OITE & ABOS Orthopedic Board Prep: 100 MCQs Part 260

About This Board Review Set

This is Part 260 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 260

This module focuses heavily on: Arthroplasty, Fracture, Knee, Nerve.

Sample Questions from This Set

Sample Question 1: An 18-year-old rugby player has had pain in his ring finger after missing a tackle 1 week ago. Examination reveals tenderness in the distal palm, and he is unable to actively flex the distal interphalangeal (DIP) joint. Radiographs are norm...

Sample Question 2: One year after undergoing anterior cervical decompression and fusion, what percentage of patients still have dysphagia?...

Sample Question 3: Assuming that the fracture shown in this radiograph (Figure 1) is aligned on the anteroposterior radiograph and heals in this position, secondary to fracture malalignment, there will be loss of active...

Sample Question 4: A patient who underwent total knee arthroplasty now reports a loss of sensation in the area circled in Figure 38. This area is innervated by which of the following nerves?...

Sample Question 5: 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...

Why Active MCQ Practice Works

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

Comprehensive 100-Question Exam

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Question 1

An 18-year-old rugby player has had pain in his ring finger after missing a tackle 1 week ago. Examination reveals tenderness in the distal palm, and he is unable to actively flex the distal interphalangeal (DIP) joint. Radiographs are normal. What is the most appropriate management?

Explanation

DISCUSSION: Flexor digitorum profundus rupture or “rugger jersey finger” often occurs in the ring finger after the player misses a tackle and catches the digit on the shirt of the opposing player. Surgical repair is required for zone I-type injuries.
REFERENCES: Moiemen NS, Elliot D: Primary flexor tendon repair in zone I. J Hand Surg Br 2000;25:78-84.
Strickland JW: Flexor tendon injuries: I. Foundations of treatment. J Am Acad Orthop Surg 1995;3:44-54.

Question 2

One year after undergoing anterior cervical decompression and fusion, what percentage of patients still have dysphagia?

Explanation

DISCUSSION
Dysphagia after anterior cervical diskectomy and fusion is a common, usually transient finding after anterior cervical approaches to the spine. While it has been reported to occur in up to 70% of patients 2 weeks following surgery, in most cases the symptoms quickly resolve. There is, however, a small subset of patients for whom symptoms of dysphagia will persist. Lee and associates prospectively studied the rate of dysphagia after anterior cervical diskectomy and fusion, reporting a 15% rate of dysphagia at 12 months, and 12% at 24 months. Phillips and associates analyzed the 2-year data from the PCM FDE clinical trial and found a 12.1% incidence of dysphagia in the ACDF arm.
RECOMMENDED READINGS
Lee MJ, Bazaz R, Furey CG, Yoo J. Risk factors for dysphagia after anterior cervical spine surgery: a two-year prospective cohort study. Spine J. 2007 Mar-Apr;7(2):141-7. Epub 2007 Jan 22. PubMed PMID: 17321961. View Abstract at PubMed
Smith-Hammond CA, New KC, Pietrobon R, Curtis DJ, Scharver CH, Turner DA. Prospective analysis of incidence and risk factors of dysphagia in spine surgery patients: comparison of anterior cervical, posterior cervical, and lumbar procedures. Spine (Phila Pa 1976). 2004 Jul 1;29(13):1441-6. PubMed PMID: 15223936. View Abstract at PubMed
Edwards CC 2nd, Karpitskaya Y, Cha C, Heller JG, Lauryssen C, Yoon ST, Riew KD. Accurate identification of adverse outcomes after cervical spine surgery. J Bone Joint Surg Am. 2004 Feb;86-A(2):251-6. PubMed PMID: 14960668. View Abstract at PubMed
Phillips FM, Lee JY, Geisler FH, Cappuccino A, Chaput CD, DeVine JG, Reah C, Gilder KM, Howell KM, McAfee PC. A prospective, randomized, controlled clinical investigation comparing PCM cervical disc arthroplasty with anterior cervical discectomy and fusion. 2-year results from the US FDA IDE clinical trial. Spine (Phila Pa 1976). 2013 Jul 1;38(15):E907-18. doi: 10.1097/BRS.0b013e318296232f.
Rihn JA, Kane J, Albert TJ, Vaccaro AR, Hilibrand AS. What is the incidence and severity of dysphagia after anterior cervical surgery? Clin Orthop Relat Res. 2011 Mar;469(3):658-65. PMID: 21140251.View Abstract at PubMed

Question 3

Assuming that the fracture shown in this radiograph (Figure 1) is aligned on the anteroposterior radiograph and heals in this position, secondary to fracture malalignment, there will be loss of active

Explanation

EXPLANATION:
This is a transverse proximal phalanx fracture with apex volar angulation. The fracture displaces into an apex volar angulated position under the pull of the central slip on the distal fragment and the interossei insertions at the base of proximal phalanx. Although it is possible to lose motion in flexion or extension of the MP or PIP joints, the biomechanics will not allow full extension of the PIP joint. If allowed to heal in apex palmar malunion, the predicted corresponding extensor lags are for a 10-degree lag at 16 degrees of angular deformity, a 24-degree lag at 27 degrees of deformity, and a 66-degree lag at 46 degrees of deformity. These fractures usually can be treated with closed reduction with or without percutaneous pinning. With surgical treatment, there may be loss of motion both at the MP and PIP joints.

Question 4

A patient who underwent total knee arthroplasty now reports a loss of sensation in the area circled in Figure 38. This area is innervated by which of the following nerves?

Explanation

DISCUSSION: The saphenous nerve follows the saphenous vein, giving off the infrapatellar branch that crosses the knee anteriorly to supply the peripatellar skin. A longitudinal incision can interrupt the nerve, leaving the terminal distribution without sensation.
REFERENCE: Last RJ: Anatomy: Regional and Applied, ed 6. London, England, Churchill Livingstone, 1978, pp 140-150.

Question 5

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 6

An otherwise healthy 35-year-old woman reports dorsal wrist pain and has trouble extending her thumb after sustaining a minimally displaced fracture of the distal radius 3 months ago. What is the next most appropriate step in management?

Explanation

DISCUSSION: Extensor pollicis longus tendon rupture can occur after a fracture of the distal radius, even a minimally displaced one. Poor vascularity of the tendon within the third dorsal compartment is the suspected etiology, not the displaced fracture fragments. Tendon transfer will suitably restore active extension of the thumb interphalangeal joint.
REFERENCES: Christophe K: Rupture of the extensor pollicis longus tendon following Colles fracture. J Bone Joint Surg Am 1953;35:1003-1005.
Hove LM: Delayed rupture of the thumb extensor tendon: A 5-year study of 18 consecutive cases. Acta Orthop Scand 1994;65:199-203.

Question 7

A 54-year-old man sustained a small superficial abrasion over the left acromioclavicular joint after falling from his bicycle. Examination reveals no other physical findings. Radiographs show a displaced fracture of the lateral end of the clavicle distal to a line drawn vertically to the coracoid process. Management should consist of

Explanation

DISCUSSION: Displaced clavicular fractures lateral to the coracoid process (Neer type II and III) are best managed nonsurgically with sling immobilization and physical therapy, starting with pendulum exercises and progressing to active-assisted exercises when comfortable. Supervised therapy should be performed for 3 months or until full painless motion is achieved. In one study by Robinson and Cairns, this form of treatment provided patients with a 86% chance of avoiding a secondary reconstructive procedure.
REFERENCES: Robinson CM, Cairns DA: Primary nonoperative treatment of displaced lateral fractures of the clavicle. J Bone Joint Surg Am 2004;86:778-782.
Deafenbaugh MK, Dugdale TW, Staeheli JW, et al: Nonoperative treatment of Neer type II distal clavicle fractures: A prospective study. Contemp Orthop 1990;20:405-413.

