessary to determine their role in the Workers' Compensation system.
Incorrect Answers:
1: A functional capacity evaluation (FCE) is set of tests, practices and observations that are combined to determine the ability of the evaluated to function in a variety of circumstances (most often employment) in an objective manner.
3: Permanent disability is any lasting disability that results in a reduced earning capacity after maximum medical improvement is reached; this implies that MMI must be reached before this is determined.
4: Impairment rating is an objective data point obtained by a physician reviewing the patient's overall condition during a functional capacity evaluation.
5: This is the process a patient uses to tell their employer they want a personal physician to treat them for a work injury.
A physician receives a summons that he is being sued. The first step should be to
call the patient and apologize.
notify the medical liability carrier.
contact an attorney with whom the physician is familiar with and have the attorney review the records.
be sure to discard any handwritten phone messages because they are not discoverable.
find a colleague with a similar subspecialty and have the colleague review the record before doing anything.
The most appropriate first step is to notify the medical liability carrier. The medical liability carrier will assign an attorney who is likely to be more appropriate. A review by a colleague may be requested by the defense attorney but that should be at their discretion. Patient apology is appropriate early on when and if you discover an error.
Records should be reviewed, but never altered.
Currently, what is the most common clinical study type in the orthopaedic literature?
Level 1 (prospective, randomized trial)
Level 2 (cohort trial)
Level 3 (retrospective case control)
Level 4 (retrospective case series)
Level 5 (expert opinion)
Although a recent push for prospective, randomized trials has been advocated by multiple orthopaedic journals, many studies published continue to be of Level 4 evidence (retrospective case series). Case series represented 64% of all studies reviewed by Freedman and associates in 2001 from the British and American volumes of Journal of Bone and Joint Surgery and from Clinical Orthopaedics and Related Research.
Obremskey and associates published that

Question 37

A 19-year-old man sustains a thigh contusion over his quadriceps muscle while skateboarding. He is treated with several days of immobilization followed by gradually increasing range of motion and activity. Histologic analysis of a biopsy of the healing muscle in the mobilization state at 4 weeks from the date of injury would be characterized by Review Topic

Explanation

Skeletal muscle contusions are a common cause of morbidity from sports-related injuries. The healing response involves a complex balance among muscle repair, regeneration, and scar-tissue formation. Animal models of muscle contusion have demonstrated a time-dependent histological response to postinjury protocols of immobilization and remobilization. Mobilization initiated after a brief period of immobilization resulted in better penetration of regenerative muscle through limited connective tissue scar in line with native surrounding muscle. Early mobilization in an in vivo muscle contusion model resulted in a progressive increase in myotubule, early nerve regeneration, and reduced inflammation. Immobilization results in disorganized penetration of muscle fiber through dense connective scar tissue with immobilization.

Question 38

A 12-year-old girl has the painful foot deformity seen in Figure 79. You advise her that she has juvenile bunions. How do they differ from adult bunions?

Explanation

The hallmark of the juvenile bunion is metatarsus primus varus. Increased flexibility of the first metatarsal phalangeal joint leads to increased deformity. The hallux valgus
angle is less than the adult bunion. Bursal thickenings and prominence of the medial eminence are less in a juvenile bunion.

Question 39

A 64-year-old woman with rheumatoid arthritis cannot fully extend her fingers actively at the metacarpophalangeal (MCP) level. Full passive extension is possible, but she cannot actively maintain that extension when her fingers are released. The MCP joints do extend when her wrist is passively flexed. What is the most likely cause of this problem?

Explanation

EXPLANATION:
Loss of MCP extension is common in the setting of rheumatoid arthritis, but potential causes are varied. An understanding of various etiologies is needed to address the multiple facets of inflammatory arthropathy, for which causes include extensor tendon rupture, MCP joint flexion contracture/dislocation, subluxation of the extensor tendons at the MCP joint (sagittal band rupture), and posterior interosseous nerve (PIN) palsy. These causes are differentiated during an examination. Extensor tendon ruptures, as seen with caput ulnae syndrome (Vaughan-Jackson syndrome) allow for passive MCP extension, not active extension or the ability to maintain extension actively, and would not involve finger extension with passive flexion tenodesis of the wrist. Flexion contractures of the MCP joints, as may be seen in dislocations, would not allow active or passive motion. Subluxation of the extensor tendons at the MCP joints, as seen in attenuation of the sagittal bands, will usually preclude the initiation of active extension, but patients will be able to maintain extension of the MCP joints once they are placed in extension by the examiner. With a PIN palsy, no active extension or active hold is possible, but passive extension and tenodesis with wrist flexion are maintained. Synovitis of the elbow is the most likely cause of the PIN palsy. An extensor tenosynovitis or caput ulnae syndrome would not prohibit MCP extension unless the condition progressed to the point of causing other pathology.

Question 40

Which of the following genetic disorders has an X-linked recessive inheritance pattern?

Explanation

Hemophilia A is inherited in an X-linked recessive fashion.
linked recessive disorders occur when a mutation occurs on the X chromosome that causes the phenotype to be expressed in males and in females who are homozygous for the gene mutation. These disorders are much more common in males since they only have one X chromosome. Other X-linked recessive disorders include: Duchenne muscular dystrophy, Becker's muscular dystrophy, Hunter's syndrome, and spondyloepiphyseal dysplasia (SED) tarda.
Vanderhave et al. reviewed the orthopaedic consideration in patients with hemophilia. Amongst other things, they discuss arthroplasty in patients with this condition. While they are at higher risk for stiffness and acute hemarthrosis following total knee arthroplasty, ~90-95% of patients have good or excellent results.
Illustration A shows how hemophilia is inherited through a punnett square. Illustration B shows how a weak clotting mechanism causes increased bleeding in patients with hemophilia.
Incorrect Answers:

Question 41

A 3-year-old boy sustains a complete paralysis following a high thoracic spinal cord injury consistent with a SCIWORA-type injury (spinal cord injury without radiographic abnormality). Subsequent progressive spinal deformity will develop in what percent of patients with this injury?

Explanation

DISCUSSION: Spinal cord injury in skeletally immature patients almost always leads to the development of paralytic spinal deformity. The age at injury is the most important factor affecting the development of scoliosis. Spinal cord injury that occurs more than 1 year prior to skeletal maturity is almost always followed by the development of scoliosis. In one study, scoliosis developed in 100% of children who were younger than age 10 years at the time of spinal cord injury. Scoliosis can occur after injury at any level. Spasticity is often a contributing factor. Up to two thirds of patients who have paralytic scoliosis prior to skeletal maturity will eventually require surgery for curve control.
REFERENCES: Mayfield JK, Erkkila JC, Winter RB: Spine deformity subsequent to acquired childhood spinal cord injury. J Bone Joint Surg Am 1981;63:1401-1411.
Lancourt JE, Dickson JH, Carter RE: Paralytic spinal deformity following traumatic spinal cord injury in children and adolescents. J Bone Joint Surg Am 1981;63:47-53.
Dearolf WW III, Betz RR, Vogel LC, Levin J, Clancy M, Steel HH: Scoliosis in pediatric spinal cord injured patients. J Pediatr Orthop 1990;10:214-218.

Question 42

A 13-year-old boy injured his knee playing basketball and is now unable to bear weight. Examination reveals tenderness and swelling at the proximal anterior tibia, with a normal neurologic examination. AP and lateral radiographs are shown in Figures 1a and 1b. Management should consist of

Explanation

DISCUSSION: The patient has a displaced intra-articular tibial tuberosity fracture; therefore, the treatment of choice is open reduction and internal fixation. Periosteum is often interposed between the fracture fragments and prevents satisfactory closed reduction. Fortunately, most patients with this injury are close to skeletal maturity and therefore, growth arrest and recurvatum are unusual. Nondisplaced fractures can be treated with a cast, but displaced fractures are best treated with open reduction and internal fixation. Intra-articular fractures can disrupt the joint surface and are sometimes associated with a meniscal tear; therefore, arthroscopy may be needed at the time of open reduction and internal fixation.
REFERENCES: McKoy BE, Stanitski CL: Acute tibial tubercle avulsion fractures. Orthop Clin North Am 2003;34:397-403.
Zionts LE: Fractures around the knee in children. J Am Acad Orthop Surg 2002;10:345-355.

Question 43

During C1-C2 transarticular screw fixation, screw misplacement is most likely to result in injury to the

Explanation

DISCUSSION: With C1-C2 transarticular screw fixation, the following structures are potentially at risk: vertebral artery, spinal cord, occiput-C1 joint, and hypoglossal nerve. The vertebral artery is most vulnerable to injury with drill misdirection or anatomic variations in the vertebral foramen. The hypoglossal nerve may be injured if the drill, tap, or screw passes too far anterior to the lateral mass of C1. This complication is extremely rare. The occiput-C1 joint may be injured if the screw trajectory is too cephalad or cranially directed; however,this scenario is very unlikely because the exposure tends to direct the screw into a caudally inclined direction. This caudal orientation has the potential to cause vertebral artery injury, especially in patients who have a large vertebral foramen in the lateral mass of C2 because of erosions (rheumatoid arthritis) or anatomic variation. CT of the vertebral foramen is recommended when C1-C2 transarticular fixation is being considered. Spinal cord injury is extremely unlikely because of the very large size of the spinal canal in the upper cervical spine; the spinal cord lies far away from the lateral masses of C1 and C2.
REFERENCES: Mueller ME, Allgower M, et al: Manual of Internal Fixation, ed 3. New York, NY, Springer-Verlag, 1991, pp 634-636.
Gebhard JS, Schimmer RC, Jeanneret B: Safety and accuracy of transarticular screw fixation C1-C2 using an aiming device: An anatomic study. Spine 1998;23:2185-2189.

Question 44

The thickest bone in the occiput is located

Explanation

DISCUSSION: Anatomic studies have shown that the thickest bone of the occiput is at the level of the external occipital protuberance. It ranges from 11.5 mm to 15.1 mm in men and from 9.7 mm to 12 mm in women. In general, the bone thins as it extends distally from the external occipital protuberance and it also moves laterally from the midline. The structures at risk during screw placement include the venous sinuses.
REFERENCES: Nadim Y, Lu J, Sabry FF, et al: Occipital screws in occipitocervical fusion and their relation to the venous sinuses: An anatomic and radiographic study. Orthopedics 2000;23:717-719.
Ebraheim N, Lu J, Biyani A, et al: An anatomic study of the thickness of the occipital bone: Implications for occipitocervical instrumentation. Spine 1996;21:1725-1729.

Question 45

Chemotherapy for this condition is

Explanation

DISCUSSION
This patient has a dedifferentiated liposarcoma within a preexisting atypical lipomatous tumor. The imaging demonstrates a large fatty mass with increased internal septations proximally (the atypical lipomatous tumor) and a solid enhancing mass distally (the dedifferentiated portion). A biopsy reveals a high-grade liposarcoma. The other diagnostic responses do not reflect sarcomatous transformation of the lesion.
Surgical treatment of a high-grade sarcoma involves wide surgical resection. Radiation decreases local recurrence but does not clearly influence overall survival. The role of chemotherapy in high-grade soft-tissue sarcomas remains investigational; there is a modest (8%-15%) associated improvement in overall survival.
Intramuscular lipomas and atypical lipomatous tumors are treated with marginal resection alone. Radiation therapy for soft-tissue sarcomas may be given before or after surgery. When administered before surgery, patients have a higher wound complication rate but better long-term function attributable to lower rates of lymphedema, fibrosis, and contractures.
RECOMMENDED READINGS
Schlieman M, Smith R, Kraybill WG. Adjuvant therapy for extremity sarcomas. Curr Treat Options Oncol. 2006 Nov;7(6):456-63. Review. PubMed PMID: 17032558.View Abstract at PubMed
Yang JC, Chang AE, Baker AR, Sindelar WF, Danforth DN, Topalian SL, DeLaney T, Glatstein E, Steinberg SM, Merino MJ, Rosenberg SA. Randomized prospective study of the benefit of adjuvant radiation therapy in the treatment of soft tissue sarcomas of the extremity. J Clin Oncol. 1998 Jan;16(1):197-203. PubMed PMID: 9440743.View Abstract at PubMed
Soft tissue tumors. In: Damron TA, ed. Orthopaedic Surgery Essentials: Oncology and Basic Science. Philadelphia, PA: Lippincott Williams and Wilkins; 2008:87-92

Question 46

A 25-yo man sustains the injury shown in Figures 29a and 29b as a result of high-speed trauma. Examination reveals diffuse weakness in the lower extremities that is slightly worse on the right side, and decreased rectal tone and sensation. A CT scan is shown in figures 29c and 29d. Definitive treatment of the injury to the spine is delayed because of a severe pulmonary contusion. At 15 days after the injury, the patient’s neurological status remains unchanged. Management should now consist of

Explanation

Anterior decompression is preferred for patients who have incomplete neurologic injury with a compression or burst fracture, if the posterior ligament complex has not been disrupted. Progressive ambulation with a TLSO may be indicated for a simple wedge compression fracture. If the compression is greater than 40% and no neural deficit, then posterior stabilization may be indicated to prevent further collapse and neural deficit. Wedge compression with subluxation or dislocation indicates disruption of posterior ligament complex requiring posterior instrumentation and fusion. Compression and distraction injuries of the middle complex should be treated by Harrington or C-D distraction and compression instrumentation. (Bohlman: The Spine, 1992 pp1047-1056)

Question 47

What is the usual mechanism of injury for the fracture shown in Figures 49a and 49b?

Explanation

Figures 49a and 49b show a severely comminuted, displaced fracture of the distal tibial metaphysis with intra-articular extension, i.e. pilon fx, or the so-called “distal tibial explosion fracture.” According to the article by Kellam JF and Waddell JP, there are “two mechanisms that can cause this fracture, a rotational pronation dorsiflexion force, and an axial compression force with the foot in either neutral or dorsiflexion at the moment of impact. Because of these mechanisms of injury, two fracture patterns were observed in the series of patients reported. The rotational pattern results in several large metaphyseal fragments, and usually a fibular fracture of a short oblique type above the level of the ankle joint…The second and unfortunately the more common fracture pattern is caused by a severe axial compression force which causes marked comminution of the distal tibial metaphysis, loss of bone substance due to impaction, superior migration of the talus, and loss of the ankle cartilage space.”

Question 48

Figure 34 shows the standing AP radiograph of a 2-year-old girl who has a left bowleg deformity. Her mother states that she first noticed the problem when the child began walking at age 10 months, and the deformity has worsened over the past 6 months. Examination reveals a definite lateral thrust of the knee during the stance phase of gait. Management should consist of

Explanation

DISCUSSION: Infantile tibia vara is a developmental condition characterized by a varus angulation of the proximal end of the tibia that is caused by a growth disturbance of the proximal medial physis. In a study of 42 affected extremities in 24 children younger than age 3 years, it was found that daytime ambulatory brace treatment favorably altered the natural history of tibia vara. Another study of 27 patients with stage II Langenskiöld disease found a success rate of 70% (improved alignment without the need for osteotomy) using brace treatment. These authors also noted that children with unilateral disease were more likely to obtain correction of the deformity compared with those with bilateral disease. In this patient, observation is not warranted because untreated tibia vara has a significant risk for progressive worsening. Osteotomy is best reserved for those patients who, despite bracing, do not show satisfactory clinical and radiographic improvement by age 4 years. Elevation of the medial tibial plateau is a treatment option for older patients who have more advanced disease. An MRI scan would not provide any useful clinical information at this time.
REFERENCES: Zionts LE, Shean CJ: Brace treatment of early infantile tibia vara. J Pediatr Orthop 1998;18:102-109.
Richards BS, Katz DE, Sims JB: Effectiveness of brace treatment in early infantile Blount’s disease. J Pediatr Orthop 1998;18:374-380.
Raney EM, Topoleski TA, Yaghoubian R, Guidera KJ, Marshall JG: Orthotic treatment of infantile tibia vara. J Pediatr Orthop 1998;18:670-674.

Question 49

A 6 year-old-boy falls from his bunk bed and suffers the injury seen in Figures A and B. Upon presentation to the emergency room he is noted to have a pink hand with brisk capillary refill, but no palpable pulses. After closed reduction in the operating room and the procedure seen in Figures C and D, he remains well perfused, pulses are still not palpable, but triphasic pulses can be heard on doppler examination. What is the most appropriate course of action? Review Topic

Explanation

A "pink pulseless" hand, especially those with strong triphasic doppler signals can be treated with observation. In the presented case it would be appropriate to place long arm immobilization (cast or splint) and observe.
Pediatric supracondylar humerus fractures presenting with vascular compromise can present a challenge for clinical decision making. If the hand lacks adequate perfusion on presentation it requires emergent treatment with closed reduction and pinning. If perfusion does not return, then surgical exploration of the antecubital fossa is required. Treatment of the "pink pulseless hand" remains controversial. If the hand is well perfused but lacks palpable pulses then it should be expeditiously reduced and pinned. If the hand remains well perfused with triphasic doppler signals, no additional intervention is required. Recommendations vary if the hand is perfused, and pulses cannot be detected on palpation or doppler.
If there is a normal neurovascular exam on presentation, but abnormal after reduction and pinning, then one must consider that the reduction may have entrapped the brachial artery. If hardware removal and fracture re-displacement does not improve pulses/perfusion of the hand, or if the fracture can not be reduced without diminishing perfusion, then open reduction is indicated to evaluate the brachial artery.
Shah et al. present their preferred algorithm for treatment of a pink pulseless hand. They note that even with good clinical perfusion there may be a vascular injury or entrapment of the brachial artery. Thus they recommend if the hand is pink with no palpable pulse, perform a doppler exam. Triphasic doppler signals allow for observation, while abnormal or non-detectable doppler signals require surgical exploration. If an AIN or median nerve injury is present, exploration is considered. A diagram of their algorithm can be seen in Illustration A.
Weller et al. present a retrospective review of 1297 supracondylar humerus fractures. They had 20 patients (1.5%) with a pink pulseless hand with good doppler signals following closed reduction and fixation. These patients were treated with close observation. One patient developed inadequate perfusion nine hours after reduction and required vascular repair. The remaining 19 patients regained palpable pulses prior to discharge or prior to the first follow-up visit. They recommend observation despite non-palpable pulses as long as other signs of perfusion (capillary refill and doppler signals) suggest the hand is well perfused.
Figures A and B are AP and lateral radiographs of a type III supracondylar humerus fracture. Figures B and C demonstrate this fracture following closed reduction and percutaneous pinning with three lateral pins. Illustration A is a flow chart of a proposed decision making algorithm for a pink pulseless hand as presented by Shah et al.
Incorrect Answers:
reduction and fixation. Answer 2- Changing the pattern of fixation would only be indicated if the current construct did not provide stable fixation of the fracture. Answer 3- Following reduction and fixation of a supracondylar humerus fracture the most appropriate dressing is rigid long arm immobilization in a splint or cast. If there is concern for edema or perfusion then a cast should be bivalved. Answer 5- Surgical exploration of the antecubital fossa would be indicated if the hand had inadequate perfusion, or if the fracture could not be reduced and fixed without causing a notable decrease in pulses or perfusion.

Question 50

The comparative outcomes of needle aponeurotomy (NA) and collagenase Clostridium histolyticum (CCH) use in the treatment of Dupuytren contracture indicate that patients treated with CCH have

Explanation

A 48-year-old woman presents with an insidious onset of dorsal wrist pain and decreased motion. Her radiographs are unremarkable, showing no carpal collapse or malalignment. MRI reveals avascular necrosis of the capitate. Her condition does not improve with immobilization. What would be the most appropriate surgical intervention?
A. Proximal row carpectomy
B. Vascularized bone graft
C. Radial shortening osteotomy
D. Capitate shortening osteotomy
Osteonecrosis of the capitate is a rare condition that presents with an insidious onset of dorsal wrist pain. When nonsurgical treatment fails to alleviate symptoms, surgical intervention is appropriate. When collapse of the capitate is present, partial excision of the capitate with interposition, partial wrist arthrodesis, or wrist denervation can be considered. In the absence of collapse, capitate-preserving options are available. Vascularized grafting is a mainstay of treatment. Grafting with distal radius vascularized grafts based on the 1,2 intercompartmental supraretinacular artery or the 4 + 5 extensor compartment artery and second metacarpal graft based on the first dorsal metacarpal artery have been described.

Question 51

-What is the most appropriate initial treatment for her condition?

Explanation

DISCUSSION FOR QUESTIONS 73 THROUGH 75
This patient has a history most consistent with multidirectional instability. A lax capsule causes subluxation of the shoulder and strain on the rotator cuff and may result in pain and instability. The capsule is most closely associated with the cause of her problem. Initial treatment for multidirectional instability is physical therapy focusing on restoring balance to the shoulder with rotator cuff and scapular stabilization exercises. Nonsurgical therapy should be protracted and is the mainstay of treatment in this scenario. This patient has exhausted all nonsurgical measures and is now a candidate for surgical reconstruction. Capsular plication will best address the lax capsule and provide the best option for reducing her symptoms. The rotator cuff and biceps tendon may be secondarily strained but are not the primary sources of the problem. The brachial plexus does not address the etiology, but rather the symptoms that may occur as a result of instability of the shoulder joint.
Complete rest will not alleviate the patient's underlying condition because the shoulder girdle may still be weak and symptoms likely will return. A corticosteroid injection and arthroscopic surgery are too invasive as initial treatment for this condition. Arthroscopic rotator cuff repair, a biceps tenodesis, and superior labral anterior-posterior repair are unlikely to result in symptomatic improvement for this patient and are not associated with pathologic findings in the setting of multidirectional instability.

Question 52

One week ago a 25-year-old man slipped on the ice and fell, catching himself on a railing. He sustained an anterior shoulder dislocation that was subsequently reduced without difficulty in the emergency department, and he was discharged in a sling. He is now back for follow-up and reports no pain. Examination reveals no weakness on external rotation strength testing. What is the most appropriate management for this patient? Review Topic

Explanation

On the basis of the patient's age, lack of weakness, and the fact that this is a first-time traumatic shoulder dislocation, he is unlikely to have sustained a rotator cuff tear. Immobilization should be continued for 2 more weeks. Scheduling a surgical stabilization procedure at this time is not indicated. Immediate therapy is contraindicated because of the acuity of the injury. A cortisone injection is not indicated in an acute traumatic shoulder dislocation.

Question 53

The patient has no postsurgical complications and begins physical therapy rehabilitation. The boy and his parents stress they “want to get the therapy over with as fast as possible” to expedite his return to sports, and the surgeon and rehabilitation team consider their request. Compared to nonaccelerated rehabilitation, patients who follow an early accelerated rehabilitation protocol experience

Explanation

DISCUSSION
The MR image shows bone bruises (“kissing contusions”) consistent with an ACL tear. During the ACL subluxation event, the posterolateral tibia plateau subluxes anteriorly, making contact with the mid portion of the lateral femoral condyle and resulting in this characteristic bone bruise pattern on MRI. Randomized clinical trials comparing early accelerated vs nonaccelerated rehabilitation programs have demonstrated no significant differences in longterm results with regard to function, reinjury, and successful return to play. These studies did not address timing of return to play with an early accelerated rehabilitation program. At 2 and 3 years postsurgically, there are no differences in laxity, number of graft failures, or KOOS scores.

Question 54

A 68-year-old man with no significant medical history underwent a total knee arthroplasty 4 years ago. A radiograph is shown in Figure 55. He reports that he had no problems with the knee until 6 weeks ago when he noted the gradual onset of pain following a colonoscopy. Examination reveals a painful, swollen knee. Knee aspiration reveals a WBC count of 40,000/mm 3 . Management should consist of

Explanation

DISCUSSION: The treatment of choice for a late hematogenous infection is two-stage resection arthroplasty and reimplantation, with parenteral antibiotics prior to reimplantation. This is particularly true when septic loosening has occurred as in this patient. Open irrigation and debridement with polyethylene exchange has been used successfully when the duration of symptoms is 3 weeks or less. Long-term suppressive antibiotics are most commonly used when the patient’s medical condition precludes further surgery. Delayed reimplantation has been shown to be superior to immediate reimplantation in multiple studies. Little data support the use of arthroscopic irrigation and debridement.
REFERENCES: Swanson KC, Windsor RE: Diagnosis of infection after total knee arthroplasty, in Callaghan JJ, Rosenberg AG, Rubash HE, et al (eds): The Adult Knee. Philadelphia, PA, JB Lippincott, 2003, vol 2, pp 1485-1491.
Hanssen AD, Rand JA, Osmon DR: Management of the infected total knee arthroplasty, in Morrey BF (ed): Joint Replacement Arthroplasty, ed 3. Philadelphia, PA, Churchill-Livingstone, 2003, pp 1070-1089.

Question 55

Figures 76a and 76b are the sagittal T1-weighted MRI scans of an active 27-year-old man who has had left dominant extremity shoulder pain and weakness for the past 5 months. He denies any history of a precipitating event but recalls that the pain began around the time he started lifting weights after a year off from lifting. Examination reveals full range of active and passive motion, negative Hawkins and Neer impingement signs, 5/5 abduction strength, 5/5 external rotation strength with arm adducted at his side, and a negative belly press, Gerber lift-off, and O'Brien's test. He does have weakness with resisted external rotation with the arm abducted to 90 degrees. Radiographs are unremarkable. An MRI arthrogram shows no rotator cuff tear or labral tears. What is the most likely diagnosis? Review Topic

Explanation

Examination reveals weakness of the teres minor muscle, and the MRI scan shows moderate isolated atrophy of the teres minor muscle belly. This is consistent with quadrilateral space syndrome, which is compression of the axillary nerve and posterior circumflex humeral artery in the quadrilateral space (bounded by the teres minor, teres major, long head of triceps and the humerus). This syndrome has been related to compression of the neurovascular structures by muscle hypertrophy consistent with the patient's history of lifting weights near the onset of symptoms. The next step in confirming the diagnosis is a subclavian arteriogram with the arm in adduction as well as in abduction and external rotation. Suprascapular nerve compression would be manifested by atrophy and weakness of both the supraspinatus and infraspinatus (if occurring at the suprascapular notch) or just infraspinatus (if occurring at the spinoglenoid notch). The patient does not demonstrate signs or symptoms of either impingement syndrome or scapular dyskenisia.

Question 56

Which of the following procedures is not part of the routine evaluation of a patient with suspected metastatic disease to bone?

Explanation

DISCUSSION: The work-up for a patient with an unknown primary lesion that is metastatic to bone includes a search for the primary tumor and other sites of metastasis. This involves conducting a thorough history and physical examination, appropriate laboratory studies, bone scan, chest radiograph, and CT of the chest, abdomen, and pelvis. In women, a mammogram may be indicated. CT of the brain is not necessary in the early stages of a metastatic work-up.
REFERENCES: Simon MA, Bartucci EJ: The search for the primary tumor in patients with skeletal metastases of unknown origin. Cancer 1986;58:1088-1095.
Frassica FJ, Gitelis S, Sim FH: Metastic bone disease: General principles, pathophysiology, evaluation, and biopsy. Instr Course Lect 1992;41:293-300.

