OITE & ABOS Orthopedic Board Prep: 100 High-Yield MCQs

About This Board Review Set

This is Part 140 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 140

This module focuses heavily on: Arthroplasty, Elbow, Fracture, Hip, Infection, Shoulder.

Sample Questions from This Set

Sample Question 1: Figures below show the AP and lateral radiographs obtained from a 54-year-old woman who has worseninggroin pain 18 months after a primary left total hip arthroplasty. The pain is worst when climbing stairs, when rising from a seated positio...

Sample Question 2: Figure 10 is the radiograph of a 44-year-old man with a long-standing history of severe hip pain and a limp. Which clinical scenario most likely could occur when performing total hip arthroplasty on this patient?...

Sample Question 3: After excising a mass from the thigh that was thought to be a lipoma, the pathology reveals that the mass is a high-grade sarcoma. Subsequent treatment should include...

Sample Question 4: A 42-year-old man reports persistent arm pain after undergoing intramedullary nailing of a humeral shaft fracture 13 months ago.Physical exam shows near normal shoulder and elbow range-of-motion. Infection work-up is normal. A radiograph is...

Sample Question 5: Anotherwisehealthyyear-oldwomanhaspain2yearsaftertotalhiparthroplasty.Theclinicalphotographinbelowdemonstratesherskinenvelope,andassociatedradiograph.HerC-reactive proteinlevelisnormal,andhererythrocytesedimentationrateismildlyelevated.Thew...

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

00:00

Start Quiz

Question 1

Figures below show the AP and lateral radiographs obtained from a 54-year-old woman who has worsening groin pain 18 months after a primary left total hip arthroplasty. The pain is worst when climbing stairs, when rising from a seated position, and during resisted hip flexion. Her pain improved early after surgery but did not completely resolve. Her C-reactive protein and erythrocyte sedimentation rate results of less than 1 mg/dL and 10 mm/hr, respectively, were obtained in the office. What is the best next step?

Explanation

DISCUSSION:
Iliopsoas impingement is a potential cause of persistent groin pain after a total hip arthroplasty. This patient’s history gives groin pain with resisted hip flexion and during activities that require this level of function. The radiographs depict an acetabular component with substantial retroversion. Typical options for the management of iliopsoas tendon impingement include injections, tenotomy, and acetabular revision. Recently, Chalmers and associates reported more predictable groin pain resolution with 8 mm or more of anterior acetabular component when overhang was revised. The radiographs clearly show more retroversion, with a cup prominence of more than 8 mm anteriorly. MRI with MARS could potentially help in the diagnosis of this impingement but would not help in management (option A). An ultrasound- guided injection would need to be administered into the iliopsoas tendon sheath to be of help and, in this case, would likely be performed for diagnostic purposes due to the extreme anterior overhang (option C). Option D would be useful for mild cases of iliopsoas impingement but likely would not help much in this more extreme case.

Question 2

Figure 10 is the radiograph of a 44-year-old man with a long-standing history of severe hip pain and a limp. Which clinical scenario most likely could occur when performing total hip arthroplasty on this patient?

Explanation

CLINICAL SITUATION FOR QUESTIONS 11 THROUGH 13
Figures 11a and 11b are the radiographs of a 35-year-old woman with end-stage debilitating osteoarthritis of the right hip. She is contemplating total hip arthroplasty (THA). She has a history of right hip dysplasia and underwent hip osteotomy as an adolescent. Over the years, she has failed nonsurgical treatment including weight loss, activity modifications, and intra-articular injections. Her infection workup reveals laboratory findings within defined limits.

Question 3

After excising a mass from the thigh that was thought to be a lipoma, the pathology reveals that the mass is a high-grade sarcoma. Subsequent treatment should include

Explanation

DISCUSSION: Following excision of a suspected benign soft-tissue tumor that proves to be malignant, repeat excision of the tumor bed is recommended. The initial surgical margins are inadequate after an intralesional or marginal excision, necessitating additional surgery for more definitive local control. While radiation therapy and/or chemotherapy may help to reduce the risk of local recurrence in patients with microscopic residual disease, local control is improved following repeat excision. Radiation therapy alone is inadequate to address poor surgical margins, and would likely be given postoperatively. Bisphosphonates have no current role in the treatment of soft-tissue sarcoma.
REFERENCES: Noria S, Davis A, Kandel R, et al: Residual disease following unplanned excision of soft-tissue sarcoma of an extremity. J Bone Joint Surg Am 1996;78:650-655.
Bell RS, O’Sullivan B, Liu FF, et al: The surgical margin in soft-tissue sarcoma. J Bone Joint Surg Am 1989;71:370-375.

Question 4

A 42-year-old man reports persistent arm pain after undergoing intramedullary nailing of a humeral shaft fracture 13 months ago. Physical exam shows near normal shoulder and elbow range-of-motion. Infection work-up is normal. A radiograph is shown in Figure

Explanation

Plate fixation (with bone graft as needed) is the procedure of choice for humeral shaft nonunions.
Rubel et al in a combined cadaveric and clinical study comparing one versus two plate constructs for humeral nonunions found that the two plate construct was significantly stiffer, but had no difference in healing rate compared with a single plate construct; 92% of the humeral shaft nonunion patients went onto union with rigid plate fixation.
Ring et al successfully treated a cohort of osteoporotic humeral shaft nonunions with locked plating. They
report 100% union rate with locking plate fixation of these humeral shaft nonunions, with use of autograft in >50% of their cases. Subjective shoulder scores were excellent or good in 22 of 24 patients.
Brinker and O'Connor analyzed the current available evidence for exchange nailing of nonunions and could not recommend this treatment for humeral shaft nonunions.
OrthoCash 2020

Question 5

An otherwise healthy year-old woman has pain 2 years after total hip arthroplasty. The clinical photograph in below demonstrates her skin envelope, and associated radiograph. Her C-reactive protein level is normal, and her erythrocyte sedimentation rate is mildly elevated. The white blood cell count is normal. Hip aspiration attempted under fluoroscopy generates no fluid. What is the best definitive treatment?

Explanation

DISCUSSION:
This patient clearly has a chronically infected total hip arthroplasty, indicated by the open, draining sinus, as well as trochanteric bone resorption on radiographs, and two years of pain. Recently, specific guidelines have been published to better help the clinician define infection. Repeating the hip aspiration is unnecessary, because infection is already evident. Initiating a wound care consult would not address the underlying infection. The determination whether to retain the components or perform a two-stage exchange is based more on the acuity of infection. In this particular case, the patient is chronically infected. Irrigation and debridement with a liner exchange and retention of the components are reserved for the acute setting.

Question 6

An 80-year-old man has had increasing shoulder pain for the past 4 months. He reports that it began with soreness and stiffness after chopping some wood. A coronal MRI scan is shown in Figure 16. Initial management should consist of

Explanation

DISCUSSION: The MRI scan shows a massive tear of the supraspinatus tendon with medial retraction to the level of the glenoid. This is most likely an attritional tear with a high risk of failure of the repair. The preferred treatment is nonsurgical management for pain and stiffness. Acromioplasty and coracoacromial ligament release in this setting are controversial, as they can result in the devastating complication of anterosuperior subluxation of the humerus.
REFERENCES: Rockwood CA Jr, Williams GR Jr, Burkhead WZ Jr: Debridement of degenerative, irreparable lesions of the rotator cuff. J Bone Joint Surg Am 1995;77:857-866.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 299-312.

Question 7

Which of the following factors will adversely affect bone ingrowth in a revision porous-coated stem?

Explanation

DISCUSSION: The optimal conditions for bony ingrowth include a pore size of 100 to 400 mm, interface micromotion of 50 mm or less, intimate contact between the bone and the implant, circumferential porous coating of the implant, and use of a biocompatible material. Stem designs with patch coatings have a poor record of bony ingrowth, especially in the revision setting. Failure of ingrowth in the previous stem would be the result of its own mechanical milieu and would not necessarily predict results for the new stem.
REFERENCES: Berry DJ, Harmsen WS, Ilstrup D, Lewallen DG, Cabanela ME: Survivorship of uncemented proximally porous-coated femoral components. Clin Orthop 1995;319:168-177.
Cook SD, Thomas KA, Haddad RJ Jr: Histologic analysis of retrieved human porous-coated total joint components. Clin Orthop 1988;234:90-101.
Spector M: Historical review of porous-coated implants. J Arthroplasty 1987;2:163-177.

Question 8

Which of the following is most predictive of a medial side ankle injury in the presence of a fibula fracture above the level of the joint?

Explanation

DISCUSSION: Isolated Lauge-Hansen supination-external rotation-type ankle fractures comprise 20% to 40% of ankle fractures and nonsurgical management is effective for managing SER-2 ankle fractures. Tornetta and associates recently showed that medial ankle tenderness, ecchymosis, and swelling are not reliable findings when trying to determine deltoid competence. Stress radiographs showing a medial clear space of greater than 4 mm or one that is also 1 mm greater than the superior joint space, or any lateral talar subluxation are indicative of deltoid incompetence and indicative of a SER-4 ankle fracture.
REFERENCES: McConnell T, Creevy W, Tornetta P III: Stress examination of supination external rotation-type fibular fractures. J Bone Joint Surg Am 2004:86;2171-2178.
Kristensen KD, Hansen T: Closed treatment of ankle fractures: Stage II supination-eversion fractures followed for 20 years. Acta Orthop Scand 1985;56:107-109.
Michelson JD: Fractures about the ankle. J Bone Joint Surg Am 1995;77:142-152.

Question 9

What is the most prevalent adverse event associated with allogeneic blood transfusion?

Explanation

DISCUSSION: Clerical error leading to acute hemolysis and even death occurs in 1:12,000 to 1:50,000 transfusions. Bacterial contamination leading to sepsis/shock occurs in 1:1 million transfusions. HIV transmission is approximately 1:500,000 transfusions and hepatitis C is 1:103,000 transfusions. Anaphylactic reactions occur in 1:150,000 transfusions.
REFERENCES: Aubuchon JP, Birkmeyer JD, Busch MP: Safety of the blood supply in the United States: Opportunities and controversies. Ann Intern Med 1997;127:904-909.
Popovsky MA, Whitaker B, Arnold NL: Severe outcomes of allogeneic and autologous blood donation: Frequency and characterization. Transfusion 1995;35:734-737.

Question 10

Which of the following zones of articular cartilage has the highest concentration of proteoglycans?

Explanation

The fundamental structure of normal adult articular cartilage is divided into four different zones: superficial, transitional, deep, and calcified. These layers vary in chondrocyte morphology, size and orientation of collagen bundles, and water and proteoglycan content. The deep zone has the highest concentration of proteoglycans and the lowest concentration of water. The tidemark is a boundary between the calcified and uncalcified layers of articular cartilage.

Question 11

A 12-year-old boy with an ankle fracture undergoes closed reduction under sedation in the emergency department. Figure 27 shows a lateral radiograph of the ankle after two attempts at closed reduction. Based on these findings, treatment should now consist of Review Topic

Explanation

The widening of the physis associated with incomplete reduction of this fracture suggests that periosteum is interposed at the fracture site. Clinical and animal study findings suggest that the interposed periosteum may lead to premature physeal closure. Repeated forceful attempts at reduction may subject the physis to further injury and should be avoided. Growth problems are common in children with Salter-Harris type I fractures of the lower extremities. Nonunions are rare in children with Salter-Harris type I fractures.

Question 12

Figure 35 shows the lateral radiograph of a 15-year-old basketball player who felt a dramatic pop in his knee when landing after a lay-up. The patient reports that he cannot bear weight on the injured extremity. Management should consist of

Explanation

DISCUSSION: Tibial tubercle avulsion is an injury of the adolescent knee that most often occurs just before the end of growth. The fracture usually occurs with jumping, either at push-off or landing. This patient has a type III injury. In type III injuries, the articular surface is disrupted, and meniscal injury and compartment syndrome can occur. Open reduction is the treatment of choice, and anterior fasciotomy should be considered prophylactically at the time of surgery. Although the fracture heals with an anterior epiphysiodesis of the proximal tibia, little growth remains in this patient and no special handling of the physis is warranted.
REFERENCES: Ogden JA, Tross RB, Murphy MJ: Fractures of the tibial tuberosity in adolescents. J Bone Joint Surg Am 1980;62:205-215.
Pape JM, Goulet JA, Hensinger RN: Compartment syndrome complicating tibial tubercle avulsion. Clin Orthop 1993;295:201-204.

Question 13

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."
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect answers:
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.
Incorrect answers:
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.
Incorrect answers:
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.
Incorrect Answers:
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.
Incorrect answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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)?
FOR ALL MCQS CLICK THE LINK ORTHO MCQ BANK

Question 14

A 10-year-old boy with severe hemophilia A (factor VIII) sustained an injury to his right forearm 2 hours ago when a classmate fell on his arm during a scuffle. Examination reveals moderate swelling in the forearm, decreased sensation in the distribution of the median and ulnar nerves, and pain on passive extension of the fingers. What is the most appropriate sequence of treatment?

Explanation

DISCUSSION: The patient has severe hemophilia with a volar forearm hemorrhage and an emerging compartment syndrome. Therefore, it is critical to normalize the clotting deficiency as the first step in treatment. In a patient who has a factor VIII level of less than 1% and no inhibitors to factor VIII, transfusion with 4 unit/kg will typically raise the factor VIII level to 100%. Continuous transfusion can then be used to maintain this level. Compartment pressures can be safely measured after infusion of factor VIII. Because the hemorrhage is of limited duration and any surgery is considered serious in a patient with hemophilia, the compartment pressure should be measured before making a decision regarding a fasciotomy. However, it is important to note that the use of factor VIII concentrates allows both emergency and elective surgery provided that adequate hematology backup is available. Splinting the elbow and wrist in flexion reduces the pressure in the volar compartments, protects the forearm from further trauma, and makes the patient more comfortable.
REFERENCES: Greene WB: Diseases related to the hematopoietic system, in Morrissy RT, Weinstein SL (eds): Lovell & Winter’s Pediatric Orthopaedics, ed 4. Philadelphia, Pa, Lippincott-Raven, 1996, pp 345-391.
Greene WB, McMillan CW: Nonsurgical management of hemophilic arthropathy, in Barr JS (ed): Instructional Course Lectures 38. Park Ridge, Ill, American Academy of Orthopaedic Surgeons, 1989, pp 367-381.
Naranja RJ Jr, Chan PS, High K, Esterhai JL Jr, Heppenstall RB: Treatment considerations in patients with compartment syndrome and an inherited bleeding disorder. Orthopedics 1997;20:706-711.

Question 15

A 23-year-old woman with a history of bilateral recurrent ankle sprains, progressive cavovarus feet, and a family history of high arches and foot deformities is seen for evaluation. Management consisting of bracing and physical therapy has been poorly tolerated. Heel varus is partially corrected with a Coleman block. There are thick calluses under the first metatarsal heads. Sensation to touch and Weinstein monofilament is normal. Tibialis anterior and peroneus brevis are weak but present. What is the most appropriate management?

Explanation

DISCUSSION: The history and presentation are consistent with type I Charcot-Marie-Tooth (CMT), the most common form of hereditary peripheral motor sensory neuropathy. Type I CMT is the most common, occurring in 50% of patients with CMT, and is characterized by marked slowing of motor neuron velocities, and inconsistent slowing of sensory neuron velocities. Peroneus longus to brevis transfer is indicated to release the overpull of the peroneus longus, and restore the eversion and dorsiflexion function of the peroneus brevis. A lateralizing calcaneal osteotomy with proximal translation is indicated to correct heel varus given that the Coleman block only allows for partial correction of heel varus. Proximal translation of the posterior tuber corrects for the increased calcaneal dorsiflexion, improving the lever arm for the triceps surae. A medial column closing wedge osteotomy is often required to correct a rigid, or semirigid plantar flexed first ray to allow for a balanced, plantigrade foot. Triple arthrodesis is indicated for rigid, arthritic hindfoot deformities. Transfer of the posterior tibial tendon to the tibialis anterior is not indicated since it is an out-of-phase transfer. Transfer of the posterior tibial tendon, when performed, should be to the lateral aspect of the foot. A medializing calcaneal osteotomy would accentuate the heel varus. There is no indication for Botox in CMT; Botox injection of the calf would further weaken push-off during gait. Bracing of a progressive semirigid or rigid deformity is not recommended.
REFERENCES: Younger AS, Hansen ST Jr: Adult cavovarus foot. J Am Acad Orthop Surg 2005;13:302-315.
Sammarco GJ, Taylor R: Cavovarus foot treated with combined calcaneus and metatarsal ostetotomies. Foot Ankle Int 2001;22:19-30.
Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL,

American Academy of Orthopaedic Surgeons, 2003, pp 135-143.

Question 16

An anterior approach to the sacroiliac joint is indicated with which of the following concomitant injuries?

Explanation

DISCUSSION: An anterior approach to the sacroiliac joint is indicated with the presence of a symphysis dislocation, which can be reduced through the same approach. The other choices are all relative contraindications to this approach. A sacroiliac dislocation or malalignment can lead to gait abnormalities, pelvic obliquity, back or buttock pain, as well as neurological changes. The first referenced article by Simpson et al noted that an anterior approach was safe and that excellent results correlated significantly with anatomic reductions of the SI joint. The second reference discusses pelvic ring injuries in depth and covers typical treatment protocols.

Question 17

A 14-year-old gymnast presents after a fall from the balance beam with a hyperextension injury to her left knee. She could ambulate with pain but was unable to continue exercise due to pain. On examination she has a swollen knee with painful

Explanation

The patient has a mild to moderately displaced tibial eminence fracture, which can be treated with closed reduction, casting, and supportive care provided successful closed reduction is achieved.
Tibial eminence fractures are rare but occur more often in pediatric populations, often in the setting of sports-related injuries. Debate continues over operative vs nonoperative treatment, as well as fixation type (screw vs suture) for openly treated fractures. Past evidence suggested closed treatment was adequate but there has been an increase in operative management. Closed treatment is suggested for minimally displaced fractures (Type I and reducible Type II) and open treatment for completely displaced fractures (non-reducible Type II and Type III).
Wilfinger et al provide the results of a closed reduction protocol at their institution including 38 patients with long term followup. All patients underwent aspiration and closed reduction in the OR under fluoroscopic guidance followed by long leg casting in hyperextension and graduated weight bearing over weeks. No patients complained of persistent pain, swelling, giving way, or disability at follow up.
However, Edmonds et al in a retrospective review compare open reduction internal fixation (ORIF), arthroscopic-assisted internal fixation (AAIF), and closed reduction with casting (CRC) for pediatric patients with displaced tibial spine fractures. They report improved reduction but also increased arthrofibrosis in ORIF and AAIF groups
compared to CRC, but of the 24% of patients with long term followup results, there was no difference in functional outcomes across all 3 groups. There was a 17% rate of later operation for the CRC group patients. They suggest closed treatment for fractures with <5mm displacement, otherwise ORIF or AAIF.
Gans et al conducted a systematic review focused on the questions of open vs closed reduction, and screw vs suture fixation. The 26-article review found insufficient evidence to have any clear recommendations. They did find reduced laxity and improved range of motion for minimally displaced fractures that had an open reduction, and that completely displaced fractures treated nonoperative had higher rates of nonunion.
Figures A and B are AP and lateral knee radiographs demonstrating a moderately displaced (Meyers and McKeever Type II) tibial spine fracture in a skeletally immature patient.
Incorrect Responses

Question 18

Figures 163a through 163c show the radiograph and MRI scans of a 45-year-old woman with severe right arm pain. She has had symptoms for 6 months without resolution despite multiple nonsurgical treatments. Examination reveals weakness in the right triceps and wrist flexors with decreased sensation in the middle finger and a positive Spurling's sign. What is the most appropriate treatment for the patient's symptoms? Review Topic

Explanation

The patient has symptoms and signs of cervical radiculopathy despite a long course of nonsurgical management. Therefore, surgical decompression is indicated and is best performed through an anterior cervical diskectomy and arthrodesis. Single level anterior cervical diskectomy and arthrodesis have been shown to produce significant improvements in arm pain and neurologic function. Anterior cervical foraminotomy, while reported, has insufficient data to support its use and it places the vertebral artery at significant risk. Posterior cervical foraminotomy is contraindicated given the ventral spinal cord compression; foraminotomy places the patient at risk for spinal cord injury. The patient has one-level cervical disease, therefore a corpectomy is unnecessary. Posterior laminoplasty is used to treat myelopathy, not radiculopathy.