Question 8

Figures A and B show the six-month follow-up radiographs of a 62-year-old woman who sustained a hip fracture in a fall. Prior to the fall, the patient was active and had no difficulty with ambulation. The patient underwent open reduction and internal fixation with a sliding hip screw device. She has difficulty with ambulation, continues to walk with a walker, and reports startup pain. What is the most appropriate management at this time? Review Topic

Explanation

The radiographs demonstrate a healed fracture with penetration of the screw through the femoral head into the acetabulum as well as osteonecrosis and collapse of the femoral head (Figure 129b). Conversion to total hip arthroplasty with a long stem is necessary to bypass the femoral cortical defects from the screw holes. A primary tapered stem is not appropriate because of the proximal femoral deformity and the stress risers associated with the screw holes. Removal of hardware, valgus osteotomy, and revision of the internal fixation are not appropriate in the presence of the femoral head collapse and acetabular penetration.

Question 9

The blood supply to the anterior cruciate ligament is primarily derived from what artery?

Explanation

DISCUSSION: Microvascular studies have shown that the majority of the blood supply to the cruciate ligaments comes from the middle geniculate artery, although there is collateral flow through the other geniculates and from bone.
REFERENCES: Arnoczky SP: Blood supply to the anterior cruciate ligament and supporting structures. Orthop Clin North Am 1985;16:15-28.
Arnoczky SP, Rubin RM, Marshall JL: Microvasculature of the cruciate ligaments and its response to injury. J Bone Joint Surg Am 1979;61:1221-1229.

Question 10

Figure 242 is the anteroposterior radiograph of a 28-year-old man who underwent resection and reconstruction for an Ewing sarcoma. What is the most common functional deficit encountered during rehabilitation?

Explanation

Question 11

A 34-year-old woman who is a professional skier (Figure 42)

Explanation

Question 12

A 25-year-old patient who was wearing a seat belt in the back chair of a car involved in a head-on collision undergoes a laparotomy. During surgery, an injury to the sigmoid colon is identified and treated. Two days later the patient has back pain when sitting in a chair. What is the most likely diagnosis?

Explanation

Number four is correct because it fits the injury pattern and symptoms of the scenario given above. (Chance/Seat Belt Fracture) Number one is incorrect because it is the most “likely” diagnosis in this injury pattern. It would need more of a direct blow type of injury to be true. Number two is incorrect because it does not fit the injury pattern. The burst fracture is usually an axial/vertical loading injury. Number three is incorrect because the patient is having back pain only and no lower extremity or bowed/bladder complaints that you would typically find in a cauda equina syndrome. Number five is incorrect because it does not fit the injury pattern of the scenario given above with comparison to the number four answer.

Question 13

Figures 8a through 8d show the radiographs and CT scans of a 14-year-old girl who has a painful, rigid planovalgus foot. Management consisting of arch supports and anti-inflammatory drugs failed to provide relief. A below-knee walking cast resulted in pain resolution, but she now reports that the pain has recurred. Management should now consist of

Explanation

DISCUSSION: Tarsal coalitions commonly present in the preadolescent age group as a rigid, planovalgus foot. Small coalitions of the calcaneonavicular joint or the middle facet of the talocalcaneal joint can be excised with interposition of fat or muscle tissue. Isolated calcaneocuboid joint coalitions are very rare. This patient has an associated large talocalcaneal coalition; therefore, resection is contraindicated. Surgery is warranted after failure of nonsurgical management, and because of the involvement of two joints, the only viable option for the severely symptomatic foot is triple arthrodesis.
REFERENCES: Vincent KA: Tarsal coalition and painful flatfoot. J Am Acad Orthop Surg 1998;6:274-281.
Olney BW: Tarsal coalition, in Drennan JC (ed): The Child’s Foot and Ankle. New York, NY, Raven Press, 1992, pp 169-181.

Question 14

A 63-year-old woman had a primary total hip arthroplasty 7 years ago that included a proximally coated titanium stem, a cobalt alloy femoral head, a titanium hemispherical acetabular component, and a polyethylene liner. She did well for 4 years but has now had two dislocations and reports pain and weakness around the left hip. She denies any fevers, chills, or constitutional symptoms. On examination, the patient walks well without any signs of an antalgic or Trendelenburg gait. Her abductor mechanism demonstrates good strength. Her erythrocyte sedimentation rate and C-reactive protein level are normal. On radiographs, all components appear well fixed and in good alignment. What is the most appropriate treatment at this time?

Explanation

DISCUSSION:
Trunnionosis is a recently recognized complication following total hip arthroplasty and can occur when a cobalt alloy femoral head is used on a titanium alloy or cobalt alloy femoral stem. Patients often present with pain or swelling around the hip but at times can present with instability. Certain femoral stem designs have been associated with increased reports of trunnionosis. In a patient with a cobalt alloy femoral head who presents with instability, swelling, and weakness around the hip, the potential for trunnionosis and
an adverse local tissue reaction should be considered.

Question 15

What percent of adult patients with rheumatoid arthritis test positive for rheumatoid factor?

Explanation

Rheumatoid factor is present in 80% to 90% of adult patients with rheumatoid arthritis. Although rheumatoid factor is very sensitive, it is not very specific. Antinuclear antibodies (ANA) can be detected in 30% to 40% of patients with rheumatoid arthritis.

Question 16

During particle-induced osteolysis around implants, what cell secretes most of the interleukin-6 (IL-6)?

Explanation

DISCUSSION: During osteolysis, IL-6 is secreted by fibroblasts in the membrane surrounding the prosthesis. IL-6 also can be secreted by osteoblasts in other settings, but they are not the predominant source of IL-6 in particle-induced osteolysis. The remaining cells are not major sources of IL-6.
REFERENCE: Bukata SV, Gelinas J, Wei X, et al: PGE2 and IL-6 production by fibroblasts in response to titanium wear debris particles is mediated through a Cox-2 dependent pathway. J Orthop Res 2004;22:6-12.

Question 17

intermittent PTH injections increase bone mass, 2) continous infusion lead to bone resorption, and 3) dosing should not continue past 2 yrs. Thus, intermittent parathyroid hormone is anabolic to bone and is used as a treatment of osteoporosis (forteo).