Question 57

Figure 61 is the radiograph of a 34-year-old woman who was involved in a rollover motor vehicle accident. On arrival at the trauma center she is hypotensive and tachycardic. An abdominal CT scan reveals a spleen laceration. The patient remains hypotensive despite resuscitation and is taken to surgery for an emergent laparotomy and splenectomy. After surgery her delta base is -9 mmol/L. What is the most appropriate management of her pelvic ring injury? Review Topic

Explanation

1 HR >110
Bilateral pulmonary contusions seen on chest radiograph
SBP = 90mmHg
Unilateral femur fracture
Lactate = 2.5 mMol/L
Pulmonary contusion severe enough to be diagnosed on chest radiograph alone is an indicator that the patient may benefit from damage control orthopaedics (DCO).
Despite the patient's overall stable nature, suffering pulmonary injury severe enough to be seen on x-ray alone suggests that temporary stabilization with staged definitive fixation may avoid potential morbidity.
Pape et al. review the evolution and balance of early total care (ETC) and DCO. Summarizing the literature, the authors report several standalone indicators that would justify DCO regardless of stable status. This includes: Injury Severity Score of greater than 40, Injury Severity Score of greater than 20 with chest trauma, multiple injuries with severe pelvic/abdominal trauma/ hemorrhagic shock, bilateral femoral fractures, pulmonary contusion noted on radiographs alone, hypothermia of less than 35 degrees C), and a head injury with an Abbreviated Injury Score of 3 or greater.
Figure A exhibits a right femoral shaft fracture. Illustration A exhibits a summarized table stating the criterion used to determine the condition of a polytrauma patient. (Table from Pape et al, PMID: 19726738)
Incorrect answers:

Question 58

Which of the following best describes the course of the median nerve at the elbow?

Explanation

DISCUSSION: The median nerve courses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, and deep to the superficial head of the pronator teres muscle. The median nerve lies within the interval between the flexor digitorum superficialis muscle and the flexor digitorium muscle as it progresses toward the wrist.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 118-131.
Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System. Part 1, Anatomy, Physiology and Metabolic Disorders. West Caldwell, NJ, Ciba-Geigy, 1991, vol 8,

pp 46-47.

Question 59

A 58-year-old man has a painful right hip 3 years after undergoing a large head metal-on-metal total hip arthroplasty (THA) in which the components are well positioned. MR imaging confirms a cystic mass around the hip and metal ion levels show a marked increase in cobalt compared to chromium levels. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level are within defined limits. What is the most likely cause for his discomfort?

Explanation

CLINICAL SITUATION FOR QUESTIONS 42 THROUGH 45
Figures 42a through 42e are the radiographs, MR image, and MR arthrogram of a 25-year-old collegiate soccer player who has new-onset left groin pain. He played competitive soccer from a young age and has either competed or practiced 5 to 6 times per week since the age of

Question 60

A 17-year-old boy has had elbow pain for the past 6 weeks. A radiograph, MRI scans, and biopsy specimens are shown in Figures 65a through 65e. What is the most likely diagnosis?

Explanation

DISCUSSION: The findings are consistent with an osteoblastoma. The radiographs show a bone-forming lesion of the distal humerus. The lesion has an osseous component extending out of the native cortex with a thin sclerotic border. The T₂-weighted MRI scan shows the lesion extending anteriorly beyond the native cortex. No fluid-fluid levels are seen. Histology shows large osteoblasts producing osteoid and woven bone. The tissue between the spicules of bone and osteoid contains thin fibrous tissue and capillaries. Osteoid osteoma is a smaller lesion usually with sclerotic reactive bone around a small nidus. The histology differentiates osteoblastoma from osteosarcoma because no malignant cells are seen. There is no cartilage production or chondroblasts in the histologic specimen, eliminating chondroblastoma. Giant cell tumors of bone typically occur in a epiphyseal metaphyseal location, most commonly after skeletal maturity, and contain numerus giant cells.
REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 87-102.
Campanacci M: Bone and Soft Tissue Tumors, ed 2. New York, NY, Springer-Verlag, 1999,

pp 415-433.

Question 61

Figure 69 is the radiograph of a 9-year-old who has posterior hindfoot pain while running. What is the most likely diagnosis?

Explanation

DISCUSSION
Sever disease is a traction apophysitis at the Achilles tendon insertion on the calcaneus. Plain radiographs may be unremarkable for this condition. Other osteochondroses of the foot include Kohler disease (tarsal navicular), Freiberg infraction (lesser metatarsal head), and Thiemann disease (great toe phalanx).
RECOMMENDED READINGS
Sullivan RJ. Adolescent foot and ankle conditions. In: Pinzur MD, ED. Orthopaedic Knowledge Update: Foot and Ankle 4. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2008:47-55.
Feldman DS. Osteochondrosis. In: Spivak JM, Di Cesare PE, Feldman Ds, et al, eds. Orthopaedic: A Study Guide. New York, NY: McGraw-Hill; 1999:765-766.
Schantz K, Rasmussen F. Thiemann's finger or toe disease. Follow-up of seven cases. Acta Orthop Scand. 1986 Feb;57(1):91-3. PubMed PMID: 3962642. View Abstract at PubMed

Question 62

Which of the following is the most sensitive parameter to detect the increased inflammatory response seen with both postoperative infection and the use of instrumentation in spinal surgery?

Explanation

CORRECT
DISCUSSION: The most sensitive parameter to detect inflammation elicited by implants and infection is the C-reactive protein (CRP).
CRP is an acute phase reactant that increases sharply immediately after surgery within 6 hours after tissue damage. CRP then peaks 2-3 days later and returns to normal levels 5-21 days after the inciting event. In contrast, ESR reaches its peak on days 4-11, then remains elevated for a prolonged period of time.
Takahashi et al performed a Level 3 study of patients who had undergone spinal surgery with and without instrumentation, with a primary outcome of infection. They concluded that renewed elevation of C-reactive protein, white blood cell count, and body temperature after postoperative days 4 to 7 may be a key indicator of postoperative infection.

Question 63

Polyethylene wear of the bearing surface has been recognized as a mode of failure in total knee arthroplasty; therefore, many patients are offered polyethylene exchange. In terms of success rates, this surgical procedure has been reported to have a

Explanation

DISCUSSION: Engh and associates reported on the results of 63 knees (56 patients) following polyethylene exchange. The mean interval between exchange and the index total knee arthroplasty was 59 months. The mean follow-up after exchange was 7.4 years. Seven of 48 knees with adequate follow-up failed. Greater failure occurred if there was more severe wear before the exchange. Greater undersurface wear also resulted in a higher failure rate. Perioperative osteolysis or intraoperative observation of metallosis did not have an impact on the failure of polyethylene exchange. The risk of infection is no different from other total knee arthroplasty revisions.
REFERENCES: Wasielewski RC, Parks N, Williams I, et al: Tibial insert undersurface as a contributing source of polyethylene wear debris. Clin Orthop 1997;345:53-59.
Engh GA, Koralewicz LM, Pereles TR: Clinical results of modular polyethylene insert exchange with retention of total knee arthroplasty components. J Bone Joint Surg Am 2000;82:516-523.

Question 64

A 10-year-old girl who is Risser stage 0 has back deformity associated with neurofibromatosis type 1 (NF1). She has no back pain. Examination shows multiple cafe-au-lait nevi with normal lower extremity neurologic function and reflexes. Standing radiographs of the spine show a short 50-degree right thoracic scoliosis with a kyphotic deformity of 55 degrees (apex T8). A 10-degree progression in scoliosis has occurred during the past 1 year. There is no cervical deformity. MRI shows mild dural ectasia, primarily in the upper lumbar region. Management should consist of Review Topic

Explanation

Scoliotic deformities in patients with NF1 are often dysplastic with short, angular curves. Posterior arthrodesis is made more difficult by the presence of kyphosis and of weak posterior elements caused by dural ectasia. Combined anterior and posterior spinal arthrodesis is generally preferred for progressive dysplastic curves to maximize deformity correction and to decrease the risk of pseudarthrosis. Anterior fusion may also prevent crankshaft phenomenon in young children. Brace treatment is not effective for large, rigid, or dysplastic curves.

Question 65

A 14-year-old patient with an L3 myelomeningocele underwent anterior and posterior spinal fusion for a curve of 50°. Follow-up examination 1 week after the procedure now reveals persistent drainage from the posterior wound. Results of laboratory cultures show Streptococcus viridans, Staphylococcus aureus, and Enterococcus. In addition to IV antibiotics, surgical irrigation, and debridement, management should include

Explanation

DISCUSSION: The rate of wound infections has dramatically decreased with the routine use of prophylactic antibiotics. Factors known to increase the risk of infection include instrumentation, prolonged surgical time, excessive blood loss, poor perioperative nutritional status, a history of surgery, and a history of infection. The use of allograft does not result in an increased rate of infection. Adequate treatment requires early diagnosis and intervention. Temperature elevation and persistent wound drainage are highly suspicious for infection. An erythrocyte sedimentation rate and a WBC are not useful in diagnosis unless serial examinations show rising levels. Patients should be taken to the operating room where the entire wound can be reopened, irrigated, and debrided. Bone graft can be washed and replaced. Hardware should not be removed. The wound should be closed over suction drains. IV antibiotics should be given for a period of at least 10 days, followed by 6 weeks orally. Leaving the wound open to granulate with dressing changes results in prolonged hospitalization, inadequate treatment of the infection, and a poor cosmetic result.
REFERENCES: Lonstein JE: Complications of treatment, in Bradford DS, Lonstein JE, Moe JH, et al (eds): Moe’s Textbook of Scoliosis and Other Spinal Deformities, ed 2. Philadelphia, Pa, WB Saunders, 1987, p 476.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 713-721.

Question 66

Which of the following best describes the pathologic anatomy of cam impingement of the hip? Review Topic

Explanation

Cam impingement creates shearing forces that result in an outside-in directed detachment of the labrum in the anterosuperior quadrant. Retroversion of the acetabulum is associated with pincer impingement. The impingement is exhibited with hip flexion. Cam impingement involves a morphologic abnormality of the femoral head. Pincer lesions result from stresses of a normal femoral neck against an abnormal acetabular rim. Cam impingement is not associated with osteonecrosis.

Question 67

Thyroid hormone regulates skeletal growth at the physis by stimulation of

Explanation

DISCUSSION: Children with hypothyroidism have delayed bone age, reduced thickness of the physis, disorganization of the cartilage columns of the physis, and impaired differentiation of proliferating chondrocytes into hypertrophic cells. As a result, these children have severe growth retardation, and slipped capital femoral epiphysis may develop because of mechanical weakening of the physis. Thyroid hormone regulates terminal differentiation of the growth plate chondrocytes, with a resultant increase in type X collagen and alkaline phosphatase. These substances are important factors in matrix mineralization. Insulin-like growth factors and FGF-2 appear to act synergistically to stimulate mitotic activity of the growth plate chondrocytes. TGF-b= and PTHrP stimulate proteoglycan synthesis and mitotic activity of the chondrocytes and inhibit type X collagen and alkaline phosphatase activity.
REFERENCES: Ballock RT: Regulation of skeletal growth and maturation by thyroid hormone, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 301-317.
Rosier RN, O’Keefe RJ, Reynolds PR, Hicks DG, Puzas JE: Expression and function of TGF-b= and PTHrP in the growth plate, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 285-299.
Trippel SB: IGF-I and FGF-2 in growth plate regulation, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 263-283.

Question 68

A year-old man with a body mass index of 31 had a month gradual onset of right medial knee pain. Examination revealed a small effusion, stable ligaments, a normally tracking patella, and mild medial joint line tenderness. Standing radiographs show mild medial joint space narrowing. Effective treatment at this stage of early medial compartmental osteoarthritis includes

Explanation

DISCUSSION:
According to the 2008 AAOS Clinical Practice Guideline, Treatment of Osteoarthritis of the Knee (Nonarthroplasty), level 1 evidence confirms that weight loss and exercise benefit patients with knee osteoarthritis. The other responses have either inclusive evidence (a valgus-directing brace) or no evidence to support their use (glucosamine 1,500 mg/day and chondroitin sulfate 800 mg/day as well as
arthroscopic debridement and lavage).

Question 69

Figures below show the radiographs obtained from an 86-year-old-woman who has had chronic left hip pain for several years. She now uses a walker and a wheelchair for ambulation. She is medically healthy. What is the most appropriate surgical intervention?

Explanation

DISCUSSION:
This 86-year-old woman has poor bone quality and osteoarthritis of the left hip. Her lateral radiograph confirms Dorr type C bone quality. A hybrid left THA with a cemented femoral stem would be the treatment of choice.

Question 70

Figure 39 shows the radiograph of a 4-month old infant who has been undergoing weekly casting since birth for a congenital equinovarus deformity. Management should now consist of

Explanation

DISCUSSION: The radiograph shows the development of a rocker-bottom foot deformity. A rocker-bottom foot occurs in the treatment of clubfoot when casting is continued in the presence of a very tight gastrocnemius-soleus complex and an uncorrected hindfoot. While there are some preliminary reports on using Botox injection and continued casting for the equinus deformity, most authors recommend posterior or posterior medial release. Percutaneous tenotomy has been recently recommended with the resurgence of the Ponsetti technique.
REFERENCES: Lehman WB, Atar D: Complications in the management of talipes equinovarus, in Drennan JC (ed): The Child’s Foot and Ankle. New York, NY, Raven Press, 1992,

pp 135-136.
Herring JA: Tachdjian’s Pediatric Orthopedics, ed 4. Philadelphia, PA, WB Saunders, 2002,

pp 927-935.
Tachdjian MO: Pediatric Orthopedics, ed 2. Philadelphia, PA, WB Saunders, 1990,

pp 2461-2564.

Question 71

A complication unique to computer navigation of total knee arthroplasty (TKA) is

Explanation

CLINICAL SITUATION FOR QUESTIONS 111 THROUGH 113
Figure 111 is the anteroposterior radiograph of a 79-year-old woman with a presurgical diagnosis of osteonecrosis who sustained a periprosthetic tibia fracture following her total knee arthroplasty (TKA).

Question 72

A 78-year-old man has a history of worsening bilateral calf pain with activity. MRI scans are shown in Figures 31a through 31d. His symptoms are not improved with forward flexion of the lumbar spine. His lower extremity pain is relieved when he sits or ceases activity. Which of the following tests would be most helpful in establishing a diagnosis? Review Topic

Explanation

The differential diagnosis of degenerative lumbar stenosis is extensive. Vascular and neurogenic claudication frequently coexist in the older population. Therefore, it is important to determine the specific etiology of a patient's lower extremity claudication prior to any surgical intervention. Vascular claudication is relieved with cessation of activity, whereas neurogenic claudication requires that the patient sit down or flex the lumbar spine forward to increase the canal diameter. Because this patient does not experience improvement in his symptoms with sitting or forward flexion, it is likely that he is experiencing vascular claudication. The ankle-brachial index (ABI) is the ratio of the blood pressure in the lower legs to the blood pressure in the arms. Compared with the arm, lower blood pressure in the leg is a sign of peripheral vascular disease. The ABI is calculated by dividing the systolic blood pressure in the arteries at the ankle and foot by the higher of the two systolic blood pressures in the arms. An ABI value between 0.40 to 0.80 is moderately decreased and such patients often experience symptoms such as intermittent claudication. Selective nerve root blocks prove to be more useful in identifying specific level(s) of involvement in patients experiencing radicular pain and paresthesias. Their utility is less helpful in lower extremity claudication. Electrophysiologic studies are rarely useful, except in identifying the presence and source of a peripheral neuropathy. About 80% of patients with symptomatic lumbar stenosis will demonstrate electromyographic changes. Osteoarthritis of the hip may be associated with buttock, groin, hip, and thigh pain.
Decreased range of motion and hip joint pain, especially in internal rotation and abduction, are common findings in patients with degenerative arthritis of the hip. While post-myelography CT has been found superior to MRI as a single study for the preoperative planning of decompression for lumbar spinal stenosis, it will not assist in differentiating vascular from neurogenic claudication.

Question 73

A 15-year-old boy reports feeling a pop and notes sudden giving way of the left knee while playing basketball. He has immediate pain and swelling in the knee. An AP radiograph is shown in Figure 32. A small avulsion fragment from the lateral tibial margin is the only finding. What is the most likely diagnosis?

Explanation

DISCUSSION: An avulsion fracture from the lateral tibial margin carries the eponym Segond fracture and is pathognomonic for an anterior cruciate ligament (ACL) tear. The fragment is located posterior to Gerdy’s tubercle and is superior and anterior to the fibular head. It represents an avulsion of the lateral capsular ligament of the knee and is caused by the same mechanism that causes the ACL tear. The pes anserinus is the insertion point of the medial hamstrings and would not be affected in a lateral avulsion injury. The posterior cruciate ligament may be seen on a lateral view if associated with an avulsion fragment, but a tear of the PCL generally cannot be diagnosed on an AP view. The insertion of the iliotibial band is broad and is unlikely to produce an avulsion injury such as that seen in the radiograph. This view is not consistent with the appearance of a lateral collateral ligament injury.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 533-557.
Larson RL, Tailon M: Anterior cruciate ligament insufficiency: Principles of treatment. J Am Acad Orthop Surg 1994;2:26-35.

Question 74

-Use of the shorter, anterior screw may result in

Explanation

Question 75

It is recommended that invasive dental work be completed prior to the initiation of which of the following medications?

Explanation

Bisphosphonate therapy combined with invasive dental work increases the risk for development osteonecrosis of the jaw.
Bisphosphonates are a class of drugs that prevent bone mass loss by inhibiting osteoclast resorption. They are used in the treatment of vertebral compression fractures, non-vertebral fragility fractures, osteogenesis imperfecta, multiple myeloma, and avascular necrosis. Because bisphosphonates have been associated with osteonecrosis of the jaw, it is suggested that all invasive dental work be completed prior to initiation of treatment.
Pazianas et al. (2011) review the safety profile of bisphosphonates. Specifically, they cite gastrointestinal discomfort, atypical femur fractures, osteonecrosis of the jaw, ocular inflammation, and musculoskeletal pain as common side effects. They state there is limited evidence surrounding bisphosphonate's association with esophageal cancer and atrial fibrillation.
Pazianas et al. (2007) reviewed 11 publications that reported 26 cases of osteonecrosis of the jaw following initiation of bisphosphonate treatment. Age >60 years, female sex, and previous invasive dental treatment were the most common characteristics of those who developed ONJ.
Illustration A shows the various bisphosphonates and their mechanisms of action. Illustration B shows an example of osteonecrosis of the jaw, a side effect that has been linked to bisphonphonate treatment.
Incorrect Answers:

Question 76

What is the most common mechanism of injury that produces turf toe?

Explanation

DISCUSSION: The most common mechanism of injury for turf toe is a hyperextension injury to the MTP joint. The foot is typically in a dorsiflexed position with the heel raised when an external force drives the MTP joint into further dorsiflexion. The joint capsule usually tears at the metatarsal neck because its attachment is weaker there than at the proximal phalanx. Some compression injuries to the dorsal articular surface of the metatarsal head can result from extension or hyperextension.
REFERENCES: Clanton TO, Ford JJ: Turf toe injury. Clin Sports Med 1994;13:731-741.
Rodeo SA, O’Brien S, Warren RF, et al: Turf toe: An analysis of metatarsophalangeal joint sprains in professional football players. Am J Sports Med 1990;18:280-285.

Question 77

A 47-year-old man who works as a carpenter reports a 12-month history of painful mechanical locking of his dominant elbow in the mid range of movement. He also has progressive pain at terminal extension that has not responded to medication, rest, and intra-articular cortisone injection. Active range of movement is from 35 degrees to 130 degrees, and he has full pronation and supination. The ulnar nerve is stable, and he has no subjective or objective neurologic dysfunction in the hand. Radiographs are shown in Figures 22a and 22b. What is the most appropriate treatment? Review Topic

Explanation

The most appropriate treatment is arthroscopic capsular release, loose body removal, and osteophyte decompression. The patient has moderate osteoarthritis of the dominant elbow, with mechanical symptoms suggestive of loose osteochondral body formation. Because the patient has failed to respond to the typical nonsurgical therapeutic options, it is unlikely that further oral medication will be helpful, and job modification may not be practical at this stage. Soft-tissue arthroplasty may be reasonable to consider when less invasive methods, such as arthroscopy, fail. Isolated radial head arthroplasty would not sufficiently address the symptoms. Total elbow arthroplasty is indicated in cases of more advanced disease in older patients with lower physical demands.

Question 78

Explanation

Dynamic patellofemoral joint contact measurements on cadaveric knees with simulated increased Q angle demonstrated that forces shifted to the lateral facet. The lateral shift in the patella was most pronounced from 40 to 90 degrees of flexion. At lower degrees of flexion, the lateral shift was significantly less. At higher degrees of flexion, the continued shift of the patella was not as pronounced.

Question 79

An 11-year-old boy has had a fever and pain and swelling over the lateral aspect of his right ankle for the past 3 days. Examination reveals warmth, swelling, and tenderness over the lateral malleolus, and he has a temperature of 103.2 degrees F (39.5 degrees C). Laboratory studies show a WBC count of 13,200/mm 3 with 61% neutrophils, an erythocyte sedimentation rate of 112 mm/h, and a C-reactive protein of 15.7. Radiographs and a T 2 -weighted MRI scan are shown in Figures 13a through 13c. Aspiration yields 1 mL of purulent fluid. Management should now consist of

Explanation

DISCUSSION: The initial signs and symptoms of acute hematogenous osteomyelitis vary widely but usually include fever, bone pain, and impaired use of the involved extremity. In lower extremity infections, the child may limp or refuse to walk. Examination often reveals bone tenderness. In more advanced cases, erythema, warmth, and swelling may be present. The WBC and neutrophil counts are not always elevated, but the erythocyte sedimentation rate will be abnormal in more than 90% of patients. When the infection is diagnosed early, before a subperiosteal abscess has formed, antibiotics alone may be adequate to treat the infection. This patient has a more advanced infection, however, with the MRI scan revealing a subperiosteal abscess that was confirmed by aspiration. When an abscess is present, surgical drainage is generally indicated to remove devitalized tissue and to enhance the efficacy of the antibiotics. Further studies, such as bone or indium scans, are not necessary and will delay

definitive treatment.
REFERENCES: Scott RJ, Christofersen MR, Robertson WW Jr, et al: Acute osteomyelitis in children: A review of 116 cases. J Pediatr Orthop 1990;10:649-652.
Vaughan PA, Newman NM, Rosman MA: Acute hematogenous osteomyelitis. J Pediatr Orthop 1987;7:652-655.

Question 80

Which of the following associated type acetabular fracture patterns is defined based on the fact that all articular segments are detached from the intact portion of the ilium, which remains attached to the sacrum through the sacroiliac joint?

Explanation

DISCUSSION: There are 5 simple and 5 associated fracture types according to the classification system created by Judet and Letournel. The key feature which distinguishes both column fractures from other associated types is that all articular segments are detached from the intact portion of the ilium, which remains attached to the sacrum through the SI joint. Although the transverse plus posterior wall, T-shaped, and anterior plus posterior hemi-transverse fractures all show involvement of the anterior and posterior columns, they are not “both columns” because a portion of the articular surface remains in its normal position, attached to intact ilium. The intact ilium is responsible for the "spur sign" noted most prominently on the obturator oblique radiograph.

Question 81

The patient undergoes a mobile-bearing UKA. When compared to a fixed-bearing metal-backed unicompartmental arthroplasty, this procedure is associated with a

Explanation

DISCUSSION
A patient with medial compartment arthritis and a correctable varus deformity with no clinical or examination findings of knee instability most likely has an intact ACL. The pattern of medial compartment osteoarthritis most commonly associated with an intact ACL is that of anteromedial osteoarthritis. An incompetent ACL is commonly associated with a fixed varus deformity and radiographic signs of posteromedial wear. An incompetent ACL is a relative contraindication to a mobile-bearing UKA. When evaluating patients for a mobile-bearing UKA, a stress radiograph will allow the orthopaedic surgeon to determine the correction of the varus deformity and assess the lateral compartment. Inability to fully correct the deformity or narrowing of the lateral compartment with valgus stress should influence the surgeon against UKA. Joint registries across the world have shown decreased survivorship associated with TKA and UKA in men compared to other age groups, but survivorship is lower for UKA than TKA. No studies to date have shown differences in survivorship between fixed- or mobile-bearing UKAs. The complication that is unique to mobile-bearing UKA is bearing spinout, and this occurs in fewer than 1% of mobile-bearing UKA procedures. In vivo and in vitro polyethylene wear in mobile-bearing UKA is low. Arthritis progression may be faster for mobile-bearing UKAs than fixed-bearing UKAs.
The radiographs reveal a fracture of the extensively porous coated stem. This entity, although rare, is associated with higher risk for occurrence when thin stems are implanted in patients with thick cortices and there is a lack of proximal stable support for the prosthesis. Nonsurgical care likely would not help this patient. A triple-phase bone scan would not add any information that would change the treatment plan.

Question 82

Figures 48a through 48c show the lateral radiograph and MRI scans of a 60-year-old man who has had pain in his thigh for 1 month. The next most appropriate step in management should consist of

Explanation

DISCUSSION: The patient has a presumed metastatic bone tumor. The approach to evaluating a patient with a bone tumor of unknown primary origin is to obtain laboratory studies that include a CBC, an erythrocyte sedimentation rate, a serum protein electrophoresis, a calcium level, a urinalysis, and a prostate-specific antigen. In addition, a bone scan, a radiograph of the chest, and CT scans of the chest and abdomen should be obtained. These evaluations can identify the primary site in 85% of patients. GI studies rarely are of diagnostic value. Prophylactic stabilization is contraindicated until a diagnosis is confirmed by histology.
REFERENCES: Frassica FJ, Frassica DA, McCarthy EF, Riley LH III: Metastatic bone disease: Evaluation, clinicopathologic features, biopsy, fracture risk, nonsurgical treatment, and supportive management. Instr Course Lect 2000;49:453-459.
Rougraff BT, Kneisl JS, Simon MA: Skeletal metastases of unknown origin: A prospective study of a diagnostic strategy. J Bone Joint Surg Am 1993;75:1276-1281.

Question 83

A 7-year-old girl with spinal muscular atrophy (SMA) type II has popping of the left hip. Examination reveals painless subluxation of the joint in adduction with palpable reduction in abduction. Radiographs show coxa valga, subluxation of the left hip, and pelvic obliquity with elevation of the left hemipelvis. Treatment should consist of

Explanation

DISCUSSION: Observation is the treatment of choice. Hip subluxation and dislocation are not uncommon in patients with SMA type II who are unlikely to be ambulatory. Scoliosis occurs in these patients 100% of the time and frequently creates pelvic obliquity. However, in long-term follow-up, patients with SMA type II and hip dislocations had little associated pain or functional limitations because of hip instability. In addition, recurrent hip subluxation after surgical treatment has been documented. Given the rarity of symptoms from hip instability in long-term follow-up, and the possibility of recurrent dislocation, surgical intervention for hip instability may expose SMA type II patients to undue surgical risk for minimal if any functional gain.
REFERENCES: Sporer SM, Smith BG: Hip dislocation in patients with spinal muscular atrophy. J Pediatr Orthop 2003;23:10-14.
Thompson CE, Larsen LJ: Recurrent hip dislocation in intermediate spinal atrophy.

J Pediatr Orthop 1990;10:638-641.

Question 84

An investigation studying whether physical therapy or subacromial injection can be successfully used to treat shoulder pain is conducted. Two groups are identified. One group is prescribed physical therapy, while the other receives a subacromial injection. The groups have similar baseline demographics and shoulder pathologies. Ten patients are randomized in each group and findings show that there is no significant difference in any patient-reported outcome measure. An increase in sample size would reduce the risk of what parameter?

Explanation

A football player injures his knee when he is tackled and falls awkwardly. He does not note any discreet “pop,” but pain prevents him from returning to the game. An effusion is noted the following day and an MRI scan is ordered. Selected images are shown in Figures 1 through 3. Based on these images, physical examination findings likely include

Question 85

A 23-year-old otherwise healthy 6-ft, 4-in basketball player complains of pain in his knees. An examination reveals localized tenderness to palpation over the inferior pole of the patella. The patient notes a significant exacerbation of his pain when the examiner takes the knee from flexion to extension. Review Topic

Explanation

Patellar tendonitis is common in jumping sports such as basketball and volleyball. The pain is localized to the inferior border of the patella and is exacerbated by extension of the knee. Treatment for the vast majority of patients is nonsurgical and includes nonsteroidal anti-inflammatory drugs, physical therapy, and orthoses (patella tendon strap). Iliotibial band friction most commonly occurs in cyclists and runners (especially those who run up hills) and is a result of abrasion between the iliotibial band and the lateral femoral condyle. Localized tenderness with the knee flexed at 30 degrees is common. The Ober test may be helpful in making the diagnosis. Semimembranosis tendonitis most commonly occurs in male athletes during their fourth decade of life. The diagnosis is usually made with an MRI scan or nuclear imaging. Quadriceps tendonitis is similar to patellar tendonitis but is much less common. The pain may be associated with clicking and is localized to the superior border of the patella.