Question 19

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 20

In obstetrical brachial plexus palsy, which of the following signs is associated with the poorest prognosis for recovery in a 2-month-old infant?

Explanation

DISCUSSION: Persistent Horner’s sign (ptosis, myosis, and anhydrosis) is a sign of proximal injury, usually avulsion of the roots from the cord which disrupts the sympathetic chain. Root rupture or avulsion proximal to the myelin sheath has less chance of healing. Two-month-old infants with persistent weakness in the other areas described may still have a good prognosis for recovery. Concurrent clavicle fracture has been shown to have no prognostic value.
REFERENCES: Clarke HM, Curtis CG: An approach to obstetrical brachial plexus injuries. Hand Clin 1995;11:563-581.
Narakas AO: Injuries to the brachial plexus, in Bora FW (ed): The Pediatric Upper Extremity: Diagnosis and Management. Philadelphia, PA, WB Saunders, 1986, p 247.

Question 21

Plate fixation of olecranon fractures is recommended over tension band wire fixation when

Explanation

Tension band wire fixation of olecranon fractures is recommended for fracture patterns that are proximal to the coronoid process and are relatively transverse to withstand compressive forces. When comminution is present, a neutralization technique such as plating is preferred over a compressive technique such as tension band wire fixation. Such neutralization plating, if performed correctly, does not have the risk of narrowing the sigmoid notch as tension band wire fixation would. Fractures of the tip of the olecranon, transverse fractures, fractures associated with osteoporosis, and displaced fractures are all relative indications for tension band wire fixation.

Question 22

A 50-year-old woman has a painful hallux valgus and a painful callus beneath the second metatarsal head. A radiograph is shown in Figure 46. To correct these problems, treatment of the great toe deformity should consist of

Explanation

DISCUSSION: The patient has a significant hallux valgus and instability of the first ray, causing transfer metatarsalgia to the second metatarsal head. Therefore, the best procedure is fusion of the metatarsal cuneiform joint with soft-tissue realignment of the first metatarsophalangeal joint. This procedure provides the best chance of relieving symptoms under the second metatarsal head, as well as correcting the hallux valgus.
REFERENCE: Sangeorzan BJ, Hansen ST Jr: Modified Lapidus procedure for hallux valgus. Foot Ankle 1989;9:262-266.

Question 23

An active 60-year-old man is evaluated 4 years following surgical correction of a hallux valgus deformity. The patient reports that a hallux varus deformity developed rapidly following his initial surgery. Conservative management consisting of wider shoes, toe strapping, and anti-inflammatory drugs has failed to provide relief. Examination reveals a hallux varus deformity with restricted painful motion of the metatarsophalangeal joint and callus formation under the second metatarsal head. What is the next most appropriate step in management?

Explanation

DISCUSSION: Hallux varus may occur as a complication following hallux valgus surgery, most commonly a modified McBride-type procedure. Conservative management is the initial treatment of choice; however, if unsuccessful, surgical options for reconstruction include soft-tissue reconstruction or metatarsophalangeal joint arthrodesis. The patient has evidence of joint arthrosis, making an arthrodesis the preferred method of reconstruction. Fascial arthroplasty, Silastic arthroplasty, and Keller resection arthroplasty will not correct the underlying deformity.
REFERENCES: Kitaoka HB, Patzer GL: Arthrodesis versus resection arthroplasty for failed hallux valgus operations. Clin Orthop 1998;347:208-214.
Ouzounian TJ: Metatarsophalangeal arthrodesis for salvage of failed hallux valgus surgery. Foot Ankle Clin 1997;2:741-752.

Question 24

Figure 54 is the lateral radiograph of a 55-year-old man who is evaluated for a 2-year history of pain and stiffness of his right metatarsophalangeal (MTP) joint. Upon examination he has dorsal bossing, severe crepitation, and pain with passive range of motion. There is pain with the "grind" test. Dorsiflexion is limited to 0 degrees. No sesamoid tenderness is present. What is the most appropriate surgical treatment?

Explanation

DISCUSSION
The radiograph reveals end-stage degenerative changes of the first MTP joint with a dorsal loose body. MTP arthritis and decreased joint dorsiflexion is referred to as hallux rigidus. A chevron bunionectomy is used to correct hallux valgus deformity without arthritis. The cheilectomy is used in lesser degrees of joint destruction. Resection of the proximal phalanx results in a floppy toe and is generally not recommended.
RECOMMENDED READINGS
McNeil DS, Baumhauer JF, Glazebrook MA. Evidence-based analysis of the efficacy for operative treatment of hallux rigidus. Foot Ankle Int. 2013 Jan;34(1):15-32. doi: 10.1177/1071100712460220. Review. PubMed PMID: 23386758.
View Abstract at PubMed
Deland JT, Williams BR. Surgical management of hallux rigidus. J Am Acad Orthop Surg. 2012 Jun;20(6):347-58. doi: 10.5435/JAAOS-20-06-347. Review. PubMed PMID: 22661564.
View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 55 THROUGH 58
Figures 55a and 55b are the anteroposterior and lateral radiographs of a 57-year-old man who fell off of a ladder 10 days ago and landed on his left foot. He is now unable to weight bear on the left. He has no history of trauma to this foot, and his medical history is unremarkable. Upon examination his left foot is swollen and tender. Pulses and sensation are intact.

A B

Question 25

What imaging study should be obtained next to further evaluate this patient? Review Topic

Explanation

The MRI scan shows a C7 burst fracture. A CT scan of the cervical spine will allow for optimal evaluation of this C7 burst fracture. Specifically, it will provide additional osseous detail and will assist with the detection of additional fractures, including those of the posterior elements. Additional CT imaging of the thoracic and lumbar spine is required to rule out concommitant injuries (which may be present in 10% to 15% of patients). Anteroposterior and lateral cervical spine radiographs would be a good option for further evaluation but are not included in the available choices here. Cervical spine flexion and extension radiographs should not be obtained in a patient who is known to have a relatively unstable spine and a neurologic deficit. Electromyography and nerve conduction velocity studies are best used to evaluate for cervical radiculopathy secondary to degenerative abnormalities and are usually not indicated in the acute trauma setting.

Question 26

An adult patient with a grade I isthmic spondylolisthesis at L5-S1 is most likely to have weakness of the

Explanation

DISCUSSION: Adult patients with isthmic spondylolisthesis most commonly have neurologic symptoms due to foraminal stenosis at the level of the spondylolisthesis. In this scenario, the patient is most likely to have weakness of the L5 myotome, which would cause weakness of the extensor hallucis longus.
REFERENCES: Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 311-317.
Lauerman WC, Cain JE: Isthmic spondylolisthesis in the adult. J Am Acad Orthop Surg 1996;4:201-208.

Question 27

-What is the most appropriate initial treatment?

Explanation

DISCUSSION FOR QUESTIONS 83 AND 84
Based upon the history and description of the wound, this patient has sustained a frostbite injury to the anterior skin without evidence of infection. Frostbite, a thermal injury to local tissues, can be classified into first-, second-, third-, and fourth-degree injuries. First-degree injuries are characterized by a central whitish area surrounded by erythema. Second- and third-degree injuries are characterized by blisters that appear within the first 24 hours. Second-degree blisters are clear or cloudy, while third-degree blisters are hemorrhagic. Fourth-degree injuries are characterized by tissue necrosis. Treatment of a frostbite injury should begin as soon as it is identified, even if severity has not been determined. Treatment includes protection against mechanical irritation and keeping the injured area away from heat. The limb should be elevated and clear blisters debrided; dark blisters should be drained but not debrided. Topical treatment includes aloe application every 6 hours (silver sulfadiazine for open wounds). Nonsteroidal anti-inflammatory drugs can be given along with PCN G (500,000 U) or clindamycin (600 mg) IV every 6hours for 48 to 72 hours as prophylaxis against infection.Multiple skin incisions on the front of the knee place the skin at healing risk after surgery.
Skin oxygenation is further compromised by a lateral release, which disrupts the superior lateral geniculate artery in the peripatellar vascular anastomosis. When addressing compromised perfusion to the skin, the orthopaedic surgeon may consider not performing a lateral release, using the medial parapatellar incision,and/or not using a tourniquet during surgery. In this patient, the use of cold therapy further compromised perfusion to the skin. This patient’s wound does not reflect infection, but rather frostbite from the compromised skin perfusion and the application of cold therapy.

The physiologic responses to the effects of freezing temperatures on limbs have been categorized into 4 phases. Phase I, cooling and freezing, is characterized by vasoconstriction and vasospasm. The freezing results in mechanical destruction of cell membranes in endothelial cells in small capillaries. Phase II,rewarming, initiates as heat absorbed by the limb begins an exothermic reaction as extracellular and intracellular crystals melt. Intracellular swelling occurs and small capillaries become highly permeable,resulting in extravasation of fluid and causing edema and blisters. Phase III is characterized by progressive tissue injury resulting from inflammation, vascular stasis, and thrombosis leading to ischemia.Phase IV is recovery that can progress along 3 potential pathways: complete healing, healing with later sequelae, or early tissue necrosis leading to gangrene.
CLINICAL SITUATION FOR QUESTIONS 85 THROUGH 87
Figure 85 is the radiograph of a 13-year-old right-handed baseball player who has experienced 2 months of right-dominant shoulder pain. As a pitcher, he says he cannot “throw hard” without pain, and he develops a dull ache if he throws more than 15 pitches.

Question 28

Fixed hyperextension of the metatarsophalangeal joint is associated with

Explanation

DISCUSSION: Claw toe and hammer toe deformities are associated with dorsal subluxation of the interossei, which can no longer serve to flex the metatarsophalangeal joint. The extensor digitorum longus then loses its tenodesing effect on the proximal interphalangeal and distal interphalangeal joints and works unopposed to extend the metatarsophalangeal joint and the proximal phalanx. Without the antagonistic action of the extensor digitorum longus, the extrinsic flexors become unopposed flexors of the proximal and distal interphalangeal joints.
REFERENCES: Marks RM: Anatomy and pathophysiology of lesser toe deformities. Foot Ankle Clin 1998;3:199-213.
Myerson MS, Shereff MJ: The pathological anatomy of claw and hammer toes. J Bone Joint Surg Am 1989;71:45-49.

Question 29

A 45-year-old man sustains a low-velocity gunshot wound to the base of the right thumb. The open wound is allowed to heal by secondary intention, resulting in a contracture of the first web space. Clinical photographs are shown in Figures 49a through 49c. Treatment should now consist of

Explanation

DISCUSSION: The contracture is too large for a Z-plasty, which allows a 75% increase in length. Excision of the scar with placement of a skin graft is prone to contracture. A posterior interosseous fasciocutaneous flap will provide enough well-vascularized tissue and is well suited to reach the first dorsal web space.
REFERENCES: Buchler U, Frey HP: Retrograde posterior interosseous flap. J Hand Surg Am 1991;16:283-292.
Brunelli F, Valenti P, Dumontier C, et al: The posterior interosseous reverse flap: Experience with 113 flaps. Ann Plast Surg 2001;47:25-30.

Question 30

When the elbow is extended and an axial load is applied, what percent of stress distribution occurs across the ulnohumeral and radiohumeral articular surface, respectively?

Explanation

DISCUSSION: When load is applied to the wrist, most of the stress is absorbed by the radius. As the load is transferred through the forearm, the interosseous membrane transfers some of the load from the radius to the ulna. The load at the elbow is distributed with 40% at the ulnohumeral articulation and 60% at the radiohumeral articulation.
REFERENCES: Halls AA, Travill R: Transmission of pressure across the elbow joint. Anat Rec 1964;150:243.
Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000.

Question 31

While lifting weights, a patient feels a pop in his arm. He has the deformity shown in Figure 30. If left untreated, the patient will have the greatest deficiency in

Explanation

DISCUSSION: The patient has a distal biceps rupture. While the distal biceps contributes to elbow flexion, its main function is forearm supination.
REFERENCES: Baker BE, Bierwagen D: Rupture of the distal tendon of the biceps brachii: Operative versus non-operative treatment. J Bone Joint Surg Am 1985;67:414-417.
D’Arco P, Sitler M, Kelly J, et al: Clinical, functional, and radiographic assessments of the conventional and modified Boyd-Anderson surgical procedures for repair of distal biceps tendon ruptures. Am J Sports Med 1998;26:254-261.
Pearl ML, Bessos K, Wong K: Strength deficits related to distal biceps tendon rupture and repair: A case report. Am J Sports Med 1998;26:295-296.

Question 32

What is the most likely cause of recurrent symptoms following excision of a third web space neuroma?

Explanation

DISCUSSION: When a recurrent neuroma forms at the end of the resected nerve, it does not retract far enough because either the transection was not proximal enough or it is tethered by plantar neural branches. The transverse intermetatarsal ligament may reform, but it is not associated with pathology. Synovial cysts and synovitis are part of the differential diagnosis but are not associated with neuroma excision. Complex regional pain syndrome may result from neuroma excision, but this is rare and the symptoms are different.
REFERENCES: Beskin JL: Recurrent interdigital neuromas, in Nunley JA, Pfeffer GB, Sanders RW, Trepman E (eds): Advanced Reconstruction: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 481-484.
Amis JA, Siverhus SW, Liwnicz BH: An anatomic basis for recurrence after Morton’s neuroma excision. Foot Ankle 1992;13:153-156.

Question 33

During a knee arthroscopy on a 38-year-old patient with isolated medial knee pain and no lateral symptoms, a routine examination of the lateral compartment reveals a discoid lateral meniscus. The discoid lateral meniscus is not torn. Based on these findings, what is the most appropriate action? Review Topic

Explanation

The most appropriate action is to note this finding in the surgical report but do nothing surgically in the lateral compartment. Multiple studies have shown that asymptomatic discoid lateral menisci seen on routine knee arthroscopies for other pathology need not be addressed surgically. They do not cause problems later in life and do not need to be treated prophylactically.

Question 34

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 35

-A 42-year-old woman has had right wrist pain for 2 years. She tried splint wear and naproxen and has had 3 steroid injections, each time experiencing less relief.

Explanation

Question 36

Figures 46a through 46e show the radiographs of a 22-year-old man who injured his wrist in a motorcycle accident. He has no other injuries. What is the best course of action?

Explanation

DISCUSSION: The patient has a fracture-dislocation of the radiocarpal joint. Attached to the large radial styloid fragment are the extrinsic wrist ligaments to the carpus. This injury should be treated with open reduction and internal fixation of the styloid fracture. Radiolunate fusion or extrinsic ligament repair is suggested when the extrinsic ligaments are ruptured, resulting in ulnar translocation of the carpus.
REFERENCES: Dumontier C, Meyer ZU, Reckendorf G, et al: Radiocarpal dislocations: Classification and proposal for treatment: A review of twenty-seven cases. J Bone Joint Surg Am 2001;83:212.
Bilos ZJ, Pankovich AM, Yelda S: Fracture-dislocation of the radiocarpal joint: A clinical study of five cases. J Bone Joint Surg Am 1977;59:198-203.

Question 37

14A 14B An 18-year-old man was involved in an altercation during which he sustained the injuries shown in Figures 14a and 14b. His Glasgow Coma Scale (GCS) score is 11 (a GCS score of 9-12 indicates moderate head injury). The neurosurgeons elect to not place an intracranial pressure (ICP) monitor. The patient responds appropriately to stimuli and is hemodynamically stable. What is the most appropriate initial treatment?

Explanation

DISCUSSION
Although management of femoral shaft fractures in patients with head injuries remains controversial, most practitioners agree that "damage-control principles" are appropriate for patients with evolving head injuries. This patient has a subarachnoid hemorrhage and a decreased GCS but is responding appropriately. The best treatment is a damage-control approach for the femur that will cause minimal blood loss and allow the brain injury (and swelling) to equilibrate. External fixation can be performed expeditiously and with minimal blood loss, which will reduce further injury to the brain. Special attention should be paid to maintaining cerebral perfusion pressure higher than 70 mmHg. Admission to the intensive care unit is recommended for monitoring of this injury. Knee immobilizers are not tolerated well by young muscular men with femur shaft fractures. A GCS score of 11 or higher can be observed without ICP monitoring.
RECOMMENDED READINGS
Flierl MA, Stoneback JW, Beauchamp KM, Hak DJ, Morgan SJ, Smith WR, Stahel PF. Femur shaft fracture fixation in head-injured patients: when is the right time? J Orthop Trauma. 2010 Feb;24(2):107-14. PubMed PMID: 20101135. View Abstract at PubMed
Roberts CS, Pape HC, Jones AL, Malkani AL, Rodriguez JL, Giannoudis PV.Damage control orthopaedics: evolving concepts in the treatment of patients who have sustained orthopaedic trauma. Instr Course Lect. 2005;54:447-62. Review. PubMed PMID: 15948472. View Abstract at PubMed

Question 38

Figures 1a and 1b are the recent radiographs of an 82-year-old man with rheumatoid arthritis who underwent total knee arthroplasty (TKA) 18 years ago. These radiographs reveal osteolysis with loosening of the tibial component. Aspiration and laboratory study findings for infection are negative. During the revision TKA, treatment of tibial bone loss should consist of

Explanation

DISCUSSION

Video 1 for reference
For severe tibial defects (Anderson Orthopaedic Research Institute [AORI] types 2 and 3), metaphyseal fixation is necessary to achieve construct fixation during revision TKA. Metaphyseal fixation may be achieved with cement, structural allograft, or conical metallic implants. The major concerns regarding structural allograft are graft resorption and mechanical failure and technical issues related to fashioning the graft and obtaining a good host-allograft interface. In a systematic review, porous metal cones were associated with a decreased loosening rate in AORI 2 and 3 defects compared to structural allografts. Metallic trabecular metal cones and metaphyseal porous coated sleeves provide a stable construct with which to support the tibial component during revision TKA. Clinical results with these devices include good metaphyseal fixation for severe tibial bone defects.

Question 39

A polytrauma patient sustains a right bicondylar tibial plateau fracture and a right humeral shaft fracture both treated with open reduction and internal fixation. He also underwent statically locked intramedullary nailing of a left femoral shaft fracture. What is the appropriate weightbearing status?

Explanation

The standard treatment for a bicondylar tibial plateau fractures is a period of post-operative non-weight bearing.
Tingstad et al found favorable results of immediate weightbearing on humeral shaft fractures treated with plating and full weightbearing did not have any effect on the union or malunion rates.
Brumback et al evaluated the feasibility, safety and efficacy of immediate
weightbearing after treatment of femoral shaft fractures with statically locked IM nail. All the patients went on to union and no loss of fixation occurred.
OrthoCash 2020

Question 40

A 15-year-old girl with a midshaft fibular lesion has histologic findings consistent with Ewing’s sarcoma. Following induction chemotherapy, local control typically consists of

Explanation

DISCUSSION: The current treatment regimen for Ewing’s sarcoma typically involves induction chemotherapy followed by local control and further chemotherapy. Local control consists of surgery only, radiation therapy only, or a combination of the two. In bones that are easily resectable (expendable) with wide margins, surgery is usually recommended. For areas that cannot be resected (ie, large bulky pelvic tumors), radiation therapy alone is sometimes the preferred method of local control. If surgery is chosen and the margins are close, radiation therapy can be used as an adjuvant treatment. Amputation is rarely required for an isolated fibular lesion. Observation without adequate local control results in local recurrence.
REFERENCES: Nesbit ME Jr, Gehan EA, Burgert EO Jr, et al: Multimodality therapy for the treatment of primary, non-metastatic Ewing’s sarcoma of the bone: A long-term follow-up of the first intergroup study. J Clin Oncol 1990;8:1664-1674.
Simon M, Springfield D, et al: Ewing’s Sarcoma: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, p 296.