Explanation

BMP proteins, which are part of the larger transforming growth factor-beta super family, bind to serine/threonine receptors on the cell surface. This binding causes phosphorylation of SMAD proteins, which in turn forms a complex that enters the nucleus and initiates the transcription of several genes involved in osteoblastic differentiation. Adenylate cyclase is
a transmembrane protein that acts intracellularly to activate the G protein pathways. Myc is a proto-oncogene that encodes for a transcription factor involved in numerous cell- activation pathways, but is not directly phosphorylated by BMP receptor.
ß-catenin is an intracellular molecule that plays a key role in the Wnt signaling pathway. This pathway is also involved in osteoblastic differentiation, but differs in target proteins within the cell.
A 45-year-old previously healthy woman has experienced weakness and fatigability for 2 months. She states she feels best in the morning, but tires easily with exertion. If she sits and rests her strength improves, but she easily tires with each activity. When her fatigue is most severe, she has double vision. Physical examination is
positive for ptosis with upward gaze after 20 seconds. When she holds her arms out straight she shows good initial strength, but rapidly decreasing strength with time. What is the pathologic cause of her muscle weakness?
Ig antibodies at the neuromuscular (NM) junction
Decreased release of acetylcholine at the NM junction
Decrease in myelin sheath of axonal nerves with loss of NM junction
Absence of dystrophin with excess calcium at sarcolemma
The patient has myasthenia gravis, which has its onset in middle age and causes progressive weakness because of the loss of acetylcholine receptors secondary to autoimmune antibodies at the NM junction. Rest periods allow uptake of acetylcholine and initial strength, but easy fatigability. Treatment is aimed at immunomodulation; acetyl cholinesterase inhibitors often coupled with thymectomy can control symptoms.
Decreased release of acetylcholine at the NM junction is the effect of a nondepolarizing drug or toxin botulinum. Patients with muscular dystrophy lack dystrophin that acts at the sarcolemma to regulate calcium channels, and onset of this condition occurs at a younger age. The decrease in myelin indicates Charcot-Marie-Tooth disease and is
often seen with long axon degeneration, such as in the feet and lower legs.
You are studying a single continuous variable after administration of a defined treatment intervention. Your statistician informs you the data are not normally distributed. What is the best test to analyze the data?
Analysis of variance (ANOVA)
Regression analysis
Student t test
Mann-Whitney U test
The Mann-Whitney U test is used when data are nonparametric, meaning either not normally distributed or variances are not equal among groups. Both the Student t test and ANOVA are used with parametric, normally distributed data. A regression analysis is a
statistical model that allows for control of potentially confounding variables. It is used to assess the relationship between a dependent variable and (usually) multiple independent variables.
Which of the following is the mechanism of action of aspirin?
Inhibition of vitamin K-dependent carboxylation
Inhibition of factor Xa through antithrombin binding
Binding of cyclooxygenase (COX)-1 and COX-2
Direct thrombin inhibition
Glycoprotein IIIb agonist binding
Aspirin works by the irreversible binding of cycloxygenase (COX). This effect inhibits platelet generation of thromboxane A2, resulting in an antithrombotic effect. In addition, there is a decrease in the level of prostaglandin production due to the COX-1 binding.
Aspirin's effects and respective mechanisms of action vary with dose:
Low doses (typically 75 to 81 mg/day) are sufficient to irreversibly acetylate serine 530 of cyclooxygenase (COX)-1. This effect inhibits platelet generation of thromboxane A2, resulting in an antithrombotic effect.
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Intermediate doses (650 mg to 4 g/day) inhibit COX-1 and COX-2, blocking prostaglandin (PG) production, and have analgesic and antipyretic effects. Illustration A shows the mechanism of action of aspirin.
InCORRECT Answers: 1,2,4,5: Aspirin does not have any of these mechanisms of action.
A study is proposed in which 2 groups of patients are randomized to treatment with bisphosphonates or placebo. This is an example of what study type?
Crossover design trial
Parallel design trial
Cohort study
Case series
In a parallel design trial, participants are randomized to 2 or more groups, each of which receives a different treatment or intervention. For example, Group A receives the drug and Group B receives the placebo. This type of
design allows for comparison between groups. In a crossover design clinical trial, both groups receive both interventions over a defined time period. For example, Groups A and B both receive the drug as well as the placebo. This allows for within-participant comparisons. In a cohort study, patient groups are followed over time on the basis of having or not having received an exposure. Cohort studies are not randomized. In a case series, patients often receive a particular treatment and the outcomes are then examined.
An otherwise healthy 50-year-old man who is a smoker undergoes a posterior spine fusion with instrumentation for spondylolisthesis. What can the patient do to minimize his risk for pseudarthrosis?
Increase calcium and vitamin D intake
Avoid all nonsteroidal anti-inflammatory drugs (NSAIDs)
Maintain smoking cessation
Engage in early physical therapy to strengthen the trunk musculature
Smoking is the biggest risk factor for nonunion and should be strictly avoided. NSAIDs interfere with bone healing, but not as strongly as smoking. Early mobilization would potentially stress the construct, inducing movement that leads to nonunion. Without history of calcium and vitamin D deficiency, increasing intake would not decrease the risk of nonunion.
When making a comparison to autograft incorporation, the inflammatory process in allograft tissue anterior cruciate ligament (ACL) reconstruction
occurs earlier.
occurs later.
is prolonged.
is shortened.
Compared to similar autograft, allograft tissue demonstrates a prolonged inflammatory response, slower rate of biological incorporation and remodeling, and a higher proportion of large-diameter collagen fibrils. Native ACL inserts
into bone through a transition of 4 distinct zones: tendon, unmineralized fibrocartilage, mineralized fibrocartilage, and bone. This transition is not reproduced with tendon grafts, which instead heal with interposed fibrovascular scar at the graft-tunnel interface. The scar rapidly remodels to form perpendicular fibers resembling Sharpey fibers and, eventually, mature bone growth into the outer portion of the graft. The intra- articular portion of allograft undergoes an initial phase of necrosis followed by repopulation by host synovial cells into the acellular collagen scaffold.
Revascularization and maturation complete the ligamentization of graft tissue.
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?
Correlation coefficient of MRSA
Prevalence of MRSA
Incidence of MRSA
Relative risk of MRSA
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.
A 48-year-old man who is scheduled to undergo total knee replacement has an X-linked clotting disorder that leads to abnormal bleeding and recurrent, spontaneous hemarthrosis. Before undergoing surgery, he should have replacement therapy of
protein C and S.
vitamin K.
von Willebrand factor.
factor VIII.
Hemophilia A is an X-linked recessive deficiency of factor VIII that can lead to significant bleeding problems including recurrent spontaneous hemarthroses that can lead to synovitis and joint destruction. von Willebrand disease is a lack of von Willebrand factor that leads to decreased platelet aggregation; more commonly patients have mucosal bleeding and not hemarthroses. Vitamin K deficiency is not hereditary; it is typically attributable to inadequate dietary intake, malabsorption, and loss of storage sites from hepatocellular disease. Protein C and S deficiencies are autosomal-dominant diseases that lead to thrombosis, not bleeding, as protein C and S shut off thrombin formation.
What is the recommended optimal timing of presurgical antibiotic administration to prevent infection in patients undergoing total joint replacement surgery?
Within 1 hour before incision
Within 2 hours before incision
Immediately after incision
Within 1 hour after incision
The current recommendation for antibiotic prophylaxis for major orthopaedic surgical procedures is to administer intravenous antibiotics within 1 hour of surgical incision. Redosing of antibiotics should occur 3 to 4 hours after the initial dose for procedures that extend beyond 3 to 4 hours. Little evidence supports postsurgical antibiotic use beyond 24 hours. As you move beyond 1 hour from time of administration of antibiotics, risk for infection increases and rates of bacterial cell death decline. It is not acceptable to
administer presurgical antibiotics after incision.
Bacterial resistance to antibiotics in biofilm is an example of
avoidance.
decreased susceptibility.
inactivation.
mutation. CORRECT answer: 1
Three basic mechanisms of antibiotic resistance have been identified: avoidance, decreased susceptibility, and inactivation. Biofilm formation is a classic example of avoidance, whereby the biofilm creates a physical barrier to the antibiotic. Bacteria can decrease their susceptibility to antibiotics by mutating the antibiotic target or generating a mechanism to inactivate the antibiotic. Biofilm formation develops when a sufficient mass of bacteria forms on a surface. The cell-to-cell signaling becomes sufficient to activate transcription of genes needed for biofilm formation in a process known as quorum sensing. Once the bacteria produce a mature biofilm, they enter a greatly reduced or stationary phase of growth. Lastly, high-shear