Question 86

A 73-year-old man stepped off a street curb and felt a crack in his left hip. He is now unable to bear weight. A radiograph is shown in Figure 54a. Biopsy specimens are shown in Figures 54b and 54c. What is the most likely diagnosis?

Explanation

DISCUSSION: The biopsy specimens reveal a high-grade spindle cell lesion adjacent to an area of benign cartilage. This is consistent with a dedifferentiated chondrosarcoma. The radiograph shows a pathologic fracture through a lesion characterized by calcification within the left greater trochanter. Distal to the area of calcification, there is a more osteolytic, destructive appearance. Synovial sarcoma has a biphasic appearance histologically with areas of glandular differentiation that stain positive with keratin. Metastatic prostate cancer, although osteoblastic in appearance, would have a glandular histologic appearance. There is no cartilage in these lesions. Classic low-grade chondrosarcoma does not have an area of high-grade pleomorphic spindle cells within the lesion. A periosteal osteosarcoma is a surface-based lesion with a sunburst radiographic pattern. Although there may be cartilage in the lesion histologically, there are also malignant cells producing osteoid. Dedifferentiated chondrosarcoma is an aggressive, high-grade variant of chondrosarcoma.
REFERENCES: Wold LE, Adler CP, Sim FH, et al: Atlas of Orthopedic Pathology, ed 2. Philadelphia, PA, WB Saunders, 2003, p 269.
Mercuri M, Picci P, Campanacci L, et al: Dedifferentiated chondrosarcoma. Skeletal Radiol 1995;24:409-416.

Question 87

A 30-year-old man has pain in the left arm after a motor vehicle accident. His neurovascular examination is intact, and radiographs are shown in Figures 25a and 25b. What is the best course of management?

Explanation

DISCUSSION: The floating elbow is best managed with early open reduction and internal fixation of the humeral and forearm fractures, followed by early range of motion. These fractures predispose the elbow to stiffness, and early range of motion is recommended.
REFERENCES: Solomon HB, Zadnik M, Eglseder WA: A review of outcomes in 18 patients with floating elbow. J Orthop Trauma 2003;17:563-570.
Yokoyama K, Itoman M, Kobayashi A, et al: Functional outcomes of “floating elbow” injuries in adult patients. J Orthop Trauma 1998;12:284-290.

Question 88

CLINICAL SITUATION Figures 1 through 3 are the radiographs of a 25-year-old man who is brought to the emergency department after a motorcycle collision. He is complaining of isolated knee pain. Examination reveals swelling, popliteal ecchymosis, joint line pain, and limited knee joint motion. His pulses and sensation are normal. Figures 4 through 8 are the axial and coronal CT scan sections of the injury. Intra-operative patient positioning for definitive fixation should be

Explanation

Discussion: Medial plateau fracture dislocations are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the anteroposterior radiograph include an intact lateral column (lateral articular surface still in continuity with tibial shaft), centrolateral articular impaction, shortening, and condylar widening. The medial femoral condyle stays with the fractured medial tibial plateau segment.
Initial management of axially unstable tibial plateau fractures with soft tissue swelling should consist of spanning external fixation and closed manipulative realignment. This allows for soft tissue recovery with the knee joint provisionally stabilized in reduced station. It also provides time for pre-operative planning, which is typically empowered via a CT scan with reconstructions. If the pattern was initially misdiagnosed as a more typically bicondylar tibial plateau fracture, the CT scan will clarify the misconception and allow for better surgical decision making.
Supine positioning is preferred for definitive fixation, but surgical approaches vary. Attempting to stabilize a medial partial articular pattern in the supine position from a lateral utility approach is fraught with difficulties. Lateral locked plating is not designed for this indication. The lateral utility approach allows for visualization of the centrolateral impaction and lateral meniscal peripheral capsular avulsion repair, but when used alone leads to biomechanically unsound implant placement. The primary plate should be on the medial side of the tibia rather than the intact lateral column.

Question 89

When performing a posterior cruciate ligament reconstruction with a tibial inlay-type approach, what is the approximate anatomic distance of the popliteal artery from the screws used for fixation of the bone block?

Explanation

DISCUSSION: Miller and associates reported the results of a cadaveric study of the vascular risk of a posterior approach for posterior cruciate ligament reconstruction using the tibial inlay technique. The average distance from the screw to the popliteal artery was 21.1 mm
(range, 18.1 mm to 31.7 mm). Other approaches, such as the transtibial tunnel technique which involves drilling an anterior-posterior tunnel, have also been studied in cadavers. Matava and associates noted that increasing flexion reduces but does not completely eliminate the risk of arterial injury during arthroscopic posterior cruciate ligament reconstruction. However, this study did not use the small, medial utility incision recommended by Fanelli and associates, which creates an interval for the surgeon’s finger between the medial gastrocnemius and the posteromedial capsule so that any migration of the guidepin can be palpated and changed prior to any injury to the posterior neurovascular bundle.
REFERENCES: Matava MJ, Sethi NS, Totty WG: Proximity of the posterior cruciate ligament insertion to the popliteal artery as a function of the knee flexion angle: Implications for posterior cruciate ligament reconstruction. Arthroscopy 2000;16:796-804.
Miller MD, Kline AJ, Gonzales J, et al: Vascular risk associated with posterior approach for posterior cruciate ligament reconstruction using the tibial inlay technique. J Knee Surg 2002;15:137-140.
Johnson DH, Fanelli GC, Miller MD: PCL 2002: Indications, double-bundle versus inlay technique and revision surgery. Arthroscopy 2002;18:40-52.

Question 90

The most appropriate next surgical procedure is

Explanation

DISCUSSION
This patient’s arthritis likely has progressed to the lateral compartment. The location and degree of local pain and tenderness are the most important physical findings. History and physical findings indicate arthritis progression to the lateral and anterior compartments. This scenario suggests the need for conversion of the unicompartmental arthroplasty to TKA.

Question 91

The cavovarus deformity associated with Charcot-Marie-Tooth (CMT) disease is caused by which of the following?

Explanation

DISCUSSION: The most common inherited neuromuscular disease seen by orthopaedic surgeons is CMT, which is an inherited autosomal-dominant disease. It is more commonly seen in men due to the nature of the inheritance. Identification of cavus deformity in the foot of a child should arouse suspicion.
REFERENCES: Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 135-143.
Charcot-Marie-Tooth Disease (CMT) Penn State Hershey Medical Center.
www.hmc.psu.edu/healthinfo/c/cmt.htm

Question 92

A 23-year-old man reports a 6-year history of recurrent instability in the right dominant shoulder. He has not undergone surgery and has essentially stopped all of his sporting activities. On examination, he has instability and apprehension in the midrange of motion (abduction of 45 to 60 degrees with external rotation) and a palpable clunk representing a transient dislocation over the anterior glenoid rim. A three-dimensional CT scan is shown in Figure 31. What is the most appropriate surgical intervention to provide him with reliable stability postoperatively? Review Topic

Explanation

In the setting of significant anteroinferior glenoid bone deficiency (greater than 20% to 25%), both open and arthroscopic Bankart repairs have demonstrated higher rates of failure. Bony glenoid augmentation procedures such as the Bristow-Latarjet, which describe coracoid transfers to reconstruct the deficient glenoid, have led to decreased rates of recurrent shoulder instability. In this scenario, the patient has a significant loss of glenoid bone. There are also several clues in the history to suspect bone deficiency: multiple recurrences, a long history of recurrence, and instability in the midranges of motion. A bony augmentation procedure such as the Latarjet has been well-described to provide a well functioning and stable shoulder joint. A hemiarthroplasty is not indicated in the absence of arthritis. Subscapularis advancement will not address the bone loss.

Question 93

A 25-year-old volleyball player reports pain and clicking in his dominant shoulder during overhand serving. Three months of physical therapy fail to provide relief. Radiographs are normal, and an MRI scan is shown in figures 18a and 18b. Atrophy and weakness are most likely to be localized to which of the following muscles?

Explanation

The MRI of the shoulder shows multiple ganglion type cysts of the genoid labrum. These cyst have a correlation with overhead type repeative motion. It has been suggested in the volleyball players that the rapid deceleration after a spike can lead to a SLAP(superior labral) lesion. This in turn can lead to genoid cyst formation. Now remember that the suprascapular nerve comes off the superior trunk of the Brachial plexus, goes under the superortransverse scapular ligament (in the scapular notch, nerve under artery above). It then descends right behind the posterior glenoid/labrum. Therefore, a large cyst in this area will impinge/entrap the nerve. This nerve supplies the infraspinatus muscle and over time will give you atrophy/ pain of this muscle. 87.

Question 94

In a patient with a major head injury and a femoral shaft fracture, intraoperative hypotension during femoral fixation has been associated with which of the following?

Explanation

DISCUSSION: Hypoxia and hypotension are associated with lower GCS scores in polytrauma patients with major head injuries, but whether early fracture fixation adversely affect CNS outcomes has been controversial. New studies, however, have found no association between early surgery and decreased discharge GCS scores. The referenced study by Scalea et al reviewed 171 patients with pelvic or lower extremity fractures and head injuries; they showed no difference in CNS outcomes or mortality in patients who underwent early fixation. The second reference by Brundage et al showed improved outcomes (including high GCS scores at time of discharge) in those who had early fixation of femoral shaft fractures in the head-injured patient. The last referenced study by Jaicks et al found a lower discharge GCS in the early fracture fixation group compared with the late group. However, they also found that early fracture fixation was associated with hypoxemia and hypotension, as well as greater fluid administration.

Question 95

Figures 82a through 82c show the radiograph and 3-dimensional (3-D) CT scans of a 2-year-old boy whose scoliosis has progressed 15 degrees during the past year. The child is clinically healthy. He has been walking since 11 months of age. An MRI scan of the entire spine revealed no other anomalies. What additional study is indicated? Review Topic

Explanation

Renal anomalies are found in as many as one-third of patients with congenital scoliosis, so a renal ultrasound should be obtained. There may be other anomalies, including cardiac. There are no other anomalies on MRI, so flexion-extension cervical spine radiographs are not indicated. There is no associated marrow or platelet problem with hemivertebra. There is no indication for blood cultures because this is a noninfection disorder. The radiographs and 3-D CT scans show a hemivertebra scoliosis already beyond 45 degrees. Resection of the hemivertebra with stabilization is the indicated treatment. The scoliosis will get worse with observation and bracing. Fusion posteriorly can only minimally correct and not stop progression of the scoliosis.

Question 96

Which of the following is an advantage of computer-assisted navigation used to place medullary nail interlocking screws compared to a freehand techinque?

Explanation

DISCUSSION: Computer-assisted navigation has been shown to reduce radiation exposure for surgeons when performing interlocking of medullary nails compared to free-hand technique.
Ricci et al compared two fluoroscopic navigation tracking technologies, optical and electromagnetic versus standard freehand fluoroscopic targeting, in a standardized foam block model for placement of interlocking screws. They found that fluoroscopy time (seconds) and number of fluoroscopy images were significantly less when using the computer-guided systems than for freehand-unguided insertion. Average distance of pin placement from the target in the foam blocks was significantly greater for controls than for each of the navigated systems.
Suhm et al performed a prospective controlled clinical study to compare fluoroscopic guidance with fluoroscopy-based surgical navigation for distal locking of intramedullary implants. The surgical navigation group showed increased procedure time, but equivalent precision with reduced radiation exposure. There was no significant difference in the technical reliability between both groups.

Question 97

A 50-year-old woman with a 2-part surgical neck proximal humerus fracture and metaphyseal comminution

Explanation

DISCUSSION
Proximal humerus fractures account for approximately 5% of all fractures, with incidence increasing to reflect an aging population and related osteoporosis. Treatment is dependent upon the mechanism of injury, the patient’s physiologic age and activity level, the fracture pattern, and rotator cuff integrity. Most of these injuries are nondisplaced or minimally displaced and are associated with a good overall prognosis with nonsurgical treatment and temporary impairment. A patient with a nondisplaced surgical neck fracture should be treated without surgery. K-wire stabilization, although technically difficult to achieve, is an option for compliant patients with 2-part, 3-part, and valgus-impacted 4-part fractures who have adequate bone stock. Valgus-impacted 4-part fractures pose reduced risk for osteonecrosis because of the preserved blood supply through the medial hinge, which allows for this technique. For displaced 2-part fractures accompanied by
metaphyseal comminution, K-wire fixation cannot provide adequate stability to initiate a graduated home exercise or outpatient physical therapy program. Formal open reduction with intramedullary or plate fixation in addition to bone grafting (fibular strut allograft) is the best surgical option for the clinical scenario involving a displaced surgical neck fracture with comminution. Osteosynthesis of 3-part fractures may be feasible for physiologically young and active patients without humeral head involvement and osteoporosis.
Current indications for primary hemiarthroplasty include most 4-part fractures, 3-part fractures and dislocations in elderly patients with osteoporotic bone, head-splitting articular segment fractures, and chronic anterior or posterior humeral head dislocations with more than 40% of articular surface involvement. Because of the intra-articular nature of this patient’s 4-part injury in this scenario, hemiarthroplasty with anatomic reconstruction of the greater and lesser tuberosities is most appropriate. Relative indications for hemiarthroplasty also include fractures with more than 20 degrees of varus, associated moderate to severe osteopenia, and revision surgery for failed osteosynthesis. Currently accepted indications for rTSA include scenarios in which the fracture pattern, level of comminution, bone quality, and rotator cuff deficiency preclude plate fixation or hemiarthroplasty. Scenarios involving 4-part fractures and associated rotator cuff tears and tuberosity comminution are best served with a reverse shoulder prosthesis. One of the positive attributes of this implant is the ability to achieve functional forward flexion and abduction regardless of tuberosity healing, position, and degree of comminution. Caution is warranted with this surgical technique because complication rates are higher than for hemiarthroplasty reconstruction. Acute, irreducible 2-part fracture-dislocations of the proximal humerus necessitate open reduction and internal fixation of the affected tuberosities (posterior, lesser tuberosity; anterior, greater tuberosity) through screw, anchor, and/or suture fixation. These fracture-dislocations can be managed with this technique because of the integrity of the vascular supply, which is maintained by the soft-tissue attachments to the intact tuberosities. Repeated attempts at a closed reduction in the 37-year-old with the posterior fracture-dislocation could result in neurovascular injury and myositis ossificans and should be avoided. Arthroplasty reconstruction in this scenario should not be the index procedure in light of concerns regarding implant survivorship in patients of this age and their assumed elevated activity levels.
RECOMMENDED READINGS
Harrison AK, Gruson KI, Zmistowski B, Keener J, Galatz L, Williams G, Parsons BO, Flatow EL. Intermediate outcomes following percutaneous fixation of proximal humeral fractures. J Bone Joint Surg Am. 2012 Jul 3;94(13):1223-8. doi: 10.2106/JBJS.J.01371. View Abstract at PubMed
Iannotti JP, Ramsey ML, Williams GR Jr, Warner JJ. Nonprosthetic management of proximal humeral fractures. Instr Course Lect. 2004;53:403-16. Review. View Abstract at PubMed
Mata-Fink A, Meinke M, Jones C, Kim B, Bell JE. Reverse shoulder arthroplasty for treatment of proximal humeral fractures in older adults: a systematic review. J Shoulder Elbow Surg. 2013 Dec;22(12):1737-48. doi: 10.1016/j.jse.2013.08.021. Review. View Abstract at PubMed
Jobin CM, Galdi B, Anakwenze OA, Ahmad CS, Levine WN. Reverse shoulder arthroplasty for the management of proximal humerus fractures. J Am Acad Orthop Surg. 2015 Mar;23(3):190-201. doi: 10.5435/JAAOS-D-13-00190. Epub 2015 Jan 28. Review. View Abstract at PubMed
Bae JH, Oh JK, Chon CS, Oh CW, Hwang JH, Yoon YC. The biomechanical performance of locking plate fixation with intramedullary fibular strut graft augmentation in the treatment of unstable fractures of the proximal humerus. J Bone Joint Surg Br. 2011 Jul;93(7):937-41. View Abstract at PubMed
Kontakis G, Koutras C, Tosounidis T, Giannoudis P. Early management of proximal humeral fractures with hemiarthroplasty: a systematic review. J Bone Joint Surg Br. 2008 Nov;90(11):1407-13. doi: 10.1302/0301-620X.90B11.21070. Review. PubMed PMID: 18978256. View Abstract at PubMed
Hertel R, Hempfing A, Stiehler M, Leunig M. Predictors of humeral head ischemia after intracapsular fracture of the proximal humerus. J Shoulder Elbow Surg. 2004 Jul-Aug;13(4):427-33. PubMed PMID: 15220884. View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 67 THROUGH 70
Figure 67 is the radiograph of a right-hand-dominant 70-year-old woman who arrives at the emergency department with acute left shoulder pain following a fall down a flight of stairs. She expresses acute diffuse left shoulder pain and swelling. Prior to her injury, she had full active painless shoulder range of motion.

Question 98

What is the most common problem seen following epiphysiodesis for limb-length discrepancy?

Explanation

DISCUSSION: Errors in timing are by far the most common in this technically safe procedure. Incomplete growth arrest has been reported in up to 15% of patients versus timing errors in 61%. Fracture through the site has been reported rarely. Neurovascular and cartilaginous injury are extremely uncommon but always need to be considered when performing surgery in the vicinity of these structures.
REFERENCES: Blair VP III, Walker SJ, Sheridan JJ, Schoenecker PL: Epiphysiodesis: A problem of timing. J Pediatr Orthop 1982;2:281-284.
Raney ER: Limb-length discrepancy, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 1519-1526.

Question 99

A 16-year-old girl injured her hip in a fall. Radiographs are shown in Figures 14a and 14b. She denies any history of pain prior to the fall and is currently asymptomatic. A bone scan, MRI scan, and biopsy specimens are shown in Figures 14c through 14f. What is the most likely diagnosis?

Explanation

DISCUSSION: Although the classic radiographic appearance of fibrous dysplasia is one of a central metaphyseal lesion with ground glass matrix, it is not unusual to see either a more radiodense-appearing lesion or a more peripheral location. The histologic finding of spicules of woven bone without osteoblastic rimming in a bland fibrous background is diagnostic of fibrous dysplasia. The imaging studies could be consistent with low-grade osteosarcoma, osteoblastoma, or osteomyelitis, but all have a very different histologic picture. Observation is indicated in the absence of symptoms, impending fracture, or deformity. Fibrous dysplasia most commonly occurs in the proximal femur.
REFERENCES: Huvos AG: Bone Tumors: Diagnosis, Treatment, and Prognosis. Philadelphia, PA, WB Saunders, 1991, pp 30-43.
DiCaprio MR, Enneking WF: Fibrous dysplasia: Pathophysiology, evaluation, and treatment.

J Bone Joint Surg Am 2005;87:1848-1864.

Question 100

A resident arrives to the operating room late for a LEFT carpal tunnel release procedure. The patient is prepped and draped under general anaesthesia, and the attending surgeon and assistant are about to make an incision to the RIGHT carpal tunnel. The resident mentions to the attending surgeon that surgery was booked for the opposite limb, but he ignores the residents confers by saying the surgical mark is under the drape. What would be the most appropriate course of action for the resident at this time? Review Topic

Explanation

The most appropriate course of action for the resident at this time would be to perform a surgical timeout prior to the operation.
Wrong-site surgery is completely preventable by having the surgeon, in consultation with the patient when possible, place his or her initials on the operative site using a permanent marking pen and then operating through or adjacent to his or her initials. The intended site should be marked such that the mark will be visible after the patient has been prepped and draped. A "time-out" procedure should be done before the initiating of any surgical procedure to confirm the type of procedure, site, and side with all operating room personnel including residents.
Haynes et al. reviewed the effect of surgical safety checklists before surgery on the morbidity and mortality in a global population. They found the rate of death was 1.5% before the checklist was introduced and declined to 0.8% afterward (P=0.003). Inpatient complications occurred in 11.0% of patients at baseline and in 7.0% after introduction of the checklist (P<0.001).
Incorrect Answers:

Full Question & Answer Text (for Search Engines)

Question 1:

What is the most consistent finding regarding glenohumeral kinematics in patients with symptomatic tears of the rotator cuff?

Options:

No superior translation during abduction
Retention of ball-and-socket kinematics with more than 30 degrees of abduction
Loss of ball-and-socket kinematics with less than 30 degrees of abduction
Superior translation of the humeral head with more than 30 degrees of abduction
Superior translation of the humeral head with external rotation

Correct Answer: Superior translation of the humeral head with more than 30 degrees of abduction

Explanation:

Question 2:

Options:

an orthosis and an immediate return to running.
no running for 6 weeks and use of a bone stimulator at night.
a University of California Biomechanics Laboratory (UCBL) orthosis and a gradual return to running.
immobilization in a short leg cast with no weight bearing for 6 to 8 weeks.
open reduction and internal fixation.

Correct Answer: immobilization in a short leg cast with no weight bearing for 6 to 8 weeks.

Explanation:

Question 3:

Options:

Improved cognitive function
Improved caregiver satisfaction
Improved nutrition
Decreased pain
Improved mobility

Correct Answer: Improved caregiver satisfaction

Explanation:

Question 4:

Options:

Penicillin
Sulfur
Shellfish
Chicken or eggs
Lidocaine

Correct Answer: Chicken or eggs

Explanation:

Question 5:

Options:

Superior approach with trochanteric slide
Direct anterior approach with a chevron modification of the standard greater trochanteric osteotomy
Lateral approach with a partial greater trochanter osteotomy
Posterolateral approach with an extended trochanteric osteotomy

Correct Answer: Posterolateral approach with an extended trochanteric osteotomy

Explanation:

Question 6:

Options:

Scaphoid fracture
Radiocarpal dislocation
Midcarpal dislocation
Transscaphoid dorsal perilunate dislocation
Volar lunate dislocation

Correct Answer: Transscaphoid dorsal perilunate dislocation

Explanation:

Question 7:

5 standard deviations below young normals (< -2.5). The Z-score represents a comparison to age-matched normals.

Options:

Johnell et al. published a study on the predictive value of BMD for hip and other fractures. They found that lower BMD was associated with a higher risk of osteoporotic fracture. They concluded that BMD is a risk factor for fracture of substantial importance and is similar in both sexes.
Lee et al. published a study on T-Score discordance of BMD in patients with atypical femoral fractures (AFF). They found that the prevalence of T-score discordance between the hip and lumbar spine was relatively high in patients with AFF, and the presumed age at the initiation of bisphosphonate therapy was younger in patients with discordant T-scores.
Incorrect Answers:

Correct Answer: Johnell et al. published a study on the predictive value of BMD for hip and other fractures. They found that lower BMD was associated with a higher risk of osteoporotic fracture. They concluded that BMD is a risk factor for fracture of substantial importance and is similar in both sexes.

Explanation:

You are planning on performing a study to determine if there is a difference in healing rates for distal femur fractures by placing patients on Vitamin D after injury. With regards to your study, the statistician mentions a power analysis. What is the purpose of power analysis and when should it be performed?
This patient has an impending subtrochanteric femur fracture and should be stabilized with cephalomedullary nailing.
Bisphosphonates have been shown to prevent osteoporotic fractures. They suppress osteoclastic recruitment and activity and induce apoptosis of osteoclasts. However, they have also been associated with subtrochanteric femur fractures. Cortical stress reactions in the form of lateral cortical thickening have been documented when radiographs were performed during the prodromal period preceding these fractures. If radiographs are obtained and demonstrate lateral cortical thickening in the presence of thigh pain, the entire femur should be stabilized with prophylactic cephalomedullary nailing to prevent fracture.
Shane et al. performed a review of atypical subtrochanteric and diaphyseal
femoral fractures. They report that long-term bisphosphonate use is associated with these injuries. Bisphosphonates localize in areas that are developing stress fractures and suppress intracortical remodeling. When bisphosphonate use has stopped, the risk of fracture decreases over time. They conclude that teriparatide may advance the healing of atypical femur fractures after surgical treatment.
Koh et al. studied the natural history of femoral stress lesions associated with bisphosphonate therapy. They determined certain features that predispose to complete stress fractures. They found all patients had thigh pain before fracture. They conclude that cortical stress reactions associated with prolonged antiresorptive therapy and the "dreaded black line" should be prophylactically stabilized to avoid a complete fracture.
Figure A is a radiograph of the proximal femur demonstrating lateral cortical thickening with the "dreaded black line." Illustration A is the same image with an arrow indicating the "dreaded black line."
Incorrect Answers:
Which of the following statements regarding bone mineral density (BMD) is true?
The 2017 American College of Rheumatology/American Association of Hip and Knee Surgeons Guideline for the Perioperative Management of Antirheumatic Medication states that hydroxychloroquine can be continued and etanercept
should be held for 2 weeks prior to undergoing total hip arthroplasty.
Patients with rheumatoid arthritis (RA) report high satisfaction following hip or knee replacement despite the higher rates of infection, dislocation, and readmission rates. Patients with RA may present on a variety of different biologic and nonbiologic medications used to control their systemic RA.
Optimal preoperative management of these immunosuppressant medications may help mitigate some of the risks of postoperative complications in RA patients.
Singh et al. reviewed the evidence surrounding the benefits and harms of various antirheumatic medications. They found evidence for traditional DMARDs, biologic agents, and nonbiologic agents in acute and established RA totaling 74 recommendations. They concluded that these recommendations are not prescriptions and that ultimate decision making should be patient- specific in a shared-decision
making process between the patient and physician.
Goodman et al. performed a multistep literature review on optimal antirheumatic medication management prior to joint replacement surgery. They were able to provide recommendations on when to continue, when to withhold, and when to restart these medications, and the optimal perioperative dosing of glucocorticoids. They concluded that these guidelines will help physicians manage antirheumatic medications at the time of elective THA or TKA.
Incorrect Answers:
An 83-year-old woman presents complaining of thigh pain. The pain has been progressing over the last few months. She denies any night chills or recent weight loss. She has smoked 1 pack per day for the last 40 years. Her current medications are alendronate and citalopram. Her current imaging is shown in Figure A. What is the next best step in treatment?
The patient is presenting with complex regional pain syndrome (CRPS) type 1 after a distal 1/3 tibial shaft fracture. The best diagnostic test for this is a thorough history and physical exam.
CRPS is a disorder of increased sympathetic activity in a region of prior trauma. Cases can be classified as type 1, where there is no demonstrable nerve damage, or type 2, where a specific nerve is affected. Patients will typically present with cool and mottled skin that atrophic and absent of hair. Many times the affected limb will be noticeably cooler than the contralateral side. In advanced stages, there will be joint contractures and extensive osteopenia on radiographs. Several diagnostic aids have been developed, but remain inadequate to diagnostic sensitivity compared to a thorough history and physical.
Shah et al. reviewed the diagnosis and treatment of CRPS. The authors reported that sweat quantification testing, skin thermography, and electromyography may be useful aids in diagnosis, but there is a lack of diagnostic sensitivity to make these tests reliable. The authors concluded that evidence suggests gabapentin, prazosin, propranolol, nifedipine, and mexiletine are the best medications for treatment.
Hogan et al. reviewed the diagnosis and treatment of CRPS. The authors reported that the most sensitive means for diagnosis is a good history and physical exam as there is no single test to confirm the diagnosis. The authors recommended a multidisciplinary team approach including pain specialists, physical therapists, and orthopedic surgeons as syndrome response to medications is variable.
Figures A and B demonstrate an AP and lateral radiograph of the right tibia and fibula with a distal 1/3 tibia fracture. Illustration A depicts that Lankford and Evans classification for CRPS.
Incorrect Answers:
A 72-year-old female with rheumatoid arthritis is scheduled to undergo total hip arthroplasty. She presents for her preoperative visit and asks about dosing of her antirheumatic medications. She currently takes etanercept weekly and hydroxychloroquine daily. Which of the following is the best dosing recommendation for her antirheumatic medications prior to surgery?
the entire right lower extremity, with sensitivity to cold temperatures. Physical exam demonstrates hyperesthesia of the extremity, thin and shiny appearing skin, cyanotic appearing with skin cool to the touch. What is the likely diagnosis and what is the best diagnostic test?
In a 5-year-old female without a history of trauma or rashes and with persistent oligoarthritis that improves during the day, the most likely diagnosis is juvenile idiopathic arthritis (JIA). Early-onset JIA is associated with chronic uveitis.
JIA is defined by the American College of Rheumatology as persistent arthritis and swelling in one or more joints for 6 weeks or longer in a patient younger than 16 years of age. It is a diagnosis of exclusion, usually entailing pattern recognition after a thorough history and physical exam. Serologic studies, including rheumatoid factor (RF), antinuclear antibody (ANA), and HLA-B27, may be helpful to rule out other etiologies (septic arthritis, systemic lupus erythematosus, rheumatic fever); however, these are neither sensitive nor specific. In patients with JIA, evaluation for possible uveitis by an ophthalmologist should be considered. Although this patient could have Lyme disease given the likely recent exposure to ticks during her camping trip, the lack of a rash, unresponsiveness to antibiotics, and polyarthritic nature make it less likely.
Arvikar et al. compared clinical features of systemic autoimmune arthritides to those of Lyme arthritis. They found that patients with Lyme arthritis usually had a clinical picture of monoarticular knee arthritis, whereas patients with systemic autoimmune arthritis manifested with polyarthritis. They concluded that systemic autoimmune arthritis with or without a history of Lyme disease should be treated with disease-modifying antirheumatic drugs (DMARDs).
Punaro et al. reviewed common rheumatologic conditions in children who may present to orthopaedic surgeons. For JIA, they reported a typical history of oligoarthritis for 6 weeks or more in a white female patient, with a peak onset between ages 1 and 3 years. Uveitis was typically chronic, bilateral, and asymptomatic. They concluded that while serologic tests were useful in
excluding other diagnoses, they were less useful in confirming JIA.
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A 40-year-old patient sustains the injury in Figures A and B six months ago and underwent the appropriate fixation method. The patient is continuing to experience a tremendous amount of pain in
returning from summer camp. She denies any antecedent trauma, fevers, or rashes. Antibiotics prescribed by her primary care doctor have provided no significant relief, but she reports feeling better at
the end of the day. Labs reveal a negative rheumatoid factor. Which of the following is most commonly associated with her diagnosis?
The hardware shown in Figure A is a tension band plate. It is able to perform its function due to the Hueter-Volkmann Law.
Bones undergo continuous remodeling and turnover which are sensitive to the surrounding mechanical environment. Bone remodeling is governed by Wolff’s law, while the mechanical influence on longitudinal bone growth is controlled by the Hueter– Volkmann law. Wolff’s law relates to the adaptation of bone to its mechanical environment, and involves bone apposition stimulated by intermittent increased stress and bone resorption following reduced intermittent stress. The Hueter–Volkmann law relates to immature bone growth suppression through sustained compressive loading and growth acceleration by reduced loading or distraction.
Villemure et al. performed a review of growth plate mechanics and mechanobiology. They report that growth plates are sensitive to the surrounding mechanical environment. There are a number of clinical conditions of the skeleton that are thought to result from abnormal mechanical loading conditions influencing longitudinal growth prior to skeletal maturity, such as clubfoot (associated with limb position in utero), slipped capital femoral epiphysis, tibia vara, spondylolisthesis, and scoliosis.
Shabtai et al. performed a review of the limits of growth modulation using tension band plates in the lower extremities. Tension band plates have been found to be safe and effective at correcting pediatric frontal plane angular deformities. They found that the success rate for idiopathic cases nears 100%. The success rate for pathologic cases is lower and they have a higher complication rate. They conclude that tension band plates are a reasonable option for all but the most extreme frontal and sagittal plane deformities.
Figure A is a bilateral knee radiograph of a pediatric patient with tension band plates on the right tibia. Illustration A is a bilateral knee radiograph of the same pediatric patient.
The physis appears to have partially closed down and the angle of the screws has changed. One of the screws has broken which happens frequently.
Incorrect Answers:
A 5-year-old girl presents with an 8-week history of pain and swelling in the right knee, right shoulder, and left elbow after
Limb buds develop at 4 weeks and are first able to be visualized by transvaginal ultrasound at 8 weeks.
In a developing fetus, limb buds form at 26 days. The development of the limb is guided by a complex interaction of gene transcription factors and regulatory loops. The most important genes in limb development are sonic hedgehog (SHH), HOX genes, and WNT genes. Ultrasound evaluation is increasingly
being utilized to diagnose and guide treatment for developmental anomalies of a fetus. The limb buds of the fetus can be first seen at 8 weeks of gestation.
Krakow et al. reported on the prenatal diagnosis of fetal developmental dysplasias. They found that differentiating these disorders in the prenatal period can be challenging because they are rare and because many of the ultrasound findings are not necessarily pathognomic for a specific disorder.
Oetgen et al. authored a review on prenatal diagnosis of musculoskeletal conditions. They note that ultrasonography is a safe and cost-effective tool used to prenatally detect common musculoskeletal conditions such as clubfoot, skeletal dysplasias, limb-length discrepancies, spinal abnormalities, and hand and other upper extremity deformities.
Illustration A is a pictorial representation of limb bud formation Incorrect Answers:
The hardware shown in Figure A relies on which of the following principles to achieve its function?
Both Hemophilia A and B are inherited by X-linked recessive patterns. Hemophilia A is caused by factor VIII deficiency, whereas hemophilia B is caused by factor IX deficiency.
Factor VIII deficiency, also known as Hemophilia A, most commonly affects males due to the X-linked recessive inheritance pattern and occurs with a frequency of 1:5000 males. Factor IX deficiency, also known as hemophilia B, also only affects males due to X-linked recessive inheritance, with a frequency of 1:30000 males. Both disorders commonly present with recurrent spontaneous hemarthroses that affect large joints, typically the knee, leading to chronic synovitis and eventually joint destruction. Initial treatment involves factor replacement to within 60% normal, joint aspiration, and immobilization until the physical exam is normal. Treatment for chronic synovitis involves radiosynovectomy, open synovectomy, or arthroscopic synovectomy. End- stage joint destruction requires reconstructive surgery with aggressive factor replacement pre- and postoperatively.
Luck et al. performed a review on hemophilic arthropathy and recommended treatment options for hemophilic arthropathy. The authors recommend that infants get
primary prophylaxis with factor replacement prior to developing a "target" joint. In patients that experience a hemarthrosis, factor replacement with joint aspiration and immobilization until a normal physical exam are paramount for reducing chronic synovitis. Synovectomy, either arthroscopic or open, is recommended for chronic synovitis to reduce the progression of arthropathy. Then arthroplasty is reserved for end-stage joint destruction characteristic of recurrent synovitis.
Zingg et al. performed a retrospective review of 43 consecutive TKA in patients with hemophilic arthropathy. At 9.5 years follow-up there were two hematogenous infections, three revisions, 94% good-to-excellent patient- reported outcomes, and significantly increased ROM compared to preoperative examination. The authors concluded that TKA remains a successful option for end-stage arthropathy for hemophiliacs, but outcomes do not reach the level of non-hemophiliacs.
Journeycake et al. performed a retrospective review on 28 arthroscopic synovectomies performed on pediatric hemophiliac patients with chronic synovitis. At 5-years follow-up 76% of affected joints had stable or improved levels of function. The authors concluded that arthroscopic synovectomy provides a reliable means for limiting current hemorrhage in the affected joint and improving ROM.
Illustration A depicts a pedigree with an X-linked recessive inheritance pattern. Notice how only males are affected, but women can be carriers. Illustration B depicts the process by which recurrent hemarthroses leading to chronic synovitis and then arthropathy.
Incorrect Answers:
deficiency of von Willibrand factor; which assists in platelet adhesion. It is inherited in autosomal recessive pattern with the gene locus found on chromosome 12.
In terms of fetal limb bud development, which of the following is true?
Fluoroquinolones such as levofloxacin act by block DNA replication by inhibiting DNA gyrase.
Fluoroquinolone antibiotics are bactericidal, and their mechanism of action works through the inhibition of DNA gyrase. Side effects of fluoroquinolones include inhibition
of early fracture healing through toxic effects on chondrocytes and increased rates of tendinitis, with a special predilection for the Achilles tendon.
Levine et al. published a review on fluoroquinolones. They report that fluoroquinolones act by inhibiting DNA topoisomerases such as DNA gyrase (topoisomerase II). Due to increasing antibiotic resistance, their use is limited to specific clinical scenarios.
Additionally, their use in children is restricted due to a potential for growth disturbance and cartilage damage.
Perry et al. performed an experimental study on the inhibition of fracture healing by levofloxacin and trovafloxacin in rats. They found that experimental fractures systemically exposed to levofloxacin or trovafloxacin have diminished healing during the early stages of fracture repair. They, therefore, concluded that the administration of quinolones during early fracture repair may compromise fracture healing in humans.
Illustration A is an image illustrating the targets of the various antibiotic classes. Incorrect Answers:
Which of the following bleeding disorders is caused by an X- linked recessive mutation?
An isotonic muscle contraction is a muscle contraction with constant tension such as the upwards and downwards motions of a biceps curl.
The word “isotonic” is derived from two Greek words: “iso”, meaning “same”, and “tonikos” meaning “tension”. An isotonic muscle contraction is one during which the muscle maintains the same tension as it shortens. There are two types of isotonic contractions: concentric and eccentric. In a concentric isotonic contraction, the muscle shortens while contracting. In an eccentric isotonic contraction, the muscle lengthens during contraction.
Ashe et al. review exercise programs used in physical therapy. They report that muscle strengthening can be classified into isotonic, isometric, and isokinetic contractions.
Isotonic exercises involve the development of muscular force through range of motion or movement. Isokinetic exercises involve the force generation at a constant speed.
Isometric exercises involve the development of force without movement, as in tensing and holding a muscle
at a certain part of the range.
Illustration A is an image which illustrates the difference between isotonic and isometric contractions.
Incorrect Answers:
Which of the following correctly describes a class of antibiotics and its mechanism of action?
The third step in applying EBM is to appraise the evidence.
Evidence-based medicine (EBM) refers to an explicit process of using and evaluating information to make medical decisions. When applying EBM in practice, there are 5 steps that should be followed: 1) formulate an answerable question, 2) gather evidence, 3) appraise the evidence, 4)
implement the evidence, and 5) evaluate the process to determine the efficacy of the proposed treatment.
Bernstein published a review on EBM. He advocates for the use of a five-step process for sound decision making: formulate answerable questions, gather evidence, appraise the evidence, implement the valid evidence, and evaluate the process.
Spindler et al. published a review on reading and reviewing the orthopaedic literature. They focus on the third step of EBM: appraising the evidence. They report that systematic review assists the orthopaedic surgeon in interpreting study results and in understanding the relative validity of these results in the hierarchy of evidence.
Illustration A is a table listing the 5 steps of EBM.
Incorrect Answers:
4: Gathering evidence is the second step of EBM.
Which of the following activities describes an isotonic muscle contraction?
On average, physicians interrupt patients within 23 seconds of their interview.
The patient-physician interaction often begins with an initial "survey of problems" through an open-ended question designed to give the patient the freedom to speak and explain
their reason for seeking care. This is followed by a set of focused or closed-ended questions designed to elicit additional details and clarification. Unfortunately, physicians are often quick to interrupt or redirect patients prior to the completion of their reason for seeking care. This practice may lead to missed information, poor communication, and poor
patient satisfaction. Time constraints on physicians may contribute to this behavior. Marvel et al. looked at 264 patient-physician interviews by board-certified family practice physicians. They found patients' initial statement of concern were only complete 28% of the time with an average physician redirection
time of 23.1 seconds. They found patients only needed an additional 6 seconds to complete their statement of concern compared to those who were
redirected by the physician. They conclude that obtaining a complete patient agenda takes little time and can improve interview efficacy and increase data collection.
Incorrect Answers:
When applying evidence-based medicine (EBM) in practice, there are 5 steps that should be followed. Which of the following describes the third step?
For upper extremity surgery, the majority of narcotic pills prescribed by hand surgeons are not consumed by patients.
Patients in the United States are treated very aggressively for pain control. This is due, in part, to The Joint Commission, which has controversially identified pain as the "5th vital sign." An opioid epidemic has ensued which has been linked to a decreased the life expectancy in the United States for three consecutive years beginning in 2014. As a result, unused prescription pain medication following upper extremity surgery represents a liability for patients and surgeons. Following simple soft tissue surgeries (trigger finger, carpal tunnel, mass removal) patients typically only require pain
medication for 2-3 days, and there is no difference in pain control between narcotic or anti-inflammatory medication.
Stanek et al. implemented a standardized postoperative opioid prescription protocol for a group of academic hand surgeons. They found that the protocol decreased the opioid prescription size by 15%, prescription variability, and decreased refills. The authors recommend the development of specific prescription guidelines.
Rodgers et al. interviewed 250 patients after upper extremity surgery about opioid consumption. They reported that patients most frequently received 30 narcotic pills, which provided relief in 92% of cases. The authors found that patients undergoing bone procedures used on average 14 pills, most patients took medication for less than two days post-operatively, and the number of pills consumed on average was 10, with 19 pills unused. As a result, the authors advocated for more limited narcotic prescriptions post-operatively.
Weinheimer et al. randomized patients undergoing hand surgery to receive either Norco or acetaminophen/ibuprofen. They found no difference in time until patients were pain- free, average VAS scores, or the absolute number of those patients who were pain-free. They did find that the narcotic group experienced more adverse side effects (23% vs 3%), ultimately recommending for limiting narcotics post-operatively.
Incorrect answers:
During a new patient office visit, a physician asks an initial open- ended question to the patient. On average, how much time elapses before the physician redirects the patient's initial statement of concern?
The patient’s laboratory workup is likely to reveal hypovitaminosis D. Metabolic and endocrine abnormalities should be considered in patients who exhibit poor fracture healing, especially in those who lack history and exam findings suggestive of infection.
In addition to ruling out infection, a nonunion workup should include tests to identify metabolic and endocrine abnormalities. 25-hydroxyvitamin D3, synthesized from cholecalciferol in the liver, is the laboratory study of choice to determine vitamin D deficiency. Low vitamin D is a common, and easily treated, form of malnourishment in orthopedic trauma patients. Other important factors that can negatively impact fracture healing include protein malnourishment, diabetes mellitus, nicotine use, and HIV.
Warner et al. showed perioperative vitamin D deficiency correlated with
inferior clinical outcomes in patients who underwent operative fixation of ankle fractures. Of the 98 patients studied, 36 (37%) were found to be deficient in vitamin D (<20 ng/ml) and 31 (32%) were found to have a vitamin D insufficiency (> 20 ng/ml, <30 ng/ml). They concluded insufficient vitamin D may result in worse outcomes in orthopedic trauma patients recovering from fracture fixation.
Brinker et al. reviewed metabolic and endocrine abnormalities in 37 patients with nonunions. Inclusion criteria were: 1) an unexplained nonunion that occurred despite adequate reduction and stabilization; 2) history of multiple low-energy fractures with at
least one nonunion; or 3) a nonunion of a nondisplaced pubic rami or sacral ala fracture. Of the 37 patients who met screening criteria, 31 (84%) had metabolic or endocrine abnormalities. Vitamin D deficiency, discovered in 25 of 37 patients (68%), was the most common newly diagnosed abnormality. The authors conclude all patients with nonunion who meet their screening criteria should be referred to an endocrinologist.
Bishop et al. reviewed the assessment of compromised fracture healing and advocate for a metabolic and endocrine workup in the presence of nonunion. If an endocrinology consultation is unavailable, the initial laboratory screening should include 25- hydroxyvitamin D, calcium, thyroid-stimulation hormone, phosphorus, and alkaline phosphatase levels. They also emphasize that the presence of normal inflammatory markers does not exclude the possibility of infection, which should remain in consideration until fracture union and resolution of symptoms.
Incorrect Answers
However, the rate of infection is lower than hypovitaminosis D and both can occur simultaneously.
A hand surgeon plans on performing a carpal tunnel release on a healthy 45- year-old female. Which of the following is true regarding pain management for this case in the post-operative setting?
The ideal scenario to use the ANOVA test is when comparing parametric continuous data (i.e. BMI) for three or more groups.
In statistical analyses, data can be described as discrete (categorical, ordinal) or continuous. Discrete data are observations that can be expressed as categories such as gender, race, or disease status. Continuous data, such as age, are observations for which the difference between the numbers have meaning on a numerical scale. The ANOVA test is used to compare differences in mean values (i.e. continuous data) when there are more than two independent sample groups. When discrete data is compared in the setting of two or more independent sample groups, the chi-squared (parametric) or Fischer's exact test (non-parametric) may be utilized.
Kuhn et al. reviewed statistical tests when discrete data are analyzed. They reported that data may be either discrete (i.e. categorical) or continuous (i.e. age, BMI, height). They presented examples of tests used for discrete data including the chi-square test and Fischer's exact test. They emphasized the importance of scrutinizing the data presented prior to selecting a statistical test.
Greenfield et al. reviewed statistical tests when continuous data are analyzed. They reported that statistical tests for continuous data must be used if the outcome of interest is a comparison of sample means for data that are continuous (i.e. the height of populations). They discuss one-sample t-tests, independent two-sample t-tests, paired t- tests, and ANOVA.
Illustration A demonstrates an algorithm that is helpful in selecting the correct statistical test.
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A 40-year-old Hispanic male presents with persistent pain seven months after open reduction internal fixation of a closed distal tibial fracture. His postoperative course was unremarkable and weight- bearing was resumed at six weeks. Exam reveals a well-healed incision with tenderness at the fracture site. There is no swelling or erythema. Radiographs demonstrate intact hardware and an oligotrophic nonunion. Laboratory workup is most likely to support which of the following interventions:
General anesthesia carries an increased risk of thromboembolism compared to spinal anesthesia. The remaining statements are false.
There have been multiple factors that demonstrate an increased risk of venous thromboembolism (VTE). Some of these risk factors include a previous VTE, obesity (BMI
> 30), surgery type (i.e. total joint arthroplasty),
hypercoagulable states (i.e. cancer, inheritable traits), myocardial infarction (MI), congestive heart failure, family history of VTE, hormone replacement therapy, elevated hormone conditions, varicose veins, and general anesthesia (increased risk compared to epidural/spinal anesthesia). Current AAOS guidelines recommend mechanical prophylaxis in all total hip and knee arthroplasty patients and chemoprophylaxis is recommended, but no optimal regimen is recommended. Chemical prophylaxis should be individualized for each patient and their risk factors.
Geerts et al. put forth their recommendations on the prevention of VTE from the American College of Chest Physicians in 2008. Some of the important points include aspirin not being recommended as a monotherapy (this recommendation was changed in 2012 and is now accepted as monotherapy), recommendation for mechanical prophylaxis, and recommendation for routine chemoprophylaxis for elective hip and knee arthroplasty for a minimum of 10 days.
Caprini et al. retrospectively reviewed 939 patients with either a DVT, PE, or PE and DVT and their treatment. They found that there was lower than anticipated use of low molecular weight heparin, insufficient bridging of patients to warfarin, and insufficient continuation of anticoagulation following hospitalization. They concluded that hospitals need to re-evaluate adherence to VTE treatment guidelines and develop strategies to optimize therapy.
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An orthopedic surgery intern is preparing to perform statistical analyses for his research project. He presents to the department statistician inquiring about the Analysis of Variance (ANOVA) test. Which of the following below is the ideal scenario to use the ANOVA test?
While almost all patients undergoing major orthopaedic procedures receive VTE prophylaxis, this is often not within the ACCP post-operative VTE prophylaxis guidelines.
VTE events typically occur following hospital discharge, within the first 2 to 6 weeks following surgery. Risk is increased with major orthopaedic surgery due to greater soft tissue disruption, venous stasis from limb manipulation, and post-operative immobility. VTE following major orthopaedic hip and knee surgery represents not only a significant cause of postoperative morbidity and mortality but contributes a substantial economic burden. Prophylaxis is the single-most-important factor mitigating the risk of VTE. Therefore adherence to the AAOS and ACCP guidelines is recommended.
Friedman et al. evaluated compliance of physicians with American College of Chest Physicians (ACCP) post-operative VTE prophylaxis guidelines following TKA and THA. The authors found moderate compliance overall, with 47% of THA and 61% of TKA patients receiving appropriate prophylaxis in terms of type, duration, start time, and dose. Compliance with Warfarin use was the lowest, while that with low-molecular-weight heparin was significantly higher. They concluded that while almost all patients received prophylaxis, this was often not within the guidelines.
Oster et al. investigated the economic consequences of VTE following major orthopaedic hip or knee surgery. The authors found that 2.2% of patients developed clinically significant VTE, 62% after hospital discharge and that patients who developed in-hospital VTE had a significantly longer length of hospital stay and associated costs than those that did out-of-hospital and were later readmitted. They concluded that the economic impact of VTE was
substantial regardless of setting.
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Which of the following statements is true as it relates to the risk of thromboembolism?
Those utilizing opioids prior to elective hip and knee arthroplasty are at elevated risk of complications. Weaning opioids preoperatively has been shown to improve postoperative outcomes.
Nonoperative management of osteoarthritis (OA) is focused on reducing pain and limiting functional impairment with medications, physical therapy, activity modification, weight
loss, and intra-articular corticosteroid injections.
Pharmacologic management of OA includes NSAIDs and tramadol (per the AAOS CPGs). Opioids have been increasingly used for OA despite the lack of evidence behind their usage. Chronic opioid usage may improve OA-related pain but it has been associated with numerous adverse effects and worse musculoskeletal treatment outcomes.
Gaffney et al. in their review of perioperative pain management for hip and knee arthroplasty, describe the role of opioids, cryotherapy, acetaminophen, NSAIDs, tramadol, anticonvulsants, spinal analgesia, epidural analgesia, peripheral nerve blocks, and periarticular injections. They recommend IV dexamethasone on POD1, scheduled Tylenol, scheduled NSAIDs (Celebrex vs naproxen vs ketorolac), and PRN tramadol, oxycodone, or hydromorphone for breakthrough pain.
Nguyen et al. performed a retrospective matched cohort comparing patients undergoing hip or knee arthroplasty who were either opioid-naive, chronic opioid users, or chronic opioid users weaned of opioids preoperatively. They found that chronic opioid users who were able to reduce their preoperative opioid use by half prior to arthroplasty had outcomes (SF12 physical component and WOMAC) superior to those who were unable to decrease preoperative opioid use.
Sing et al. performed a retrospective review including 1263 patients undergoing primary THA or TKA, finding that patients who utilized opioids preoperatively had elevated postoperative pain, consumed a greater amount of morphine equivalents, walked fewer meters, had a longer postoperative length of stay, were more likely to be discharged to a care facility, and had 4-
5x greater 90d complications. They conclude that opioid users are a high-risk group.
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Which of the following is true regarding venous thromboembolism (VTE) following major orthopaedic hip or knee surgery?
This patient has developed CRPS following fixation of a distal radius fracture. All of the above are characteristics of CRPS except for decreased perfusion to the fingertips.
CRPS is divided into two general categories: Type I, occurring in the absence of a specific nerve injury, and Type II, resulting from presence of a specific nerve injury. The incidence is 6-26 cases per 100,000 person-years, mostly affecting females (4:1), and smokers. The International Association of the Study of Pain (IASP) has developed the Budapest Criteria for the diagnosis of CRPS. These include sensory (reports of hyperesthesia and/or allodynia), vasomotor (reports of temperature asymmetry and/or skin color changes and/or skin color asymmetry), sudomotor/edema (reports of edema and/or sweating changes and/or sweating asymmetry), and motor (reports of decreased ROM, weakness, or trophic changes to hair or nails) changes. Vitamin C following distal
radius fracture fixation has been suggested as preventative, though still somewhat controversial. Following development of CRPS, treatment includes psychotherapy, occupational therapy, sympathetic blockade, and antidepressants.
Birklein and Schlereth comprehensively review CRPS. The authors describe how after a trauma there is an abundance of inflammatory mediators which stimulate the peripheral nerves. In addition, the proinflammatory cytokine network stimulates bone cell and fibroblast proliferation and potentially endothelial dysfunction. They note that these molecular changes lead to autonomic disturbances and an overwhelming pain response.
Koh et al. also present a review of CRPS. The authors stress that CRPS is a clinical diagnosis and one of exclusion. They discuss that CRPS is best treated within a multidisciplinary team including orthopaedic surgeons, pain management, therapy, and psychological services. Early diagnosis is furthermore critical. Finally, the authors advocated vitamin C administration on the day of fracture as prophylaxis against CRPS.
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A 65-year old male with worsening right hip osteoarthritis has failed nonsurgical management and would like to proceed with total hip arthroplasty. He has consulted with a pain management specialist and is treating his pain with opioids. If he is able to successfully decrease the amount of opioids he takes preoperatively by 50%, what effect would that have on his postoperative functional outcome?
Etanercept is a biologic disease modifying anti-rheumatic drug (DMARD) which works by binding and inhibiting TNF-a, in effect suppressing the autoimmune response associated with rheumatoid arthritis (RA).
There are a number of DMARDs commonly used in the medical management of RA. TNF- a is a frequent target, given its pivotal role as one of the major cytokines driving the progression of RA. Etanercept is one example of a TNF-a inhibitor that is often used to treat RA, juvenile RA, psoriatic arthritis, and ankylosing spondylitis. Infliximab, adalimimab, golimumab are other
commonly used TNF-a inhibitors. Before initiating these medications, patients and physicians should be aware of the possibility of reactivation of latent tuberculosis as well
as increased rates of infection and lymphomas with long- term use.
Saleh et al. reviewed the perioperative management of RA patients. They note that patients that are maintained on etanercept perioperatively have a significantly increased rate of perioperative infection. The authors discuss recommendations that etanercept be held at least one half-life prior to surgery and in some instances up to 4-5 half-lives before surgery. They recommend restarting the medication at 2 weeks post-operatively so long as the surgical sites are healing uneventfully.
Nikiphorou et al. evaluated the impact of biologic agents on the surgical treatment of RA. The authors discussed that although rates of major joint replacements (THA/TKA) for osteoarthritis are increasing, the rates of THA/TKA for RA has been essentially unchanged over >10 years. They concluded that effective medical management of RA has led to fewer orthopedic surgeries being performed in the RA population.