Question 41

Figure 7 shows the MRI scan of a 23-year-old competitive rugby player who has anterior ankle pain and swelling. He states that he has been playing for many years and has sprained his ankle several times. Examination will reveal what specific hallmark feature?

Explanation

DISCUSSION: The history and MRI findings indicate the presence of anterior tibiotalar osteophytes. This is frequently observed in soccer, rugby, and football athletes who play on grass or turf surfaces and repetitively push off and change directions. Examination may reveal an effusion but no loss of subtalar motion. A positive external rotation (Klieger) test is described as pain at the distal ankle with external rotation of the foot and is observed in patients with syndesmosis sprains. This patient may have an increased anterior drawer because of a history of sprains; however, this finding is not specific for anterior impingement of tibiotalar osteophytes. The most specific finding on physical examination is pain with forced dorsiflexion.
REFERENCES: Ogilvie-Harris DJ, Mahomed N, Demaziere A: Anterior impingement of the ankle of the ankle treated by arthroscopic removal of bony spurs. J Bone Joint Surg Br 1993;75:437-440.
Cannon LB, Hackney RG: Anterior tibiotalar impingement associated with chronic ankle instability. J Foot Ankle Surg 2000;39:383-386.

Question 42

A 78-year-old woman has a history of chronic low back pain. She denies any extremity problems. Her pain is worse in the morning, and gets better, although it does not go away, as the day goes on. An MRI scan of the lumbar spine is shown in Figure 88. She denies any acute worsening of her symptoms, although in general, her symptoms are slowly worsening. She takes nonsteroidal anti-inflammatory drugs as needed for her pain, but otherwise takes no other medications. What is the next most appropriate step in management? Review Topic

Explanation

The patient has MRI findings throughout her lumbar spine consistent with old compression fractures. Given the imaging findings and advanced age, she is at high risk for osteoporosis and subsequent fragility fractures. Management should consist of a DEXA scan to evaluate her degree of osteoporosis and begin medical treatment as appropriate. Because acute fracture is unlikely, and she has no neurologic compromise, neither bracing nor surgical treatment is indicated.

Question 43

Which of the following prophylactic regimens for the prevention of deep venous thrombosis after knee arthroplasty has received a grade 1A recommendation in favor of its use from the American College of Chest Physicians (ACCP) in the 2004 guidelines?

Explanation

DISCUSSION: In the 2004 ACCP guidelines, there were three prophylactic regimens that received a grade 1A favorable recommendation. These included low-molecular-weight heparin, warfarin, or fondaparinux, as long as they are used for at least 10 days. If warfarin is used, the target INR should be 2.0 to 3.0, according to the guidelines. Pneumatic compression sleeves have gained popularity in the orthopaedic community but have not received a grade 1A rating from the ACCP at this time. Use of aspirin by itself is discouraged by the ACCP.
REFERENCE: Geerts WH, Pineo GF, Heit JA, et al: Prevention of venous thromboembolism: The seventh ACCP Conference on antithrombotic and thrombolytic therapy. Chest 2004;126:338S-400S.

Question 44

A 56-year-old man who tripped and fell out of his golf cart onto his right shoulder 4 days ago now reports mild pain while chipping. Examination reveals mild bruising over the lateral clavicle but good shoulder range of motion and strength. A radiograph is shown in Figure 9. Appropriate treatment at this time should include which of the following?

Explanation

Treatment of this minimally displaced distal clavicle fracture should begin with nonsurgical management consisting of sling therapy followed by gentle motion therapy. Any form of surgical intervention at this time is unnecessary because this fracture pattern has a high incidence of union. A bone stimulator may be used if healing becomes delayed.

Question 45

A hip compression screw is placed in a test jig and a bending load is applied to the tip of the screw. After the load is released, the screw returns completely to its original shape. What is this type of deformation called?

Explanation

When an implant is loaded below the yield point, by definition, it undergoes elastic deformation, meaning that all of the deformation recovers when the load is removed. If it is loaded above the yield point, then plastic or permanent deformation occurs. Fatigue is the gradual accumulation and progression of cracks in the material, which, after many cycles of loading, can lead to gross failure. Creep is the gradual accumulation of permanent (plastic) deformation over time, which may occur with polymeric materials but is not typical of metals or ceramics. Torsion refers to a torque being applied about the long axis of a bone or an implant. In general, the materials and dimensions of an implant are chosen to avoid plastic deformation or fatigue failure during typical clinical use.

Question 46

A 15-year-old boy has had pain in the right knee for the past 3 months. He denies any history of trauma. Examination reveals a firm mass in the distal thigh; the remainder of the examination is unremarkable. A radiograph is shown in Figure 24. What further work-up should be completed prior to biopsy?

Explanation

DISCUSSION: The radiograph shows an aggressive destructive lesion. In this age group, and based on the anatomic location, a primary malignant tumor (osteosarcoma) is likely. Additional staging studies to identify metastatic disease are imperative prior to any biopsy. MRI of the femur helps to reveal skip metastasis and provides information regarding the anatomic location of the lesion. CT of the chest and a bone scan evaluate for distant metastatic spread. A bone scan is also useful in evaluating the extent of local bone activity about the lesion.
REFERENCES: Simon MA, Finn HA: Diagnostic strategy for bone and soft tissue tumors. J Bone Joint Surg Am 1993;75:622-631.
Simon M, Springfield D, et al: Biopsy: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, p 6.

Question 47

A 4-year-old boy who was struck by a motor vehicle has a right pneumothorax requiring placement of a chest tube, an open (Gustilo) grade IIIA midshaft fracture of the left femur, and a closed displaced subtrochanteric fracture of the right femur. He also sustained a subdural hematoma that requires neurosurgical intervention. In addition to irrigation and debridement of the left femur, treatment should include

Explanation

In children ages 3 to 5, who have sustained multiple trauma, the treatment priority is initially their more serious life threatening injuries. Once other injuries are stabilized, then femoral fractures can be treated. External fixation is rarely needed in this age group, except in the multi-trauma patient with ipsilateral fractures or contralateral fractures. It is also useful in patients with head injuries, in open fractures, and when traction has not prevented significant shortening and angulation of the fracture.

Question 48

A 30-year-old man who underwent an anterior lumbar diskectomy and fusion at L4-5 and L5-S1 through an anterior retroperitoneal approach 1 month ago now reports he is unable to obtain and maintain an erection. The most likely cause of this condition is

Explanation

DISCUSSION: Sexual dysfunction is a common condition after extensive anterior lumbar surgical dissection. Erectile dysfunction usually is nonorganic but may be related to parasympathetic injury. The parasympathetic nerves are deep in the pelvis at the level of S2-3 and S3-4 and usually are not involved in the surgical field for anterior L4-5 and L5-S1 procedures. Retrograde ejaculation is the result of injury to the sympathetic chain on the anterior surface of the major vessels crossing the L4-5 level and at the L5-S1 interspace. Erectile function and orgasm are not affected by sympathetic injury. The pudendal nerve is primarily a somatic nerve and is not located in the surgical field.
REFERENCES: Flynn JC, Price CT: Sexual complications of anterior fusion of the lumbar spine. Spine 1984;9:489-492.
Johnson RM, McGuire EJ: Urogenital complications of anterior approaches to the lumbar spine. Clin Orthop 1981;154:114-118.

Question 49

Figures A and B are radiographic images of an 85-year-old woman with isolated left hip pain. She describes a non-syncopal fall from standing 4 hours ago. Physical examination reveals pain with log-rolling the left thigh and the inability to bear weight on the affected leg. The radiologist reports no fracture in the left hip. What would be the next best step? Review Topic

Explanation

Absent plantar sensation at presentation
Depression at 3 months post-injury
Use of an intramedullary nail
Free tissue transfer instead of rotational flap
Need for multiple debridements
The presence of depression at the 3 months post-injury is a significant predictor of worse long term outcome as well as lower return to work rates in patients that present with limb threatening lower extremity trauma.
The findings of the Lower Extremity Assessment Project (LEAP study) has challenged many of the long-held beliefs of lower extremity trauma surgery, including the concept that patients with absent plantar sensation should undergo immediate amputation . The LEAP study has also brought to light the importance of socioeconomic and psychosocial factors in patient outcomes following these injuries.
Bosse et al analyzed a subgroup of 55 patients from the LEAP study with absent plantar sensation at presentation. Those patients that underwent limb salvage despite absent sensation (n=26) had no significant difference in functional outcome when compared with either insensate patients who underwent amputation or a matched control group of sensate patients with similar injuries. All but one patient in the salvage group had return of some sensation at 2-year follow up and the authors concluded that an insensate plantar foot at presentation should not be included in the algorithm for amputation.
Mackenzie and Bosse reviewed the results of the LEAP study with particular emphasis on the social and economic variables that influence outcomes in severe lower extremity. The authors note that 19% of patients screened positive for severe depression. The presence of anxiety, pain and depression at 3 months post-injury were significant predictors of poor outcome
Incorrect Answers:
tissue for type IIIB tibia fractures. Answer 5: The number of debridements has not been shown to influence outcome.

Question 50

Which of the following is considered a risk factor for the development of low back pain?

Explanation

DISCUSSION: Risk factors associated with low back pain include poor physical fitness, smoking, a history of repetitive bending or stooping on the job, or whole body vibration exposure. Some radiographic factors such as stenosis, spondyloarthropathy, severe deformity, or instability are also associated with low back pain. Gender, weight, transitional anatomy, or facet trophism are not associated with low back pain.
REFERENCE: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 627-643.

Question 51

An adult patient with a grade I isthmic spondylolisthesis at L5-S1 is most likely to have weakness of the Review Topic

Explanation

Adult patients with isthmic spondylolisthesis most commonly have neurologic symptoms due to foraminal stenosis at the level of the spondylolisthesis. In this scenario, the patient is most likely to have weakness of the L5 myotome, which would cause weakness of the extensor hallucis longus.

Question 52

The therapeutic effect of etanercept in the treatment of rheumatoid arthritis is primarily mediated through

Explanation

DISCUSSION: Etanercept is a fusion protein that combines the ligand-binding domain of the TNF-α receptor to the Fc portion of human immunoglobulin G (IgG). Protein serves as a competitive inhibitor of TNF-α signaling. COX2 is the target of NSAIDs, including newer formulations that are more COX2-specific. The remaining responses are not direct targets of etanercept.
REFERENCES: Weinblatt ME, Kremer JM, Bankhurst AD, et al: A trial of etanercept, a recombinant tumor necrosis factor receptor: Fc fusion protein, in patients with rheumatoid arthritis receiving methotrexate. N Engl J Med 1999;340:253-259.
Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 489-530.

Question 53

A 13-year-old girl with Down syndrome has bilateral chronic patellar dislocations. She denies knee pain. She is able to straighten her knees and walks with a symmetric but awkward gait. She does not flex her knees in midstance. Examination reveals that the patellae cannot be brought into a reduced position. Management should consist of

Explanation

DISCUSSION: Chronic dislocation of the patella is occasionally seen in patients with Down syndrome. In early childhood, patellar realignment may restore stability of the patellae. In later childhood, bony changes in the patellar groove interfere with stability, even if surgical realignment is performed. Realignment can also lead to increased knee pain postoperatively. In asymptomatic patients who are able to extend their knees, continued observation is the management of choice.
REFERENCES: Dugdale TW, Renshaw TS: Instability of the patellofemoral joint in Down syndrome. J Bone Joint Surg Am 1986;68:405-413.
Mendez AA, Keret D, MacEwen GD: Treatment of patellofemoral instability in Down’s syndrome. Clin Orthop 1988;234:148-158.

Question 54

A 23-year-old woman with recurrent anterior instability undergoes an open Bankart procedure. Six months after surgery the patient reports shoulder

Explanation

The axial MRI scan shows rupture of the subscapularis tendon with dislocation of the biceps tendon. Treatment should include a biceps tenotomy or tenodesis in conjunction with a subscapularis repair. A pectoralis major transfer may be necessary in chronic cases where the subscapularis is irreparable, but in this patient the tendon is repairable. As a single operation, biceps tenolysis will not correct the instability, and would likely result in a cosmetic deformity. Physical therapy will not restore subscapularis function.

Question 55

Which of the following lumbar disk components has the highest tensile modulus to resist torsional, axial, and tensile loads? Review Topic

Explanation

The annulus fibrosis has a multilayer lamellar architecture mode of type I collagen fibers. Each successive layer is oriented at 30 degrees to the horizontal in the opposite direction, leading to a “criss-cross” type pattern. This composition allows the annulus, which has the highest tensile modulus, to resist torsional, axial, and tensile loads.

Question 56

Of all the pelvic ring injury types, anteroposterior compression type III pelvic ring injuries have the highest rate of which of the following?

Explanation

DISCUSSION: Of the pelvic ring injuries, APC type III have the highest rate of mortality, blood loss, and need for transfusion. They also have a high rate of urogenital injury and abdominal organ injury. Lateral compression injuries (especially type III) have the highest rate of head injury. Vertical shear and combined injuries also have significant rates of concomitant injuries. The referenced article by Dalal et al is a review of Shock Trauma's pelvic ring injuries; they found significant increases in associated injuries as the grade of pelvic ring injury increased, regardless of mechanism/pattern. The aforementioned information was also found to be true with their patient review.

Question 57

Compared with percutaneous pinning with Kirschner wires (K-wires), the treatment of metacarpal neck fractures with cannulated intramedullary screws is associated with

Explanation

EXPLANATION:
In a biomechanical study, headless compression screws showed superior load to failure, higher three-point bending strength, and greater strength in axial loading compared with percutaneous K-wire fixation for metacarpal neck fractures. Headless compression screws provide greater initial stability to allow earlier motion in the postoperative period. No data comparing infection rates between the two methods of fixation are available; however, it is assumed that K-wires placed outside of the skin would have increased rates of infection. Neither fixation method would increase the time to healing.

Question 58

273 In an athlete who has full, painless range of motion and a normal neurological examination, which of the following is considered an absolute contraindication to participation in a collision sport such as football?

Explanation

The combination of congenital stenosis with instability, disk disease (bulge or herniation), degenerative change (osteophytes), MR imaging evidence of cord abnormality, neurologic findings lasting longer than 36 hours, or more than one recurrence is considered an absolute contraindication to sports participation. Congenital stenosis (Pavlov ratio less than 0.8) without instability is not considered a contraindication to play. Congenital anomalies of the upper cervical spine are an absolute contraindication to participation in all contact sports. This includes os odontoideum, odontoid hypoplasia or aplasia, and atlantooccipital fusion, even if asymptomatic. During play, if neurological symptoms resolve quickly and the neurologic examination is normal with full motor strength, the patient may return to the game. Persistence of symptoms or lack of a pain-free range of motion requires further evaluation, including cervical spine radiographs. Players should be restricted from further play until they have recovered full muscle strength. Cervical disk herniations can have serious permanent neurologic complications. A disk bulge without herniation as demonstrated by MR imaging, can be treated conservatively with activity modification. Return to play may occur when pain-free full range of motion is demonstrated and radicular symptoms are completely resolved. Symptomatic disk herniation with cord or root impingement may require anterior diskectomy with interbody fusion. A limited fusion (one or two levels) of the subaxial cervical spine is not considered a contraindication to future play if the segments above and below the fusion are normal. A return to play cannot be recommended until there is radiographic evidence that the graft is well incorporated, the symptoms are completely resolved, and the player demonstrates a painless range of motion and full motor strength. With the exception of spear tackler Õs spine, there is no evidence that transient neurapraxia of the cord predisposes an individual to subsequent permanent quadriplegia or quadriparesis.
Thomas BE, et al. Cervical spine injuries in football players. J AM Acad Orthop Surg 1999;7:338-347
Torg JS et al: Neurapraxia of the cervical spinal with transientquadriplegia. JBJS Am 1986:68:1354-

Question 59

Osteoclasts originate from which of the following cell types?

Explanation

DISCUSSION: Osteoclasts originate from the monocyte/macrophage lineage. Fibroblasts and osteoprogenitor cells originate from mesenchymal stem cells and do not form osteoclasts. Plasma cells reside in the bone marrow and are derivatives of the hematopoietic system. Megakaryocytes are also in the bone marrow and synthesize platelets.
REFERENCES: Zaidi M, Blair HC, Moonga BS, et al: Osteoclastogenesis, bone resorption, and osteoclast-based therapeutics. J Bone Miner Res 2003;18:599-609.
Brinker MR: Bone (Section 1), in Miller M (ed): Review of Orthopaedics, ed 2. Philadelphia, PA, WB Saunders, 1996, pp 1-35.
Zuscik MJ, Drissi MH, Reynolds PR, et al: Molecular and cell biology in orthopaedics, in Einhorn TA, O’Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006,

in press.

Question 60

A 55-year-old woman with a 15-year history of systemic lupus erythematosus has had left shoulder pain for the past 3 months. She reports that the pain has grown progressively worse over the past few months, and her shoulder function is severely limited. She is presently being treated with azathioprine and has used corticosteroids in the past. AP and axillary radiographs are shown in Figures 19a and 19b, and MRI scans are shown in Figures 19c and 19d. Which of the following forms of management will yield the most predictable pain relief and return of shoulder function?

Explanation

DISCUSSION: Prosthetic shoulder arthroplasty has been shown to provide predictable results for treating stage III and stage IV osteonecrosis of the humeral head. The decision to resurface the glenoid (total shoulder arthroplasty versus humeral hemiarthroplasty) usually is made based on the radiographic and intraoperative appearance of the glenoid. Core decompression of the humeral head has been reported to be effective for earlier stages (pre collapse) but would not be appropriate for a patient with stage IV disease.
REFERENCES: Hattrup SJ, Cofield RH: Osteonecrosis of the humeral head: Results of replacement. J Shoulder Elbow Surg 2000;9:177-182.
L’Insalata JC, Pagnani MJ, Warren RF, et al: Humeral head osteonecrosis: Clinical course and radiographic predictors of outcome. J Shoulder Elbow Surg 1996;5:355-361.
Cruess RL: Steroid-induced avascular necrosis of the head of the humerus: Natural history and management. J Bone Joint Surg Br 1976;58:313-317.

Question 61

A 16-year-old girl sustains the closed injury shown in Figure 1. On physical examination, she is found to have a complete radial nerve palsy. Her fracture is treated nonsurgically, and her nerve palsy is followed clinically for improvement. What muscle is most likely to improve last as her nerve recovers?

Explanation

A 35-year-old man reports ulnar sided wrist pain. Radiographs show ulnar positive variance with cystic changes in the ulnar head and lunate. His body mass index (BMI) is 22, and he has had a 1.5-pack-per-day smoking history for the past 10 years. He undergoes an oblique ulnar shortening osteotomy with volar placement of the plate. Nine months after surgery, he reports continued pain, and radiographs reveal a nonunion. Of the factors cited for this patient, which has been shown to most likely increase the risk of nonunion?

Question 62

A coach of three football teams—the B team, junior varsity team, and varsity team—wants to study the average times in the 40-yard dash for his players. Which test would help him determine if the mean 40-yard dash times for the athletes on one team are different from those on the other teams?

Explanation

Data collected in research studies fall into one of two categories—continuous or discrete. Continuous data can be displayed on a curve. Examples include height, weight, and time recorded in a 40-yard dash. Discrete data represent data that fall into specific categories such as gender or the presence or absence of a risk factor. ANOVA is used to determine statistical significance in mean values of continuous data when there are more than two independent samples. The 2-sample t test compares mean values of continuous data between two independent groups. The Chi-square test and Fisher's exact tests are tests used to analyze discrete data.

Question 63

Which of the following is considered a contraindication to the use of a reverse total shoulder arthroplasty? Review Topic

Explanation

The reverse total shoulder arthroplasty depends on a functional deltoid muscle which is innervated by the axillary nerve to restore elevation for the patient. Pseudoparalysis is an indication for a reverse shoulder arthroplasty. Acromioplasty has not been correlated with poor results with a reverse shoulder arthroplasty. As long as the patient does not have an active infection, prior infections are not a contraindication. Patients can still have pain and pseudoparalysis from a chronic rotator cuff tear, despite having normal cartilage, and they will still benefit from a reverse total shoulder arthroplasty if other treatments have failed.