environments seem to stimulate biofilm production.
A patient with Paget disease who is intolerant of bisphosphonates is given calcitonin. What is the mechanism of action of calcitonin?
Promotes reabsorption of phosphate in the renal tubules
Interferes with osteoclast maturation
Interferes with intestinal absorption of calcium
Upregulates osteoblast formation
Calcitonin is a hormone that reduces serum calcium concentration by directly interfering with osteoclast maturation via receptors. Calcitonin inhibits phosphate reabsorption and decreases calcium reabsorption in the kidneys. By attenuating cartilage breakdown and stimulating cartilage formation via inhibitory pathways of matrix metalloproteinases, calcitonin also has a
chondro-protective effect on articular cartilage. Calcitonin has no major effects on intestinal absorption of calcium, but may aid in small-bowel secretion of sodium, potassium, chloride, and water. Calcitonin also has no receptor effect on osteoblasts.
A cartilage water content increase is the hallmark of which
osteoarthritis stage?
Prearthritis
Early
Late
Terminal
The first stage of osteoarthritis is marked by an increase in water content secondary to disruption of the matrix framework. This is followed by an increase in chondrocyte anabolic and catabolic activity in response to tissue damage. Wnt-induced signal protein 1 increases chondrocyte protease expression. Failure to restore tissue balance ultimately leads to continued destruction and osteoarthritis. One hallmark of osteoarthritic cartilage is a reduced repair mechanism attributable to decreased chondrocyte response to growth factor stimulation (transforming growth factor-alpha and insulin-like growth factor-1).
Mitochondrial dysfunction and increased production of reactive oxygen species may promote cell senescence, a progressive slowing of cellular activity. Microscopic evidence of cartilage degeneration begins with fibrillation of the superficial and transition zones, followed by disruption of the tidemark by subchondral blood vessels and eventual subchondral bone remodeling. This process ultimately leads to cartilage degradation with decreased water content in the late and terminal phases of osteoarthritis.
What is the plasma half-life of warfarin?
1 to 2 hours
4 to 6 hours
12 to 18 hours
36 to 42 hours
Warfarin, which is dosed daily, can take 72 to 96 hours to reach therapeutic levels. It has a plasma half-life of 36 to 42 hours. Low-molecular heparins have a plasma half-life of 4 to 5 hours, and fondaparinux has a half-life of 17 to 21 hours. Warfarin will not affect the International Normalized Ratio (INR) until 2 to 3 days after it is given. Patients on chronic warfarin therapy should
have treatment stopped 3 to 5 days before elective surgery to allow the INR to normalize.
A 70-year-old woman with a body mass index (BMI) of 34 and a history of hypercholesterolemia has elected to undergo total hip arthroplasty. Her son recently learned he has Factor V Leiden following an episode of pulmonary embolism. What are this patient's risk factors for thromboembolic disease?
Type of surgery, age, and BMI
Type of surgery, hypercholesterolemia, and age
Age, BMI, and hypercholesterolemia
BMI, type of surgery, and hypercholesterolemia
Risk stratification is one of the most critical clinical evaluations before undergoing total joint arthroplasty. Many factors have been identified to increase risk for venous thromboembolism (VTE). The major factors include previous VTE, obesity, type of surgery (such as total joint arthroplasty), hypercoagulable states, myocardial infarction, congestive heart failure, family history of VTE, and hormonal replacement therapy.
Hypercholesterolemia is not a risk factor for thromboembolic disease.
DNA replication occurs during which phase of the cell cycle?
M
S
R
G1
G2
The cell cycle consists of four distinct phases: initial growth (G1), DNA replication/synthesis (S), a gap (G2), and mitosis (M) (see illustration).
The G1 and G2 phases of the cell cycle represent the “gaps” or growth phases in the cell cycle that occur between DNA synthesis and mitosis. G0 cells are in a stable state and have not entered the cell cycle. During the S phase, the DNA is synthesized and replicated. During the M phase or mitosis, all genetic material divides into two daughter cells.
The cells are diploid (2N) in the G0 and G1 phases. The cells become tetraploid (4N) at the end of S and for the entire G2 phases. There is no R phase in the cell cycle.
What antithrombotic agent is a selective factor I0a inhibitor?
Warfarin
Low-molecular-weight heparin
Rivaroxaban
Aspirin
Rivaroxaban is a selective factor I0a inhibitor. Aspirin is a cyclooxygenase inhibitor. Low-molecular-weight heparin is a nonspecific anticoagulant. Warfarin is a vitamin K antagonist and reduces production of clotting factors II, VII, IX, and X.
A 68-year-old woman had advanced right knee arthritis and total knee replacement was planned. She learned she had primary biliary cirrhosis at age 41 and now has advancing liver failure. Preoperative coagulation tests show a baseline International Normalized Ratio (INR) of 1.36. Appropriate methods to prevent thromboembolic
disease as recommended by the 2011 AAOS Clinical Practice Guideline, Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee
Arthroplasty, include
use of mechanical prophylaxis (eg, pneumatic calf compressors) while in the hospital.
oral warfarin with a goal INR between 2.0 and 3.0.
low-dose warfarin for 3 weeks postsurgically beginning 48 hours after surgery.
no prophylaxis because this patient already is partially anticoagulated secondary to her liver disease.
The 2011 AAOS Clinical Practice Guideline, Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty, recommends the use of mechanical prophylaxis for patients at increased risk
for bleeding (including those with liver disease or hemophilia). This recommendation is the consensus of the workgroup that established these guidelines because there was insufficient evidence to justify a stronger recommendation in this clinical scenario. The other responses use no prophylaxis or pharmacological prophylaxis. Pharmacological prophylaxis is not recommended in patients who are at increased risk for bleeding.
The pharmacokinetics of which deep venous thrombosis (DVT) prophylactic agent are affected by liver function and dietary intake?
Dalteparin
Warfarin
Fondaparinux
Enoxaparin
Warfarin is an oral vitamin K antagonist that is rapidly absorbed from the gastrointestinal tract. It accumulates in the liver, where it is metabolized and excreted. The pharmacokinetics of warfarin can be affected by certain drugs or disease states that influence liver function. Fondaparinux is a synthetic factor Xa inhibitor that is eliminated through the kidneys. Both Dalteparin and Enoxaparin are low-molecular-weight heparins that activate antithrombin and inhibit factors Xa and IIa. Like Fondaparinux, they are eliminated through the kidneys and should be used with caution in patients with kidney disease.
What infection-control measure has been shown to have the most notable impact in reducing surgical-site infections?
Intravenous antibiotic administration within 1 hour of surgical incision
Screening and decolonization of patients colonized with methicillin-resistant
<em>Staphylococcus aureus</em>
Horizontal laminar flow
Use of enclosed body exhaust suits
Timely administration of prophylactic antibiotics is the most important factor shown to decrease surgical-site infections. The use of horizontal laminar flow and body exhaust suits has not been shown to significantly affect infection rates.
The resistance to pullout of a screw in osteoporotic bone is increased by all of the following EXCEPT?
Placement parallel to the trabecular pattern
Purchase in cortical bone
Use of a fixed angle (locking screw construct)
Tapping prior to screw placement
Augmentation with polymethylmethacrylate
Of the options listed, tapping prior to screw placement is the only variable that does not increase the pullout strength of a screw in osteoporotic bone.
Cornell reviews internal fixation in osteoporotic bone. According to this article, the quality of the bone is the primary determinant of the holding power of an individual screw. Other factors that increase the pullout strength include fixation in cortical bone (cortical bone has greater mineral density and, therefore, greater resistance to screw pullout than trabecular bone), screws placed parallel to the trabecular pattern, and screw fixation augmented with PMMA. The addition of a locking plate will also increase the resistance to failure by creating a fixed angle construct. Tapping prior to placement of the screw has not been shown to increase resistance to pullout, on the contrary studies have shown
this decreases resistance to pullout.
Turner et al examined the holding strength of small and large diameter screws in healthy bovine and diseased human bone. They found the screw diameter, trabecular orientation of the bone, and mineral content of the bone all affect the holding strength. A larger diameter screw, parallel placement to the trabecular pattern, and purchase in bone with a higher density all increase the holding strength.
Gigantism affects which region of the growth plate labeled in Figure A?
A
B
C
D
E
Gigantism, like achondroplasia, affects the proliferative zone (Region C of Figure A) of the growth plate. In Figure A, Region A is the epiphysis, Region B is the resting zone, Region D is the hypertrophic zone, and Region E is the metaphysis. Illustration A is another depiction of the physis which is labeled. Gigantism is typically caused by a pituitary adenoma which over secretes growth hormone. Its effect on the proliferative zone results in bone overgrowth and excessive height and limb length. Acromegaly may also be
caused by a pituitary adenoma that over secretes growth hormone, but has its effect once the physis has closed.
Plain radiographs do not provide an accurate assessment of bone mineral density (BMD) until what percentage of mineral has been lost?