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A 60-year-old female underwent open reduction and internal fixation of a distal radius fracture 3 weeks ago. She returns to your clinic and appears anxious. She complains of pain and difficulty sleeping. When you remove her splint her entire hand and wrist are sensitive. You suspect that she has developed complex regional pain syndrome (CRPS). All of the following are common signs or symptoms of CRPS EXCEPT:
All of the statements listed above are true EXCEPT for answer 2 - BMP-2 is not FDA indicated for single-level posterolateral lumbar fusions.
Bone morphogenetic proteins are a member of the TGF-beta superfamily. It is an osteoinductive material that induces mesenchymal stems cells to differentiate into bone- forming osteoblasts. There has been an increasing amount of literature published around its use in long bone procedures, spinal procedures, and nonunions. Currently, the FDA indications for rhBMP-2 are acute open tibial shaft fractures treated within 14 days and single level ALIFs with a lumbar tapered fusion device.
Hsu et al. authored a systematic review including 6 articles on the cost- effectiveness of BMP-2 compared to iliac crest bone graft (ICBG) in lumbar and cervical arthrodesis procedures. They conclude that in lumbar arthrodesis procedures BMP-2 is only cost- effective when taking into account societal costs such as productivity and lost wages.
Carreon et al. performed a cost-utility analysis on an RCT that they performed comparing BMP-2 to ICBG in posterolateral lumbar fusions. There are more complications, increased need for additional treatment and revision surgery in patients over 60 years old receiving ICBG compared with rhBMP-2/ACS, which account for an increased cost utility for the ICBG group.
Glassman et al., in the paper that the aforementioned study worked off of, performed an RCT of rhBMP-2/ACS (Infuse bone graft) versus iliac crest bone
graft (ICBG) for lumbar spine fusion in patients over 60 years of age. They conclude that BMP-2 is a viable ICBG replacement in older patients in terms of safety, clinical efficacy, and cost-effectiveness.
Cheng et al. looked at the osteogenic activity of fourteen different BMPs on mesenchymal progenitor cells. They found BMP-2, 6, and 9 induced high levels of alkaline phosphatase activity in pluripotent stem cells. They conclude BMP-
2, 6, and 9 may play important roles in inducing osteoblast differentiation of mesenchymal stem cells.
Illustration A (Cheng et al.) is a figure demonstrating the distinct osteogenic activity of human BMPs. BMP-2, 6, and 9 are the most potent agents to induce osteoblast lineage differentiation of mesenchymal progenitor cells while most BMPs can promote the terminal differentiation of committed osteoblast precursors.
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Which of the following medications specifically target tumor necrosis factor alpha (TNF-a)?
Fretting corrosion results from the relative micromotion between two affixed materials placed under a load and is characterized by the formation of pits,
grooves, and oxide debris. This may be seen at modular junctions.
The process of fretting corrosion involves the physical disruption of the passivated layer at the junction of two materials due to friction caused by micromotion under pressure.
The increased surface roughness and release of metallic oxide debris may then, in turn, lead to other types of corrosion such as crevice corrosion. Fretting corrosion has been described at the head-neck junction in total hip arthroplasty, and the risk is increased with an increasing number of component interfaces.
Brown et al. describe fretting corrosion within the context of modular hip tapers. The authors note that while modularity increases versatility, this comes at the cost of interfacial corrosion which may result in both device failure as well as the release of metal ions with local soft tissue reactions. They conclude that longer neck extension was associated with increased fretting corrosion
and that this can potentially be mitigated by increasing the stability of the interface.
Goldberg et al. performed in vitro corrosion testing of modular hip tapers. The authors found that once fretting corrosion created an environment suitable for crevice corrosion, corrosion continued regardless of continued mechanical loading. They concluded that mechanical loading had a significant impact on initiating the corrosion process.
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temperature cycling causing rapid expansion/contraction of the metal. This may be a consideration during the manufacturing process of implants but is not seen in vivo.
When considering using recombinant human BMP-2 in orthopaedic surgery, all of the following are true EXCEPT:
The null hypothesis in this randomized controlled trial is that there is no difference in cement penetration during TKA with or without tourniquet use. As there was significant crossover (tourniquet use in the "no tourniquet" cohort), accepting the null hypothesis when it is false would result in beta (type 2) error.
In hypothesis testing, the assertion that the observed findings did not occur by chance alone but rather occurred because of a true association between variables is confirmed or rejected. By convention, the null hypothesis suggests that there is no significant association between variables while the alternative hypothesis suggests that there is a significant association. Alpha (type 1) error occurs when the null hypothesis is rejected
when it is, in fact, true (false positive effect). Beta (type 2) error occurs when the null hypothesis is
accepted when it is, in fact, false (false negative effect).
Kocher et al. reviewed power analyses, statistical errors, and the concept of statistical power. They discuss that beta represents the chance of a type II error, while alpha represents the chance of a type I error, and that conventionally beta is set at 0.2 and alpha at 0.05. The authors recommended that when a study observes no difference, the power of the study, or (1 - beta), should be reported.
Lochner et al. investigated the rates of beta error in randomized controlled trials in orthopedic trauma. They reported a 90% beta error rate in these trials, which exceeds accepted standards. The authors recommended that future authors perform pre-study power and sample-size calculations to
reduce these rates.
Illustration A shows a Bayesian analysis table demonstrating the relationship between alpha, beta, and the null hypothesis.
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Which of the following types of corrosion is defined by the formation of pits, grooves, and oxide debris due to the relative micromotion between two affixed materials placed under a load?
Tobramycin is an aminoglycoside that acts primarily by disrupting protein synthesis through irreversibly binding to 30S ribosomal subunit, leading to altered cell membrane permeability, disruption of the cell envelope, and eventual cell death.
Exchange nailing with an antibiotic-impregnated intramedullary nail is often implemented in the treatment of chronic osteomyelitis with septic tibial nonunion as it provides both fracture stabilization and antibiotic elution. Vancomycin and tobramycin are often added to the polymethylmethacrylate (PMMA) cement for broad-spectrum coverage.
Vancomycin disrupts cell-wall synthesis in a time-dependent manner by binding to the D- Ala-D-Ala terminal of the growing peptide. It is extremely effective in gram-positive bacteria, but ineffective against gram-negative bacilli due to its large size. Conversely, tobramycin is effective against gram-negative organisms, and works chiefly through the inhibition of bacterial protein synthesis by irreversibly binding to the 30S ribosomal subunit.
Jaeblon et al. reviews the contemporary use of PMMA in orthopaedic surgery. The authors discuss the utility of PMMA as a delivery vehicle for antibiotics, eluting from both the surface and pores of the cement as well as the microcracks within it, while simultaneously eliminating dead space. They conclude that tobramycin is popular because it comes in powder form, which is easy to mix, and because of its broad spectrum activity, which includes antipseudomonal coverage. Moreover, it has been shown to potentiate the elution of other antibiotics, such as vancomycin.
McNamara et al. reviews the mechanism of Vancomycin. The authors report how this antibiotic has increased in importance in the last decade due to the growing resistance of many gram-positive bacteria to β-lactam antibiotics. They discuss that vancomycin is a large, complex, tricyclic glycopeptide molecule that works primarily through disruption of the biosynthesis of peptidoglycan, the major structural polymer of the gram-positive
bacterial cell walls, through binding to the D-alanyl-D-alanine terminal of cell wall precursor units. The authors conclude that unlike penicillins and cephalosporins, cross- resistance with vancomycin does not develop, because vancomycin acts against different stages of cell wall synthesis and different specific targets.
Nana et al. discusses the high affinity of microorganisms to adhere to foreign materials commonly used in orthopedics, including cobalt-chromium, titanium, polyethylene, and PMMA cement through the formation of biofilms. The
authors report that S. aureus and S. epidermidis are the most common bioﬁlm-forming bacteria found in orthopedics, and, when combined with P. aeruginosa, they represent nearly 75% of bioﬁlm infections. They conclude that while no current guidelines exist for treating these infections, recent studies have shown that biofilm growth can be fully inhibited when PMMA is mixed with both daptomycin and gentamicin.
Figures A and B are the AP and lateral radiographs of an infected nonunion of a tibial shaft fracture treated initially with an intramedullary nail.
Figure C is an axial CT image illustrating the tibial fracture nonunion.
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A randomized controlled trial is undertaken to investigate whether tourniquet use increases cement penetration during total knee arthroplasty. Approximately 40% of the patients that were initially randomized to the "no tourniquet" group had tourniquets placed intraoperatively due to difficulty with visualization. Intent- to- treat analysis was conducted and the results showed no difference in the rates of cement penetration. What statistical term best applies if these results are accepted at face value?
Sclerostin is a direct antagonist of the Wnt/β-catenin pathway and thus a key regulator of the formation of mineralized bone matrix and bone mass. Anti- sclerostin antibodies result in inactivation of sclerostin, thereby promoting the anabolic Wnt/β-catenin pathway and resulting in INCREASED bone density
Sclerostin is a glycoprotein encoded by the SOST gene and produced primarily by osteocytes. It acts as a negative regulator of bone mass by directly antagonizing Wnt binding to the LRP5/6 receptor, thereby leading to β-catenin degradation and reduction of Wnt-target gene expression. This results in anti- anabolic properties, including inhibition of osteoblastic differentiation, bone formation, and loss of inhibition of osteoblast and osteocyte apoptosis. Genetic mutations resulting in loss of function or decreased expression of SOST have been linked to endosteal hyperostosis, increased bone mass, and increased bone density (as with Van Buchem disease and sclerosteosis). As a result, new immunotherapies targeting sclerostin (such as Romosozumab and
Blosozumab) are being investigated for their utility toward treating osteoporosis and have shown promising results.
Recker et al. presented a double-blinded phase 2 randomized controlled trial of blosozumab in the treatment of low bone mineral density in postmenopausal women. The authors found that administration of the monoclonal antibody resulted in significant dose- dependent increases in bone mineral density at the spine and hip. The authors concluded that the anti-sclerostin antibody was effective in the treatment of low bone mineral density in postmenopausal women.
Illustration A is a comparison of the unsuppressed Wnt pathway (left) with the Wnt- antagonized pathways (right). Sclerostin binds the LRP5/6 receptor in the place of Wnt, leading to the release of the destruction complex and β-catenin degradation. In the absence of sclerostin, the β-catenin translates into the nucleus and promotes downstream transcription of Wnt target genes.
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sclerostin lead to an under- or uninhibited Wnt/β-catenin pathway and thereby INCREASED bone mass, such as would be seen in Van Buchem disease or sclerosteosis.
Figures A through C are the radiographs and CT scan of a 33- year-old male who was treated 13-months ago for an open tibial shaft fracture. He has received several courses of intravenous antibiotics for chronic osteomyelitis. Despite continued treatment with IV antibiotics, his inflammatory markers remain elevated. The decision is made to proceed with irrigation and debridement, nail removal with exchange for a polymethylmethacrylate intramedullary nail with vancomycin and tobramycin. What is the primary mechanism of action of tobramycin?
Lubricin is a hyaluronic acid-binding proteoglycan found in synovial fluid that reduces the coefficient of friction between the surfaces of the joint.
Lubricin reduces the friction between the surfaces in the joint, leading to decreased shear forces transmitted to the hyaline cartilage. It is a glycoprotein that is produced by the chondrocytes in the superficial zone and is not a primary component of the extracellular matrix. A deficiency in lubricin has
been associated with early-onset arthritis.
Schumacher et al. first discovered what is now known to be "lubricin" by studying the superficial zone of bovine articular cartilage. The authors noted that the chondrocytes in this zone secreted this proteoglycan. In addition, they found that this molecule, or a very similar molecule, was present in synovial fluid and moreover could serve as a functional metabolic marker for chondrocytes of the superficial zone of articular cartilage.
Jay et al. analyzed the synovial fluid in both normal and lubricin-deficient samples and found that the subdiffusive and elastic behavior of synovial fluid, at physiological shear rates, was absent in fluid from a patient who lacked lubricin. They concluded that lubricin provided synovial fluid with an ability to dissipate strain energy induced by physiologic motion, which is a chondroprotective feature distinct from boundary lubrication.
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osteoblastogenesis.
Which of the following is accurate regarding sclerostin?
In the days following an intra-articular injury, the following substances are produced, contributing to articular cartilage damage and the eventual formation of post-traumatic arthritis: IL-1ß, TNF-a, nitric oxide, matrix metalloproteinases, aggrecans, and damage-associated molecular patterns.
Immediately following an intra-articular fracture, there is mechanical damage and necrosis of articular cartilage. Traditionally, orthopaedic surgeons are
taught that the most critical factor in affecting the outcomes of these patients is the accuracy of the articular reduction and restoration of the mechanical alignment. However, even in expertly reduced fractures, some patients experience poor outcomes and develop progressive, debilitating osteoarthritis. More recently, researchers have looked at inflammatory events that may also contribute to arthritis and ways to modulate these events.
Olson et al. provide a review article on the role of cytokines in post-traumatic arthritis. They note that, despite accurate articular reductions, many patients go on to develop
arthritic changes, often indistinguishable from primary OA. While mechanical alignment and structural damage are sometimes responsible, the cascade of cytokines and other signaling molecules listed above serve to catalyze these intra-articular events; developing ways to blunt this inflammatory response is of great interest.
Lewis et al. examined the relationship of inflammatory and post-traumatic arthritis in a rodent model. Tibial plateau fractures were induced in C57BL/6 and MRL/MpJ "superhealer" mice, which were killed at different time-points. Synovial fluid was inspected post-mortem for cytokine analysis, as well as gross specimens, and it was determined that an association exists between joint tissue inflammation and the development and progression of post- traumatic arthritis in mice.
Figure A is an XR of a tibial plateau fracture. Figure B is an XR of a knee demonstrating post-traumatic arthritis. Illustration A is a table of several cytokines and their functions. Illustration B is a timeline of intra-articular pathogenic events following an injury. Illustration C is a diagram showing various cellular events and pathogenic mechanisms in the acute aftermath following an intra-articular injury.
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blood vessels, IL-8 is chemotactic, BMP2 plays a role in the development of bone and cartilage, BMP5 plays a role in cartilage development, and M-CSF causes hematopoietic stem cells to differentiate into macrophages or other related cells.
A 45-year-old patient presents to your clinic for evaluation of knee pain. He has been told he has osteoarthritis and has significant pain with knee range of motion. Which of the following components of synovial fluid is most responsible for reducing the coefficient of friction in a native knee joint?
This player has sustained a tear of the medial collateral ligament (MCL). The MCL is a ligament which inserts indirectly into bone through Sharpey's fibers.
Ligaments can insert on bone either indirectly and directly. Indirect is the most common and is a fibrous insertion. The superficial fibers of the tendon insert into the periosteum, while the deep fibers insert directly into the bone. These
deep fibers are called Sharpey's fibers and are made of type I collagen. The direct insertion has both deep and superficial fiber insertions as well. Direct insertions are fibrocartilaginous and consist of four transitional zones of increasing stiffness that allow force dissipation.
Lu et al. performed a review to determine the functional attachments of soft tissue to bone. They report that a specialized interface, called an insertion site or enthesis, integrates
tendon or ligament to bone and serves to facilitate joint motion. Fibrous (indirect) insertions typically occur over large areas, presumably to distribute force and reduce stress, and are characterized by perforating mineralized collagen fibers.
Cole et al. performed a review of fixation of soft tissues to bone. They report that recreation of the enthesis relies on adequate biologic healing afforded by adequate initial fixation. The healing pattern associated with direct soft–tissue- to-bone repair, such as rotator cuff repair, is different from that associated
with fixation within bone tunnels (ex. ACL reconstruction). The process of tendon healing within osseous tunnels occurs over time.
Lui et al. performed a review of the biology and augmentation of tendon-bone insertion repair. They report that when a ligament runs parallel to the bone, like the MCL, the insertion is more likely to be indirect. When a ligament enters the bone perpendicularly, such as the ACL, the insertion is direct. Indirect insertions may be elevated off the bone without cutting the ligament itself while direct insertions require cutting the substance of the ligament to detach it.
Figure A is a T2-weighted, coronal MRI demonstrating a tear of the MCL. Illustration A is a polarized photomicrograph demonstrating Sharpey fibers, indicated by the white arrows. G represents tendon, while B represents bone (Liu et al.). Illustration B is a Safranin-O-staining photomicrograph of a direct tendon insertion site (Liu et al.).
Illustration C is an H&E photomicrograph of the same direct tendon insertion site (Liu et al.). B represents bone, CFC represents calcified fibrocartilage, UCFC represents uncalcified fibrocartilage, and T represents tendon.
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A 32-year-old male sustains the injury shown in Figure A. He undergoes surgical fixation with subsequent removal of hardware. He does well for 10 years and then presents to your office with increasing left knee stiffness and pain for the last 6 months. He reports no constitutional symptoms or recent trauma. His physical exam is notable for well-healed incisions, a mild effusion, no ligamentous instability, and 5-100 degrees of range of motion. An XR is obtained and shown in Figure B. Which of the following correctly lists the cytokines produced following the initial injury that may contribute to the findings shown in Figure B and the patient's current symptoms?
imaging is shown in Figure A. Which of the following correctly classifies the injured structure and its indirect insertion into bone?
Hypertrophic nonunions are described as having abundant callous formation without bony bridging at the fracture site and rarely require an increase in bone biology to achieve fracture healing.
A nonunion is defined as a fracture that has not healed and has no further capacity to heal without further intervention. Nonunions are typically classified as hypertrophic, oligotrophic, and atrophic. Hypertrophic nonunions show clear
evidence of ability to heal without bridging of fracture gaps. Atrophic nonunions show no evidence of biologic healing and no bridging of fracture gaps. Oligotrophic nonunions tend to fall somewhere in between hypertrophic and atrophic nonunions with some evidence of biologic activity however incomplete healing. Understanding these characteristics allows for proper identification of the nonunion and selection of appropriate intervention with regard to increasing bone biology and fracture stability to achieve healing.
Bishop et al. review the diagnosis and assessment of delayed bone healing through a systematic approach to help surgeons determine appropriate interventions to achieve healing. They state biologic capacity, fracture stability, deformity, infection, and host status should all be considered closely prior to establishing a plan of management for a nonunion.
Babhulkar et al. reviewed 113 patients diagnosed and treated for nonunions including 61 hypertrophic and 52 atrophic nonunions. They found all patients healed with improved function and pain following treatment of their nonunions. They found residual problems related to joint stiffness, limb length
discrepancy, and angular deformity.
Illustration A shows a hypertrophic nonunion of a tibial shaft fracture treated nonoperatively. Illustration B shows an atrophic nonunion following open reduction internal fixation of a humeral shaft fracture.
Incorrect Answers:
A 20-year-old male collegiate football player sustained a knee injury. His
The arrow is pointing to the superficial zone of articular cartilage in Figure A. The superficial zone of articular cartilage has the highest content of collagen and the lowest content of proteoglycans relative to the other zones.
Normal articular cartilage can be divided into 3 zones and the tidemark based on the shape of the chondrocytes and the orientation of the type II collagen. The zones, in order from closest to the joint surface, are superficial zone, intermediate (transitional) zone, and deep zone. The superficial zone has the highest content of collagen and lowest content of proteoglycans of all the zones; in contrast, the deep zone has the lowest content of collagen and the highest content of proteoglycans. The intermediate zone has amounts of collagen and proteoglycans that reside between those found in the superficial and deep zones.
Ulrich-Vinther et al. reviewed the biology of articular cartilage. They noted three distinct zones of articular cartilage that are separated from the subchondral bone by the tidemark. The authors noted that tissue engineering approaches are being used in an effort to regenerate damaged articular cartilage due to injury or aging.
Jeffery et al. studied the three-dimensional architecture of bovine articular cartilage with scanning electron microscopy. They noted that the collagen was ordered in different morphologies in each zone of articular cartilage. The authors concluded that the three- dimensional organization of collagen is important when considering cartilage structure and function.
Illustration A demonstrates the zones of articular cartilage and their spacial relationship. Illustration B shows the relationship between collagen and proteoglycans
within articular cartilage.
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While planning for revision of a failed open reduction internal fixation you are planning to increase mechanical stability across the fracture site. In addition to addressing stability, which of the following fracture scenarios is least likely to require additional bone biology in order to achieve healing?
A is characterized by:
PROMIS is a useful orthopaedic patient-reported outcomes measure (PROM) that can assess disease specific and general health questions, validated for use in foot and ankle, upper extremity, and spine patients.
Multiple tools have been developed to asses patient-reported outcomes, however, some of these are narrow in scope, cumbersome to administer, and less useful in orthopedics. PROMIS was developed by a team of NIH researchers to address these shortcomings. Domains include physical, mental, and social health. PROMIS utilizes computer adaptive testing software (CAT), allowing for fewer questions and more accurate measurements. Additionally, results are reported as T-scores, allowing for easy interpretation.
Brodke et al. provide an overview of PROMIS. They report that this tool was developed to be easy to administer and broad in scope, utilizing item response theory. This validated tool is reliable in assessing specific function of the upper and lower extremities, as well as underlying health traits.
McCormick et al. described PROM used in spine surgery. They reinforce that the benefit of PROM is to gather insight into subjective measures not typically captured in traditional research, looking at such factors as general health quality, function, and pain. The authors also note the importance of these tools as greater emphasis is placed on quality of care and patient experience.
Godil et al. studied instruments to accurately measure quality and outcomes in lumber spine surgical registries. They conducted a prospective cohort study of
58 patients undergoing TLIF for lumbar degenerative spondylolisthesis and administered several PROs. They concluded that the ODI was the best measure assessing pain and disability in lumbar surgery, citing its validity and responsiveness in measuring the effectiveness of lumbar fusion; EuroQOL-5D (EQ-5D) was found to be the best, the most valid, and responsive measure of improvement for health-related quality of life.
Illustration A is a chart depicting the main domains and subcategories analyzed with PROMIS.
Incorrect Answers:
The layer of articular cartilage that the arrow points to in Figure
As part of the World Health Organization (WHO) Surgical Safety Checklist, all of the answers listed are methods to prevent wrong-site surgery EXCEPT marking an "X" on the operative extremity. Patients should be marked unambiguously, with either a "yes" or the surgeon's initials in permanent marker, prior to induction of anesthesia.
The WHO developed the Surgical Safety Checklist in an effort to improve the safety of patients undergoing surgery. Implementation of this checklist has resulted in improved clinician safety attitudes, as well as decreased patient morbidity and mortality. A time-out or group huddle occurs prior to induction with the patient, prior to incision, and prior to the patient leaving the operating room; all team members have an opportunity to speak up and discuss any concerns during this process. The American Academy of Orthopaedic Surgeons suggest the following to prevent wrong-site surgery: Surgical team engagement, patient confirmation, signing the surgical site (in the visible
surgical field or inline with the planned incision) with a permanent marker with the patient's assistance, and utilizing separate time-outs in the case of separate surgical procedures/sites.
Haynes et al. looked at changes in safety attitude, morbidity, and mortality following implementation of the WHO Surgical Safety Checklist. They administered a survey pre- and post-intervention at 8 hospitals. Post- intervention, they found an overall improvement in safety attitudes and found that this was correlated with a reduction in post-operative complication rates.
Gillespie at al. reviewed the evidence of implementing a surgical safety checklist. They utilized a realist synthesis methodology in this study. They concluded that intervention methods and implementation strategies were not well described in the literature, surgical checklists appear to be more successful when physicians are leading their implementation, and that greater participation and ownership of safety checklists can be expected by physicians are actively engaged in their development and implementation.
Illustration A is the WHO Surgical Safety Checklist. Illustration B is an example of the correct way to mark a patient for a right shoulder surgery for a planned deltopectoral incision.
Incorrect Answers:
Which of the following instruments incorporates both general disease and disease-specific measures and has been validated for use in patients with spine, foot and ankle, and upper extremity conditions?
This patient has a catastrophic ceramic component failure and requires a thorough debridement and revision with a head and liner exchange.
Ceramic bearings in hip arthroplasty are recognized for their superior wear properties and low-friction. However, ceramics are also brittle, have a high modulus of elasticity, and are prone to fracture under certain circumstances. Catastrophic bearing failure is not as common in newer-generation ceramics, as first-generation products were more prone to failure due to flaws in the manufacturing process. Squeaking is a known complication of ceramic-on- ceramic bearings and may be associated with catastrophic failure. Obesity, trauma, and component malposition have been linked to failure, and revision procedures should address any component malposition.
Malem et al. describe a case report of a catastrophic ceramic-on-ceramic total hip replacement failure presenting as a squeaking hip. Within 5 years of her index surgery, the patient developed a painful, squeaking hip with a limited range of motion. At the time of revision, she was found to have a broken femoral head, black wear debris, and a completely worn acetabular component, suggesting that a squeaking ceramic-on-ceramic hip replacement may be a sign of catastrophic failure.
Stanat et al. provide a meta-analysis and review of squeaking in 3rd and 4th generation ceramic-on-ceramic total hip replacements. They conclude that the only significant patient- associated risk factor for squeaking was body mass index. In terms of implant type and surgical factors, they found that the presence of a Stryker Accolade stem was associated with an increased incidence of squeaking; cup version was not associated with a higher incidence of squeaking in their analysis.
Figure A is a radiograph demonstrating ceramic fracture and displacement of the femoral component in relation to the acetabular component; ceramic fragments are present around the femoral neck and cup. The partially radiolucent head is a tip-off to the older generation ceramics. Illustration A is an intra-operative photograph demonstrating a fractured ceramic femoral head. Illustration B is a revision of the hip in Figure A utilizing ceramic-on- ceramic components. Illustration C (Traina et al.) is a treatment algorithm when ceramic bearing failure is suspected.
Incorrect Answers:
All of the following can be done to improve patient safety and prevent wrong site surgery EXCEPT:
Nitrogen-containing bisphosphonates exert their action by inhibiting farnesyl pyrophosphate synthase.
Nitrogen-containing bisphosphonates inhibit osteoclasts which leads to increased bone mass and reduced bone turnover. They act on the cholesterol biosynthesis pathway enzyme, farnesyl pyrophosphate synthase. By inhibiting this enzyme in the osteoclast, they interfere with geranylgeranylation (attachment of the lipid to regulatory proteins), which causes osteoclast inactivation. Non-nitrogen containing bisphosphonates are metabolized in the cell to compounds that replace the terminal pyrophosphate moiety of ATP, forming a nonfunctional molecule that competes with ATP in the cellular energy metabolism. Due to this disruption in metabolism, the osteoclast
initiates apoptosis and dies, leading to an overall decrease in the breakdown of bone. Examples of nitrogen-containing bisphosphonates are alendronate, risedronate, pamidronate, and zolendronate. Examples of non-nitrogen containing bisphosphonates are tiludronate, clodronate, etidronate.
Reszka et al. performed a review of bisphosphonates. They report that they bind to the bone mineral, which localizes their action to the target tissue. They are rapidly cleared from the circulation via renal excretion, which minimizes exposure of all other organs.
They do not easily penetrate cell membranes, which reduces exposure to non-target tissues. They also report that alendronate and risedronate are the only pharmacologic agents shown to prevent spine and nonvertebral fractures associated with postmenopausal and glucocorticoid-induced osteoporosis.
Luo et al. performed a systematic review to determine the efficacy and safety of alendronate for adult AVN treatment. They found most studies suggested a positive short-term efficacy of alendronate treatment in reducing pain, improving articular function, slowing of bone collapse progression, and delaying the need for arthroplasty. There were no severe adverse effects associated with alendronate treatment observed and most of the included studies suggested the use of alendronate in early AVN with a small necrotic lesion to achieve better outcomes.
Illustration A (Reszka et al.) details the nitrogen and non-nitrogen containing bisphosphonates and their chemical structures. Illustration B is the mevalonate pathway, showing the action of a nitrogen-containing bisphosphonate.
Incorrect Answers:
A 60-year-old patient presents to clinic complaining of left hip squeaking and stiffness following a ceramic-on-ceramic total hip replacement five years earlier. Initially, he was extremely pleased with the operation, but these symptoms of squeaking and stiffness have developed fairly abruptly over the past 6 months. On physical exam, he has a well-healed incision, a 1 centimeter leg length discrepancy (left shorter than right), decreased hip flexion, and decreased internal rotation. A radiograph is shown in Figure A. C- reactive protein is 0.2 mg/dL (nl <0.9 mg/dL) and erythrocyte sedimentation rate is 5 mm/hr (nl 0-15 mm/hr). What would you recommend for this patient?
in the red box?
Aspirin inhibits the aggregation of platelets, which are shown in Figure C.
The coagulation cascade is a complex interaction of multiple clotting factors which ultimately leads to the aggregation of platelets to form a clot. The end result of the clotting cascade leads to the conversion of prothrombin to thrombin, causing the formation of fibrin and the subsequent aggregation of platelets in a clot. Aspirin irreversibly blocks the formation of thromboxane A2 in platelets, which inhibits platelet aggregation and thus the formation of a clot.
Hyers reviewed the mechanism of action of various anticoagulants and the pathophysiology of venous thromboembolism. He noted that while deep vein thrombosis and pulmonary embolism resulted in significant morbidity and mortality in the United States, novel anticoagulants have recently been developed that hold promise for new therapeutic options.
Brown pooled the results of 14 randomized controlled trials examining venous thromboembolism (VTE) rates. Their analysis showed that VTE rates were not significantly different when aspirin was used for anticoagulation compared with vitamin K antagonists or low molecular weight heparin (LMWH). The authors concluded that aspirin could be used for VTE prophylaxis after major orthopaedic surgery.
Figure A shows a plasma cell. Figure B shows a neutrophil. Figure C shows arrows pointing to platelets in a peripheral blood smear. Figure D features a basophil, and figure E shows an osteoclast. Illustration A shows the mechanism of action of aspirin.
Incorrect Answers:
A man with osteonecrosis of the hip is treated with a medication which inhibits the pathway shown in Figure A. Which of the following medications best matches this mechanism of action of the medication
Demineralized bone matrix (DBM) is both osteoconductive and osteoinductive.
DBM is made from the acidic extraction of bone matrix from allograft. It removes the minerals and leaves the collagenous and noncollagenous structure and proteins. It is osteoconductive and osteoinductive as it contains collagen, bone morphogenic proteins (BMPs), transforming growth factor-beta (TGF-β), and residual calcium. It does not contain mesenchymal precursor cells or impart structural support.
Ripamonti et al. performed a review of regenerative medicine and tissue engineering of bone. They report that the understanding of bone formation by autoinduction has been pivotal for setting the rules for tissue engineering. An extracellular matrix combined with TGF-β is capable of performing this task.
Grabowski et al. review bone graft and bone graft substitutes. They report that DBM is both osteoinductive and osteoconductive. DBM provides varying degrees of osteoconductive potential based on the carrier material chosen.
They also report that given the techniques used for demineralization are proprietary, the actual techniques are not published, and the process is not regulated. They conclude that the actual concentration of BMPs is varied when comparing various lots of the same preparation.
Figure A is a coronal CT slice demonstrating a depression fracture of the lateral tibial plateau.
Incorrect Answers:
Aspirin exerts its primary effect on which of the following cells (identified by black arrows)?
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Question 8:

Figure 30 shows the MRI scan of a 68-year-old woman who has left hip pain. What is the most appropriate treatment?

Options:

Open reduction and internal fixation
Total hip arthroplasty
Incisional biopsy
Proximal femoral resection and reconstruction
Arthrodesis

Correct Answer: Total hip arthroplasty

Explanation:

DISCUSSION: The patient has a large zone of osteonecrosis of the left femoral head. The wedge-shaped zone of decreased signal intensity on the T1 image in the subchondral region of the femoral head is typical. Based on these findings, total hip arthroplasty is the most appropriate treatment. Open reduction and internal fixation will not help this condition. Incisional biopsy is indicated only if the MRI scan shows a probable neoplasm. Resection of the proximal femur is indicated only for aggressive malignancy. Arthrodesis may be considered in a younger patient but not in a 68-year-old individual. Other treatments, not listed, such as core decompression, vascularized fibular transplant, and osteotomy may be options in selected patients.
REFERENCES: Urbaniak JR, Jones JP Jr (eds): Osteonecrosis: Etiology, Diagnosis, and Treatment. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 213-223.
Watson RM, Roach NA, Dalinka MK: Avascular necrosis and bone marrow edema syndrome. Radiol Clin North Am 2004;42:207-219.

Question 9:

In displaced calcaneal fractures, what fragment is the only one that remains in its anatomic position?

Options:

Posterior tubercle
Posterior articular facet
Anterior process
Sustentaculum tali
Lateral wall

Correct Answer: Sustentaculum tali

Explanation:

Question 10:

Options:

patella baja.
nonresurfaced patella.
isolated femoral revision.
noncemented tibial component.
previous use of the quadriceps turn-down technique.

Correct Answer: patella baja.

Question 11:

Which of the following best characterizes the injury shown in Figure 53? Review Topic

Options:

Stable tear drop extension injury
Facet dislocation
Unstable flexion compression injury
Stable axial load injury
Burst fracture

Correct Answer: Unstable flexion compression injury

Explanation:

Question 12:

What is the most common contracture deformity of the spastic shoulder secondary to a cerebrovascular accident?

Options:

External rotation, abduction, and extension
External rotation, adduction, and flexion
Internal rotation, abduction, and flexion
Internal rotation, adduction, and extension
Internal rotation, adduction, and flexion

Correct Answer: Internal rotation, adduction, and flexion

Explanation:

Question 13:

Etanercept is a recombinant genetically engineered fusion protein used to treat rheumatoid arthritis. What is its mode of action?

Options:

Monoclonal antibody that binds TNF-α
Blocks the binding of IL-1 to receptors
Soluble receptor that binds TNF-α
Soluble factor that binds rheumatoid factor
Directly inhibits pyrimidine synthesis

Correct Answer: Soluble receptor that binds TNF-α

Explanation:

Question 14:

Which of the following increases radiation exposure to patients and personnel during surgery?

Options:

Orienting the beam in the opposite direction of the working team and keeping the team outside a 6-foot radius of the fluoroscopy machine
Orienting the cathode ray tube beneath the patient with the image intensifier receptor as close to the patient as possible
Limiting the beam on time to only what is clinically important
The use of continuous fluoroscopy whenever possible to ensure proper placement of implants
The use of lead glasses, a thyroid shield, and a lead apron with an equivalent lead thickness of 0.25 mm

Correct Answer: The use of continuous fluoroscopy whenever possible to ensure proper placement of implants

Explanation:

Question 15:

Options:

0 to 15 degrees
20 to 30 degrees
40 to 90 degrees
100 to 120 degrees
130 to 140 degrees

Correct Answer: 40 to 90 degrees

Explanation:

Question 16:

Which of the following conditions is considered a relative contraindication to interscalene nerve block for patients scheduled to undergo shoulder surgery?

Options:

Prior shoulder surgery
History of deep venous thrombosis
Controlled seizure disorder
Respiratory insufficiency
Obesity

Correct Answer: Respiratory insufficiency

Explanation:

DISCUSSION: A common side effect of interscalene nerve block for shoulder surgery is the blockade of the ipsilateral phrenic nerve. This, in turn, results in paresis of the diaphragm and up to a 30% reduction in pulmonary function volumes. Therefore, interscalene nerve block generally is not recommended for patients whose respiratory function is compromised. Other relative and absolute contraindications for interscalene nerve blocks include allergy to local anesthetics, infection at the injection site, uncontrolled seizure disorder, coagulation abnormality, and preexisting neurologic injury.
REFERENCES: Chelly JE: Indications for upper extremity blocks, in Chelly JE (ed): Peripheral Nerve Blocks, ed 2. Philadelphia, PA, Lippincott Williams & Wilkins, 2004, pp 19-27.
Misamore GW, Sallay PI: A prospective analysis of the safety and efficacy of interscalene brachial plexus block anesthesia for shoulder surgery. J Shoulder Elbow Surg 2007;16:e39.

Question 17:

What is the most appropriate initial diagnostic imaging study for a patient with presumed diskogenic low-back pain?

Options:

MRI
Discography
CT discography
Radiography

Correct Answer: Radiography

Explanation:

Question 18:

In hip arthroplasty, the location of the medial femoral circumflex artery is best described as

Options:

superior to the piriformis tendon.
superior to the anterior rim of the acetabulum.
deep to the transverse acetabular ligament.
deep to the quadratus femoris muscle.
within the substance of the gluteus minimus.

Correct Answer: deep to the quadratus femoris muscle.

Explanation:

Question 19:

Figure 19 shows the radiograph of a 12-year-old boy who sustained an injury to his hand when another child fell on him. Management should consist of

Options:

early motion and muscle strengthening.
immobilization in a thumb spica cast with the thumb abducted.
open reduction and internal fixation through a volar approach.
open reduction and internal fixation through a dorsal approach.
closed reduction and percutaneous pin fixation.

Correct Answer: open reduction and internal fixation through a dorsal approach.

Explanation:

Question 20:

Options:

Extensor digitorum longus
Flexor digitorum longus
Peroneus longus
Extensor hallucis longus
Tibialis anterior

Correct Answer: Extensor digitorum longus

Explanation:

DISCUSSION: The recovery process from peroneal nerve palsy may take many months as axonal regrowth occurs. Of the muscles listed, the extensor hallucis is innervated most distally by the peroneal nerve. The flexor digitorum longus is innervated by the tibial nerve.
REFERENCE: Sarrafian SK: Anatomy of the Foot and Ankle, Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993, p 364.

Question 21:

Options:

oral antibiotics.
IV antibiotics.
surgical drainage of the perivertebral abscess and IV antibiotics.
bed rest.
cast immobilization.

Correct Answer: IV antibiotics.

Explanation:

DISCUSSION: The patient has diskitis. Administration of IV antibiotics speeds resolution and minimizes recurrence. Bed rest and cast immobilization have been successfully used to treat this disorder but can be associated with prolonged recovery and frequent recurrence, even when oral antibiotics are administered. A perivertebral abscess seen in association with this condition usually resolves without surgery.
REFERENCES: Ring D, Johnston CE II, Wenger DR: Pyogenic infectious spondylitis in children: The convergence of discitis and vertebral osteomyelitis. J Pediatr Orthop
1995;15:652-660.
Crawford AH, Kucharzyk DW, Ruda R, et al: Diskitis in children. Clin Orthop 1991;266:70-79.

Question 22:

The radiographs and CT scan seen in Figures 28a through 28d reveal what type of acetabular fracture pattern?

Options:

Transverse
Transverse with posterior wall
Both column
Posterior wall anterior hemitransverse
T-type

Correct Answer: Transverse with posterior wall

Explanation:

Question 23:

Options:

continued physical therapy that focuses on stretching and advances to strengthening in 4 weeks.
a cortisone injection into the subacromial space.
revision rotator cuff repair.
a sling with an abduction pillow for 2 weeks, followed by a stretching program.
open rotator cuff debridement without repair.

Correct Answer: revision rotator cuff repair.

Explanation:

Question 24:

A distal radius fracture in an elderly man is strongly predictive for what subsequent injury?

Options:

Another distal radius fracture
Insufficiency fracture of the spine
Insufficiency fracture of the pelvis
Hip fracture
Proximal humerus fracture

Correct Answer: Hip fracture

Explanation:

Question 25:

Options:

Anterior pseudarthrosis
Prior laminectomy at the osteotomy level
Sagittal decompensation of more than 20 cm on standing lateral radiographs
Kyphosis at the thoracolumbar junction
Vascular calcification at the osteotomy site

Correct Answer: Anterior pseudarthrosis

Explanation:

Question 26:

Which structure is shown in Video 27? 27

Options:

Superficial medial collateral ligament
Semimembranosus tendon
Posterior oblique ligament
Medial patellofemoral ligament

Correct Answer: Medial patellofemoral ligament

Explanation:

Question 27:

Options:

Middle glenohumeral ligament
Supraspinatus
Infraspinatus
Subscapularis
Bankart tear

Correct Answer: Subscapularis

Explanation:

Question 28:

What are the proposed biomechanical advantages of the Grammont reverse total shoulder arthroplasty when compared to a standard shoulder arthroplasty?

Options:

Lateralization of the center of rotation, lengthening the deltoid, and decreasing the deltoid moment arm
Lateralization of the center of rotation, shortening the deltoid, and decreasing acromial stress
Lateralization of the center of rotation, lengthening the deltoid, and increasing the transverse force couple
Medialization of the center of rotation, lengthening the deltoid, and increasing the deltoid moment arm
Medialization of the center of rotation, shortening the deltoid, and decreasing acromial stress

Correct Answer: Medialization of the center of rotation, lengthening the deltoid, and increasing the deltoid moment arm

Explanation:

DISCUSSION: The Grammont reverse total shoulder arthroplasty is designed to medialize the center of rotation, thereby increasing the deltoid moment arm and lengthening the deltoid.
REFERENCES: Werner CM, Steinmann PA, Gilbert M: Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-1486.
Rittmeister M, Kerschbaumer M: Grammont reverse total shoulder arthroplasty in patients with rheumatoid arthritis and nonreconstructible rotator cuff lesions. J Shoulder Elbow Surg 2001;10:17-22.

Question 29:

Options:

High tibial osteotomy
Total knee replacement
Unicondylar knee replacement
Arthroscopic partial meniscectomy

Correct Answer: Total knee replacement

Explanation:

Question 30:

Figures 28a and 28b show AP and lateral radiographs of the knee. Based on these findings, which of the following structures has most likely been injured?

Options:

Popliteal artery
Quadriceps tendon
Patellar tendon
Anterior cruciate ligament
Peroneal nerve

Correct Answer: Anterior cruciate ligament

Explanation:

Question 31:

Atraumatic neuropathy of the suprascapular nerve usually occurs at what anatomic location?

Options:

Suprascapular and spinoglenoid notches
Omohyoid muscle
Anterior trapezius muscle
Infraspinatus fascia
Teres minor superior border

Correct Answer: Suprascapular and spinoglenoid notches

Explanation:

Question 32:

Options:

This procedure is contra-indicated in patients with an ossified posterior longtudinal ligament.
Significant loss of motion can be expected due to fusion of the facet joints
The spinal cord is decompressed by increasing the medial to lateral dimension of the spinal canal
The spinal cord is decompressed by increasing the anterior to posterior dimension of the spinal canal
A unilateral approach allows less blood loss than a laminectomy and instrumented fusion

Correct Answer: This procedure is contra-indicated in patients with an ossified posterior longtudinal ligament.

Explanation:

Question 33:

Which complication is most common after syndesmotic fixation?

Options:

Synostosis of the distal tibiofibular joint
Failure of fixation with subsequent loss of reduction
Malreduction of the distal tibiofibular joint
Posttraumatic ankle arthrosis

Correct Answer: Malreduction of the distal tibiofibular joint

Explanation:

DISCUSSION
The injury radiographs reveal a supination external rotation IV ankle fracture with evidence of medial clear space widening exceeding 4 mm and an increase relative to the superior tibiotalar clear space. This indicates injury to the deltoid ligament and necessitates surgical reduction and fixation to restore and maintain ankle stability. Following stabilization of the fibula, an intraoperative stress examination of the syndesmosis such as an external rotation stress test under fluoroscopy or lateral pull on the fibula (the Cotton test) should be performed to determine the integrity of the syndesmosis. Radiographic evidence of tibiofibular clear space widening, medial clear space widening with external rotation, and lateral displacement of the distal fibula when pulled is consistent with syndesmotic injury. In contrast to the presurgical stress test, once the fibula has been reduced and stabilized lateral talar translation can occur only if the syndesmosis is injured in addition to the deltoid ligament. Failure of the syndesmotic screw without evidence of malalignment of the mortise and a pain-free ankle are not indications for further surgery because these patients have satisfactory outcomes when compared to those who have intact or removed screws. Hardware removal following fibula ORIF is indicated when patients have pain directly related to hardware prominence. Resolution of joint pain or stiffness is not a reliable outcome following hardware removal. Although fibular fracture can occur, this is a rare complication. Malreduction of the syndesmosis is the most common complication following ORIF of the syndesmosis and is improved with direct visualization; however, malreduction still may occur with direct visualization.
RECOMMENDED READINGS
Manjoo A, Sanders DW, Tieszer C, MacLeod MD. Functional and radiographic results of patients with syndesmotic screw fixation: implications for screw removal. J Orthop Trauma. 2010 Jan;24(1):2-6. doi: 10.1097/BOT.0b013e3181a9f7a5. PubMed PMID: 20035170.
View
Abstract at PubMed
Jenkinson RJ, Sanders DW, Macleod MD, Domonkos A, Lydestadt J. Intraoperative diagnosis of syndesmosis injuries in external rotation ankle fractures. J Orthop Trauma. 2005 Oct;19(9):604-9. PubMed PMID: 16247304.
View Abstract at PubMed
Stark E, Tornetta P 3rd, Creevy WR. Syndesmotic instability in Weber B ankle fractures: a clinical evaluation. J Orthop Trauma. 2007 Oct;21(9):643-6. PubMed PMID: 17921840.
View
Abstract at PubMed
Brown OL, Dirschl DR, Obremskey WT. Incidence of hardware-related pain and its effect on functional outcomes after open reduction and internal fixation of ankle fractures. J Orthop Trauma. 2001 May;15(4):271-4. PubMed PMID: 11371792.
View Abstract at PubMed

Question 34:

Options:

immediate proximal right tibial physeal arrest.
immediate distal right femoral physeal arrest.
a shoe lift and follow-up in 2 years.
observation with the expectation that the discrepancy may correct itself and not require surgery.
limb lengthening of the shorter left limb.

Correct Answer: observation with the expectation that the discrepancy may correct itself and not require surgery.

Explanation:

Question 35:

What is the most common long-term complication of the fracture shown in Figure 32?

Options:

Nonunion
Ankle arthritis
Subtalar arthritis
Talonavicular arthritis
Posterior tibial tendinitis

Correct Answer: Subtalar arthritis

Explanation:

Question 36:

Alpha fetoprotein (AFP) can be seen in many cancers, but is most commonly seen in hepatocellular carcinomas.

Options:

The diagnosis of gout can be made either by the presence of tophaceous deposits in the skin or bursae of the extremities or by the presence of which of the following?
Elevated urine pH
Elevated serum uric acid
Calcium pyrophosphate crystals in the synovial fluid
Monosodium urate crystals in the synovial fluid
Elevated serum phosphate

Correct Answer: Calcium pyrophosphate crystals in the synovial fluid

Explanation:

Gout is an inflammatory arthritis caused by the presence of monosodium urate crystals in the joint. It is characterized acutely by a painful joint that remits after 1 to 2 weeks and recurs periodically. The diagnosis of gout can be made by confirming the presence of monosodium urate crystals in the joint fluid
aspirated from the inflamed joint. Patients with gout may also have tophaceous deposits within the skin or bursae of the extremities. Elevated urine pH, serum uric acid, and serum phosphate can all be associated with numerous conditions and are not specific to gout. Calcium pyrophosphate crystals are associated with chondrocalcinosis (pseudogout).
A 72-year-old woman is evaluated for sacrococcygeal pain sustained after a twisting injury. Radiographic and MRI evaluation confirms the presence of a nondisplaced fracture at the sacrococcygeal junction. Over a 3-week period, the pain has gotten significantly better. No additional lesions or injuries are noted.
Laboratory studies show a serum calcium level of 8.8 mg/dL (normal 8.6-10.3 mg/dL) and a 25-OH Vitamin D level of 14 ng/mL (normal
80 ng/mL). What is the most appropriate treatment for this patient?
Expectant observation
Calcium supplementation
High dose vitamin D supplementation
Bisphosphonate therapy
Surgical fixation of the sacrococcygeal fracture
Chronic Vitamin D deficiency leads to problems with bone health and has been shown to increase the risk of falls in the elderly. Appropriate supplementation of Vitamin D has been shown to decrease this risk. Conversion in the skin decreases with age and may be nearly nonexistent in darkly pigmented individuals. Vitamin D3 is the preferred form for supplementation, but D2 is the form most available by prescription in the US. Hypervitaminosis D is rare and very high doses can be tolerated without significant concern for toxicity. Because the patient has sustained one insufficiency fracture, she is at risk for insufficiency fractures in other skeletal locations, rendering expectant observation insufficient. Her serum calcium is normal, and with a low Vitamin
D level, calcium utilization in her system would be inadequate. Bisphosphonate therapy in addition to calcium and vitamin D supplementation may provide a good long-term solution, but should not be instituted until the bone mineral imbalance has been adequately corrected. Surgical fixation of this fracture is not indicated, particularly in lieu of improving symptoms.
Figures 70a and 70b show the radiograph and MRI scan of a 66- year-old man who has fatigue, weight loss, and muscle weakness. Examination reveals marked pain and discomfort in the left mid leg. Biopsy specimens are shown in Figures 70c and 70d. What is the most likely diagnosis?
Mastocytosis
Multiple myeloma
Hyperparathyroidism
Metastatic carcinoma
Multicentric giant cell tumor
The signs and symptoms of hyperparathyroidism are similar to those in patients with diffuse skeletal metastases. Serum markers are very helpful in making the diagnosis. In this patient, the radiograph shows multiple lesions in the tibia and proximal fibula that have a variable appearance. For example the mid-tibial lesion is radiolucent and slightly expansile whereas the more proximal tibial lesions are radiodense. The proximal fibula lesion is mixed (radiolucent/radiodense). These findings would be very uncommon in patients with myeloma, metastatic disease, or multicentric giant cell tumor. The histopathology shows a bland fibrous stroma with multiple multinucleated
giant cells. On higher power, the stromal cells are spindled and the giant cells are relatively small in contrast to giant cell tumor where the giant cells are larger and the stromal cells are more rounded with nuclei that closely resemble those in the giant cells.
There is blood extravasation (stromal
hemorrhage) and hemosiderin deposition. The constellation of findings is most consistent with brown tumors due to hyperparathyroidism (secondary to a parathyroid adenoma in this patient).
A 68-year-old woman has had progressive pain in the right thigh for the past several months. She has a history of hypertension, treated with hydrochlorothiazide and osteoporosis treated with alendronate
for 10 years. At this point, she is virtually wheelchair bound.
Radiographs are shown in Figures 78a and 78b. Additional studies show no signs of systemic disease. What is the most likely etiology of her condition?
Prolonged use of bisphosphonates
Use of calcium-wasting diuretics
Occult metastatic cancer
Vitamin D-resistant rickets
Disuse osteopenia
The patient has been on alendronate for 10 years and has evidence of a proximal diaphyseal fatigue fracture. These have been associated with long- term use of bisphosphonates. Staging studies have failed to show systemic disease, and while metastasis with an unidentifiable primary does occur, it would be unlikely to present with this radiographic appearance, now recognized to be classic for stress fractures associated with chronic bisphosphonate usage. Hydrochlorothiazide does not cause calcium wasting. Vitamin D-resistant rickets would be a long-standing event and would present much earlier in life, often with pronounced deformities. Whereas the patient's progression to intolerance of weight bearing likely has led to some degree of disuse osteopenia, the underlying problem is the long-term bisphosphonate exposure.
A surgeon recommends an interscalene regional block to a patient undergoing shoulder arthroscopy. When asked about potential complications, which of the following is most likely to occur?
Persistent motor neuropathy
Sensory neuropathy
Complex regional pain syndrome
Pneumothorax
Cardiac arrythmia and arrest
Sensory neuropathy is the most common complication seen with interscalene regional block.
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Bishop et al. retrospectively reviewed 478 patients who had shoulder surgery under interscalene regional block. A total of 462 patients (97%) had a successful block. While all of the answers have been described, in this study no patient had a seizure, pneumothorax, cardiac event, or other major complication. Twelve (2.3%) of the 512 patients who had a block had minor complications, which included sensory neuropathy in eleven patients and a complex regional pain syndrome that resolved at three months in one patient. For ten of the eleven patients, the neuropathy had resolved by six months.
Cathepsin K is an enzyme produced by osteoclasts. What is the function of cathepsin K?
Reduction of disulfide bonds in the extracellular matrix
Bone resorption
Activation of RANK (Receptor activator of nuclear factor kappa-B)
Antagonize the action of RANK
Absorb water in the extracellular matrix
Cathepsin K is an enzyme produced and released by osteoclasts at the ruffled border that functions to resorb bone. Cathepsin K inhibitors are being clinically evaluated as potential anti-resorptive drugs for use in osteoporosis treatment. Other proteins associated with osteoclasts include tartrate-resistant acid phosphatase (TRAP) and calcitonin receptor.
Illustration A is a drawing that depicts the action of cathepsin k within osteoclasts.
What is the primary problem in rickets osteomalacia?
Defect in the zone of proliferation within the physis
Defect in type I collagen
Defect in the ext-1 gene
Low level of calcium
Production of dysplastic fibrous bone
Rickets is a disorder of bones in children that results from decreased calcium available in the blood resulting in poor mineralization of bone that can lead to fractures and deformity. The most common cause of rickets is from vitamin D deficiency but it can also be caused by poor nutrition or gastrointestinal
disease that results in poor calcium absorption such as celiac disease or severe diarrhea from other causes. Rickets is not primarily a physeal disorder. Osteogenesis imperfecta is caused by a defect in type I collagen. A defect in
the ext-1 gene is often seen in patients with multiple hereditary exostoses. Fibrous dysplasia also can result in bone deformity and fractures due to production of dysplastic fibrous bone but is not caused by calcium or vitamin D deficiency.
If an orthopaedic surgeon receives royalties from a company for his or her participation in the design and development of a product, and uses that same product for the care of his or her patients, what is the orthopaedic surgeon's obligation?
Obligated to disclose only the fact that he or she was involved in the design and development
Obligated to disclose only the company relationship if there is a state law requiring it
Obligated to disclose his or her full relationship with the company, including the fact that he or she receives royalties
No obligation to disclose this private matter to the patient
Avoid this situation because it should not exist since he or she cannot use such a product
The AAOS has a specific code of ethics and professionalism that addresses this issue: "When an orthopaedic surgeon receives anything of value, including royalties, from a manufacturer, the orthopaedic surgeon must disclose this fact to the patient." It is derived from a broader document developed by the American Medical Association, and is applicable to all physicians. At present, this is an ethical issue receiving greater federal scrutiny. This issue has had a greater effect on the public's perception of the integrity of the orthopaedic profession.
A minimally invasive plate osteosynthesis is seen in Figure 15. The resultant fracture healing can best be attributed to a fixation construct that was
stiff and stable.
flexible and stable.
facilitating direct osteonal healing.
inhibitory to endochondral ossification.
stimulatory to intramembranous ossification.
Locked plating constructs with long-working lengths provide flexible but stable constructs that promote (not inhibit) endochondral ossification. Because of the longer working length they are not stiff, and these fractures do not heal with intramembranous ossification which occurs in bones like the calvarium. Direct osteonal healing is usually seen with constructs
where absolute stability is achieved through interfragmentary compression, unlike in this case.
An orthopaedic surgeon makes an incision on a right knee and realizes that the patient was supposed to have a left total knee arthroplasty. The surgeon should do which of the following?
Leave the wound open and talk to the family immediately.
Close the wound, abort the surgery, and talk to the patient and family when the patient is awake.
Close the wound, complete the left knee arthroplasty, and talk to the family after the surgery is complete.
Complete the surgery and talk directly to the patient the following day on rounds.
Discuss the problem in the office the next week in a calm reassuring manner.
The AAOS recommendation is to complete the correct surgery, repair the incorrect surgery to as close to normal as possible, and then discuss it openly with the family after the surgery is complete. Prompt informing is necessary. Aborting the surgery then results in the patient requiring a second anesthesia and surgical time needlessly.
Spindled cells that are surrounded in mature osteoid that
connect to other similar cells via canaliculi are best described as which of the following?
Osteoblasts
Osteoclasts
Osteocytes
Histiocytes
Megakaryocytes
Osteocyte cell processes travel through canaliculi to interconnect with other osteocytes and cells on the bone surfaces. Osteoblasts are cells that produce bone matrix and are seen rimming immature bone. Osteoclasts are large multinucleated cells that resorb bone and are found in Howship's lacunae. Megakaryocytes and histiocytes are found in marrow but not mature bone cortex.
A 48-year-old woman has an open subtrochanteric femur fracture. No other injuries are reported. After thorough evaluation, it is determined that she will need emergent surgical fixation. The patient and family indicate that they are practicing Jehovah's witnesses and desire adherence to the religious standards with respect to blood product usage. The patient signs a valid advanced directive confirming these wishes. Which of the following would be considered acceptable treatment?
Whole blood
Platelets
Plasma
Starch product (ie, Hetastarch, Hespan)
Donor-directed blood from a family member who is a practicing Jehovah's witness
Jehovah's witnesses beliefs regarding blood products stems from direct interpretation of passages from the bible. The use of crystalloid, starch products such as Hetastarch and colloids are accepted. Typically Jehovah's witnesses will accept most medical treatment but refrain from the use of blood products including whole blood, packed red cells, platelets, white cells, or plasma. Any autologous transfusion, whether from the patient themself or donor directed, is forbidden. The use of cell-saver type processes is a matter of individual choice by the patient. The use of hemoglobin-based oxygen carriers are now accepted by many patients but it is important to respect the wishes of each individual patient. It is very important to discuss preoperatively with the patient and family their wishes and thoughts on what is acceptable to use. Many facilities have adopted
bloodless-surgery protocols and committees that definitively outline the measures that can be used and take into consideration the many ethical issues involved in taking care of these patients.
In a diagnostic test, the proportion of individuals who are truly free of a designated disorder identified by the test is known as
specificity.
sensitivity.
accuracy.
positive predictive value.
negative predictive value.
Specificity refers to the proportion of individuals who are truly free of the designated disorder who are so identified by the test. Sensitivity refers to the proportion of individuals who truly have the disorder who are so identified by the test. Positive predictive value refers to the proportion of individuals with a positive test who have the disorder. Negative predictive value refers to the proportion of individuals with a negative test who are free of the disorder.
Accuracy is the overall ability to identify patients with the disorder (true positives) and without the disorder (true negatives) in the study population.
An orthopaedic surgeon in his first year of practice is negotiating with a private for-profit hospital to be their employed trauma specialist. The state of employment is known to have a high rate of malpractice claims because of a favorable plaintiff legal environment. During the course of negotiations, malpractice insurance is being discussed. The surgeon should ask the hospital to provide which type of malpractice insurance policy?
Claims made with "nose" coverage
Claims made without tail coverage
No policy because of employed status and sovereign immunity
Occurrence coverage
Occurrence coverage with "nose" coverage
An occurrence policy provides coverage for all claims made during employment irrespective of when it is filed (during or postemployment) and therefore is the best option. Claims made policy only covers suits for the time employed. A prepurchased "tail" is needed to provide coverage for cases that occurred during employment but filed postemployment. Nose coverage is applicable if the surgeon was previously employed and did not have tail coverage from previous employment, but this surgeon just emerged from training where it is not applicable. Claims made without tail coverage is unwise because the surgeon would be unprotected or have to purchase his own policy postemployment.
Only in certain situations does sovereign immunity exist, and generally not in a for-profit system. Occurrence coverage with nose coverage
is incorrect because it does not apply to this surgeon with no previous employment or claims policy lacking tail coverage.
Results of a study demonstrating no difference between treatments when a difference truly exists is an example of which of the following?
Statistical insignificance
Type I error
Type II error
Fragile p-values
Negative predictive value
A type II error (also known as a beta error) occurs when results demonstrate that two groups are similar when, in reality, they are different (with regard to the statistic being measured). Type I errors show that a difference exists when, in reality, no difference exists. A statistically insignificant result may lead an investigator to conclude that no difference exists between two groups; this may be correct (and therefore not a type II error). The concept of
`fragile` p-values is that small sample sizes may result in wide variability of p- values with only one change in a data point for a given group. This singular change could be a chance occurrence, but it still can affect the statistical significance of the outcomes analysis.
Fragility of p-values is limited by increasing sample sizes. Negative predictive value is the
proportion of patients with negative test results who are correctly diagnosed.
A patient with a transverse femur fracture undergoes statically locked antegrade intramedullary nailing. Postoperatively, the patient appears to have a rotational deformity of greater than 25 degrees. The surgeon informs the patient, who chooses to undergo corrective treatment with removal of distal interlocking screws, rotational correction, and relocking of the screws. The patient goes on to heal
but has persistent hip pain and a limp that does not improve completely after extensive rehabilitation. There is complete healing, no evidence of infection, no hardware issues, no ectopic bone, and rotational studies indicate less than 2 degrees of malrotation. Functional capacity testing reveals the affected abductor and quadriceps function to be about 85% of the uninjured side and the patient returns to work and most of his recreational activities except rock climbing. Two days before the statute of limitations, the patient
files a malpractice suit alleging negligence of surgery, loss of function, consortium, and pain and suffering due to the surgeon's efforts. What action should the surgeon and the defense team take?
Settle the case because the surgeon made an error that resulted in unnecessary surgery, and thus the case is indefensible.
Settle the case because they are likely to lose the case, and it would be cheaper to settle than to defend.
Defend the case alleging that there was no error, and no damages, and that the patient is malingering.
Defend the case because despite there being an error, the error was corrected and there were little or no damages compared with expected outcomes.
Contact the patient directly to discuss why he is suing and attempt an amicable resolution.
To establish negligence, certain criteria must be met. 1) A duty was owed by the surgeon (in this case, yes, a relationship was established). 2) The duty was breached, where the provider failed to meet the standard of care (there
was a technical error, but it was corrected). 3) The breach caused an injury. In this case, the patient had an outcome that was very acceptable, as
documented with outcome studies, for femur fractures. Also, the rotational error and locking distally would have had little impact on the hip, whereas antegrade nailing itself is expected to result in some objective impairment of the hip in some patients. 4) Damages were incurred as a result. In this case, the patient returned to work and could not rock climb which could be reasonably expected with a femur fracture in some patients, and cannot be causally linked to the corrective surgery. For all practical purposes, the patient had a very acceptable outcome. Thus, settling the case for an error would be rather permissive and the important issue is that the surgeon recognized the problem, addressed it, and fulfilled his or her postoperative responsibility. The case is very defendable, and thus it is unlikely to be lost. Defending the case and alleging no error is incorrect because there was an error. The surgeon should never function outside of his or her legal counsel once a suit is filed.
You design a research study in which you ask patients who have a nonunion of the tibia to fill out a questionnaire in which they report on a variety of medical conditions and social/behavioral practices. You compare these findings to a similar group who did not develop a nonunion in order to identify medical and/or social conditions that might be risk factors for the development of tibial nonunions. This would be an example of what type of study?
Case series
Meta-analysis
Case control study
Retrospective cohort study
Prospective cohort study
A case control series starts with the occurrence of a specific disease or observation, and then compares data on those individuals to a similar group without the disease (control group) in order to identify potential risk factors for the development of the disorder. A case series is an observational study in which an investigator follows a series of patients who received a specific treatment, recording the results and outcomes of that treatment. A meta- analysis is the combination of several separate studies that look at similar hypotheses in an effort to create a larger patient population for analysis. A cohort study looks for the incidence of a specific outcome in two groups (cohorts) of patients who are similar with the exception of a particular
research variable (risk factor).
Which gene or protein is the most specific marker of mature osteoblasts but is not expressed by immature, proliferating osteoblasts?
Osteocalcin
TGF-B
COLIIA1
cFOS
IL-1
Osteocalcin is the most specific marker of the osteoblast phenotype and is expressed only in mature osteoblasts. TGF-B is a growth factor involved in the differentiation of multiple cell lines. For bone, TGF-B plays a role in stem cell differentiation into mesenchymal stem cells along osteoblast pathways. COLIIA1 is the gene for Type II Collagen and is involved in chondrocyte differentiation. cFOS is involved in osteoclast differentiation. In regards to
bone metabolism, IL-1 stimualtes osteoclastic bone resorption.
A workers' compensation carrier for a local manufacturing company requests a second opinion on a 59-year-old man who sustained a crush injury to his foot and leg at work 6 months ago. His leg and foot were pinned between a forklift and a wall when an employee he was supervising lost control of the forklift. The employer
suspects that the injured worker is malingering because the treating physician released him to work, but he has not returned to work. Which of the following elements of your history will best help you determine that the injured worker does not want to return to work out of fear of a confrontation with the employee he was supervising?
Formality
Empathy
Yes-no questions
Taking copious notes
Sitting leaning back in a chair
Empathy during the interview demonstrates compassion and earns the patient's trust; which, in turn, enables the patient to discuss any agenda or concerns he or she may otherwise feel uncomfortable revealing. It is also important to engage the patient to establish a trusting relationship and thus understand all the factors impacting the patient. A formal attitude toward the patient makes it difficult to engage the patient to be "drawn in." An engaged patient is more comfortable, reliable, and thorough when providing a history. Closed-end, yes-no questions do not allow the patient to detail all of the subtle nuances of their condition and its effect on their life. Taking copious notes likewise prevents engagement of the patient and the distraction of taking
notes may cause the physician to miss an important detail. It is better to lean forward in a chair when interviewing a patient because this suggests the physician is genuinely interested, whereas leaning back in a chair suggests the physician is simply waiting for the patient to finish talking. Avoid interrupting the patient when talking.
When a Workers' Compensation patient recovers after an injury to a point that further restoration of function is no longer anticipated, he or she is said to have reached which of the following?
Functional capacity
Maximum medical improvement
Permanent disability
Impairment rating
Predesignation
This is the definition of maximum medical improvement (MMI). The patient has essentially reached the plateau of his improvement.
Functional capacity evaluations (FCE) are based upon a theoretical model of comparing job demands to worker capabilities. The results of FCEs are often used to determine musculoskeletal capacity to return to work.
Strong et al. reported on the use of FCE in the Workers' Compensation system, and note how these FCE results are required by employers to determine the level of return to work of their employees. They also mention that the reports are frequently perceived with a negative tone. The employees reported a wider range of restrictions in their varied life roles than did the FCE reports, which deal more narrowly with work roles.
Pransky et al. reported that although FCE's are relied upon for determination of ability to perform physical work, several scientific, legal, and practical concerns persist. They note that test criteria often do not accurately reflect real-life job requirements or performance, and subjective evaluation remains common. They conclude that more research into predictive linking of FCE outcomes with occupational outcomes is necessary to determine their role in the Workers' Compensation system.
Incorrect Answers:
1: A functional capacity evaluation (FCE) is set of tests, practices and observations that are combined to determine the ability of the evaluated to function in a variety of circumstances (most often employment) in an objective manner.
3: Permanent disability is any lasting disability that results in a reduced earning capacity after maximum medical improvement is reached; this implies that MMI must be reached before this is determined.
4: Impairment rating is an objective data point obtained by a physician reviewing the patient's overall condition during a functional capacity evaluation.
5: This is the process a patient uses to tell their employer they want a personal physician to treat them for a work injury.
A physician receives a summons that he is being sued. The first step should be to
call the patient and apologize.
notify the medical liability carrier.
contact an attorney with whom the physician is familiar with and have the attorney review the records.
be sure to discard any handwritten phone messages because they are not discoverable.
find a colleague with a similar subspecialty and have the colleague review the record before doing anything.
The most appropriate first step is to notify the medical liability carrier. The medical liability carrier will assign an attorney who is likely to be more appropriate. A review by a colleague may be requested by the defense attorney but that should be at their discretion. Patient apology is appropriate early on when and if you discover an error.
Records should be reviewed, but never altered.
Currently, what is the most common clinical study type in the orthopaedic literature?
Level 1 (prospective, randomized trial)
Level 2 (cohort trial)
Level 3 (retrospective case control)
Level 4 (retrospective case series)
Level 5 (expert opinion)
Although a recent push for prospective, randomized trials has been advocated by multiple orthopaedic journals, many studies published continue to be of Level 4 evidence (retrospective case series). Case series represented 64% of all studies reviewed by Freedman and associates in 2001 from the British and American volumes of Journal of Bone and Joint Surgery and from Clinical Orthopaedics and Related Research.
Obremskey and associates published that

Question 37:

Options:

a decreased density of nerve fibrils.
lymphocytes and macrophages infiltration.
parallel penetration of muscle fiber through scar tissue.
lengthening and narrowing of myotubes.

Correct Answer: parallel penetration of muscle fiber through scar tissue.

Explanation:

Question 38:

A 12-year-old girl has the painful foot deformity seen in Figure 79. You advise her that she has juvenile bunions. How do they differ from adult bunions?

Options:

Metatarsus primus varus
Large exostosis
Rigidity of the metatarsal phalangeal joint
Greater hallux valgus angle than in adult bunions
Prominent bursal thickening over the medial eminence

Correct Answer: Metatarsus primus varus

Explanation:

Question 39:

Options:

Extensor tendon ruptures at the wrist
Subluxation of the extensor mechanisms at the MCP joint
Caput ulnae syndrome
Posterior interosseous nerve palsy

Correct Answer: Posterior interosseous nerve palsy

Explanation:

Question 40:

Which of the following genetic disorders has an X-linked recessive inheritance pattern?

Options:

Gaucher disease
Prader-Willi Syndrome
Diastrophic Dysplasia
Hemophilia A
Hypophosphatemic rickets

Correct Answer: Diastrophic Dysplasia

Explanation:

Question 41:

Options:

10%
25%
50%
75%
Greater than 75%

Correct Answer: Greater than 75%

Explanation:

Question 42:

Options:

MRI.
a long leg cast.
fasciotomy of the anterior compartment.
open reduction and internal fixation.
patellar advancement.

Correct Answer: open reduction and internal fixation.

Explanation:

DISCUSSION: The patient has a displaced intra-articular tibial tuberosity fracture; therefore, the treatment of choice is open reduction and internal fixation. Periosteum is often interposed between the fracture fragments and prevents satisfactory closed reduction. Fortunately, most patients with this injury are close to skeletal maturity and therefore, growth arrest and recurvatum are unusual. Nondisplaced fractures can be treated with a cast, but displaced fractures are best treated with open reduction and internal fixation. Intra-articular fractures can disrupt the joint surface and are sometimes associated with a meniscal tear; therefore, arthroscopy may be needed at the time of open reduction and internal fixation.
REFERENCES: McKoy BE, Stanitski CL: Acute tibial tubercle avulsion fractures. Orthop Clin North Am 2003;34:397-403.
Zionts LE: Fractures around the knee in children. J Am Acad Orthop Surg 2002;10:345-355.

Question 43:

During C1-C2 transarticular screw fixation, screw misplacement is most likely to result in injury to the

Options:

spinal cord if the screw is angled too medial.
occiput-C1 joint if the screw is angled too cephalad.
occiput-C1 joint if the screw is angled too lateral.
vertebral artery if the screw is angled too cephalad.
vertebral artery if the screw is angled too caudally.

Correct Answer: vertebral artery if the screw is angled too caudally.

Explanation:

Question 44:

The thickest bone in the occiput is located

Options:

in no predictable pattern.
at the level of the foramen magnum.
at the level of the external occipital protuberance.
4 cm below the external occipital protuberance.
4 cm lateral to the external occipital protuberance.

Correct Answer: at the level of the external occipital protuberance.

Explanation:

Question 45:

Chemotherapy for this condition is

Options:

contraindicated when pathology is benign.
associated with a high risk for subsequent myelodysplastic syndrome.
provides dramatic survival benefits.
provides modest survival benefits.

Correct Answer: provides modest survival benefits.

Explanation:

DISCUSSION
This patient has a dedifferentiated liposarcoma within a preexisting atypical lipomatous tumor. The imaging demonstrates a large fatty mass with increased internal septations proximally (the atypical lipomatous tumor) and a solid enhancing mass distally (the dedifferentiated portion). A biopsy reveals a high-grade liposarcoma. The other diagnostic responses do not reflect sarcomatous transformation of the lesion.
Surgical treatment of a high-grade sarcoma involves wide surgical resection. Radiation decreases local recurrence but does not clearly influence overall survival. The role of chemotherapy in high-grade soft-tissue sarcomas remains investigational; there is a modest (8%-15%) associated improvement in overall survival.
Intramuscular lipomas and atypical lipomatous tumors are treated with marginal resection alone. Radiation therapy for soft-tissue sarcomas may be given before or after surgery. When administered before surgery, patients have a higher wound complication rate but better long-term function attributable to lower rates of lymphedema, fibrosis, and contractures.
RECOMMENDED READINGS
Schlieman M, Smith R, Kraybill WG. Adjuvant therapy for extremity sarcomas. Curr Treat Options Oncol. 2006 Nov;7(6):456-63. Review. PubMed PMID: 17032558.
View Abstract at PubMed
Yang JC, Chang AE, Baker AR, Sindelar WF, Danforth DN, Topalian SL, DeLaney T, Glatstein E, Steinberg SM, Merino MJ, Rosenberg SA. Randomized prospective study of the benefit of adjuvant radiation therapy in the treatment of soft tissue sarcomas of the extremity. J Clin Oncol. 1998 Jan;16(1):197-203. PubMed PMID: 9440743.
View Abstract at PubMed
Soft tissue tumors. In: Damron TA, ed.
Orthopaedic Surgery Essentials: Oncology and Basic Science
. Philadelphia, PA: Lippincott Williams and Wilkins; 2008:87-92

Question 46:

- A 25-yo man sustains the injury shown in Figures 29a and 29b as a result of high-speed trauma. Examination reveals diffuse weakness in the lower extremities that is slightly worse on the right side, and decreased rectal tone and sensation. A CT scan is shown in figures 29c and 29d. Definitive treatment of the injury to the spine is delayed because of a severe pulmonary contusion. At 15 days after the injury, the patient’s neurological status remains unchanged. Management should now consist of

Options:

Posterior fusion at T10-L3 with segmental instrumentation
Laminectomy and fusion of T12-L2 with segmental instrumentation
Bed rest in a hyperextension brace
L1 vertebrectomy and anterior decompression with strut graft fusion and instrumentation
Progressive ambulation as tolerated in a custom-molded thoracolumbosacral orthosis

Correct Answer: L1 vertebrectomy and anterior decompression with strut graft fusion and instrumentation

Explanation:

Question 47:

- What is the usual mechanism of injury for the fracture shown in Figures 49a and 49b?

Options:

bending
axial loading
high-speed rotation
direct impact from anteromedial
crush from anteromedial to posterolateral

Correct Answer: axial loading

Explanation:

Question 48:

Options:

observation.
a proximal tibial and fibular osteotomy.
daytime ambulatory bracing.
elevation of the medial tibial plateau.
an MRI scan of the knee.

Correct Answer: daytime ambulatory bracing.

Explanation:

Question 49:

Options:

Remove fixation and repeat vascular exam
Add a medial pin, remove two of the lateral pins and repeat vascular exam
Maintain hardware position, apply a soft dressing and observe
Maintain hardware position, apply long arm immobilization and observe
Surgically explore the antecubital fossa

Correct Answer: Remove fixation and repeat vascular exam

Explanation:

Question 50:

The comparative outcomes of needle aponeurotomy (NA) and collagenase Clostridium histolyticum (CCH) use in the treatment of Dupuytren contracture indicate that patients treated with CCH have

Options:

greater direct costs.
better range of motion at 2 years.
a higher reintervention rate at 5 years.
better metacarpophalangeal (MCP) contracture correction at 12 months. NA and CCH are the treatment options for Dupuytren contracture. The treatments of MCP contractures with NA and CCH were compared in two randomized trials that showed equivalent outcomes at 12 months, based on correction and Unité Rhumatologique des Affections de Main (URAM) scores. A recent retrospective study showed reintervention rates at 2 years of 24% for NA and 41% for CCH. At 5 years, the rates were 61% for NA and 55% for CCH. Standardized direct costs for NA and CCH were $624 and $4,189, respectively. Including all reinterventions, the cumulative costs per digit at 5 years after NA and CCH were $1,540 and $5,952, respectively. A 2-year follow-up by Strömberg showed no difference in range of motion or patient- reported outcomes.

Correct Answer: greater direct costs.

Explanation:

Question 51:

-What is the most appropriate initial treatment for her condition?

Options:

Complete rest and a slow return to sports
Physical therapy
Corticosteroid injection
Arthroscopic surgery PREFERRED RESPONSE: 2 Question 75-After 1 year of following recommended treatment, this patient continues to experience her symptoms and has had to cease all sports activity. An MRI scan reveals no evidence of definitive labral or rotator cuff pathology. At this stage, what is the most appropriate treatment option?
Arthroscopic rotator cuff repair
Arthroscopic biceps tenodesis
Arthroscopic capsular plication
Arthroscopic superior labral anterior-posterior repair

Correct Answer: Corticosteroid injection

Explanation:

DISCUSSION FOR QUESTIONS 73 THROUGH 75
This patient has a history most consistent with multidirectional instability. A lax capsule causes subluxation of the shoulder and strain on the rotator cuff and may result in pain and instability. The capsule is most closely associated with the cause of her problem. Initial treatment for multidirectional instability is physical therapy focusing on restoring balance to the shoulder with rotator cuff and scapular stabilization exercises. Nonsurgical therapy should be protracted and is the mainstay of treatment in this scenario. This patient has exhausted all nonsurgical measures and is now a candidate for surgical reconstruction. Capsular plication will best address the lax capsule and provide the best option for reducing her symptoms. The rotator cuff and biceps tendon may be secondarily strained but are not the primary sources of the problem. The brachial plexus does not address the etiology, but rather the symptoms that may occur as a result of instability of the shoulder joint.
Complete rest will not alleviate the patient's underlying condition because the shoulder girdle may still be weak and symptoms likely will return. A corticosteroid injection and arthroscopic surgery are too invasive as initial treatment for this condition. Arthroscopic rotator cuff repair, a biceps tenodesis, and superior labral anterior-posterior repair are unlikely to result in symptomatic improvement for this patient and are not associated with pathologic findings in the setting of multidirectional instability.

Question 52:

Options:

Arthroscopic Bankart repair
MRI for possible rotator cuff tear
Physical therapy
Sling immobilization for an additional 2 weeks
Cortisone injection

Correct Answer: Sling immobilization for an additional 2 weeks

Explanation:

Question 53:

Options:

increased laxity.
increased risk for graft failure.
no differences in long-term results.
lower Knee Injury and Osteoarthritis Outcome Scores (KOOS).

Correct Answer: no differences in long-term results.

Explanation:

Question 54:

Options:

suppressive antibiotics.
open irrigation and debridement with polyethylene exchange.
one-stage resection arthroplasty and reimplantation.
two-stage resection arthroplasty and reimplantation.
arthroscopic irrigation and debridement.

Correct Answer: two-stage resection arthroplasty and reimplantation.

Explanation:

Question 55:

Options:

Scapular dyskenisia
Quadrilateral space syndrome
Subacromial impingement syndrome
Suprascapular nerve compression by a spinoglenoid notch
Suprascapular nerve compression at the suprascapular notch

Correct Answer: Quadrilateral space syndrome

Explanation:

Question 56:

Which of the following procedures is not part of the routine evaluation of a patient with suspected metastatic disease to bone?

Options:

Thorough history and physical examination
CBC count, electrolytes, and serum protein electrophoresis
Bone scan
CT of the brain
Radiograph and CT of the chest

Correct Answer: CT of the brain

Explanation:

Question 57:

Options:

Application of a pelvic binder
Application of skeletal traction
Open reduction and internal fixation
Placement of percutaneous iliosacral screws
Placement of an anterior pelvic external fixator

Correct Answer: Open reduction and internal fixation

Explanation:

The patient has a displaced iliac wing and bilateral rami fractures with superior migration of the right hip. To prevent further deformity, the patient's right hip should be placed into skeletal traction. A pelvic binder may worsen the deformity because of the iliac wing fracture. Anterior external fixation is problematic with an iliac wing fracture. Although the patient will eventually require open reduction and internal fixation and/or placement of iliosacral screws, she must be stabilized and resuscitated prior to this treatment.
(SBQ12TR.80) A 37-year-old male arrives to the trauma slot following a high-speed motorcycle crash. His Glasgow Coma score is 14 and his only orthopaedic injury is exhibited in Figure A. His current vital signs are a BP of 90/60, HR 120, and a lactate of 2.5 mMol/L. Other findings include a grade 1 splenic laceration and bilateral pulmonary contusions seen on chest radiograph. Which of the following has been suggested as an indication to perform damage control orthopedic care?
1 HR >110
Bilateral pulmonary contusions seen on chest radiograph
SBP = 90mmHg
Unilateral femur fracture
Lactate = 2.5 mMol/L
Pulmonary contusion severe enough to be diagnosed on chest radiograph alone is an indicator that the patient may benefit from damage control orthopaedics (DCO).
Despite the patient's overall stable nature, suffering pulmonary injury severe enough to be seen on x-ray alone suggests that temporary stabilization with staged definitive fixation may avoid potential morbidity.
Pape et al. review the evolution and balance of early total care (ETC) and DCO. Summarizing the literature, the authors report several standalone indicators that would justify DCO regardless of stable status. This includes: Injury Severity Score of greater than 40, Injury Severity Score of greater than 20 with chest trauma, multiple injuries with severe pelvic/abdominal trauma/ hemorrhagic shock, bilateral femoral fractures, pulmonary contusion noted on radiographs alone, hypothermia of less than 35 degrees C), and a head injury with an Abbreviated Injury Score of 3 or greater.
Figure A exhibits a right femoral shaft fracture. Illustration A exhibits a summarized table stating the criterion used to determine the condition of a polytrauma patient. (Table from Pape et al, PMID: 19726738)
Incorrect answers:

Question 58:

Which of the following best describes the course of the median nerve at the elbow?

Options:

Crosses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, deep to the superficial head of the pronator teres muscle
Crosses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, superficial to the superficial head of the pronator teres muscle
Crosses deep to the ulnar artery, deep to the fibrous arch of the superficialis muscle, deep to the superficial head of the pronator teres muscle
Crosses deep to the ulnar artery, deep to the fibrous arch of the superficialis muscle, superficial to the superficial head of the pronator teres muscle
Crosses deep to the ulnar artery, superficial to the fibrous arch of the superficialis muscle, superficial to the superficial head of the pronator teres muscle

Correct Answer: Crosses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, deep to the superficial head of the pronator teres muscle

Explanation:

Question 59:

Options:

Chronic periprosthetic infection
Trochanteric bursitis
Pseudotumor related to corrosion at the head/neck taper junction
Tendonitis from iliopsoas tendon impingement

Correct Answer: Pseudotumor related to corrosion at the head/neck taper junction

Explanation:

DISCUSSION
This patient presents with a pseudotumor likely attributable to local tissue reaction resulting from either articular metal wear debris and/or corrosion and fretting of the trunnion. The trunnion is a more likely source of the problem for a number of reasons: good position of metal articulation, increased trunnion corrosion and fretting associated with large-head THA, and markedly increased cobalt levels compared to chromium levels. Infection is very unlikely
in the setting of normal ESR and CRP findings. MR imaging findings are consistent with pseudotumor and not iliopsoas tendonitis or trochanteric bursitis.
CLINICAL SITUATION FOR QUESTIONS 42 THROUGH 45
Figures 42a through 42e are the radiographs, MR image, and MR arthrogram of a 25-year-old collegiate soccer player who has new-onset left groin pain. He played competitive soccer from a young age and has either competed or practiced 5 to 6 times per week since the age of

Question 60:

A 17-year-old boy has had elbow pain for the past 6 weeks. A radiograph, MRI scans, and biopsy specimens are shown in Figures 65a through 65e. What is the most likely diagnosis?