Question 64

-The center of rotation of the knee can be best described as

Explanation

Question 65

-A 37-year-old woman has a 2-month history of weakness in thumb and finger extension, but has normal radial deviation during extension of the wrist. An MRI scan of her forearm shows no abnormality. She does not recall any traumatic event. Needle electromyography findings show fibrillations and reduced

Explanation

Question 66

..Figures 83a and 83b are the radiographs of a 53-year-old otherwise healthy homemaker who had a syncopal episode and sustained a ground-level fall and injury to her right elbow. She presently admits to right elbow pain, swelling, and an inability to bend her elbow. What is the best initial treatment for this injury?

Explanation

He did not have an engaging Hill-Sachs lesion, the rotator cuff was unremarkable, and the capsule was not torn from the humerus. After surgery, he did well for 6 months until he jumped into a lake and again dislocated his shoulder anteriorly. He says his shoulder no longer felt stable after his reduction.

Question 67

An active, right-handed 71-year-old woman fell on her left shoulder and sustained the injury shown in the radiographs in 52a and 52b and the CT scan in 52c. Management should consist of

Explanation

Prosthetic hemiarthroplasty is the accepted form of treatment for badly displaced fractures and fracture dislocations, including 4-part fractures, head splitting fractures and fractures with impression defects involving more than 45 % of the humeral head. Displacement is classified as >1cm or angulated > 45 degrees. About 15% of all shoulder fx’s are considered displaced.

Question 68

….Figures 83a through 83c are the radiograph and MRI scans of a 16-year-old girl who had posterior knee pain after a dance recital 3 weeks ago; the pain resolved 1 week ago with ibuprofen use. What is the appropriate treatment for this patient?

Explanation

CLINICAL SITUATION FOR QUESTIONS 84 THROUGH 86
Figures 84a and 84b are the CT and MRI scans of a 17-year-old girl with a painful lumbosacral scoliosis that has been present for 12 months. Examination is notable only for pain over the left sacral region and a postural scoliosis leaning away from this side.

Question 69

-The main blood supply to the capital femoral epiphysis in a 10-year-old child is supplied from the

Explanation

Question 70

A researcher decides she wants to look at the current total number of patients who have methicillin-resistant Staphylococcus aureus (MRSA) infections in a hospital on 1 particular day. What is the researcher measuring?

Explanation

The prevalence of a disease is a measure of the number of cases of a disease at or during a specific time point or time period. In this case, the researcher wants to know the prevalence of disease on a given day. Incidence measures new cases of a disease or event per unit of time. Correlation coefficient is a measure of how 2 things correlate with one another, while relative risk is a statistical outcome that is often used in case-control or cohort studies to provide a measure of the risk of a particular disease occurring when a certain exposure has already occurred.

Question 71

An 82-year-old man has had episodic right thigh pain after undergoing a total hip arthroplasty 10 years ago. Initial postoperative radiographs are shown in Figures 26a and 26b, and current radiographs are shown in Figures 26c and 26d. What is the most likely cause of his pain?

Explanation

DISCUSSION: These radiographs are dominated by the subsidence of the femoral component. There is also evidence of polyethylene wear and femoral osteolysis in the region of the greater trochanter. There is no evidence of proximal (calcar) stress shielding, and there is a thick distal pedestal. Engh and associates defined two major signs of osseointegration - the absence of radiolucent lines around the porous-surfaced portion of the implant and new bone bridging the gap between the endosteal surface and the porous portion of the implant. Implant migration indicates failure of ingrowth. Osteolysis is a periprosthetic loss of bone secondary to particulate debris and it is often clinically silent unless it is accompanied by pathologic fracture. It is often globular. Acetabular loosening is based on radiolucent lines and implant migration. The current radiographs demonstrate subsidence of the stem with pedestal formation.
REFERENCES: Engh CA, Massin P, Suthers KE: Roentgenographic assessment of biologic fixation of porous-surface femoral components. Clin Orthop Relat Res 1990;257:107-128.
Engh CA, Hooten JP, Zettl-Schaffer KF, et al: Evaluation of bone ingrowth in proximally and extensively porous-coated anatomic medullary locking prostheses retrieved at autopsy. J Bone Joint Surg Am 1995;77:903-910.

Question 72

Which of the following articulation couplings shows the lowest coefficient of friction as tested in the laboratory?

Explanation

DISCUSSION: Alumina ceramic is highly biocompatible when used as a biomaterial for joint arthroplasty implants. It has been shown to have good hardness, low roughness, and excellent wettability, therefore resulting in very low friction. However, it is expensive and limited reports have shown the problem of fracture on impact. The exact role for ceramic articulations is unknown at present.
REFERENCES: Cuckler JM, Bearcroft J, Asgian CM: Femoral head technologies to reduce polyethylene wear in total hip arthroplasty. Clin Orthop 1995;317:57-63.
Sharkey PF, Hozack WJ, Dorr LD, Maloney WJ, Berry D: The bearing surface in total hip arthroplasty: Evolution or revolution, in Price CT (ed): Instructional Course Lectures 49. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 41-56.

Question 73

A consecutive series of 50 patients is randomized to receive either treatment A or treatment B. At a 10-year follow up, patient satisfaction with treatment is measured. Which of the following statistical calculations will provide the most information regarding the magnitude of possible differences between the two groups of patients?

Explanation

The confidence interval provides you a range of values that with a given level of confidence (usually 95%) contains the truc value. The confidence interval also reflects the limitations of data presented (i.e. if no sepsis occurred during a two year follow-up of THR, should we believe there will never be any recurrences of sepsis rate if we perform a hundred of these exchanges in the future.) Confidence internals are also essential when presenting long-term results based on survivorship curve. Without confidence intervals the picture presented to the readers can be misleading. In these cases more data are needed before any proelic (?) statements can be made.

Question 74

What is the minimum hours per day of wear that has been correlated with the effectiveness of bracing on curve progression in idiopathic scoliosis? Review Topic

Explanation

The efficacy of brace treatment for patients with adolescent idiopathic scoliosis is controversial because its effectiveness remains unproven. One of the challenges is patient noncompliance with prescribed bracing regimens. A recent study investigated curve progression based on actual brace wear using a temperature sensor to accurately assess brace wear. The total hours of brace wear correlated with lack of curve progression with a dose-response effect noted. Curves did not progress in 82% of patients who actually wore the brace more than 12 hours per day. For those who wore the brace for fewer than 7 hours per day, curves progressed in 69%. Prescribed bracing regimens (eg, 16 hours/day or 23 hours/day) had no effect on actual brace wear or curve progression.

Question 75

A soccer player who sustained a twisting injury to the right ankle while making a cut is unable to bear weight and has diffuse tenderness over the anterior and lateral aspects of the ankle. Examination also shows a positive squeeze test. Plain radiographs and a stress radiograph are shown in Figures 26a through 26c. Radiographs of the leg and knee are normal. What is the most appropriate management?

Explanation

DISCUSSION: The mechanism of injury, physical examination, and radiographs indicate a “high” ankle sprain with disruption of the distal tibiofibular ligaments and interosseous membrane. These injuries typically involve pronation and external rotation forces. In addition, recovery is significantly delayed, often requiring 6 to 8 weeks to heal. Radiographs obtained months after recovery often show calcification within the distal syndesmosis, which is not typically symptomatic. This patient has gross instability, resulting in a high incidence of chronic diastasis and subluxation leading to impaired function. Treatment should consist of reduction and stabilization with a transsyndesmotic screw because this injury demonstrates a widened syndesmosis.
REFERENCES: Boytim MJ, Fisher DA, Neumann L: Syndesmotic ankle sprains. Am J Sports Med 1991;19:294-298.
Miller CD, Shelton WR, Barrett GR, et al: Deltoid and syndesmosis ligament injury of the ankle without fracture. Am J Sports Med 1995;23:746-750.

Question 76

In a statement put forth by AAOS, the role of the orthopaedic surgeon in the face of domestic and family abuse includes all of the following EXCEPT: Review Topic

Explanation

Regardless of the social situation, the orthopaedic surgeon's primary role is to proceed and offer expeditious and appropriate care for the patient's injuries.
The statement put forth by the AAOS implores the orthopaedic surgeon to be aware of the integral components to identify, document, and care for minors, elders, and/or partners who are victims of domestic abuse.
Zilmer et al. in a JAAOS review and the basis for the AAOS statement emphasizes the ability to identify abuse, which includes, but is not limited to frequent/multiple injuries, temporal abnormalities in multiple injuries, frequent visits/utilization of the emergency department, and/or unusual injuries/fracture patterns not consistent with the clinical picture. Meticulous documentation is of paramount importance, in addition to communicating your concerns to the appropriate emergency department personnel.
Incorrect answers:

Question 77

A 14-year-old girl has idiopathic scoliosis with a 52-degree right thoracic curve and a 36-degree left lumbar curve. The rotation of the apical vertebra appears greater in the thoracic curve. A sagittal view radiograph shows the spine to be virtually straight. The iliac apophyses are Risser 2. Treatment should consist of

Explanation

The patient’s curve is beyond the limit for bracing to be effective (40 degrees). Therefore, surgical treatment should be utilized. King type II curves (predominant thoracic curve with secondary lumbar curve) historically has used selective posterior thoracic fusion with segmental hook systems and rotation maneuvers to correct the thoracic curve and compensatory lumbar curve. The patient’s primary curve is thoracic and lumbar fusion would be contraindicated.

Question 78

Figure 6 shows an object being held in an outstretched hand. To offset the moment created by the object (ignoring the weight of the forearm), the biceps must generate a force of

Explanation

DISCUSSION: Answering this question requires understanding of two important biomechanics concepts. First, because neither the object being held in the hand nor the body is moving and, hence, their accelerations are zero, the problem is one of static equilibrium in which the sum of the moments acting on the body is zero. Second, a moment is the action of a force that causes an object to rotate about any point away from its line of action. The magnitude of the moment is the magnitude of the force multiplied by the perpendicular distance between the line of action and the point (often called the moment arm or lever arm). In this problem, two forces are causing moments about the elbow. The magnitude of the moment caused by the object in the hand is 5 N times 30 cm or 150 N-cm. To maintain equilibrium, the moment caused by the biceps force must also have a magnitude of 150 N-cm. Its moment arm is 2 cm, so the magnitude of the biceps force is 150 N-cm divided by 2 cm, which equals 75 N. In general, functional loads such as the object are always at a mechanical advantage (ie, have a longer moment arm) over the muscle. Therefore, muscles must generate large forces to overcome the moments caused by even small functional loads.
REFERENCES: An KN, Chao ES, Kaufman KR: Analysis of muscle and joint loads, in Mow VC, Hayes WC (eds): Basic Orthopaedic Biomechanics, ed 2. New York, NY, Lippincott-Raven, 1997, pp 1-14.
Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 134-143.

Question 79

A 6-year-old boy with spastic diplegic cerebral palsy has a crouched gait. Examination reveals hip flexion contractures of 15 degrees and popliteal angles of 70 degrees. Equinus contractures measure 10 degrees with the knees extended. Which of the following surgical procedures, if performed alone, will worsen the crouching?

Explanation

DISCUSSION: Children with spastic diplegic cerebral palsy often have contractures of multiple joints. Because the gait abnormalities can be complex, isolated surgery is rarely indicated. To avoid compensatory deformities at other joints, it is preferable to correct all deformities in a single operation. Isolated heel cord lengthening in the presence of tight hamstrings and hip flexors will lead to progressive flexion at the hips and knees, thus worsening a crouched gait. Split posterior tibial tendon transfer is used for patients with hindfoot varus, which is not present in this patient.
REFERENCES: Gage JR: Distal hamstring lengthening/release and rectus femoris transfer, in Sussman MD (ed): The Diplegic Child. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1992, pp 324-326.
Bleck EE: Orthopaedic Management of Cerebral Palsy, in Saunders Monographs in Clinical Orthopaedics. Philadelphia, PA, WB Saunders, vol 2, 1979.

Question 80

A patient undergoes hip arthroscopy, and the pathology is seen in Figure 18. What is the most likely diagnosis?

Explanation

DISCUSSION: The motorized shaver is adjacent to the acetabular labrum, which is torn. The femoral head and acetabulum are normal in appearance. Neither the fat pad nor a loose body is identified.
REFERENCE: Byrd JWT: Operative Hip Arthroscopy. New York, NY, Thieme Medical Publishers, 1998, pp 93-104.

Question 81

You are interested in learning a new technique for minimally invasive total knee arthroplasty. The Keyhole Genuflex system seems appealing to you because the instrumentation comes with wireless controls. Which of the following represents an acceptable arrangement?

Explanation

Both the AAOS and AdvaMed, the medical device manufacturer's trade organization, have written guidelines that address potential conflicts of interest regarding interactions between physicians and manufacturer's representatives when it comes to patients' best interest. The AAOS feels that the orthopaedic profession exists for the primary purpose of caring for the patient and that the physician-patient relationship is the central focus of all ethical concerns. When an orthopaedic surgeon receives anything of significant value from industry, a potential conflict of interest exists. The AAOS believes that it is acceptable for industry to provide financial and other support to orthopaedic surgeons if such support has significant educational value and has the purpose of improving patient care. All dealings between orthopaedic surgeons and industry should benefit the patient and be able to withstand public scrutiny. A gift of any kind from industry should in no way influence the orthopaedic surgeon in determining the most appropriate treatment for his or her patient. Orthopaedic surgeons should not accept gifts or other financial support with conditions attached. Subsidies by industry to underwrite the costs of educational events where CME credits are provided can contribute to the improvement of patient care and are acceptable. A corporate subsidy received by the conference's sponsor is acceptable; however, direct industry reimbursement for an orthopaedic surgeon to attend a CME educational event is not appropriate. Special circumstances may arise in which orthopaedic surgeons may be required to learn new surgical techniques demonstrated by an expert or to review new implants or other devices on-site. In these circumstances, reimbursement for expenses may be appropriate.

Question 82

A 72-year-old man with diabetic neuropathy and 5 degrees of valgus talar tilt; he has pursued nonsurgical treatment for 30 years and now has unrelenting pain

Explanation

DISCUSSION
Arthritis of the ankle and hindfoot can pose challenges. Depending upon patient age, comorbidities, and alignment, a variety of surgical interventions may be offered. A total ankle replacement may be considered for patients older than 60 years of age who have minimal misalignment and low-demand lifestyles. In all other cases, ankle fusion must be considered. The nonsurgical care of ankle arthritis includes anti-inflammatory medication, intra-articular steroid injections, bracing with customized products such as the Arizona brace, or a molded foot and ankle orthosis.
Patients with diabetes and Charcot arthropathy may be treated nonsurgically with total-contact casting during acute and active or "hot" phases and accommodative shoes during consolidation and stable or "cool" phases. When the patient has recurrent ulcers or major anatomy changes, surgical intervention must be considered. Tibiotalocalcaneal fusion helps to realign the foot and ankle and make it more braceable in the setting of ankle and hindfoot Charcot disease.
RECOMMENDED READINGS
Queen RM, Adams SB Jr, Viens NA, Friend JK, Easley ME, Deorio JK, Nunley JA. Differences in outcomes following total ankle replacement in patients with neutral alignment compared with tibiotalar joint malalignment. J Bone Joint Surg Am. 2013 Nov 6;95(21):1927-34. doi: 10.2106/JBJS.L.00404. PubMed PMID: 24196462. View Abstract at PubMed
Nunley JA, Caputo AM, Easley ME, Cook C. Intermediate to long-term outcomes of the STAR Total Ankle Replacement: the patient perspective. J Bone Joint Surg Am. 2012 Jan 4;94(1):43-8. doi: 10.2106/JBJS.J.01613. PubMed PMID: 22218381. View Abstract t PubMed
Saltzman CL, Mann RA, Ahrens JE, Amendola A, Anderson RB, Berlet GC, Brodsky JW, Chou LB, Clanton TO, Deland JT, Deorio JK, Horton GA, Lee TH, Mann JA, Nunley JA, Thordarson DB, Walling AK, Wapner KL, Coughlin MJ. Prospective controlled trial of STAR total ankle replacement versus ankle fusion: initial results. Foot Ankle Int. 2009 Jul;30(7):579-96. doi: 10.3113/FAI.2009.0579. PubMed PMID: 19589303. View Abstract at PubMed
Faraj AA, Loveday DT. Functional outcome following an ankle or subtalar arthrodesis in adults. Acta Orthop Belg. 2014 Jun;80(2):276-9. PubMed PMID: 25090803. View Abstract at PubMed Grear BJ, Rabinovich A, Brodsky JW. Charcot arthropathy of the foot and ankle associated with rheumatoid arthritis. Foot Ankle Int. 2013 Nov;34(11):1541-7. doi: 10.1177/1071100713500490. Epub 2013 Jul 30. PubMed PMID: 23900228. View Abstract at PubMed

Question 83

A 30-year-old patient has wrist pain. A radiograph and biopsy specimen are shown in Figures 34a and 34b. What is the most likely diagnosis?

Explanation

DISCUSSION: Aneurysmal bone cysts typically present as radiolucent lesions with an expansile remodeled cortex. The histologic appearance consists of blood-filled lakes surrounded by a benign lining that contains fibroblasts, giant cells, and hemosiderin. Although the other lesions are in the radiographic differential diagnosis, these histologic findings indicate an aneurysmal bone cyst.
REFERENCES: Bieselker JL, Marcove RC, Huvos AG, Mike V: Aneurysmal bone cyst: A Clinico-pathologic study of 66 cases. Cancer 1973;26:615.
Martinez V, Sissons HA: A review of 123 cases including primary lesions and those secondary to other bone pathology. Cancer 1988;61:2291.

Question 84

The spinal cord terminates as the conus medullaris at what vertebral level in adults? Review Topic 1 T12

Explanation

The spinal cord anatomy changes at the thoracolumbar junction. The spinal cord terminates as the conus medullaris at the lower portion of L1 in women and the pedicle of L1 in men.

Question 85

The most appropriate surgical approach includes which of the following? Review Topic

Explanation

Intra-articular distal humerus fractures are best approached through a posterior elbow approach, including an olecranon chevron osteotomy to clearly visualize the reduction of the articular surface. The other stated approaches will not provide sufficient visualization of the joint surface to allow stable reduction. A closed reduction and screw fixation will not offer optimal fracture stability.

Question 86

A patient who underwent an L5-S1 diskectomy 18 months ago has persistent pain in the left leg. Figures 9a and 9b show postoperative axial T 1 -weighted MRI scans at the L5-S1 level without and with gadolinium. What is the most likely diagnosis?

Explanation

DISCUSSION: Persistent or recurrent symptoms after lumbar diskectomy are troublesome and can be difficult to assess. Gadolinium-enhanced MRI scans may be helpful. The images show enhancement about the left S1 root, a finding that is most consistent with perineural (epidural) fibrosis. The root itself does not enhance. Root enhancement has been associated with compressive radicular symptoms. A disk herniation does not enhance with gadolinium. A neurilemmoma enhances with gadolinium, but the involved root would be enlarged. There is no evidence of a fluid collection which would be consistent with an epidural abscess.
REFERENCES: Babar S, Saifuddin A: MRI of the post-discectomy lumbar spine. Clin Radiol 2002;57:969-981.
Kikkawa I, Sugimoto H, Saita K, et al: The role of Gd-enhanced three-dimensional MRI fast low-angle shot (FLASH) in the evaluation of symptomatic lumbosacral nerve roots. J Orthop Sci 2001;6:101-109.
Vroomen PC, Van Hapert SJ, Van Acker RE, et al: The clinical significance of gadolinium enhancement of lumbar disc herniations and nerve roots on preoperative MRI. Neuroradiology 1998;40:800-806.

Question 87

Five weeks after the patient completes a 6-week course of antibiotics, his ESR is 24 mm/h and CRP level is 10 mg/L, which is similar to the levels at 6 weeks. What is the most appropriate treatment at this time?