Question 18

Which of the following nerves is most commonly injured during revision surgery following a Bristow procedure?

Explanation

DISCUSSION: Because of the previously transferred bone block of coracoid and short arm flexors, the musculocutaneous nerve often scars along the anteroinferior glenohumeral capsule. Mobilization of this tissue places the nerve at greatest risk. The axillary nerve is also potentially at risk, but this is nonspecific to prior surgery, particularly the Bristow procedure.
REFERENCES: Norris TR: Complications following anterior instability repairs, in Bigliani LU (ed): Complications of Shoulder Surgery. Baltimore, MD, Williams and Wilkins, 1993,

pp 98-116.
Flatow EL, Bigliani LU, April EW: An anatomic study of the musculocutaneous nerve and its relationship to the coracoid process. Clin Orthop 1989;244:166-171.

Question 19

Embolic material generated during total knee arthroplasty (TKA) shown in Figure 29 is composed of which of the following substances?

Explanation

DISCUSSION: Emboli are created during TKA. Usually there is an increased incidence with the use of intramedullary rods that disrupt the marrow contents. These are not fat emboli per se. They are material composed of fat cells and marrow that act like pulmonary emboli to obstruct small arterioles in the lung. They are different from free fat emboli that are seen in fractures and that lead to chemical injury to the lung rather than obstructive injury.
REFERENCES: Markel DC, Femino JE, Farkas P, et al: Analysis of lower extremity embolic material after total knee arthroplasty in a canine model. J Arthroplasty 1999;14:227-232.
Pell AC, Christie J, Keating JF, et al: The detection of fat embolism by transoesophageal echocardiography during reamed intramedullary nailing: A study of 24 patients with femoral and tibial fractures. J Bone Joint Surg Br 1993;75:921-925.
McGrath BJ, Hsia J, Boyd A, et al: Venous embolization after deflation of lower extremity tourniquets. Anesth Analg 1994;78:349-353.

Question 20

A 12-year-old girl has had right knee pain for the past 3 months. Radiographs and a coronal T 2 -weighted MRI scan are shown in Figures 10a through 10c. A biopsy specimen is shown in Figure 10d. What is the most appropriate treatment for this lesion?

Explanation

DISCUSSION: The radiographs show a lytic lesion in the right proximal tibia that has a high fluid content based on the MRI findings. The radiographic appearance is consistent with either telangiectatic osteosarcoma or aneurysmal bone cyst. Low-magnification histology shows a lesion resembling an aneurysmal bone cyst, with blood lakes separated by cellular septa. However, high-magnification shows severe cytologic atypia, indicative of a telangiectatic osterosarcoma. The appropriate treatment is neoadjuvant chemotherapy followed by wide resection and reconstruction of the lesion.
REFERENCES: Unni KK: Dahlin’s Bone Tumors: General Aspects and Data on 11,087 Cases, ed 5. Philadelphia, PA, Lippincott-Raven, 1996, pp 143-160.
Arndt CA, Crist WM: Common musculoskeletal tumors of childhood and adolescence. N Engl J Med 1999;341:342-352.

Question 21

A college basketball player is struck in the eye by a player’s hand while driving to the basket. Fluorescein evaluation reveals the injury shown in Figure 18. Management should consist of

Explanation

DISCUSSION: The athlete has a corneal abrasion. Fluorescein staining identifies the break in the epithelium when examined with ultraviolet light. Topical antibiotics are used as prophylaxis against secondary bacterial infection, and the patch, applied with the lid closed, is used for comfort and to promote epithelial healing. The accompanying symptoms, including pain, tearing, and photophobia, are usually too intense to allow a return to play. Surgery is reserved for a corneal laceration with associated loss of the anterior chamber. While a proper fundoscopic examination may be a consideration, increased intraocular pressure is not typically associated with this injury. Traumatic hemorrhage in the anterior chamber (hyphema) necessitates strict bed rest during the early phases of healing; examination will most likely reveal the red fluid level of blood settling inferiorly in the anterior chamber. It is often associated with increased intraocular pressure.
REFERENCES: Brucker AJ, Kozart DM, Nichols CW, et al: Diagnosis and management of injuries to the eye and orbit, in Torg JS (ed): Athletic Injuries to the Head, Neck, and Face. St Louis, MO, Mosby-Year Book, 1991, pp 650-670.
Zagelbaum BM: Treating corneal abrasions and lacerations. Phys Sports Med 1997;25:38-44.

Question 22

Which of the following is considered an advantage of an unreamed intramedullary nail over a reamed intramedullary nail?

Explanation

The advantage of an unreamed intramedullary nail is a loose-fitting intramedullary rod. Placed in the medullary canal, it allows the endosteal circulation to regenerate rapidly and completely where space has been left between the nail and the endosteal surface. The endosteal blood vessels are destroyed during introduction of reamed intramedullary nail.

Question 23

The radiographic finding in Figure 58 is indicative of what type of acetabular fracture?

Explanation

Bilateral open reduction and internal fixation
Open reduction internal fixation on the right, reamed intramedullary nailing on the left
Temporizing external fixation on the right, open reduction and internal fixation on the left
Bilateral reamed intramedullary nailing
Bilateral temporizing external fixation
This patient presents with features of hemodynamic instability and a high injury severity score. The next most appropriate treatment would be temporizing external fixation bilaterally. This patient meets the criteria for damage control orthopaedics.
Damage control orthopaedics is an approach that contains and stabilizes orthopaedic injuries so that the patient's overall physiology does not undergo further inflammatory insult. As a result, external fixation of femoral shaft fracture and pelvic stabilization is an effective treatment under this strategy. Other indications include vascular injury and severe open fracture.
Pallister et al. reviewed the effects of surgical fracture fixation on the systemic inflammatory response to major trauma. They show that early stabilization of major long bone fractures is beneficial in reducing the incidence of acute respiratory distress syndrome and multiple organ failure. However, early fracture surgery increases the post-traumatic inflammatory response, which carries a higher complication rate compared to temporary fixation.
Tisherman et al. created clinical guidelines for the endpoints of resuscitation. Level I data found that standard hemodynamic parameters do not adequately quantify the degree of physiologic derangement in trauma patients. The initial base deficit, lactate level, or gastric pH should be used to stratify patients with regard to the need for ongoing fluid resuscitation.
Pape et al. retrospectively reviewed the impact of early total care vs. damage control orthopaedics in the treatment of femoral shaft fractures in polytrauma patients. They found a significantly higher incidence of acute respiratory distress syndrome (ARDS) with intramedullary nailing (15.1%) compared to external fixation (9.1%) when DCO subgroups were compared.
Figure A is a pelvic AP radiograph showing a right hip fracture-dislocation with an ipsilateral femoral shaft fracture. On the left side there is a displaced pertrochanteric hip fracture.
Incorrect Answers:

Question 24

Anaerobic weight training has what effect in a prepubescent 10-year-old male athlete? Review Topic

Explanation

Although anaerobic weight training in this age group does not lead to muscle hypertrophy, it can increase the efficiency of muscle action by increasing muscle memory. There is insufficient testosterone in this patient population to allow for muscle hypertrophy. Proper techniques of weight training have been shown to be safe and do not damage the growth plates or joints in these individuals.

Question 25

A 24-year-old man who plays golf noted the immediate onset of pain on the ulnar side of his hand and has been unable to swing a club for the past 6 weeks after striking a tree root with his club during his golf swing. Examination reveals full motion of the wrist, diminished grip strength, and tenderness over the hypothenar region. A CT scan of the hand and wrist is shown in Figure 26. Management should consist of

Explanation

DISCUSSION: Fractures of the hook of the hamate frequently are not identified in the acute phase. Because the fracture can be difficult to see on plain radiographs, the lack of findings can lead to a painful nonunion. A carpal tunnel view may show the fracture, but a CT scan will best detect the injury. Immobilization is the treatment of choice and will result in union in most patients unless the diagnosis is delayed. However, excision of the fragment may be necessary for patients who have nonunion, persistent pain, or ulnar nerve palsy.
REFERENCES: Carroll RE, Lakin JF: Fracture of the hook of the hamate: Acute treatment. J Trauma 1993;34:803-805.
Whalen JL, Bishop AT, Linscheid RL: Nonoperative treatment of acute hamate hook fractures. J Hand Surg Am 1992;17:507-511.