Options:

Osteoid osteoma
Osteoblastoma
Osteosarcoma
Chondroblastoma
Giant cell tumor

Correct Answer: Osteoblastoma

Explanation:

DISCUSSION: The findings are consistent with an osteoblastoma. The radiographs show a bone-forming lesion of the distal humerus. The lesion has an osseous component extending out of the native cortex with a thin sclerotic border. The T
2
-weighted MRI scan shows the lesion extending anteriorly beyond the native cortex. No fluid-fluid levels are seen. Histology shows large osteoblasts producing osteoid and woven bone. The tissue between the spicules of bone and osteoid contains thin fibrous tissue and capillaries. Osteoid osteoma is a smaller lesion usually with sclerotic reactive bone around a small nidus. The histology differentiates osteoblastoma from osteosarcoma because no malignant cells are seen. There is no cartilage production or chondroblasts in the histologic specimen, eliminating chondroblastoma. Giant cell tumors of bone typically occur in a epiphyseal metaphyseal location, most commonly after skeletal maturity, and contain numerus giant cells.
REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 87-102.
Campanacci M: Bone and Soft Tissue Tumors, ed 2.
New York, NY, Springer-Verlag, 1999,
pp 415-433.

Question 61:

Figure 69 is the radiograph of a 9-year-old who has posterior hindfoot pain while running. What is the most likely diagnosis?

Options:

Kohler disease
Thiemann disease
Freiberg infraction
Sever disease

Correct Answer: Sever disease

Explanation:

Question 62:

Which of the following is the most sensitive parameter to detect the increased inflammatory response seen with both postoperative infection and the use of instrumentation in spinal surgery?

Options:

Patient temperature
WBC count
Erythrocyte sedimentation rate
C-reactive protein
Rheumatoid Factor

Correct Answer: Patient temperature

Explanation:

CORRECT
DISCUSSION: The most sensitive parameter to detect inflammation elicited by implants and infection is the C-reactive protein (CRP).
CRP is an acute phase reactant that increases sharply immediately after surgery within 6 hours after tissue damage. CRP then peaks 2-3 days later and returns to normal levels 5-21 days after the inciting event. In contrast, ESR reaches its peak on days 4-11, then remains elevated for a prolonged period of time.
Takahashi et al performed a Level 3 study of patients who had undergone spinal surgery with and without instrumentation, with a primary outcome of infection. They concluded that renewed elevation of C-reactive protein, white blood cell count, and body temperature after postoperative days 4 to 7 may be a key indicator of postoperative infection.

Question 63:

Options:

rate of less than 50%, primarily the result of infection.
rate of greater than 50%.
lower rate in patients in which metallosis was identified.
similar rate with or without preoperative osteolysis.
similar rate regardless of the degree of wear.

Correct Answer: similar rate with or without preoperative osteolysis.

Explanation:

Question 64:

Options:

observation with repeat radiographs in 6 months.
a thoracolumbosacral orthosis (TLSO).
in situ posterior spinal fusion without instrumentation, followed by full-time TLSO bracing.
anterior spinal convex hemiepiphysiodesis.
combined anterior and posterior spinal arthrodesis with instrumentation.

Correct Answer: combined anterior and posterior spinal arthrodesis with instrumentation.

Explanation:

Question 65:

Options:

removal of all hardware.
temporary placement of antibiotic beads.
wound closure over drains.
bedside dressing changes.
a RAST test for latex allergy.

Correct Answer: wound closure over drains.

Explanation:

Question 66:

Which of the following best describes the pathologic anatomy of cam impingement of the hip? Review Topic

Options:

Retroversion of the acetabulum
Posteroinferior labral tears
Morphologic abnormality of the femoral head
Femoral anteversion
Femoral head osteonecrosis

Correct Answer: Morphologic abnormality of the femoral head

Explanation:

Question 67:

Thyroid hormone regulates skeletal growth at the physis by stimulation of

Options:

proteoglycan and aggrecan synthesis in the zone of proliferation.
fibroblast growth factor (FGF) activity.
transforming growth factor type beta (TGF- b =) and parathyroid hormone-related protein (PTHrP) activity.
chondrocyte proliferation.
chondrocyte hypertrophy, type X collagen synthesis, and alkaline phosphatase activity.

Correct Answer: chondrocyte hypertrophy, type X collagen synthesis, and alkaline phosphatase activity.

Explanation:

DISCUSSION: Children with hypothyroidism have delayed bone age, reduced thickness of the physis, disorganization of the cartilage columns of the physis, and impaired differentiation of proliferating chondrocytes into hypertrophic cells. As a result, these children have severe growth retardation, and slipped capital femoral epiphysis may develop because of mechanical weakening of the physis. Thyroid hormone regulates terminal differentiation of the growth plate chondrocytes, with a resultant increase in type X collagen and alkaline phosphatase. These substances are important factors in matrix mineralization. Insulin-like growth factors and FGF-2 appear to act synergistically to stimulate mitotic activity of the growth plate chondrocytes. TGF-
b
= and PTHrP stimulate proteoglycan synthesis and mitotic activity of the chondrocytes and inhibit type X collagen and alkaline phosphatase activity.
REFERENCES: Ballock RT: Regulation of skeletal growth and maturation by thyroid hormone, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 301-317.
Rosier RN, O’Keefe RJ, Reynolds PR, Hicks DG, Puzas JE: Expression and function of TGF-
b
= and PTHrP in the growth plate, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 285-299.
Trippel SB: IGF-I and FGF-2 in growth plate regulation, in Buckwalter JA, Ehrlich MG, Sandell LJ, Trippel SB (eds): Skeletal Growth and Development: Clinical Issues and Basic Science Advances. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1998, pp 263-283.

Question 68:

Options:

glucosamine 1,500 mg/day and chondroitin sulfate 800 mg/day.
weight loss through dietary management and low-impact aerobic exercises.
arthroscopic debridement and lavage.
a valgus-directing brace.

Correct Answer: weight loss through dietary management and low-impact aerobic exercises.

Explanation:

Question 69:

Options:

Cemented left total hip arthroplasty (THA)
Cementless left THA with a proximally porous coated femoral stem
Hybrid left THA
Cementless left THA with a diaphyseal engaging conical femoral stem

Correct Answer: Hybrid left THA

Explanation:

Question 70:

Figure 39 shows the radiograph of a 4-month old infant who has been undergoing weekly casting since birth for a congenital equinovarus deformity. Management should now consist of

Options:

surgical correction.
continued casting.
botulinum toxin injection into the gastrocnemius-soleus complex.
an ankle-foot orthosis.
observation with no further treatment.

Correct Answer: surgical correction.

Explanation:

DISCUSSION: The radiograph shows the development of a rocker-bottom foot deformity. A rocker-bottom foot occurs in the treatment of clubfoot when casting is continued in the presence of a very tight gastrocnemius-soleus complex and an uncorrected hindfoot. While there are some preliminary reports on using Botox injection and continued casting for the equinus deformity, most authors recommend posterior or posterior medial release. Percutaneous tenotomy has been recently recommended with the resurgence of the Ponsetti technique.
REFERENCES: Lehman WB, Atar D: Complications in the management of talipes equinovarus, in Drennan JC (ed): The Child’s Foot and Ankle. New York, NY, Raven Press, 1992,
pp 135-136.
Herring JA: Tachdjian’s Pediatric Orthopedics, ed 4. Philadelphia, PA, WB Saunders, 2002,
pp 927-935.
Tachdjian MO: Pediatric Orthopedics, ed 2. Philadelphia, PA, WB Saunders, 1990,
pp 2461-2564.

Question 71:

A complication unique to computer navigation of total knee arthroplasty (TKA) is

Options:

femoral shaft fracture.
intercondylar femur fracture.
ligament disruption.
nerve palsy.

Correct Answer: femoral shaft fracture.

Explanation:

DISCUSSION
Threaded pins are frequently inserted into the femoral shaft and tibial shafts or proximal tibia to attach arrays for tracking devices. There have been case reports of fractures propagating through the pin tracks, which is a complication unique to computer navigation. Intercondylar fractures can occur following posterior stabilized TKA. Vascular injury, ligament disruption, and nerve palsy are rare complications following TKA performed with or without computer navigation.
CLINICAL SITUATION FOR QUESTIONS 111 THROUGH 113
Figure 111 is the anteroposterior radiograph of a 79-year-old woman with a presurgical diagnosis of osteonecrosis who sustained a periprosthetic tibia fracture following her total knee arthroplasty (TKA).

Question 72:

Options:

Selective nerve root blocks
Electromyography and a nerve conduction velocity study of the lower extremities
Ankle-brachial index (ABI)
Bilateral hip radiographs
Post-myelography CT scan

Correct Answer: Ankle-brachial index (ABI)

Explanation:

Question 73:

Options:

Avulsion of the lateral collateral ligament
Avulsion of the pes anserinus
Avulsion of the iliotibial band
Tear of the anterior cruciate ligament
Tear of the posterior cruciate ligament

Correct Answer: Tear of the anterior cruciate ligament

Explanation:

Question 74:

-Use of the shorter, anterior screw may result in

Options:

deformity of the acetabular labrum when the hip is flexed.
injury to the femoral artery.
chondrolysis.
lack of stabilization of the epiphysis.

Correct Answer: deformity of the acetabular labrum when the hip is flexed.

Question 75:

It is recommended that invasive dental work be completed prior to the initiation of which of the following medications?

Options:

Glucosamine
Cholecalciferol
Levothyroxine
Teriparatide
Bisphosphonates

Correct Answer: Glucosamine

Explanation:

Question 76:

What is the most common mechanism of injury that produces turf toe?

Options:

Valgus stress at the first metatarsophalangeal (MTP) joint
Hyperflexion stress
Hyperextension stress
Varus stress
Axial load

Correct Answer: Hyperextension stress

Explanation:

Question 77:

Options:

Oral corticosteroid medication and changes in job activities
Soft-tissue interposition arthroplasty
Arthroscopic capsular release, loose body removal, and osteophyte decompression
Radial head arthroplasty
Total elbow arthroplasty

Correct Answer: Arthroscopic capsular release, loose body removal, and osteophyte decompression

Explanation:

Question 78:

Options:

0 to 15 degrees
20 to 30 degrees
40 to 90 degrees
100 to 120 degrees
130 to 140 degrees

Correct Answer: 40 to 90 degrees

Explanation:

Question 79:

Options:

oral antibiotics and a follow-up office appointment the next day.
incision and drainage of the distal fibular metaphysis.
indium-labeled WBC scan.
antituberculous medication for 6 months.
three-phase technetium Tc 99m bone scan.

Correct Answer: incision and drainage of the distal fibular metaphysis.

Explanation:

DISCUSSION: The initial signs and symptoms of acute hematogenous osteomyelitis vary widely but usually include fever, bone pain, and impaired use of the involved extremity. In lower extremity infections, the child may limp or refuse to walk. Examination often reveals bone tenderness. In more advanced cases, erythema, warmth, and swelling may be present. The WBC and neutrophil counts are not always elevated, but the erythocyte sedimentation rate will be abnormal in more than 90% of patients. When the infection is diagnosed early, before a subperiosteal abscess has formed, antibiotics alone may be adequate to treat the infection. This patient has a more advanced infection, however, with the MRI scan revealing a subperiosteal abscess that was confirmed by aspiration. When an abscess is present, surgical drainage is generally indicated to remove devitalized tissue and to enhance the efficacy of the antibiotics. Further studies, such as bone or indium scans, are not necessary and will delay
definitive treatment.
REFERENCES: Scott RJ, Christofersen MR, Robertson WW Jr, et al: Acute osteomyelitis in children: A review of 116 cases. J Pediatr Orthop 1990;10:649-652.
Vaughan PA, Newman NM, Rosman MA: Acute hematogenous osteomyelitis. J Pediatr Orthop 1987;7:652-655.

Question 80:

Options:

Posterior wall/ posterior column
Transverse
T-Type
Anterior column/ posterior hemitransverse
Both columns

Correct Answer: Posterior wall/ posterior column

Explanation:

Question 81:

The patient undergoes a mobile-bearing UKA. When compared to a fixed-bearing metal-backed unicompartmental arthroplasty, this procedure is associated with a

Options:

higher risk for failure attributable to wear.
higher risk for failure attributable to bearing spinout.
lower risk for loosening.
lower risk for arthritic progression of the lateral compartment.

Correct Answer: higher risk for failure attributable to bearing spinout.

Explanation:

Question 82:

Figures 48a through 48c show the lateral radiograph and MRI scans of a 60-year-old man who has had pain in his thigh for 1 month. The next most appropriate step in management should consist of

Options:

insertion of a locked intramedullary nail.
a bone scan, a radiograph of the chest, and CT of the chest, abdomen, and pelvis.
compression plating.
upper and lower gastrointestinal (GI) studies.
radiation therapy.

Correct Answer: a bone scan, a radiograph of the chest, and CT of the chest, abdomen, and pelvis.

Explanation:

Question 83:

Options:

observation.
bilateral adductor and iliopsoas releases, with nighttime abduction bracing.
proximal femoral varus osteotomy with internal fixation.
proximal femoral varus osteotomy with volume-reducing periacetabular osteotomy.
proximal femoral varus osteotomy with shelf acetabular augmentation.

Correct Answer: observation.

Explanation:

DISCUSSION: Observation is the treatment of choice. Hip subluxation and dislocation are not uncommon in patients with SMA type II who are unlikely to be ambulatory. Scoliosis occurs in these patients 100% of the time and frequently creates pelvic obliquity. However, in long-term follow-up, patients with SMA type II and hip dislocations had little associated pain or functional limitations because of hip instability. In addition, recurrent hip subluxation after surgical treatment has been documented. Given the rarity of symptoms from hip instability in long-term follow-up, and the possibility of recurrent dislocation, surgical intervention for hip instability may expose SMA type II patients to undue surgical risk for minimal if any functional gain.
REFERENCES: Sporer SM, Smith BG: Hip dislocation in patients with spinal muscular atrophy. J Pediatr Orthop 2003;23:10-14.
Thompson CE, Larsen LJ: Recurrent hip dislocation in intermediate spinal atrophy.
J Pediatr Orthop 1990;10:638-641.

Question 84:

Options:

Type I error
Type II error
Selection bias
Recall bias This study represents a randomized clinical trial with two groups. However, the sample size is small, increasing the risk for type II error, or false-negative findings. Increasing the number of patients in each group would lead to increased power, thereby reducing the risk of a type II error. A type I error is the rejection of a true null hypothesis (false-positive). A randomized trial reduces the risk of selection bias as patients are assigned to groups in a random fashion. Recall bias occurs when participants do not accurately remember previous events or experiences from the past.

Correct Answer: Type II error

Explanation:

Question 85:

Options:

Semimembranosis tendonitis
Patellar tendonitis
Iliotibial band friction syndrome
Quadriceps tendonitis

Correct Answer: Patellar tendonitis

Explanation:

Question 86:

Options:

Synovial sarcoma
Adamantinoma - metastatic prostate cancer
Chondrosarcoma
Dedifferentiated chondrosarcoma
Periosteal osteosarcoma

Correct Answer: Dedifferentiated chondrosarcoma

Explanation:

DISCUSSION: The biopsy specimens reveal a high-grade spindle cell lesion adjacent to an area of benign cartilage. This is consistent with a dedifferentiated chondrosarcoma. The radiograph shows a pathologic fracture through a lesion characterized by calcification within the left greater trochanter. Distal to the area of calcification, there is a more osteolytic, destructive appearance. Synovial sarcoma has a biphasic appearance histologically with areas of glandular differentiation that stain positive with keratin. Metastatic prostate cancer, although osteoblastic in appearance, would have a glandular histologic appearance. There is no cartilage in these lesions. Classic low-grade chondrosarcoma does not have an area of high-grade pleomorphic spindle cells within the lesion. A periosteal osteosarcoma is a surface-based lesion with a sunburst radiographic pattern. Although there may be cartilage in the lesion histologically, there are also malignant cells producing osteoid. Dedifferentiated chondrosarcoma is an aggressive, high-grade variant of chondrosarcoma.
REFERENCES: Wold LE, Adler CP, Sim FH, et al: Atlas of Orthopedic Pathology, ed 2. Philadelphia, PA, WB Saunders, 2003, p 269.
Mercuri M, Picci P, Campanacci L, et al: Dedifferentiated chondrosarcoma. Skeletal Radiol 1995;24:409-416.

Question 87:

Options:

Closed reduction and cast immobilization for 4 weeks, followed by therapy directed at regaining motion
Open reduction and internal fixation of the olecranon fracture, functional bracing of the humeral fracture, and therapy directed at regaining motion initiated at 2 weeks after surgery
Open reduction and internal fixation of the olecranon and humeral fractures, followed by therapy directed at regaining motion
Open reduction and internal fixation of the olecranon and humeral fractures, and splint immobilization for 4 weeks followed by therapy directed at regaining motion
Open reduction and internal fixation of the olecranon fracture, functional bracing of the humeral fracture, and therapy directed at regaining motion initiated at 4 weeks after surgery

Correct Answer: Open reduction and internal fixation of the olecranon and humeral fractures, followed by therapy directed at regaining motion

Explanation:

DISCUSSION: The floating elbow is best managed with early open reduction and internal fixation of the humeral and forearm fractures, followed by early range of motion. These fractures predispose the elbow to stiffness, and early range of motion is recommended.
REFERENCES: Solomon HB, Zadnik M, Eglseder WA: A review of outcomes in 18 patients with floating elbow. J Orthop Trauma 2003;17:563-570.
Yokoyama K, Itoman M, Kobayashi A, et al: Functional outcomes of “floating elbow” injuries in adult patients. J Orthop Trauma 1998;12:284-290.

Question 88:

Options:

prone.
lateral.
supine.
sloppy latera

Correct Answer: supine.

Explanation:

Question 89:

Options:

5 mm
10 mm
15 mm
20 mm
25 mm

Correct Answer: 20 mm

Explanation:

Question 90:

The most appropriate next surgical procedure is

Options:

synovectomy.
debridement, synovectomy, and placement of a thicker polyethylene liner.
resection arthroplasty and placement of a cement antibiotic spacer.
conversion to total knee arthroplasty (TKA).

Correct Answer: conversion to total knee arthroplasty (TKA).

Explanation:

Question 91:

The cavovarus deformity associated with Charcot-Marie-Tooth (CMT) disease is caused by which of the following?

Options:

Streptococcal disease during infancy
Viral infection of the motor nerves
Sex-linked selective motor imbalance
Autosomal-dominant myelin sheath disease
Germ cell defect leading to asymmetrical growth disturbance

Correct Answer: Autosomal-dominant myelin sheath disease

Explanation:

DISCUSSION: The most common inherited neuromuscular disease seen by orthopaedic surgeons is CMT, which is an inherited autosomal-dominant disease. It is more commonly seen in men due to the nature of the inheritance. Identification of cavus deformity in the foot of a child should arouse suspicion.
REFERENCES: Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 135-143.
Charcot-Marie-Tooth Disease (CMT) Penn State Hershey Medical Center.
www.hmc.psu.edu/healthinfo/c/cmt.htm

Question 92:

Options:

Arthroscopic Bankart surgery
Bony glenoid augmentation procedure
Subscapularis advancement
Open capsular shift
Hemiarthroplasty

Correct Answer: Bony glenoid augmentation procedure

Explanation:

Question 93:

Options:

Deltoid
Supraspinatus
Subscapularis Infraspinatus
Infraspinatus
Infraspinatus and teres minor

Correct Answer: Infraspinatus

Explanation:

Question 94:

In a patient with a major head injury and a femoral shaft fracture, intraoperative hypotension during femoral fixation has been associated with which of the following?

Options:

Increased time needed for rehabilitation
Increased pneumonia rate
Increased intensive care unit length of stay
Decreased discharge Glascow Coma Scale
Decreased hospital length of stay

Correct Answer: Increased time needed for rehabilitation

Explanation:

Question 95:

Options:

Renal ultrasound
Blood cultures
Flexion-extension cervical spine radiographs
Platelet count

Correct Answer: Renal ultrasound

Explanation:

Question 96:

Which of the following is an advantage of computer-assisted navigation used to place medullary nail interlocking screws compared to a freehand techinque?

Options:

Reduced fluoroscopy time
More reliable placement of interlocking screws through the nail
Reduced procedure time
Increased quality of fluoroscopic images
Improved accuracy of screw length

Correct Answer: Reduced fluoroscopy time

Explanation:

Question 97:

A 50-year-old woman with a 2-part surgical neck proximal humerus fracture and metaphyseal comminution

Options:

Initial period of sling immobilization followed by physical therapy
Open reduction and internal fixation with or without bone grafting
Reverse total shoulder arthroplasty (rTSA)
Hemiarthroplasty
Unconstrained (TSA)
Closed reduction and Kirschner wire (K-wire) stabilization

Correct Answer: Open reduction and internal fixation with or without bone grafting

Explanation:

DISCUSSION
Proximal humerus fractures account for approximately 5% of all fractures, with incidence increasing to reflect an aging population and related osteoporosis. Treatment is dependent upon the mechanism of injury, the patient’s physiologic age and activity level, the fracture pattern, and rotator cuff integrity. Most of these injuries are nondisplaced or minimally displaced and are associated with a good overall prognosis with nonsurgical treatment and temporary impairment. A patient with a nondisplaced surgical neck fracture should be treated without surgery. K-wire stabilization, although technically difficult to achieve, is an option for compliant patients with 2-part, 3-part, and valgus-impacted 4-part fractures who have adequate bone stock. Valgus-impacted 4-part fractures pose reduced risk for osteonecrosis because of the preserved blood supply through the medial hinge, which allows for this technique. For displaced 2-part fractures accompanied by
metaphyseal comminution, K-wire fixation cannot provide adequate stability to initiate a graduated home exercise or outpatient physical therapy program. Formal open reduction with intramedullary or plate fixation in addition to bone grafting (fibular strut allograft) is the best surgical option for the clinical scenario involving a displaced surgical neck fracture with comminution. Osteosynthesis of 3-part fractures may be feasible for physiologically young and active patients without humeral head involvement and osteoporosis.
Current indications for primary hemiarthroplasty include most 4-part fractures, 3-part fractures and dislocations in elderly patients with osteoporotic bone, head-splitting articular segment fractures, and chronic anterior or posterior humeral head dislocations with more than 40% of articular surface involvement. Because of the intra-articular nature of this patient’s 4-part injury in this scenario, hemiarthroplasty with anatomic reconstruction of the greater and lesser tuberosities is most appropriate. Relative indications for hemiarthroplasty also include fractures with more than 20 degrees of varus, associated moderate to severe osteopenia, and revision surgery for failed osteosynthesis. Currently accepted indications for rTSA include scenarios in which the fracture pattern, level of comminution, bone quality, and rotator cuff deficiency preclude plate fixation or hemiarthroplasty. Scenarios involving 4-part fractures and associated rotator cuff tears and tuberosity comminution are best served with a reverse shoulder prosthesis. One of the positive attributes of this implant is the ability to achieve functional forward flexion and abduction regardless of tuberosity healing, position, and degree of comminution. Caution is warranted with this surgical technique because complication rates are higher than for hemiarthroplasty reconstruction. Acute, irreducible 2-part fracture-dislocations of the proximal humerus necessitate open reduction and internal fixation of the affected tuberosities (posterior, lesser tuberosity; anterior, greater tuberosity) through screw, anchor, and/or suture fixation. These fracture-dislocations can be managed with this technique because of the integrity of the vascular supply, which is maintained by the soft-tissue attachments to the intact tuberosities. Repeated attempts at a closed reduction in the 37-year-old with the posterior fracture-dislocation could result in neurovascular injury and myositis ossificans and should be avoided. Arthroplasty reconstruction in this scenario should not be the index procedure in light of concerns regarding implant survivorship in patients of this age and their assumed elevated activity levels.
RECOMMENDED READINGS
Harrison AK, Gruson KI, Zmistowski B, Keener J, Galatz L, Williams G, Parsons BO, Flatow EL. Intermediate outcomes following percutaneous fixation of proximal humeral fractures. J Bone Joint Surg Am. 2012 Jul 3;94(13):1223-8. doi: 10.2106/JBJS.J.01371.
View Abstract at PubMed
Iannotti JP, Ramsey ML, Williams GR Jr, Warner JJ. Nonprosthetic management of proximal humeral fractures. Instr Course Lect. 2004;53:403-16. Review.
View Abstract at PubMed
Mata-Fink A, Meinke M, Jones C, Kim B, Bell JE. Reverse shoulder arthroplasty for treatment of proximal humeral fractures in older adults: a systematic review. J Shoulder Elbow Surg. 2013 Dec;22(12):1737-48. doi: 10.1016/j.jse.2013.08.021. Review.
View Abstract at PubMed
Jobin CM, Galdi B, Anakwenze OA, Ahmad CS, Levine WN. Reverse shoulder arthroplasty for the management of proximal humerus fractures. J Am Acad Orthop Surg. 2015 Mar;23(3):190-201. doi: 10.5435/JAAOS-D-13-00190. Epub 2015 Jan 28. Review.
View Abstract at PubMed
Bae JH, Oh JK, Chon CS, Oh CW, Hwang JH, Yoon YC. The biomechanical performance of locking plate fixation with intramedullary fibular strut graft augmentation in the treatment of unstable fractures of the proximal humerus. J Bone Joint Surg Br. 2011 Jul;93(7):937-41.
View Abstract at PubMed
Kontakis G, Koutras C, Tosounidis T, Giannoudis P. Early management of proximal humeral fractures with hemiarthroplasty: a systematic review. J Bone Joint Surg Br. 2008 Nov;90(11):1407-13. doi: 10.1302/0301-620X.90B11.21070. Review. PubMed PMID: 18978256.
View Abstract at PubMed
Hertel R, Hempfing A, Stiehler M, Leunig M. Predictors of humeral head ischemia after intracapsular fracture of the proximal humerus. J Shoulder Elbow Surg. 2004 Jul-Aug;13(4):427-33. PubMed PMID: 15220884.
View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 67 THROUGH 70
Figure 67 is the radiograph of a right-hand-dominant 70-year-old woman who arrives at the emergency department with acute left shoulder pain following a fall down a flight of stairs. She expresses acute diffuse left shoulder pain and swelling. Prior to her injury, she had full active painless shoulder range of motion.

Question 98:

What is the most common problem seen following epiphysiodesis for limb-length discrepancy?

Options:

Fracture through the site of the physeal resection
Direct neurovascular injury
Incomplete growth arrest from inadequate physeal excision
Persistent discrepancy from an error in the timing of the surgery
Cartilaginous injury because of inadvertent joint penetration

Correct Answer: Persistent discrepancy from an error in the timing of the surgery

Explanation:

Question 99:

Options:

Osteosarcoma
Fibrous dysplasia
Osteoblastoma
Ossifying fibroma
Osteomyelitis

Correct Answer: Fibrous dysplasia

Explanation:

DISCUSSION: Although the classic radiographic appearance of fibrous dysplasia is one of a central metaphyseal lesion with ground glass matrix, it is not unusual to see either a more radiodense-appearing lesion or a more peripheral location. The histologic finding of spicules of woven bone without osteoblastic rimming in a bland fibrous background is diagnostic of fibrous dysplasia. The imaging studies could be consistent with low-grade osteosarcoma, osteoblastoma, or osteomyelitis, but all have a very different histologic picture. Observation is indicated in the absence of symptoms, impending fracture, or deformity. Fibrous dysplasia most commonly occurs in the proximal femur.
REFERENCES: Huvos AG: Bone Tumors: Diagnosis, Treatment, and Prognosis. Philadelphia, PA, WB Saunders, 1991, pp 30-43.
DiCaprio MR, Enneking WF: Fibrous dysplasia: Pathophysiology, evaluation, and treatment.
J Bone Joint Surg Am 2005;87:1848-1864.

Question 100:

Options:

Ask the nurse to call the medical director
Ask the surgeon to revisit the surgical safety checklist
Assume the booking form was incorrect and proceed with the operation
Leave the operating room to ask a family member
Read the last clinical note for clarification

Correct Answer: Ask the nurse to call the medical director

Orthopedic Surgery Board Review MCQs: Arthroplasty, Trauma & Spine Part 255

Orthopedic Board Exam MCQs: Trauma, Spine, & Arthroplasty Review Part 224

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 224

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Chapter Index