Explanation

DISCUSSION
This patient has both serologic and synovial fluid findings that are concerning for indolent infection. He was taking antibiotics at the time of aspiration. The AAOS clinical practice guideline, The Diagnosis of Periprosthetic Joint Infections of the Hip and Knee, suggests that patients discontinue antibiotics for a minimum of 2 weeks and that a repeat aspiration should be performed in cases of contradictory findings. In this situation, the cell count is elevated
along with an elevated ESR and CRP level. As a result, the appropriate treatment at this time is to reaspirate his hip.
This patient has a periprosthetic joint infection with a draining sinus tract. He has had symptoms for several months and, as a result, irrigation and debridement are not indicated. A single-stage surgery may be performed in some centers for healthy patients with susceptible organisms. However, single-stage reconstructions are generally performed with cemented implants in patients without a draining sinus tract. A 2-stage procedure with an antibiotic spacer is the surgical treatment modality most likely to eradicate this infection.
Serologic findings have significantly improved since the time of the prior surgical procedure. Surgical intervention does not need to be delayed until these values have completely normalized.

Question 88

Figures 1 through 3 demonstrate the radiographs obtained from a 45-year-old construction worker who has wrist pain, loss of motion, and loss of strength. Nonsurgical measures have failed, and the patient requests surgery. What is the best surgical option for this patient?

Explanation

EXPLANATION:
This patient has a physically demanding occupation. His radiographs show a long-standing nonunion with avascular necrosis and collapse of the proximal pole. This condition is referred to as a scaphoid nonunion advanced collapse wrist (SNAC). He has advanced arthritis of the capitolunate joint, but the radiolunate joint is preserved. The best option for him would be scaphoid excision with four-corner fusion. Proximal row carpectomy, would be incorrect because of the advanced arthritis of the capitolunate joint. This procedure relies on normal cartilage/joint articulation of the capitate as well as of the lunate fossa of the distal radius. Proximal pole scaphoid excision alone would not address the advanced arthritis of the capitolunate joint. Scaphoid fixation with bone grafting would not address the midcarpal arthritis and advanced proximal pole collapse.

Question 89

A 14-year-old girl reports hip pain that is exacerbated by weight bearing. A radiograph and biopsy specimen are shown in Figures 16a and 16b. The best course of management should be

Explanation

DISCUSSION: The patient has a unicameral bone cyst. Because the subtrochanteric part of the femur is a high-stress region, the treatment of choice is bone curettage and grafting.
REFERENCES: Azouz EM, Karamitsos C, Reed MH, Baker L, Kozlowski K, Hoeffel JC: Types and complications of femoral neck fractures in children. Pediatr Radiol 1993;23:415-420.
Hecht AC, Gebhardt MC: Diagnosis and treatment of unicameral and aneurysmal bone cysts in children. Curr Opin Pediatr 1998;10:87-94.

Question 90

A 20-year-old man sustains the injury shown in Figures 1a and 1b in a motorcycle accident. In addition to a prompt closed reduction, his outcome might be optimized by

Explanation

DISCUSSION: Lateral subtalar dislocations, which are less common than medial subtalar dislocations, are high-energy injuries that are frequently associated with small osteochondral fractures. It is generally recommended that large fragments be internally fixed, and small fragments entrapped within the joint be excised. Although arthrosis frequently occurs after this injury and is the most common long-term complication, primary subtalar arthrodesis is not indicated. A talar neck fracture is not evident on the radiographs, and lateral subtalar dislocation usually does not lead to instability.
REFERENCE: Saltzman C, Marsh JL: Hindfoot dislocations: When are they not benign? J Am Acad Orthop Surg 1997;5:192-198.

Question 91

A 20-year-old college athlete is seen for follow-up after sustaining an injury at football practice 2 days ago. He reports that he tackled a player and felt neck pain and numbness in both arms. The numbness resolved within seconds, but his neck remains painful and stiff. He denies any history of neck pain or injury. Examination reveals limited neck motion. The neurologic examination and radiographs are normal. MRI scans of the cervical spine are shown in Figure 34. During counseling, the patient, his family, and his coach should be informed that he has an acute cervical disk herniation and cannot play

Explanation

DISCUSSION: A player who has an acute cervical disk herniation should not be allowed to return to play until the acute phase is over. Certain players with large herniations may require surgery before returning to play to eliminate the risk of disk-related stenosis and cord compression.
REFERENCES: Morganti C, Sweeney CA, Albanese SA, Burak C, Hosea T, Connolly PJ: Return to play after cervical spine injury. Spine 2001;26:1131-1136.
Vaccaro AR, Watkins B, Albert TJ, Pfaff WL, Klein GR, Silber JS: Cervical spine injuries in athletes: Current return-to-play criteria. Orthopedics 2001;24:699-705.

Question 92

Pelvic packing for a hemodynamically unstable patient with a pelvic ring fracture is best described by which of the following techniques?

Explanation

For the technique of pelvic packing patients are placed supine on an operating room table. For rotationally and/or vertically unstable fracture patterns, an external fixator is then placed to stabilize the pelvis so that the volume of the pelvis is decreased and the packing has counterforce acting against it. An approximately 6 cm to 8 cm midline incision is made extending upwards from the pubic symphysis and heading toward the umbilicus. The rectus fascia is then divided in the midline. The bladder is retracted to one side and three lap pads are packed deep to the pelvic brim. The bladder is retracted to the other side and three more lap pads are placed on that side as well. The first sponge is placed at the level of the sacroiliac joint, the second anterior to the first sponge, and the third in the retropubic space lateral and just deep to the bladder. All should be placed below the level of the pelvic brim. The fascia is then closed. If the patient is hemodynamically unstable after stabilization, then packing of the pelvis angiography should be considered.

Question 93

A 47-year-old woman has had a 1-month history of left hip and medial thigh pain that is exacerbated by sitting. Laboratory studies show a total protein level of 8.2 g/dL (normal 6.0 to 8.0) and an immunoglobulin G (IGG) level of 2,130 mg/dL (normal 562 to 1,835). A radiograph, CT scan, and biopsy specimen are shown in Figures 38a through 38c. What is the most likely diagnosis?

Explanation

DISCUSSION: The laboratory studies and histology are both consistent with myeloma. Infection should show white blood cells other than plasma cells on histology. Lymphoma would show lymphocytes, not plasma cells. The lack of bone formation on the imaging studies and the lack of osteoid on histology rule out osteosarcoma. The cells have too much cytoplasm and nuclear chromatin to be Ewing’s sarcoma cells.
REFERENCE: Mirra J: Bone Tumors: Clinical, Radiologic, and Pathologic Correlations. Philadelphia, PA, Lea & Febiger, 1989, vol 2, ch 16.

Question 94

To maximally resist apex anterior angulation in the tibia, the pins of a unilateral external fixator should be oriented in which of the following planes?

Explanation

The structural and geometric fixator properties that best neutralize the prevailing anteroposterior and transverse bending moments at a tibial fracture site were analyzed in anatomic specimens. Clinically and mechanically, anterior unilateral frames were most effective, particularly when applied with relatively stiff components with a maximal spread between the pins in each main bony fragment and with placement of the longitudinal rod.

Question 95

A 10-year-old girl has been unable to walk for the past 5 days because of bilateral hip pain. Administration of IV morphine has provided some pain relief. She is afebrile. History reveals that she had an upper respiratory tract infection 3 weeks ago that resolved uneventfully. Examination reveals moderate pain with internal rotation and abduction, while log rolling maneuvers do not cause significant pain. An MRI scan shows a small effusion of one hip; however, a bone scan and plain radiographs are normal. Initial laboratory studies showed a markedly elevated WBC count, which subsequently declined to normal levels with IV antibiotics. Current studies show an erythrocyte sedimentation rate (ESR) of 100 mm/h. Aspiration of the hip obtains 3 mL of fluid; Gram stain is negative for bacteria, but a cell count shows a WBC count of 16,500/mm 3 . Streptozyme titer of the peripheral blood is 200 units (normal is less than 100 units). Management should now consist of

Explanation

DISCUSSION: This clinical situation requires careful analysis because some data suggest infection and some a noninfectious inflammatory process. Bilateral hip involvement, the absence of significant fluid collection or fever, the streptozyme level, and the history of upper respiratory infection all suggest poststreptococcal toxic synovitis as the most likely cause for the clinical presentation. In the first 24 hours, this type of presentation might warrant incision and drainage given uncertainty of the diagnosis and the risks associated with missing an infection. However, 5 days after onset, surgery is not warranted, especially given that the patient remains afebrile and her symptoms are improving. Cardiology consultation would be appropriate. There is no evidence to suggest slipped capital femoral epiphysis. Treatment with antibiotics is not advised because there is no bacteriologic data on which to base treatment.
REFERENCES: De Cunto CL, Giannini EH, Fink CW, et al: Prognosis of children with poststreptococcal reactive arthritis. J Pediatr Infect Dis 1988;7:683-686.
Haueisen DC, Weiner DS, Weiner SD: The characterization of “transient synovitis of the hip” in children. J Pediatr Orthop 1986;6:11-17.

Question 96

A 14-year-old boy reports progressive right wrist pain. Radiographs are shown in Figure 3a, and a photomicrograph is shown in Figure 3b. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographs show a benign-appearing, well-defined lytic lesion with a thin rim of surrounding reactive bone. The photomicrograph shows spindle cells with a myxoid cartilaginous matrix. These findings are diagnostic of chondromyxoid fibroma. This is a rare, benign tumor that usually causes pain and can be locally aggressive.
REFERENCES: Lersundi A, Mankin HJ, Mourikis A, et al: Chondromyxoid fibroma: A rarely encountered and puzzling tumor. Clin Orthop Relat Res 2005;439:171-175.
Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 103-111.

Question 97

Following a chevron bunionectomy performed through a dorsal approach, a patient has persistent numbness on the dorsal and medial aspect of the hallux. What nerve has most likely been injured?

Explanation

DISCUSSION: The dorsomedial cutaneous nerve of the hallux, which is a distal branch of the superficial peroneal nerve, supplies sensation to the skin on the dorsal and medial half of the hallux and may be injured during a chevron bunionectomy. Injury to the nerve leads to particularly painful neuromas that directly impinge on the shoe. For this reason, direct medial approaches are typically preferred for access to the medial aspect of the metatarsophalangeal joint.
REFERENCE: Miller SD: Dorsomedial cutaneous nerve syndrome: Treatment with nerve transection and burial into bone. Foot Ankle Int 2001;22:198-202.

Question 98

Reconstruction of the injured structure is performed. After surgery, the patient initially notes limitation in motion, and later develops recurrent instability of the knee. Which factor most likely contributed to the development of instability?

Explanation

DISCUSSION
The anteromedial bundle originates on the anterior and proximal aspect of the lateral femoral condyle and inserts on the anteromedial aspect of the anterior cruciate ligament (ACL) footprint on the proximal tibia. The posterolateral bundle originates posterior and distal to 63 the anteromedial bundle and inserts on the posterolateral aspect of the tibial footprint. The fibers are parallel when the knee is in an extended position. As the knee moves into flexion,
the fibers of the anteromedial bundle rotate externally with respect to the posterolateral bundle. The anteromedial bundle is tensioned in both flexion and extension. The posteromedial bundle is tensioned in extension, but relaxes as the knee moves into flexion.
The lateral meniscus is more commonly injured with an acute injury to the ACL. The medial meniscus is injured more commonly when the ACL is chronically unstable.
The ACL is an intra-articular and intrasynovial structure. It is innervated by posterior articular branches from the tibial nerve. Innervation of the ACL involves several types of mechanoreceptors (Ruffini, Pacini, Golgi tendon, and free-nerve endings) that may contribute to proprioceptive function of the knee and modulation of quadriceps function.
Injury to the ACL is predominantly associated with instability to anterior translation of the tibia in extension. The ACL plays a secondary role to limit internal rotation of the tibia, and a loss of ACL stability is confirmed by the reduction of the tibia from a position of anterior translation and internal rotation (pivot shift). The radiographs demonstrate anterior placement of the femoral tunnel. The convex shape of the lateral femoral condyle can make it more difficult to visualize the anatomic femoral origin of the ACL. Failure to identify the
anatomic footprint can result in anterior placement of the femoral tunnel. Anterior ACL graft placement can result in its impingement against the posterior cruciate ligament and early limitation of knee flexion. Over time, impingement on the graft may result in stretching of the graft and recurrent knee instability symptoms.
RECOMMENDED READINGS
Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. Anatomy of the anterior cruciate ligament. Knee Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):204-13. Epub 2005 Oct 19. Review. PubMed PMID: 16235056. View Abstract at PubMed
Zantop T, Petersen W, Sekiya JK, Musahl V, Fu FH. Anterior cruciate ligament anatomy and function relating to anatomical reconstruction. Knee Surg Sports Traumatol Arthrosc. 2006 Oct;14(10):982-92. Epub 2006 Aug 5. Review. PubMed PMID: 16897068. View Abstract at PubMed

Question 99

In total knee arthroplasty, in vitro testing has shown that cross-linking can diminish the rate of polyethylene wear by 30% to 80%. What other change in material properties is possible when polyethylene is highly cross-linked?

Explanation

DISCUSSION:
The most important concern regarding highly cross-linked polyethylene relates to decreased mechanical properties. Cross-linking results in reduced ductility, tensile strength, and fatigue crack propagation resistance. These problems have not been shown to cause implant failure in the most recent clinical trials, but they remain the most important mechanical issues associated with current material processing methods.

Question 100

A 32-year-old man sustained an L1 burst fracture with 90% canal compromise, intact posterior elements, and kyphosis of 25% at the L1 level. He has an incomplete neurologic injury. Definitive management should consist of

Explanation

DISCUSSION: With an incomplete injury, the best chance for recovery occurs when the canal is cleared and the neural structures are decompressed. Anterior decompression, vertebral body reconstruction, and anterior stabilization have been shown to be highly effective in the treatment of burst-type injuries. Laminectomy alone is contraindicated because it increases the instability. Short segment posterior fixation has a high rate of failure in this type of injury at this level.
REFERENCES: Kaneda K, Abumi K: Burst fractures with neurologic deficits of the thoracolumbar spine. J Bone Joint Surg Am 1997;79:69-83.
McGuire R Jr: The role of anterior surgery in the treatment of thoracolumbar fractures. Orthopedics 1997;20:959-962.

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

MRI with MARS of the left hip
Revision of the left acetabular component
Intra-articular ultrasound-guided left hip injection
Physical therapy for the left hip

Correct Answer: Revision of the left acetabular component

Explanation:

Question 2:

Options:

Placing the hip center too inferior
Overmedializing the acetabular component
Overlengthening the extremity
Intrasurgical acetabular fracture

Correct Answer: Overlengthening the extremity

Explanation:

DISCUSSION
The radiograph reveals hip dysplasia. Patients with hip dysplasia and severe limb shortening are at high risk for sciatic nerve palsy from overlengthening. Overmedializing the acetabular component is not the preferred response because overlateralization is more of a concern if the cup is placed in the pseudoacetabulum instead of in the true acetabulum. Placing the hip center too inferior is not the preferred response because the concern in this scenario is placing the hip center too superior if the cup is placed in the pseudoacetabulum or if a large-diameter cup is used. Acetabular fractures are possible because of osteoporotic bone at the true hip center, but is less likely than overlengthening of the extremity.
CLINICAL SITUATION FOR QUESTIONS 11 THROUGH 13
Figures 11a and 11b are the radiographs of a 35-year-old woman with end-stage debilitating osteoarthritis of the right hip. She is contemplating total hip arthroplasty (THA). She has a history of right hip dysplasia and underwent hip osteotomy as an adolescent. Over the years, she has failed nonsurgical treatment including weight loss, activity modifications, and intra-articular injections. Her infection workup reveals laboratory findings within defined limits.

Question 3:

After excising a mass from the thigh that was thought to be a lipoma, the pathology reveals that the mass is a high-grade sarcoma. Subsequent treatment should include

Options:

repeat excision of the tumor bed.
chemotherapy only.
radiation therapy only.
chemotherapy and radiation therapy only.
administration of bisphosphonates.

Correct Answer: repeat excision of the tumor bed.

Explanation:

Question 4:

Options:

What is the next most appropriate step in treatment?
Exchange nailing
Manipulation under anesthesia
Nail removal and plate fixation
Percutaneous locked plating
Nail dynamization

Correct Answer: Manipulation under anesthesia

Explanation:

Question 5:

Options:

Repeat left hip aspiration
Initiation of a wound care consult and oral antibiotics
Irrigation and debridement with closure of the dehisced wound, performance of a liner exchange, and administration of intravenous antibiotics
Debridement of the wound, explant of the total hip, placement of a spacer, and administration of intravenous antibiotics

Correct Answer: Debridement of the wound, explant of the total hip, placement of a spacer, and administration of intravenous antibiotics

Explanation:

Question 6:

Options:

shoulder exercises, mild analgesics, and activity modification.
transfer of the latissimus dorsi to the greater tuberosity.
arthroscopy and debridement of the tendon edges.
arthroscopy, arthroscopic acromioplasty, coracoacromial ligament release, and mini open repair.
arthroscopy, arthrotomy, acromioplasty, and primary repair of the rotator cuff.

Correct Answer: shoulder exercises, mild analgesics, and activity modification.

Explanation:

Question 7:

Which of the following factors will adversely affect bone ingrowth in a revision porous-coated stem?

Options:

Pore size of 400 m m
Interface instability of 25 m m of micromotion
Use of a nonmodular implant
Noncircumferential metaphyseal patch coating
Failure of ingrowth in the previous stem

Correct Answer: Noncircumferential metaphyseal patch coating

Explanation:

DISCUSSION: The optimal conditions for bony ingrowth include a pore size of 100 to 400
m
m, interface micromotion of 50
m
m or less, intimate contact between the bone and the implant, circumferential porous coating of the implant, and use of a biocompatible material. Stem designs with patch coatings have a poor record of bony ingrowth, especially in the revision setting. Failure of ingrowth in the previous stem would be the result of its own mechanical milieu and would not necessarily predict results for the new stem.
REFERENCES: Berry DJ, Harmsen WS, Ilstrup D, Lewallen DG, Cabanela ME: Survivorship of uncemented proximally porous-coated femoral components. Clin Orthop 1995;319:168-177.
Cook SD, Thomas KA, Haddad RJ Jr: Histologic analysis of retrieved human porous-coated total joint components. Clin Orthop 1988;234:90-101.
Spector M: Historical review of porous-coated implants. J Arthroplasty 1987;2:163-177.

Question 8:

Which of the following is most predictive of a medial side ankle injury in the presence of a fibula fracture above the level of the joint?

Options:

Severe medial ankle tenderness
Severe medial ankle ecchymosis
Stress radiographs showing the medial clear space measuring 6 mm and the superior joint space measuring 3 mm
Inability to ambulate
Medial ankle swelling

Correct Answer: Stress radiographs showing the medial clear space measuring 6 mm and the superior joint space measuring 3 mm

Explanation:

DISCUSSION: Isolated Lauge-Hansen supination-external rotation-type ankle fractures comprise 20% to 40% of ankle fractures and nonsurgical management is effective for managing SER-2 ankle fractures. Tornetta and associates recently showed that medial ankle tenderness, ecchymosis, and swelling are not reliable findings when trying to determine deltoid competence. Stress radiographs showing a medial clear space of greater than 4 mm or one that is also 1 mm greater than the superior joint space, or any lateral talar subluxation are indicative of deltoid incompetence and indicative of a SER-4 ankle fracture.
REFERENCES: McConnell T, Creevy W, Tornetta P III: Stress examination of supination external rotation-type fibular fractures. J Bone Joint Surg Am 2004:86;2171-2178.
Kristensen KD, Hansen T: Closed treatment of ankle fractures: Stage II supination-eversion fractures followed for 20 years. Acta Orthop Scand 1985;56:107-109.
Michelson JD: Fractures about the ankle. J Bone Joint Surg Am 1995;77:142-152.

Question 9:

What is the most prevalent adverse event associated with allogeneic blood transfusion?