Question 26

Figure 16 shoes the AP radiograph of a 32-year-old man with a fracture cephalad to the fovea of the femoral head. A CT scan shows a single head fragment. After closed reduction of the hip, there is 5 mm of residual articular incongruity. Management should now include

Explanation

There seems to be no controversy in treating Pipkin 3 and 4 femoral head fractures. These are treated with an ORIF in concert with the femoral neck fracture or the acetabular fracture respectively. The difficulty stems in how to treat types land 2. In their review the authors recommend that residual joint incongruity of >2mm or an unstable hip requires and ORIF; their preferred approach was anterior. Swiontkowski Thorp Hansen Operative management of displaced femoral head fractures. J Orthopaedic Trauma. 1992 Vol 6 No 4; 437442

Question 27

Figures 55a through 55c are the clinical photograph and radiographs of a 5-year-old boy who fell and injured his right elbow. His radial pulse is thready. Which neurologic deficit most commonly is associated with this injury?

Explanation

DISCUSSION
This injury is a type III supracondylar humerus fracture with posterolateral displacement. The area of ecchymosis is anteromedial, corresponding to the proximal spike of the humeral metaphysis. The brachial artery is likely tented over this spike, leading to diminished perfusion. The median nerve also resides in this area, and any neurological deficit is likely in its most vulnerable fibers, those of the anterior interosseous nerve (AIN). The AIN contains no sensory fibers, and its motor function involves flexion of both the thumb IP joint and the index distal IP joint.
First dorsal web space anesthesia and an inability to extend the fingers would indicate radial nerve neuropraxia, which would be more likely with posteromedially displaced fractures and lead to anterolateral ecchymosis. Finger abduction is controlled by the ulnar nerve, which most often is injured in flexion injuries and iatrogenically by medially placed pins.

Question 28

-In the shoulder position of 90-degree forward flexion and internal rotation, what is the most important static stabilizer of the glenohumeral joint?

Explanation

CLINICAL SITUATION FOR QUESTIONS 48 AND 49
A 17-year-old high school wrestler sustains an abrasion over the posterior aspect of his right elbow during a match. During the next few days the abrasion becomes erythematous and he is placed on oral cephalexin 500 mg four times per day. The erythema extends proximally despite the antibiotic regimen. The patient is afebrile, there is no fluid collection associated with the lesion, and his elbow joint is not involved.

Question 29

A 32-year-old construction worker reports a persistent burning, tingling sensation on the dorsum of his right foot and significant sensitivity on the plantar surface after a 500-lb steel beam dropped on it 8 weeks ago. Initial radiographs revealed no fractures, and the skin remained intact at the time of injury. Physical therapy, anti-inflammatory drugs, and a serotonin reuptake inhibitor have failed to provide relief. What is the next most appropriate step in management?

Explanation

DISCUSSION: Following failure of physical therapy and pharmacologic management in a patient with complex regional pain syndrome, the management of choice is sympathetic blocks. While continued physical therapy would be assistive, sympathetic blocks allow a more rapid relief of symptoms. Neurostimulation is not appropriate at this stage because of its invasive nature.
REFERENCES: Cepeda MS, Lau J, Carr DB: Defining the therapeutic role of local anesthetic sympathetic blockade in complex regional pain syndrome: A narrative and systematic review. Clin J Pain 2002;18:216-233.
Perez RS, Kwakkel G, Zuurmond WW, et al: Treatment of reflex sympathetic dystrophy (CRPS type 1): A research synthesis of 21 randomized clinical trials. J Pain Symptom Manage 2001;21:511-526.
Tran KM, Frank SM, Raja SN, et al: Lumbar sympathetic block for sympathetically maintained pain changes in cutaneous temperatures and pain perception. Anesth Analg 2000;90:1396-1401.
Stanton-Hicks M, Baron R, Boas R, et al: Complex regional pain syndromes: Guidelines for therapy. Clin J Pain 1998;14:155-166.

Question 30

What anatomic site is considered at highest risk for pathologic fracture?

Explanation

DISCUSSION: The subtrochanteric femur has been identified as an anatomic site that is particularly prone to pathologic fracture. An avulsion fracture of the lesser trochanter is a sign of impending femoral fracture. While the other anatomic locations are also frequently involved in metastatic bone disease, pathologic fractures occur less commonly.
REFERENCES: Simon MA, Springfield DS, et al: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, p 683.
Harrington KD, Sim FH, Enis JE, Johnston JO, Diok HM, Gristina AG: Methylmethacrylate as an adjunct in internal fixation of pathological fractures: Experience with three hundred and seventy-five cases. J Bone Joint Surg Am 1976;58:1047-1055.

Question 31

A study is proposed in which 2 groups of patients are randomized to treatment with bisphosphonates or placebo. This is an example of what study type?

Explanation

In a parallel design trial, participants are randomized to 2 or more groups, each of which receives a different treatment or intervention. For example, Group A receives the drug and Group B receives the placebo. This type of design allows for comparison between groups. In a crossover design clinical trial, both groups receive both interventions over a defined time period. For example, Groups A and B both receive the drug as well as the placebo. This allows for within-participant comparisons. In a cohort study, patient groups are followed over time on the basis of having or not having received an exposure. Cohort studies are not randomized. In a case series, patients often receive a particular treatment and the outcomes are then examined.

Question 32

Which of the following is a recognized predictor of mortality after hip fracture?

Explanation

DISCUSSION: The ASA classification (detailed in Illustration A) was initially developed in 1963 and has been shown to be predictive of post-surgical mortality in hip fracture patients. Basic categories are as follows: 1= normal, healthy; 2= mild systemic disease; 3= severe systemic disease, not incapacitating; 4= severe incapacitating systemic condition, constant threat to life; 5= moribund patient; 6 = brain dead, organs being donated.
The study by Richmond et al looked at 836 patients treated for a hip fracture and found that this injury is not associated with significant excess mortality amongst patients older than age 85. However, in younger patients, those with ASA classifications of 3 or 4 have significant excess mortality following hip fracture that persists up to 2 years after injury.

Question 33

When reconstructing the anterior cruciate ligament (ACL), what is the most common source of potential autograft failure? Review Topic

Explanation

Technical failure is the most common reason for ACL reconstruction failure. Tunnel position is the most frequent cause for technical failure. Malpositioning of the tunnel affects the length of the graft, causing either decreased range of motion or increased graft laxity. Although graft choice is an important factor when planning an ACL reconstruction, overall outcomes with autograft tissues are fairly similar. Fixation of the graft at the femoral or tibial end is not as important as tunnel position.

Question 34

Which of the following factors increases the risk of sciatic nerve injury in primary total hip arthroplasty (THA)?

Explanation

DISCUSSION: Injury to the sciatic nerve is a relatively rare but serious complication of THA. Dissection of the sciatic nerve is not typically done during primary THA, although the nerve can be identified during the surgical approach. An anterolateral approach to THA would not necessarily be associated with any greater incidence of sciatic nerve injury than other approaches. Screw fixation for the acetabular component is often a matter of surgeon preference. Provided that the anatomic safe zones for screw fixation (posterior inferior and posterior superior) are recognized, injury to the sciatic nerve from acetabular screws can be minimized. Restoration of anatomic length is important in primary THA. Overlengthening can result in sciatic nerve palsy. Developmental dysplasia of the hip can lead to a congenitally shortened extremity with concomitant congenital shortening of the associated neurovascular structures. Overlengthening of the extremity during THA for developmental dysplasia of the hip can lead to sciatic palsy. Osteonecrosis is not an associated risk factor for sciatic nerve palsy.
REFERENCES: DeHart MM, Riley LH Jr: Nerve injuries in total hip arthroplasty. J Am Acad Orthop Surg 1999;7:101-111.
Anas P, Felix B: Evaluation and prevention of postoperative complications, in Neurologic Injury in Revision THA. New York, NY, Springer Verlag, 1999, pp 361-371.

Question 35

A patient undergoes an arthroscopic debridement for lateral epicondylitis. Postoperatively she reports pain and a sense of clicking of the elbow. Examination reveals apprehension to supination, load, and extension. What structure has been injured resulting in the clinical presentation?

Explanation

DISCUSSION: The patient has an iatrogenic injury to the lateral ulnar collateral ligament following the arthroscopic procedure. Failure to adhere to known anatomic landmarks can lead to this devastating complication. The examination findings are classic for posterolateral elbow instability.
REFERENCES: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 318.
O’ Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73:440-446.

Question 36

Which of the following nerves is most commonly injured during arthroscopy of the ankle?

Explanation

Neurological complications of account for approximately 49.1% of all complications in Ankle Arthroscopy. Nerve injuries resulted from direct trauma of portal placement. Nerves affected in order: 1) Superficial peroneal 2) Sural 3) Saphenous 4) Deep peroneal.

Question 37

Figure 3 shows the clinical photograph of a wrestler who has an acute mass in his ear. He does not wear protective headgear. The area is mildly tender and without erythema. Management should consist of

Explanation

DISCUSSION: The patient has an auricular hematoma. This injury is typically related to blunt trauma, occuring in wrestlers who do not use protective headgear. The goal of treatment is to remove the fluid, reapproximate the perichondrium to the underlying articular cartilage, and limit reaccumulation of the fluid in attempt to prevent cartilage necrosis. Aspiration and application of a compressive dressing offers the best chance to achieve this goal. There are no signs of infection such as marked tenderness, erythema, or surrounding edema to justify antibiotic use or irrigation and debridement. The mass does not warrant excision.
REFERENCES: Kaufman BR, Heckler FR: Sports-related facial injuries. Clin Sports Med 1997;16:543-562.
Griffin CS: Wrestler’s ear: Pathophysiology and treatment. Ann Plastic Surg 1992;28:131-139.

Question 38

A patient who was involved in a motor vehicle accident 2 days ago now reports neck pain. He denies any other symptoms. Radiographs reveal a type II odontoid fracture that is 2 mm anteriorly displaced. Management consists of halo vest immobilization in extension, and repeat radiographs reveal that the fracture is completely reduced. The patient is discharged to home, but later that evening he notes difficulty swallowing while trying to eat dinner. What is the most likely cause of this difficulty?

Explanation

DISCUSSION: If the neck is immobilized in excessive extension, it can be difficult for the patient to swallow. If the patient had injured the recurrent or superior laryngeal nerve at the time of the accident, it is likely to have manifested itself earlier on. Esophageal trauma or retropharyngeal edema or hematoma from the fracture also should have manifested itself earlier. Because the fracture was completely reduced, it is unlikely that moving the small fragment posteriorly would have injured the esophagus.
REFERENCES: Garfin SR, Botte MJ, Waters RL, Nickel VL: Complications in the use of halo fixation device. J Bone Joint Surg Am 1986;68:320-325.
Glaser JA, Whitehill R, Stamp WG, Jane JA: Complications associated with the halo-vest: A review of 245 cases. J Neurosurg 1986;65:762-769.

Question 39

A 13-year-old girl presents with back pain for 6 months. Figures A and B are SPECT scan and CT images taken at the time of presentation. What is the most likely diagnosis? Review Topic

Explanation

This
patient
has
spondylolysis.
Spondylolysis is a common cause of back pain in children/adolescents. It is common in sports with repetitive hyperextension (gymnasts, weightlifters, football linemen). It is best seen on lateral and oblique radiographs, CT (best study to diagnose and delineate anatomy), and SPECT.
Saifuddin et al. reviewed the orientation of the pars fracture. They found that only 32% of defects were oriented within 15° of the 45° lateral oblique plane and would be
visible on oblique radiographs. They thus recommend CT scans for spondylolysis.
Cheung et al. reviewed spondylolysis and spondylolisthesis. They advocate pars repair for symptomatic spondylolysis and low-grade, mobile spondylolisthesis with pars defects cephalad to L5 and for those with multiple-level defects.
Figure A is a 99mTc-MDP SPECT scan showing increased uptake at the right L5 pars interarticularis. Figure B is an axial helical CT image showing bilateral spondylolysis at L5. Illustration A is a corresponding sagittal reconstruction image demonstrating right pars fracture into the right L5 superior facet. Illustration B shows the appearance of osteoblastic metastasis (green arrow). Illustration C shows the options for pars repair.
Incorrect

Question 40

A 40-year-old man sustains a fracture-dislocation of C4-5. Examination reveals no motor or sensory function below the C5 level. All extremities are areflexic. The bulbocavernosus reflex is absent. The prognosis for this patient’s neurologic recovery can be best determined by

Explanation

DISCUSSION: The patient has spinal shock. Steroid administration and MRI are appropriate therapeutic and diagnostic procedures. Myelography with CT is of little value unless there is an unusual skeletal variant. Spinal cord-evoked potentials have no value. The best method to determine the patient’s neurologic recovery is repeated physical examinations over the first 48 to 72 hours.
REFERENCES: Spivak JM, Connolly PF (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 183-184.
Herkowitz HN, Garfin SR, Eismont FJ: Rothman-Simone The Spine, ed 5. Philadelphia, PA, Saunders Elsevier, 2006, pp 1185-1194.

Question 41

Figures 28a through 28c show the MRI scans of a 30-year-old woman who weighs 290 lb and has low back and left leg pain. She also reports frequent urinary dribbling, which her gynecologist has advised her may be related to obesity. Examination will most likely reveal

Explanation

DISCUSSION: The patient will most likely exhibit ipsilateral weakness of the tibialis anterior. Gaenslen’s test is designed to detect sacroiliac inflammation as a source of low back pain. Beevor’s sign tests the innervation of the rectus abdominus and paraspinal musculature (L1 innervation). The extensor hallucis longus is predominantly innervated by L5. The peroneals are predominantly innervated by S1.
REFERENCES: Hoppenfeld S: Physical Examination of the Spine and Extremities. Appleton, WI, Century-Crofts, 1976.
Hollinshead WH (ed): Anatomy for Surgeons: The Back and the Limbs, ed 3. Philadelphia, PA, Harper & Rowe, 1982.

Question 42

Iliosacral screws placed for stabilization of posterior pelvic ring injuries (eg, sacroiliac dislocation) that exit the sacrum anteriorly are most likely to injure which of the following structures?

Explanation

DISCUSSION: Iliosacral screws have gained popularity for posterior stabilization of pelvic ring disruptions, but complications attributed to incorrect placement are a clinical problem. The L5 nerve root is at greatest risk and is in closest proximity to a malpositioned screw (exiting the sacrum). The L4 root is more anterior at this level. The S1 root is still intraosseous at this level and is at risk but not from the screw exiting anteriorly at this level. The arteries are at risk but are more anterior and are at less risk than the L5 nerve root.
REFERENCE: Ebraheim NA, Haman SP, Xu R, Stanescu S, Yeasting RA: The lumbosacral nerves in relation to dorsal SI screw placement and their locations on plain radiographs. Orthopedics 2000;23:245-247.

Question 43

Figures 26a and 26b show the radiograph and MRI scan of a 22-year-old man with knee pain. What is the most likely diagnosis?

Explanation

DISCUSSION: The lesion is an osteochondroma. This is demonstrated by a pedunculated bone-forming lesion where the medullary space of the lesion communicates with the medullary space of the host bone. The cortex of the exostosis is in continuity with the cortex of the underlying bone. The MRI scan reveals that there is no significant cartilage cap, alleviating concern for malignant conversion to a chondrosarcoma. Osteoblastoma and osteosarcoma typically have mixed areas of bone formation and bone destruction. Malignant fibrous histiocytoma of bone is usually purely lytic.
REFERENCES: Vaccaro AR (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 197-215.
Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 103-111.

Question 44

A 65-year-old woman sustained an axial load on the arm followed by an abduction injury after falling on ice. Treatment in the emergency department consisted of reduction of an anterior dislocation. She now has a positive drop arm sign and a positive lift-off test. An MRI scan is shown in Figure 9. Based on these findings, management should consist of

Explanation

DISCUSSION: Dislocation of the long head of the biceps tendon is the result of a defect in the region of the rotator cuff interval, coracohumeral ligament-superior glenohumeral ligament pulley, or an associated tear of the medial insertion of the subscapularis tendon. In the case of an intra-articular dislocation of the long head of the biceps tendon associated with a tear of the subscapularis tendon, stabilization of the biceps tendon is difficult in this situation; therefore, biceps release or tenodesis and repair of the subscapularis tendon is the treatment of choice.
REFERENCES: Eakin CL, Faber KJ, Hawkins RJ, et al: Biceps tendon disorders in athletes.