Options:

Clerical error leading to transfusion reaction
Anaphylactic reaction
HIV transmission
Hepatitis C transmission
Bacterial contamination leading to sepsis/shock

Correct Answer: Clerical error leading to transfusion reaction

Explanation:

DISCUSSION: Clerical error leading to acute hemolysis and even death occurs in 1:12,000 to 1:50,000 transfusions. Bacterial contamination leading to sepsis/shock occurs in 1:1 million transfusions. HIV transmission is approximately 1:500,000 transfusions and hepatitis C is 1:103,000 transfusions. Anaphylactic reactions occur in 1:150,000 transfusions.
REFERENCES: Aubuchon JP, Birkmeyer JD, Busch MP: Safety of the blood supply in the United States: Opportunities and controversies. Ann Intern Med 1997;127:904-909.
Popovsky MA, Whitaker B, Arnold NL: Severe outcomes of allogeneic and autologous blood donation: Frequency and characterization. Transfusion 1995;35:734-737.

Question 10:

Which of the following zones of articular cartilage has the highest concentration of proteoglycans?

Options:

Superficial
Transitional
Deep
Calcified
Tidemark

Correct Answer: Deep

Explanation:

Question 11:

Options:

at least two more attempts at closed reduction in the emergency department before the patient’s sedation wears off.
at least two attempts at closed reduction in the operating room under general anesthesia with muscle relaxation.
acceptance of the reduction because the alignment is satisfactory and growth problems are rare with Salter-Harris type I fractures.
open reduction, extraction of any interposed periosteum, and smooth wire fixation to prevent nonunion.
open reduction, extraction of any interposed periosteum, and smooth wire fixation to decrease the chance of premature physeal closure.

Correct Answer: open reduction, extraction of any interposed periosteum, and smooth wire fixation to decrease the chance of premature physeal closure.

Explanation:

Question 12:

Options:

closed reduction and casting in extension.
open reduction with suture fixation of the proximal fragment.
closed reduction, followed by functional bracing.
open reduction and internal fixation with screws and complete proximal tibial epiphysiodesis.
open reduction and internal fixation with screws.

Correct Answer: open reduction and internal fixation with screws.

Explanation:

Question 13:

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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect answers:
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.
Incorrect answers:
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.
Incorrect answers:
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.
Incorrect Answers:
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.
Incorrect answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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.
Incorrect Answers:
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)?
FOR ALL MCQS CLICK THE LINK ORTHO
MCQ BANK

Question 14:

Options:

Measurement of volar compartment pressures and, if elevated, a bolus transfusion of 4 unit/kg of factor VIII concentrate, followed by continuous transfusion of factor VIII
Splinting of the extremity with the elbow flexed and the wrist in extension, elevation of the extremity, observation, and if no improvement, continuous transfusion of factor VIII (4 unit/kg)
A bolus transfusion of 4 unit/kg of factor VIII concentrate, followed by continuous transfusion of factor VIII, measurement of forearm compartment pressures, splinting of the extremity with the elbow and wrist flexed, and surgical release of the volar forearm compartments if pressures are elevated
A bolus transfusion of 4 unit/kg of factor VIII concentrate, followed by continuous transfusion of factor VIII and an emergency fasciotomy
A bolus transfusion of 4 unit/kg of factor VIII concentrate, laboratory studies consisting of serum electrolytes and creatine phosphokinase levels, IV injections of bicarbonate to alkalize the urine, and renal dialysis

Correct Answer: A bolus transfusion of 4 unit/kg of factor VIII concentrate, followed by continuous transfusion of factor VIII, measurement of forearm compartment pressures, splinting of the extremity with the elbow and wrist flexed, and surgical release of the volar forearm compartments if pressures are elevated

Explanation:

Question 15:

Options:

Continued bracing, physical therapy, and Botox injections in the triceps surae
Peroneus longus to brevis transfer, medializing calcaneal osteotomy, and transfer of the extensor digitorum longus to the peroneus tertius
Peroneus longus to brevis transfer, and transfer of the posterior tibial tendon to the tibialis anterior tendon
Peroneus longus to brevis transfer, first metatarsal cuneiform dorsal closing wedge osteotomy, and lateralizing calcaneal osteotomy with proximal translation
Triple arthrodesis

Correct Answer: Peroneus longus to brevis transfer, first metatarsal cuneiform dorsal closing wedge osteotomy, and lateralizing calcaneal osteotomy with proximal translation

Explanation:

DISCUSSION: The history and presentation are consistent with type I Charcot-Marie-Tooth (CMT), the most common form of hereditary peripheral motor sensory neuropathy. Type I CMT is the most common, occurring in 50% of patients with CMT, and is characterized by marked slowing of motor neuron velocities, and inconsistent slowing of sensory neuron velocities. Peroneus longus to brevis transfer is indicated to release the overpull of the peroneus longus, and restore the eversion and dorsiflexion function of the peroneus brevis. A lateralizing calcaneal osteotomy with proximal translation is indicated to correct heel varus given that the Coleman block only allows for partial correction of heel varus. Proximal translation of the posterior tuber corrects for the increased calcaneal dorsiflexion, improving the lever arm for the triceps surae. A medial column closing wedge osteotomy is often required to correct a rigid, or semirigid plantar flexed first ray to allow for a balanced, plantigrade foot. Triple arthrodesis is indicated for rigid, arthritic hindfoot deformities. Transfer of the posterior tibial tendon to the tibialis anterior is not indicated since it is an out-of-phase transfer. Transfer of the posterior tibial tendon, when performed, should be to the lateral aspect of the foot. A medializing calcaneal osteotomy would accentuate the heel varus. There is no indication for Botox in CMT; Botox injection of the calf would further weaken push-off during gait. Bracing of a progressive semirigid or rigid deformity is not recommended.
REFERENCES: Younger AS, Hansen ST Jr: Adult cavovarus foot. J Am Acad Orthop Surg 2005;13:302-315.
Sammarco GJ, Taylor R: Cavovarus foot treated with combined calcaneus and metatarsal ostetotomies. Foot Ankle Int 2001;22:19-30.
Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL,
American Academy of Orthopaedic Surgeons, 2003, pp 135-143.

Question 16:

An anterior approach to the sacroiliac joint is indicated with which of the following concomitant injuries?

Options:

Ipsilateral symphysis dislocation
Ipsilateral posterior wall acetabular fracture
Contralateral sacral ala fracture
Contralateral sacroiliac dislocation
L5-S1 retrolisthesis

Correct Answer: Ipsilateral symphysis dislocation

Explanation:

Question 17:

Options:

Immediate weight-bearing as tolerated with hinged knee brace 0-90 degrees
Transphyseal ACL reconstruction with hamstring autograft
Physeal spearing ACL reconstruction with hamstring autograft
Application of long leg cast following successful fluoroscopic closed reduction
Application of long leg cast for 1-2 weeks with transition to hinged knee brace 0-90 degrees, progressive weight-bearing, and physical therapy for quadriceps strengthening

Correct Answer: Immediate weight-bearing as tolerated with hinged knee brace 0-90 degrees

Explanation:

Question 18:

Options:

Posterior laminoplasty
Posterior cervical foraminotomy
Anterior cervical foraminotomy
Anterior cervical diskectomy and arthrodesis
Anterior corpectomy and arthrodesis

Correct Answer: Anterior cervical diskectomy and arthrodesis

Explanation:

Question 19:

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 20:

In obstetrical brachial plexus palsy, which of the following signs is associated with the poorest prognosis for recovery in a 2-month-old infant?

Options:

Persistent inability to bring the hand to the mouth with the elbow stabilized at the side
Persistent inability to actively abduct the arm past 90 degrees
Persistent inability to externally rotate the shoulder past 20 degrees
Persistent unilateral ptosis, myosis, and anhydrosis
History of clavicle fracture at birth

Correct Answer: Persistent unilateral ptosis, myosis, and anhydrosis

Explanation:

DISCUSSION: Persistent Horner’s sign (ptosis, myosis, and anhydrosis) is a sign of proximal injury, usually avulsion of the roots from the cord which disrupts the sympathetic chain. Root rupture or avulsion proximal to the myelin sheath has less chance of healing. Two-month-old infants with persistent weakness in the other areas described may still have a good prognosis for recovery. Concurrent clavicle fracture has been shown to have no prognostic value.
REFERENCES: Clarke HM, Curtis CG: An approach to obstetrical brachial plexus injuries. Hand Clin 1995;11:563-581.
Narakas AO: Injuries to the brachial plexus, in Bora FW (ed): The Pediatric Upper Extremity: Diagnosis and Management. Philadelphia, PA, WB Saunders, 1986, p 247.

Question 21:

Plate fixation of olecranon fractures is recommended over tension band wire fixation when

Options:

the fracture is proximal and only involves the olecranon tip.
the fracture is transverse.
the fracture is comminuted.
the fracture is widely displaced.
there is associated osteoporosis.

Correct Answer: the fracture is comminuted.

Explanation:

Question 22:

Options:

excision of the base of the phalanx of the great toe with dorsiflexion osteotomy of the second metatarsal.
osteotomy of the proximal phalanx of the great toe.
distal first metatarsal osteotomy with soft-tissue realignment of the great toe.
fusion of the metatarsal cuneiform joint with soft-tissue realignment of the first metatarsophalangeal joint.
joint replacement arthroplasty of the first metatarsophalangeal joint.

Correct Answer: fusion of the metatarsal cuneiform joint with soft-tissue realignment of the first metatarsophalangeal joint.

Explanation:

Question 23:

Options:

Fascial arthroplasty
Metatarsophalangeal joint arthrodesis
Metatarsophalangeal joint Silastic arthroplasty
Extensor tendon reconstruction
Keller resection arthroplasty

Correct Answer: Metatarsophalangeal joint arthrodesis

Explanation:

Question 24:

Options:

Chevron bunionectomy
Cheilectomy and removal of loose body
MTP arthrodesis
Resection of proximal phalanx

Correct Answer: MTP arthrodesis

Explanation:

Question 25:

What imaging study should be obtained next to further evaluate this patient? Review Topic

Options:

Cervical spine flexion and extension radiographs
AP radiograph of the cervical spine
CT of the cervical, thoracic, and lumbar spine
Electromyography and nerve conduction velocity studies of the upper extremities
MRI of the lumbar spine

Correct Answer: CT of the cervical, thoracic, and lumbar spine

Explanation:

Question 26:

An adult patient with a grade I isthmic spondylolisthesis at L5-S1 is most likely to have weakness of the

Options:

anterior tibialis.
quadriceps.
gastrocsoleus.
extensor hallucis longus.
iliopsoas.

Correct Answer: extensor hallucis longus.

Explanation:

DISCUSSION: Adult patients with isthmic spondylolisthesis most commonly have neurologic symptoms due to foraminal stenosis at the level of the spondylolisthesis. In this scenario, the patient is most likely to have weakness of the L5 myotome, which would cause weakness of the extensor hallucis longus.
REFERENCES: Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 311-317.
Lauerman WC, Cain JE: Isthmic spondylolisthesis in the adult. J Am Acad Orthop Surg 1996;4:201-208.

Question 27:

-What is the most appropriate initial treatment?

Options:

Run a wound culture and return to the operating room for arthrotomy, irrigation, and debridement.
Return to the operating room, blister debridement, split-thickness skin grafting, and prophylactic intravenous (IV) penicillin G (PCN G) every 6 hours
Return to the operating room, blister debridement, apply topical aloe, and prophylactic IV PCN G every 6 hours
Bedside blister debridement, apply topical aloe, and prophylactic IV PCN G every 6 hours

Correct Answer: Bedside blister debridement, apply topical aloe, and prophylactic IV PCN G every 6 hours

Explanation:

DISCUSSION FOR QUESTIONS 83 AND 84
Based upon the history and description of the wound, this patient has sustained a frostbite injury to the anterior skin without evidence of infection. Frostbite, a thermal injury to local tissues, can be classified into first-, second-, third-, and fourth-degree injuries. First-degree injuries are characterized by a central whitish area surrounded by erythema. Second- and third-degree injuries are characterized by blisters that appear within the first 24 hours. Second-degree blisters are clear or cloudy, while third-degree blisters are hemorrhagic. Fourth-degree injuries are characterized by tissue necrosis. Treatment of a frostbite injury should begin as soon as it is identified, even if severity has not been determined. Treatment includes protection against mechanical irritation and keeping the injured area away from heat. The limb should be elevated and clear blisters debrided; dark blisters should be drained but not debrided. Topical treatment includes aloe application every 6 hours (silver sulfadiazine for open wounds). Nonsteroidal anti-inflammatory drugs can be given along with PCN G (500,000 U) or clindamycin (600 mg) IV every 6hours for 48 to 72 hours as prophylaxis against infection.Multiple skin incisions on the front of the knee place the skin at healing risk after surgery.
Skin oxygenation is further compromised by a lateral release, which disrupts the superior lateral geniculate artery in the peripatellar vascular anastomosis. When addressing compromised perfusion to the skin, the orthopaedic surgeon may consider not performing a lateral release, using the medial parapatellar incision,and/or not using a tourniquet during surgery. In this patient, the use of cold therapy further compromised perfusion to the skin. This patient’s wound does not reflect infection, but rather frostbite from the compromised skin perfusion and the application of cold therapy.
The physiologic responses to the effects of freezing temperatures on limbs have been categorized into 4 phases. Phase I, cooling and freezing, is characterized by vasoconstriction and vasospasm. The freezing results in mechanical destruction of cell membranes in endothelial cells in small capillaries. Phase II,rewarming, initiates as heat absorbed by the limb begins an exothermic reaction as extracellular and intracellular crystals melt. Intracellular swelling occurs and small capillaries become highly permeable,resulting in extravasation of fluid and causing edema and blisters. Phase III is characterized by progressive tissue injury resulting from inflammation, vascular stasis, and thrombosis leading to ischemia.Phase IV is recovery that can progress along 3 potential pathways: complete healing, healing with later sequelae, or early tissue necrosis leading to gangrene.
CLINICAL SITUATION FOR QUESTIONS 85 THROUGH 87
Figure 85 is the radiograph of a 13-year-old right-handed baseball player who has experienced 2 months of right-dominant shoulder pain. As a pitcher, he says he cannot “throw hard” without pain, and he develops a dull ache if he throws more than 15 pitches.

Question 28:

Fixed hyperextension of the metatarsophalangeal joint is associated with

Options:

dorsal subluxation of the interossei.
dorsal subluxation of the lumbricals.
fibrosis of the plantar plate.
attenuation of the extensor longus tendon.
extrinsic flexor paralysis.

Correct Answer: dorsal subluxation of the interossei.

Explanation:

Question 29:

Options:

Z-plasty.
a posterior interosseous fasciocutaneous flap.
a reverse cross-finger flap from the index finger.
excision of the contracture with placement of a full-thickness skin graft.
excision of the contracture with placement of a split-thickness skin graft.

Correct Answer: a posterior interosseous fasciocutaneous flap.

Explanation:

Question 30:

When the elbow is extended and an axial load is applied, what percent of stress distribution occurs across the ulnohumeral and radiohumeral articular surface, respectively?

Options:

20% and 80%
40% and 60%
50% and 50%
60% and 40%
80% and 20%

Correct Answer: 40% and 60%

Explanation:

Question 31:

While lifting weights, a patient feels a pop in his arm. He has the deformity shown in Figure 30. If left untreated, the patient will have the greatest deficiency in

Options:

shoulder flexion.
elbow flexion.
forearm pronation.
forearm supination.
wrist flexion.

Correct Answer: forearm supination.

Explanation:

Question 32:

What is the most likely cause of recurrent symptoms following excision of a third web space neuroma?

Options:

Traumatic neuroma tethered by plantar neural branches
Regeneration of the transverse intermetatarsal ligament
Development of an intermetatarsal synovial cyst
Complex regional pain syndrome
Metatarsophalangeal joint synovitis

Correct Answer: Traumatic neuroma tethered by plantar neural branches

Explanation:

Question 33:

Options:

Complete lateral meniscectomy
Lateral meniscal repair
Saucerization of the lateral meniscus
Microfracture of the lateral femoral condyle
Do nothing surgically to the lateral meniscus

Correct Answer: Do nothing surgically to the lateral meniscus

Explanation:

Question 34:

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 35:

-A 42-year-old woman has had right wrist pain for 2 years. She tried splint wear and naproxen and has had 3 steroid injections, each time experiencing less relief.

Options:

Examination revealed tenderness at and just proximal to the radial styloid, with pain exacerbated with thumb flexion and wrist ulnar deviation. What
is the best next step in treatment?
Physical therapy
Continued splint wear
Repeat injection into the first dorsal wrist compartment
Incision of the first dorsal wrist compartment at the volar edge
Incision of the first dorsal wrist compartment at the dorsal edge

Correct Answer: Repeat injection into the first dorsal wrist compartment

Question 36:

Figures 46a through 46e show the radiographs of a 22-year-old man who injured his wrist in a motorcycle accident. He has no other injuries. What is the best course of action?

Options:

Radiolunate fusion
Open repair of the volar extrinsic wrist ligaments
Open reduction and internal fixation
Thumb spica cast immobilization for 6 weeks
External fixator

Correct Answer: Open reduction and internal fixation

Explanation:

Question 37:

Options:

- Knee immobilizer
- Immediate spanning external fixation
- Immediate intramedullary nailing
- Immediate plate fixation

Correct Answer: - Immediate spanning external fixation

Explanation:

DISCUSSION
Although management of femoral shaft fractures in patients with head injuries remains controversial, most practitioners agree that "damage-control principles" are appropriate for patients with evolving head injuries. This patient has a subarachnoid hemorrhage and a decreased GCS but is responding appropriately. The best treatment is a damage-control approach for the femur that will cause minimal blood loss and allow the brain injury (and swelling) to equilibrate. External fixation can be performed expeditiously and with minimal blood loss, which will reduce further injury to the brain. Special attention should be paid to maintaining cerebral perfusion pressure higher than 70 mmHg. Admission to the intensive care unit is recommended for monitoring of this injury. Knee immobilizers are not tolerated well by young muscular men with femur shaft fractures. A GCS score of 11 or higher can be observed without ICP monitoring.
RECOMMENDED READINGS
Flierl MA, Stoneback JW, Beauchamp KM, Hak DJ, Morgan SJ, Smith WR, Stahel PF. Femur shaft fracture fixation in head-injured patients: when is the right time? J Orthop Trauma. 2010 Feb;24(2):107-14. PubMed PMID: 20101135.
View Abstract at PubMed
Roberts CS, Pape HC, Jones AL, Malkani AL, Rodriguez JL, Giannoudis PV.Damage control orthopaedics: evolving concepts in the treatment of patients who have sustained orthopaedic trauma. Instr Course Lect. 2005;54:447-62. Review. PubMed PMID: 15948472.
View Abstract
at PubMed

Question 38:

Options:

filling the tibial defect with methylmethacrylate.
revision of the tibial component with porous metal augmentation.
reconstruction with iliac crest bone graft.
reconstruction with structural allograft.

Correct Answer: revision of the tibial component with porous metal augmentation.

Explanation:

DISCUSSION
Video 1 for reference
For severe tibial defects (Anderson Orthopaedic Research Institute [AORI] types 2 and 3), metaphyseal fixation is necessary to achieve construct fixation during revision TKA. Metaphyseal fixation may be achieved with cement, structural allograft, or conical metallic implants. The major concerns regarding structural allograft are graft resorption and mechanical failure and technical issues related to fashioning the graft and obtaining a good host-allograft interface. In a systematic review, porous metal cones were associated with a decreased loosening rate in AORI 2 and 3 defects compared to structural allografts. Metallic trabecular metal cones and metaphyseal porous coated sleeves provide a stable construct with which to support the tibial component during revision TKA. Clinical results with these devices include good metaphyseal fixation for severe tibial bone defects.

Question 39:

Options:

Non-weight bearing bilateral lower extremities and right upper extremity
Weight bearing as tolerated bilateral lower extremities and right upper extremity
Non-weight bearing left lower extremity and weight bearing as tolerated right upper and right lower extremities
Non-weight bearing right lower extremity and weight bearing as tolerated right upper and left lower extremities
Weight bearing as tolerated bilateral lower extremities and non-weight bearing right upper extremity

Correct Answer: Non-weight bearing right lower extremity and weight bearing as tolerated right upper and left lower extremities

Explanation:

Question 40:

A 15-year-old girl with a midshaft fibular lesion has histologic findings consistent with Ewing’s sarcoma. Following induction chemotherapy, local control typically consists of

Options:

radiation therapy only.
curettage and bone grafting.
wide resection.
below-knee amputation.
observation.

Correct Answer: wide resection.

Explanation:

Question 41:

Options:

A palpable effusion
Positive anterior drawer test
Positive external rotation test
Pain with forced dorsiflexion
Loss of subtalar motion

Correct Answer: Pain with forced dorsiflexion

Explanation:

Question 42:

Options:

DEXA scan
Brace treatment with a Jewett hyperextension brace
Anterior lumbar corpectomy and arthrodesis with instrumentation
Posterior lumbar decompression and fusion
Vertebral cement augmentation

Correct Answer: DEXA scan

Explanation:

Question 43:

Options:

Warfarin with a targeted international normalized ratio (INR) of 2.0 to 3.0 for 10 to 14 days
Low-molecular-weight heparin used for at least 3 days
Pneumatic compression sleeves used while the patient is in the hospital
Fondaparinux used for 5 to 7 days
Aspirin for 4 weeks

Correct Answer: Warfarin with a targeted international normalized ratio (INR) of 2.0 to 3.0 for 10 to 14 days

Explanation:

DISCUSSION: In the 2004 ACCP guidelines, there were three prophylactic regimens that received a grade 1A favorable recommendation. These included low-molecular-weight heparin, warfarin, or fondaparinux, as long as they are used for at least 10 days. If warfarin is used, the target INR should be 2.0 to 3.0, according to the guidelines. Pneumatic compression sleeves have gained popularity in the orthopaedic community but have not received a grade 1A rating from the ACCP at this time. Use of aspirin by itself is discouraged by the ACCP.
REFERENCE: Geerts WH, Pineo GF, Heit JA, et al: Prevention of venous thromboembolism: The seventh ACCP Conference on antithrombotic and thrombolytic therapy. Chest 2004;126:338S-400S.

Question 44:

Options:

Intramedullary pinning
Bone stimulator
Sling for comfort, followed by gentle range-of-motion exercises
Open reduction and internal fixation with a plate and screws
Arthroscopic distal clavicle resection

Correct Answer: Sling for comfort, followed by gentle range-of-motion exercises

Explanation:

Question 45:

Options:

Plastic
Elastic
Fatigue
Creep
Torsion

Correct Answer: Elastic

Explanation:

Question 46:

Options:

None
MRI of the distal femur
MRI of the entire femur
MRI of the entire femur and a bone scan
MRI of the entire femur, CT of the chest, and a bone scan

Correct Answer: MRI of the entire femur, CT of the chest, and a bone scan

Explanation:

Question 47:

Options:

Closed reduction of both fractures and immediate spica casting
Bilateral skin traction for 3 weeks, followed by spica casting
External fixation of both femora
External fixation of the left femur and a long leg cast brace for the right femur
External fixation of the left femur and use of a reamed intramedullary nail in the right femur

Correct Answer: External fixation of both femora

Explanation:

Question 48:

Options:

disruption of the sympathetic nerves during anterior lumbar exposure.
traction on the parasympathetic nerve at the L4-5 level.
not related to the surgical dissection.
injury to the pudendal nerves in the anterior sacral region during dissection at the L5-S1 level.
sexual dysfunction secondary to retrograde ejaculation.

Correct Answer: not related to the surgical dissection.

Explanation:

Question 49:

Options:

Stress view radiographs of the left hip
Non-weight bearing and pelvic bone scan in 7 days
Non-weight bearing and repeat the CT scan after 48 hours from injury
MRI hip and pelvis
Weight bearing activity as tolerated with close follow-up

Correct Answer: Stress view radiographs of the left hip

Explanation:

The next best step would be an MRI hip and pelvis to investigate for an occult fracture of the left hip.
Moderate evidence supports MRI as the advanced imaging of choice for diagnosis of presumed hip fracture not apparent on initial radiographs. MRI has been shown to be able to detect occult fractures earlier than bone scan, with better spatial resolution. Usually the MRI should be obtained in less than 24 hours from the time of injury. For situations in which MRI is not immediately available, bone scan can be considered after 72 hours form the time of injury. However, this may compromise patient care and put the patient at risk of fracture displacement.
Cannon et al. reviewed the imaging of choice in occult hip fracture. They showed that physical examination yields a poor sensitivity identifying occult hip fractures, with log-rolling and straight-leg raise as 50% and 70%, respectively. The most sensitive modality for occult fracture identification was MRI.
Iwata et al. retrospectively reviewed a cohort of 35 patients with clinically suspected fractures of the hip that underwent MRI. All radiographs were negative. In 26 of these patients, a T1-weighted coronal MRI showed a hip fracture with 100% sensitivity.
Roberts et al. reviewed the 2015 AAOS Clinical Practice Guideline: Management of Hip Fractures in the Elderly. They report moderate evidence that supports MRI as the advanced imaging of choice for diagnosis of presumed hip fractures not apparent on initial radiographs.
Figure A is a AP radiograph of the left hip and pelvis. Apart from a healed fracture of the ischiopubic rami and generalized osteopenia, there is no obvious hip fracture. Figure B is a coronal CT image that does not demonstrate evidence of an acute hip fracture. Illustration A is a T1 weighted MR image that shows a non displaced fracture (white arrow) through the intertrochanteric region of the left proximal femur.
Incorrect Answers:
(SBQ12TR.32) A 20-year-old male is taken to the emergency department following a motorcycle collision with the injury seen in Figures A and B. He undergoes serial debridements with placement of an antibiotic bead pouch, followed by intramedullary nailing and free tissue transfer. His preoperative examination is notable for absent plantar sensation. Which of the following is predictive of a worse long term outcome in this patient?
Absent plantar sensation at presentation
Depression at 3 months post-injury
Use of an intramedullary nail
Free tissue transfer instead of rotational flap
Need for multiple debridements
The presence of depression at the 3 months post-injury is a significant predictor of worse long term outcome as well as lower return to work rates in patients that present with limb threatening lower extremity trauma.
The findings of the Lower Extremity Assessment Project (LEAP study) has challenged many of the long-held beliefs of lower extremity trauma surgery, including the concept that patients with absent plantar sensation should undergo immediate amputation . The LEAP study has also brought to light the importance of socioeconomic and psychosocial factors in patient outcomes following these injuries.
Bosse et al analyzed a subgroup of 55 patients from the LEAP study with absent plantar sensation at presentation. Those patients that underwent limb salvage despite absent sensation (n=26) had no significant difference in functional outcome when compared with either insensate patients who underwent amputation or a matched control group of sensate patients with similar injuries. All but one patient in the salvage group had return of some sensation at 2-year follow up and the authors concluded that an insensate plantar foot at presentation should not be included in the algorithm for amputation.
Mackenzie and Bosse reviewed the results of the LEAP study with particular emphasis on the social and economic variables that influence outcomes in severe lower extremity. The authors note that 19% of patients screened positive for severe depression. The presence of anxiety, pain and depression at 3 months post-injury were significant predictors of poor outcome
Incorrect Answers:
tissue for type IIIB tibia fractures. Answer 5: The number of debridements has not been shown to influence outcome.

Question 50:

Which of the following is considered a risk factor for the development of low back pain?

Options:

Gender
Facet trophism
Vibration exposure
Weight
Transitional vertebrae

Correct Answer: Vibration exposure

Explanation:

Question 51:

An adult patient with a grade I isthmic spondylolisthesis at L5-S1 is most likely to have weakness of the Review Topic

Options:

flexor hallucis longus.
quadriceps.
gastrocsoleus.
extensor hallucis longus.
iliopsoas.

Correct Answer: extensor hallucis longus.

Explanation:

Question 52:

The therapeutic effect of etanercept in the treatment of rheumatoid arthritis is primarily mediated through

Options:

antagonism of tumor necrosis factor-alpha (TNF-α).
antagonism of matrix metalloproteinases (MMPs).
inhibition of COX2.
stimulation of interleukin-1 (IL-1).
stimulation of tissue inhibitors of metalloproteinases (TIMPs).

Correct Answer: antagonism of tumor necrosis factor-alpha (TNF-α).

Explanation:

Question 53:

Options:

lateral retinacular release and medial reefing.
patellar tendon transfer medially.
lateral release and patellar tendon transfer.
femoral and tibial derotation osteotomies.
continued observation.

Correct Answer: continued observation.

Explanation:

Question 54:

A 23-year-old woman with recurrent anterior instability undergoes an open Bankart procedure. Six months after surgery the patient reports shoulder

Options:

Physical therapy
Biceps tenolysis
Subscapularis repair
Supraspinatus repair
Pectoralis major repair

Correct Answer: Subscapularis repair

Explanation:

Question 55:

Which of the following lumbar disk components has the highest tensile modulus to resist torsional, axial, and tensile loads? Review Topic

Options:

Nucleus pulposus
Cartilaginous end plate
Anterior longitudinal ligament
Annulus fibrosis
Cellular matrix

Correct Answer: Annulus fibrosis

Explanation:

Question 56:

Of all the pelvic ring injury types, anteroposterior compression type III pelvic ring injuries have the highest rate of which of the following?

Options:

Head injury
Pulmonary injury
Traumatic amputation
Need for transfusion
Upper extremity fractures

Correct Answer: Head injury

Explanation:

Question 57:

Compared with percutaneous pinning with Kirschner wires (K-wires), the treatment of metacarpal neck fractures with cannulated intramedullary screws is associated with

Options:

increased rates of soft-tissue infection.
greater initial construct stiffness and peak load until failure.
a slower return of digital range of motion.
an earlier time to bony union.

Correct Answer: greater initial construct stiffness and peak load until failure.

Explanation:

EXPLANATION:
In a biomechanical study, headless compression screws showed superior load to failure, higher three-point bending strength, and greater strength in axial loading compared with percutaneous K-wire fixation for metacarpal neck fractures. Headless compression screws provide greater initial stability to allow earlier motion in the postoperative period. No data comparing infection rates between the two methods of fixation are available; however, it is assumed that K-wires placed outside of the skin would have increased
rates of infection. Neither fixation method would increase the time to healing.

Question 58:

Options:

A history of c4-C5 anterior discectomy and fusion
A history of spinal cord neurapraxia with transient quadriparesis that has now resolved
Os odontoideum
Congenital C5-C6 fusion
Congenital Stenosis
back answer Question 03.273

Correct Answer: Os odontoideum

Explanation:

The combination of congenital stenosis with
instability
, disk disease (bulge or herniation), degenerative change (osteophytes), MR imaging evidence of cord abnormality, neurologic findings lasting longer than 36 hours, or more than one recurrence is considered an absolute contraindication to sports participation. Congenital stenosis (Pavlov ratio less than 0.8) without instability is not considered a contraindication to play. Congenital anomalies of the upper cervical spine are an absolute contraindication to participation in all contact sports. This includes os odontoideum, odontoid hypoplasia or aplasia, and atlantooccipital fusion, even if asymptomatic. During play, if neurological symptoms resolve quickly and the neurologic examination is normal with full motor strength, the patient may return to the game. Persistence of symptoms or lack of a pain-free range of motion requires further evaluation, including cervical spine radiographs. Players should be restricted from further play until they have recovered full muscle strength. Cervical disk herniations can have serious permanent neurologic complications. A disk bulge without herniation as demonstrated by MR imaging, can be treated conservatively with activity modification. Return to play may occur when pain-free full range of motion is demonstrated and radicular symptoms are completely resolved. Symptomatic disk herniation with cord or root impingement may require anterior diskectomy with interbody fusion. A limited fusion (one or two levels) of the subaxial cervical spine is not considered a contraindication to future play if the segments above and below the fusion are normal. A return to play cannot be recommended until there is radiographic evidence that the graft is well incorporated, the symptoms are completely resolved, and the player demonstrates a painless range of motion and full motor strength. With the exception of spear tackler Õs spine, there is no evidence that transient neurapraxia of the cord predisposes an individual to subsequent permanent quadriplegia or quadriparesis.
Thomas BE, et al. Cervical spine injuries in football players. J AM Acad Orthop Surg 1999;7:338-347
Torg JS et al: Neurapraxia of the cervical spinal with transientquadriplegia. JBJS Am 1986:68:1354-

Question 59:

Osteoclasts originate from which of the following cell types?

Options:

Fibroblasts
Monocytes
Megakaryocytes
Plasma cells
Osteoprogenitor cells

Correct Answer: Monocytes

Explanation:

Question 60:

Options:

Stretching exercises with a physical therapist
Arthroscopic debridement
Core decompression of the humeral head
Humeral hemiarthroplasty
Resection of the proximal humerus

Correct Answer: Humeral hemiarthroplasty

Explanation:

Question 61:

Options:

Brachioradialis (BR)
Extensor carpi radialis brevis (ECRB)
Extensor carpi ulnaris (ECU)
Extensor indicis proprius (EIP) The incidence of radial nerve palsy after a humeral shaft fracture has been estimated as being between 7% and 22%. Controversy remains regarding the need for early exploration in a patient presenting with a closed humerus fracture and concurrent radial nerve palsy, because approximately 77% of patients treated without exploration have spontaneous recovery of radial nerve function. Within 3 to 4 months of the injury, the BR and extensor carpi radialis longus (ECRL) should begin to show signs of reinnervation. Anatomic studies have demonstrated a relatively consistent order of the radial nerve motor branches in the forearm (proximal to distal): BR, ECRL, supinator, ECRB, extensor digitorum communis, ECU, extensor digit quinti, abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis, and EIP. Because the EIP is the last motor branch from the radial nerve, it is likely to be the last to recover following a high radial nerve palsy.

Correct Answer: Extensor indicis proprius (EIP) The incidence of radial nerve palsy after a humeral shaft fracture has been estimated as being between 7% and 22%. Controversy remains regarding the need for early exploration in a patient presenting with a closed humerus fracture and concurrent radial nerve palsy, because approximately 77% of patients treated without exploration have spontaneous recovery of radial nerve function. Within 3 to 4 months of the injury, the BR and extensor carpi radialis longus (ECRL) should begin to show signs of reinnervation. Anatomic studies have demonstrated a relatively consistent order of the radial nerve motor branches in the forearm (proximal to distal): BR, ECRL, supinator, ECRB, extensor digitorum communis, ECU, extensor digit quinti, abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis, and EIP. Because the EIP is the last motor branch from the radial nerve, it is likely to be the last to recover following a high radial nerve palsy.

Explanation:

Question 62:

Options:

Independent 2-sample t test
Analysis of variance (ANOVA)
Chi-square test
Fisher's exact test

Correct Answer: Analysis of variance (ANOVA)

Explanation:

Data collected in research studies fall into one of two categories—continuous or discrete. Continuous data can be displayed on a curve. Examples include height, weight, and time recorded in a 40-yard dash. Discrete data represent data that fall into specific categories such as gender or the presence or absence of a risk factor. ANOVA is used to determine statistical significance in mean values of continuous data when there are more than two independent samples. The 2-sample
t
test compares mean values of continuous data between two independent groups. The Chi-square test and Fisher's exact tests are tests used to analyze discrete data.

Question 63:

Which of the following is considered a contraindication to the use of a reverse total shoulder arthroplasty? Review Topic

Options:

Prior shoulder joint infection
Pseudoparalysis
Prior partial acromioplasty
Absent glenohumeral joint space narrowing
Axillary neuropathy

Correct Answer: Axillary neuropathy

Explanation:

Question 64:

-The center of rotation of the knee can be best described as

Options:

remaining fixed during flexion.
moving posterior as flexion increases.
shifting forward and then back with flexion.
shifting posterior on the lateral side with flexion.
sliding forward on the medial side with increasing flexion.

Correct Answer: shifting posterior on the lateral side with flexion.

Question 65:

Options:

recruitment in the extensor pollicis longus, abductor pollicis longus, extensor digitorum communis, and extensor carpi ulnaris muscles. Which nerve is most likely compressed?
Median
Radial
Anterior interosseous
Posterior interosseous
Lateral antebrachial cutaneous

Correct Answer: Anterior interosseous

Question 66:

Options:

Closed reduction with immobilization
Closed reduction with percutaneous pinning
Open reduction, bicolumnar fixation with plate and screws
Open reduction, bicolumnar fixation with Kirschner wires DISCUSSION.. The radiographs and CT scans indicate a comminuted and displaced intra-articular fracture of the distal humerus. Rigid internal fixation with bicolumnar orthogonal or parallel plating is the treatment of choice for most fractures of the distal humerus that involve the joint surface. Closed reduction and variations thereof will not yield a stable environment for healing. To achieve adequate exposure for fixation, a chevron olecranon osteotomy is the preferred approach. Disadvantages associated with this approach include complications such as nonunion of the osteotomy site and intra-articular adhesions. Prominent hardware may need to be removed during a secondary procedure, and intraoperative conversion to an elbow arthroplasty may be limited. The most common complications after open reduction and internal fixation include elbow stiffness, nonunion (2%-10%), and ulnar neuropathy (0%-12%).

Correct Answer: Open reduction, bicolumnar fixation with plate and screws

Explanation:

CLINICAL SITUATION FOR QUESTIONS 84 THROUGH 87
Figure 84 is the glenoid CT scan of a 20-year-old man who dislocated his shoulder anteriorly while playing football. He had persistent instability 2 months after the injury, but he did not have a sulcus sign or posterior instability. He underwent an arthroscopic Bankart repair with 4 bioabsorbable anchors with simple sutures through the labrum and capsule.
He did not have an engaging Hill-Sachs lesion, the rotator cuff was unremarkable, and the capsule was not torn from the humerus. After surgery, he did well for 6 months until he jumped into a lake and again dislocated his shoulder anteriorly. He says his shoulder no longer felt stable after his reduction.

Question 67:

An active, right-handed 71-year-old woman fell on her left shoulder and sustained the injury shown in the radiographs in 52a and 52b and the CT scan in 52c. Management should consist of

Options:

hemiarthroplasty
open reduction and internal fixation
closed reduction and percutaneous pinning
a sling and early pedulum exercises
a sling and swathe for 6 weeks, followed by shoulder rehabilitation

Correct Answer: hemiarthroplasty

Explanation:

Question 68:

Options:

Biopsy and resection of lesion
Observation and serial radiographs
Tc-99 whole-body bone scan and fine-cut CT scan
Evaluation by a pediatric oncologist DISCUSSION… The images reveal a small reactive-type lesion in the posteromedial aspect of the distal femur consistent with an avulsive cortical irregularity. Also referred to as a cortical desmoid, periosteal desmoid, or “tug lesion,” it is seen most commonly in young adolescents, with a slight preponderance in boys, with one-third occurring bilaterally. It is thought to be related to repeated microtrauma with pulling of the adductor magnus or medial gastrocnemius head. Proper treatment involves recognition of this benign disorder without further work-up. Often best seen on an oblique radiograph, the lack of soft-tissue mass or bone destruction leads to the benign diagnosis. Serial radiographs may show complete resolution by age 20.

Correct Answer: Observation and serial radiographs

Explanation:

Question 69:

-The main blood supply to the capital femoral epiphysis in a 10-year-old child is supplied from the

Options:

artery of the ligamentum teres.
epiphyseal branch of the lateral femoral circumflex artery.
posterosuperior and posteroinferior retinacular branches of the lateral femoral circumflex artery.
posterosuperior and posteroinferior retinacular branches of the medial femoral circumflex artery. DISCUSSION-Before the age of 4 years, blood to the femoral head is supplied by the medial and lateral femoral circumflex arteries as well as the artery of the ligamentum teres. After the age of 4, the blood supply through the artery of the ligamentum teres diminishes. The lateral femoral circumflex system regresses,and its flow into the physis and epiphysis diminishes significantly so the medial femoral circumflex artery becomes the predominant blood supply to the metaphysis. The medial femoral circumflex artery provides the principal blood supply to the proximal femur via its posterosuperior and posteroinferior retinacular branches.

Correct Answer: posterosuperior and posteroinferior retinacular branches of the medial femoral circumflex artery. DISCUSSION-Before the age of 4 years, blood to the femoral head is supplied by the medial and lateral femoral circumflex arteries as well as the artery of the ligamentum teres. After the age of 4, the blood supply through the artery of the ligamentum teres diminishes. The lateral femoral circumflex system regresses,and its flow into the physis and epiphysis diminishes significantly so the medial femoral circumflex artery becomes the predominant blood supply to the metaphysis. The medial femoral circumflex artery provides the principal blood supply to the proximal femur via its posterosuperior and posteroinferior retinacular branches.

Question 70:

Options:

Correlation coefficient of MRSA
Prevalence of MRSA
Incidence of MRSA
Relative risk of MRSA

Correct Answer: Prevalence of MRSA

Explanation:

Question 71:

Options:

Acetabular osteolysis
Femoral osteolysis
Acetabular loosening
Femoral loosening
Femoral and acetabular loosening

Correct Answer: Femoral loosening

Explanation:

DISCUSSION: These radiographs are dominated by the subsidence of the femoral component. There is also evidence of polyethylene wear and femoral osteolysis in the region of the greater trochanter. There is no evidence of proximal (calcar) stress shielding, and there is a thick distal pedestal. Engh and associates defined two major signs of osseointegration - the absence of radiolucent lines around the porous-surfaced portion of the implant and new bone bridging the gap between the endosteal surface and the porous portion of the implant. Implant migration indicates failure of ingrowth. Osteolysis is a periprosthetic loss of bone secondary to particulate debris and it is often clinically silent unless it is accompanied by pathologic fracture. It is often globular. Acetabular loosening is based on radiolucent lines and implant migration. The current radiographs demonstrate subsidence of the stem with pedestal formation.
REFERENCES: Engh CA, Massin P, Suthers KE: Roentgenographic assessment of biologic fixation of porous-surface femoral components. Clin Orthop Relat Res 1990;257:107-128.
Engh CA, Hooten JP, Zettl-Schaffer KF, et al: Evaluation of bone ingrowth in proximally and extensively porous-coated anatomic medullary locking prostheses retrieved at autopsy. J Bone Joint Surg Am 1995;77:903-910.

Question 72:

Which of the following articulation couplings shows the lowest coefficient of friction as tested in the laboratory?

Options:

Cobalt-on-polyethylene
Cobalt-on-cobalt
Titanium-on-polyethylene
Stainless steel-on-polyethylene
Ceramic-on-ceramic

Correct Answer: Ceramic-on-ceramic

Explanation:

Question 73:

- A consecutive series of 50 patients is randomized to receive either treatment A or treatment B. At a 10-year follow up, patient satisfaction with treatment is measured. Which of the following statistical calculations will provide the most information regarding the magnitude of possible differences between the two groups of patients?

Options:

Meta-analysis
Confidence interval
Analysis of variance (ANOVA)
Statistical significance (p-value)
Survivorship analysis (Kaplan-Meier)

Correct Answer: Confidence interval

Explanation:

Question 74:

What is the minimum hours per day of wear that has been correlated with the effectiveness of bracing on curve progression in idiopathic scoliosis? Review Topic

Options:

Prescribed brace wear 23 hours/day
Prescribed brace wear 16 hours/day
Actual brace wear more than 12 hours/day
Actual brace wear 6 hours/day

Correct Answer: Actual brace wear more than 12 hours/day

Explanation:

Question 75:

Options:

Short leg non-weight-bearing cast for 6 weeks
Air-stirrup splint and limited activity in 3 to 6 weeks
Air-stirrup splint and resumption of activities as tolerated
Immediate repair of the peroneal retinaculum
Immediate reduction and placement of a syndesmotic screw

Correct Answer: Immediate reduction and placement of a syndesmotic screw

Explanation:

Question 76:

In a statement put forth by AAOS, the role of the orthopaedic surgeon in the face of domestic and family abuse includes all of the following EXCEPT: Review Topic

Options:

Be aware that he or she may be the first physician to be caring for the victims
Ensure that they maintain comprehensive and accurate medical records documenting the events and examinations
Care should resume once the patient's social situation is evaluated and assessed
Transfer an elderly victim who is in immediate danger to a hospital emergency department and notify the emergency department physician of the transfer and the reasons for your concern
Advocate for appropriate legislation and public policy

Correct Answer: Be aware that he or she may be the first physician to be caring for the victims

Explanation:

Question 77:

- A 14-year-old girl has idiopathic scoliosis with a 52-degree right thoracic curve and a 36-degree left lumbar curve. The rotation of the apical vertebra appears greater in the thoracic curve. A sagittal view radiograph shows the spine to be virtually straight. The iliac apophyses are Risser 2. Treatment should consist of

Options:

Anterior fusion of the lumbar curve
Anterior and posterior fusion of the thoracic curve
Posterior fusion of the thoracic curve
Posterior fusion of the thoracic and lumbar curves
Application of a brace until the iliac apophyses are Risser 4 or 5, followed by surgical correction

Correct Answer: Posterior fusion of the thoracic curve

Explanation:

Question 78:

Figure 6 shows an object being held in an outstretched hand. To offset the moment created by the object (ignoring the weight of the forearm), the biceps must generate a force of

Options:

5 N.
15 N.
30 N.
75 N.
150 N.

Correct Answer: 75 N.

Explanation:

Question 79:

Options:

Iliopsoas release from the lesser trochanter
Iliopsoas release at the pelvic brim
Hamstring lengthening
Heel cord lengthening
Split posterior tibial tendon transfer

Correct Answer: Heel cord lengthening

Explanation:

Question 80:

A patient undergoes hip arthroscopy, and the pathology is seen in Figure 18. What is the most likely diagnosis?

Options:

Femoral head articular defect
Acetabular articular defect
Haversian fat pad hypertrophy
Labral tear
Loose body

Correct Answer: Labral tear

Explanation:

Question 81:

Options:

The local Keyhole representative has invited you and your spouse out to dinner at a local restaurant to discuss your interest in their new minimally invasive total knee system, the Keyhole Genuflex knee.
Keyhole has offered to pay your tuition to attend a CME course sponsored by the American Association of Hip & Knee Surgeons where both the Genuflex and the competing Styph total knee are discussed and demonstrated.
Keyhole will pay your expenses to attend a workshop, in Phoenix at their company headquarters, to learn how to implant the Genuflex knee and to see how the implant is manufactured and tested.
Keyhole will pay you $500 for each knee that you implant if you switch from your current total knee system.
After you have implanted 25 Genuflex knees, Keyhole will list you on their website as a consultant, pay you a consulting fee of $5,000 per year, and invite you to a golf tournament for their consultants at a resort.

Correct Answer: Keyhole will pay your expenses to attend a workshop, in Phoenix at their company headquarters, to learn how to implant the Genuflex knee and to see how the implant is manufactured and tested.

Explanation:

Question 82:

A 72-year-old man with diabetic neuropathy and 5 degrees of valgus talar tilt; he has pursued nonsurgical treatment for 30 years and now has unrelenting pain

Options:

Ankle replacement
Ankle fusion
Tibiotalocalcaneal fusion
Total contact cast
Intra-articular steroid injection

Correct Answer: Ankle fusion

Explanation:

DISCUSSION
Arthritis of the ankle and hindfoot can pose challenges. Depending upon patient age, comorbidities, and alignment, a variety of surgical interventions may be offered. A total ankle replacement may be considered for patients older than 60 years of age who have minimal misalignment and low-demand lifestyles. In all other cases, ankle fusion must be considered. The nonsurgical care of ankle arthritis includes anti-inflammatory medication, intra-articular steroid injections, bracing with customized products such as the Arizona brace, or a molded foot and ankle orthosis.
Patients with diabetes and Charcot arthropathy may be treated nonsurgically with total-contact casting during acute and active or "hot" phases and accommodative shoes during consolidation and stable or "cool" phases. When the patient has recurrent ulcers or major anatomy changes, surgical intervention must be considered. Tibiotalocalcaneal fusion helps to realign the foot and ankle and make it more braceable in the setting of ankle and hindfoot Charcot disease.
RECOMMENDED READINGS
Queen RM, Adams SB Jr, Viens NA, Friend JK, Easley ME, Deorio JK, Nunley JA. Differences in outcomes following total ankle replacement in patients with neutral alignment compared with tibiotalar joint malalignment. J Bone Joint Surg Am. 2013 Nov 6;95(21):1927-34. doi: 10.2106/JBJS.L.00404. PubMed PMID: 24196462.
View Abstract at PubMed
Nunley JA, Caputo AM, Easley ME, Cook C. Intermediate to long-term outcomes of the STAR Total Ankle Replacement: the patient perspective. J Bone Joint Surg Am. 2012 Jan 4;94(1):43-8. doi: 10.2106/JBJS.J.01613. PubMed PMID: 22218381.
View Abstract t
PubMed
Saltzman CL, Mann RA, Ahrens JE, Amendola A, Anderson RB, Berlet GC, Brodsky JW, Chou LB, Clanton TO, Deland JT, Deorio JK, Horton GA, Lee TH, Mann JA, Nunley JA, Thordarson DB, Walling AK, Wapner KL, Coughlin MJ. Prospective controlled trial of STAR total ankle replacement versus ankle fusion: initial results. Foot Ankle Int. 2009 Jul;30(7):579-96. doi: 10.3113/FAI.2009.0579. PubMed PMID: 19589303.
View Abstract at
PubMed
Faraj AA, Loveday DT. Functional outcome following an ankle or subtalar arthrodesis in adults. Acta Orthop Belg. 2014 Jun;80(2):276-9. PubMed PMID: 25090803.
View Abstract at PubMed
Grear BJ, Rabinovich A, Brodsky JW. Charcot arthropathy of the foot and ankle associated with rheumatoid arthritis. Foot Ankle Int. 2013 Nov;34(11):1541-7. doi: 10.1177/1071100713500490. Epub 2013 Jul 30. PubMed PMID: 23900228.
View Abstract at
PubMed

Question 83:

A 30-year-old patient has wrist pain. A radiograph and biopsy specimen are shown in Figures 34a and 34b. What is the most likely diagnosis?

Options:

Aneurysmal bone cyst
Giant cell tumor
Brown tumor
Pigmented villonodular synovitis
Telangiectatic osteosarcoma

Correct Answer: Aneurysmal bone cyst

Explanation:

Question 84:

The spinal cord terminates as the conus medullaris at what vertebral level in adults? Review Topic 1 T12

Options:

Correct Answer: L2

Explanation:

The spinal cord anatomy changes at the thoracolumbar junction. The spinal cord terminates as the conus medullaris at the lower portion of L1 in women and the pedicle of L1 in men.

Question 85:

The most appropriate surgical approach includes which of the following? Review Topic

Options:

Anterior approach of Henry
Lateral Kocher approach
Medial column approach
Posterior extensile elbow approach with olecranon chevron osteotomy
Closed reduction and percutaneous screw fixation

Correct Answer: Posterior extensile elbow approach with olecranon chevron osteotomy

Explanation:

Question 86:

Options:

Epidural abscess
Neurilemmoma of the left S1 root
L5-S1 diskitis
Recurrent left L5-S1 disk herniation
Left S1 perineural fibrosis

Correct Answer: Left S1 perineural fibrosis

Explanation:

Question 87:

Options:

Delay further surgical intervention until his ESR and CRP level normalize
Delay further surgical intervention until his ESR normalizes
Delay further surgical intervention until his CRP level normalizes
Proceed with surgical intervention if the patient’s condition is medically optimized

Correct Answer: Proceed with surgical intervention if the patient’s condition is medically optimized

Explanation:

Question 88:

Options:

Proximal row carpectomy
Excision of the proximal pole of the scaphoid
Bone grafting with fixation of the scaphoid
Scaphoid excision with four-corner fusion

Correct Answer: Scaphoid excision with four-corner fusion

Explanation:

Question 89:

A 14-year-old girl reports hip pain that is exacerbated by weight bearing. A radiograph and biopsy specimen are shown in Figures 16a and 16b. The best course of management should be

Options:

a steroid injection.
curettage and bone grafting.
radiation therapy.
observation.
internal fixation without a bone graft.

Correct Answer: curettage and bone grafting.

Explanation:

Question 90:

A 20-year-old man sustains the injury shown in Figures 1a and 1b in a motorcycle accident. In addition to a prompt closed reduction, his outcome might be optimized by

Options:

a subtalar arthrodesis.
screw fixation of the talar neck.
repair of the medial subtalar capsule.
temporary transarticular pin fixation.
evaluation for and excision or fixation of osteochondral fractures.

Correct Answer: evaluation for and excision or fixation of osteochondral fractures.

Explanation:

Question 91:

Options:

until his symptoms resolve and the MRI findings return to normal.
until his symptoms resolve and his physical examination findings return to normal.
until he undergoes surgical decompression.
until he undergoes surgical decompression and fusion.
again because it is considered a career-ending injury.

Correct Answer: until his symptoms resolve and his physical examination findings return to normal.

Explanation:

Question 92:

Pelvic packing for a hemodynamically unstable patient with a pelvic ring fracture is best described by which of the following techniques?

Options:

Placing a pelvic external fixator followed by packing the pelvis with lap pads via a subumbilical incision
Placing lap pads for packing via a subumbilical incision in the angiography suite
Placing lap pads for packing using the lateral window of the ilioinguinal approach (anterior approach to the internal iliac fossa)
Packing the retroperitoneum with lap pads after exploration of the abdomen by the general surgeons
Direct exploration of the pelvic vasculature via a midline incision followed by packing with lap pads

Correct Answer: Placing a pelvic external fixator followed by packing the pelvis with lap pads via a subumbilical incision

Explanation:

Question 93:

Options:

Osteomyelitis
Lymphoma
Myeloma
Ewing’s sarcoma
Osteosarcoma

Correct Answer: Myeloma

Explanation:

Question 94:

- To maximally resist apex anterior angulation in the tibia, the pins of a unilateral external fixator should be oriented in which of the following planes?

Options:

Coronal
Sagittal
Anteromedial, midway between the sagittal and the coronal
Proximal pins sagittal, distal pins coronal
Proximal pins coronal, distal pins sagittal

Correct Answer: Sagittal

Explanation:

Question 95:

Options:

discontinuation of antibiotics and administration of nonsteroidal anti-inflammatory drugs, followed by physical therapy.
incision and drainage of both hips.
in situ pinning of both hips.
broad-spectrum antibiotics in accordance with the recommendations of a pediatric infectious diseases consultant.
continued use of IV antibiotics for 2 weeks, followed by oral antibiotics until the ESR returns to normal.

Correct Answer: discontinuation of antibiotics and administration of nonsteroidal anti-inflammatory drugs, followed by physical therapy.

Explanation:

Question 96:

A 14-year-old boy reports progressive right wrist pain. Radiographs are shown in Figure 3a, and a photomicrograph is shown in Figure 3b. What is the most likely diagnosis?

Options:

Enchondroma
Nonossifying fibroma
Chondromyxoid fibroma
Osteosarcoma
Chondrosarcoma

Correct Answer: Chondromyxoid fibroma

Explanation:

DISCUSSION: The radiographs show a benign-appearing, well-defined lytic lesion with a thin rim of surrounding reactive bone. The photomicrograph shows spindle cells with a myxoid cartilaginous matrix. These findings are diagnostic of chondromyxoid fibroma. This is a rare, benign tumor that usually causes pain and can be locally aggressive.
REFERENCES: Lersundi A, Mankin HJ, Mourikis A, et al: Chondromyxoid fibroma: A rarely encountered and puzzling tumor. Clin Orthop Relat Res 2005;439:171-175.
Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 103-111.

Question 97:

Following a chevron bunionectomy performed through a dorsal approach, a patient has persistent numbness on the dorsal and medial aspect of the hallux. What nerve has most likely been injured?

Options:

Lateral plantar nerve
Deep peroneal nerve
Dural nerve
Medial plantar nerve
Dorsomedial cutaneous nerve of the hallux

Correct Answer: Dorsomedial cutaneous nerve of the hallux

Explanation:

DISCUSSION: The dorsomedial cutaneous nerve of the hallux, which is a distal branch of the superficial peroneal nerve, supplies sensation to the skin on the dorsal and medial half of the hallux and may be injured during a chevron bunionectomy. Injury to the nerve leads to particularly painful neuromas that directly impinge on the shoe. For this reason, direct medial approaches are typically preferred for access to the medial aspect of the metatarsophalangeal joint.
REFERENCE: Miller SD: Dorsomedial cutaneous nerve syndrome: Treatment with nerve transection and burial into bone. Foot Ankle Int 2001;22:198-202.

Question 98:

Options:

Inadequate graft strength
Failure to restore graft length
Malposition of the femoral tunnel
Malposition of the tibial tunnel

Correct Answer: Malposition of the femoral tunnel

Explanation:

DISCUSSION
The anteromedial bundle originates on the anterior and proximal aspect of the lateral femoral condyle and inserts on the anteromedial aspect of the anterior cruciate ligament (ACL) footprint on the proximal tibia. The posterolateral bundle originates posterior and distal to
63
the anteromedial bundle and inserts on the posterolateral aspect of the tibial footprint. The fibers are parallel when the knee is in an extended position. As the knee moves into flexion,
the fibers of the anteromedial bundle rotate externally with respect to the posterolateral bundle. The anteromedial bundle is tensioned in both flexion and extension. The posteromedial bundle is tensioned in extension, but relaxes as the knee moves into flexion.
The lateral meniscus is more commonly injured with an acute injury to the ACL. The medial meniscus is injured more commonly when the ACL is chronically unstable.
The ACL is an intra-articular and intrasynovial structure. It is innervated by posterior articular branches from the tibial nerve. Innervation of the ACL involves several types of mechanoreceptors (Ruffini, Pacini, Golgi tendon, and free-nerve endings) that may contribute to proprioceptive function of the knee and modulation of quadriceps function.
Injury to the ACL is predominantly associated with instability to anterior translation of the tibia in extension. The ACL plays a secondary role to limit internal rotation of the tibia, and a loss of ACL stability is confirmed by the reduction of the tibia from a position of anterior translation and internal rotation (pivot shift). The radiographs demonstrate anterior placement of the femoral tunnel. The convex shape of the lateral femoral condyle can make it more difficult to visualize the anatomic femoral origin of the ACL. Failure to identify the
anatomic footprint can result in anterior placement of the femoral tunnel. Anterior ACL graft placement can result in its impingement against the posterior cruciate ligament and early limitation of knee flexion. Over time, impingement on the graft may result in stretching of the graft and recurrent knee instability symptoms.
RECOMMENDED READINGS
Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. Anatomy of the anterior cruciate ligament. Knee Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):204-13. Epub 2005 Oct 19. Review. PubMed PMID: 16235056.
View
Abstract at PubMed
Zantop T, Petersen W, Sekiya JK, Musahl V, Fu FH. Anterior cruciate ligament anatomy and function relating to anatomical reconstruction. Knee Surg Sports Traumatol Arthrosc. 2006 Oct;14(10):982-92. Epub 2006 Aug 5. Review. PubMed PMID: 16897068.
View Abstract at PubMed

Question 99:

Options:

Increased ductility
Increased wettability
Diminished fatigue strength
Decreased resistance to abrasive wear

Correct Answer: Diminished fatigue strength

Explanation:

Question 100:

Options:

bed rest for 8 weeks, followed by mobilization in a total contact thoracolumbosacral orthosis.
immediate laminectomy only.
anterior decompression, vertebral body reconstruction, and stabilization.
in situ posterior fusion.
short segment posterior fixation and fusion.

Correct Answer: anterior decompression, vertebral body reconstruction, and stabilization.

Orthopedic Surgery Board Review MCQs: Arthroplasty, Ligament & Spine | Part 149

OITE & ABOS Orthopedic Board Prep: Adult Reconstruction, Trauma & Upper Extremity MCQs Part 140

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 140

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index