J Am Acad Orthop Surg 1999;7:300-310.
Sethi N, Wright R, Yamaguchi K: Disorders of the long head of the biceps tendon. J Shoulder Elbow Surg 1999;8:644-654.
Walch G, Boileau P: Subluxations and dislocations of the tendon of the long head of the biceps. J Shoulder Elbow Surg 1998;7:100-108.

Question 45

What phase of overhead throwing puts the rotator cuff at most risk of injury from internal impingement?

Explanation

Internal impingement occurs when there is repetitive contact of the posterior superior aspect of the glenoid with the humeral head causing damage to the undersurface of the supraspinatus and anterior aspect of the infraspinatus tendons, as well as posterior superior glenoid labrum. This occurs when the arm is in maximum abduction and external rotation such as during the late cocking phase of the normal throwing motion. The 6 phases of throwing are wind up, early cocking, late cocking, deceleration, and follow through. When the arm is repeatedly placed in the abducted externally rotated position, the anterior capsule can become lax and posterior capsular contractures can develop. When there are kinetic chain abnormalities such as scapular internal rotation or muscle fatigue, there is exacerbation of abnormal anterior humeral head translation and increased contact of the rotator cuff on the posterior glenoid rim, with concomitant increased risk of injury
and symptoms.

Question 46

A 56-year-old man with poorly controlled diabetes mellitus has rapidly developing and advancing erythema, warmth and swelling with bullae formation on the left lower extremity. These findings appear to be advancing proximally several millimeters per hour. Culture results are most likely to reveal

Explanation

Discussion: Necrotizing fasciitis (NF) results in the death of the body's soft tissue. It is a severe disease of sudden onset that spreads rapidly. Symptoms include red or purple skin in the affected area, with severe pain, fever, and vomiting. The most commonly affected areas are the limbs and perineum. Early diagnosis is difficult as the disease often looks like a simple superficial skin infection in the early stages. While a number of laboratory and imaging modalities can raise the suspicion for necrotizing fasciitis, the gold standard for diagnosis is a surgical exploration in the setting of high suspicion. When in doubt, a small "keyhole" incision can be made into the affected tissue. If a finger easily separates the tissue along the fascial plane,
the diagnosis is confirmed and an extensive debridement should be performed. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score can be utilized to risk stratify people who have signs of cellulitis and determine the likelihood of necrotizing fasciitis being present. It uses six serologic measures, including C-reactive protein, total white blood cell count, hemoglobin, sodium, creatinine and glucose.
Polymicrobial synergistic infection was the most common cause of necrotizing fasciitis (48 patients; 53.9%) with streptococci and enterobacteriaceae being the most common isolates. Group-A streptococcus was the most common cause of monomicrobial necrotizing fasciitis. The most common associated comorbidity was diabetes mellitus (63 patients; 70.8%).

Question 47

A 56-year-old woman sustains a type IIIB open tibial shaft fracture. She undergoes irrigation and debridement and intramedullary nailing with flap coverage 24 hours later. Cultures are taken pre-debridement and post-debridement. She develops a surgical site infection at 6 weeks, which requires removing the hardware and placing show Commented [1]: an external fixator. Deep cultures are most likely to pathogens found in

Explanation

Discussion: One study found only 8% of organisms grown on pre-debridement cultures eventually caused infection; 7% of cases with negative pre-debridement cultures became infected. Of cases that did become infected, pre-debridement cultures grew the infecting organism only 22% of the time. Post-debridement cultures were more accurate in predicting infection. However, of cases that became infected, the infecting organism was present on post-debridement cultures only 42% of the time. It is concluded that pre-debridement and post-debridement bacterial cultures from open fracture wounds are of essentially no value. It is recommended that they not be done.
In another study, before any interventions were performed, initial aerobic and anaerobic cultures of the wounds of 117 consecutive open extremity fractures grades I through III were obtained. The results of these cultures were correlated with the development of a wound infection. If an infection occurred, the organism grown from the infected wound was compared with any organism grown from the primary wound cultures. Of the initial cultures, 76% (89/117) did not demonstrate any growth, while the other 24% (28/117) only grew skin flora. There were only 7 (6%) wound infections, and 71% (5/7) initially did not grow any organisms. Of the isolates that grew from the initial cultures, none were the organisms that eventually led to

Question 48

During spinal deformity surgery, which of the following is the most specific early indicator of an intraoperative injury to the spinal cord? Review Topic

Explanation

Transcranial motor-evoked potentials provide the most specific early indicator of an intraoperative spinal cord injury. Somatosensory-evoked potentials are routinely used but do not have the sensitivity and specificity of motor-evoked potentials. EMG evaluations are routinely used for root evaluation following pedicle screw placement. BAERs are typically used in monitoring brain surgery.

Question 49

What mechanism of injury is most likely to cause a fracture of the anteromedial facet of the coronoid?

Explanation

Early range of motion
Hinged elbow brace for 4 weeks
Repair lateral collateral ligament
Remove and upsize implant
Remove and downsize implant
The intraoperative images are consistent with overstuffing of the ulnohumeral joint during a radial head replacement. The most appropriate next step would be removing and downsizing the implant.
Overstuffing the radiohumeral joint by >2.5 mm can significantly alter elbow kinematics. It has also shown to lead to pain and early joint disease. The most sensitive method to assess for overstuffing of the joint is by direct visualisation intraoperatively. This can be performed by visualising the lateral aspect of the ulnohumeral joint when the radial head is resected and comparing this to when the trial radial head is reduced in place. In comparison, radiographic asymmetry of the medial ulnohumeral joint has been shown to be less sensitive. Radiographic findings of incongruity of ulnohumeral joint only occurs when significant overlengthening of the radius occurs.
Frank et al. examined the effect of radial head thickness in seven cadaver specimens. They found that incongruity of the medial ulnohumeral joint would only become apparent radiographically after overlengthening of the radius by >or=6 mm.
Doornberg et al. examined seventeen computed tomography scans of the elbow to investigate the height of the radial head relative to the lateral edge and central ridge of the coronoid process. They found that the radial head was on average only 0.9 mm more proximal than the lateral edge of the coronoid process.
Figure A shows intraoperative radiographs of a patient that has undergone a radial head arthroplasty. There is significant widening of the medial ulnohumeral joint on an AP radiograph as well as widening of the ulnohumeral joint on the lateral radiograph,
Incorrect Answers:

Question 50

A 34-year-old male arrives intubated with a closed head injury to the trauma bay after a motor vehicle accident. After initial hospital workup and resuscitation, he is transferred to the intensive care unit. In addition to multiple systemic injuries, he sustained the closed injury shown in Figure A. Intracompartmental pressure monitoring of the limb measure in a range from 28-30 mm Hg. Which of the following sustained blood pressure measurements would support the treatment of limb fasciotomy? Review Topic 1 110/60 mmHg 2 115/55 mmHg 3 92/64 mmHg

Explanation

A reported indication to perform fasciotomy includes an ICP measurement that is elevated to 30 mm Hg below the diastolic blood pressure. This would be the case if this patient's blood pressure was consistently around 115/55 mmHg (dBp=55; ICP=30; delta p = dBp-ICP = 25 mmHg).
Given the poor outcomes associated with missed compartment syndromes, it is important to obtain both clinical and objective data when determining if a patient needs fasciotomies. A clinical assessment is the diagnostic cornerstone of acute compartment syndrome. However, the intracompartmental pressure measurement has been advocated to help confirm the diagnosis in patients where there remains uncertainty after clinical exam - especially with intubated patients. An absolute compartment pressure >30 mm Hg or a difference in diastolic pressure and compartments pressure (delta p) <30 mm Hg may help to confirm the necessity for fasciotomy.
McQueen et al. prospectively reviewed 116 patients with tibia fractures that had continuous monitoring of their anterior compartment for 24 hours. They found that using an absolute pressure of 30 mmHg would have resulted in 50 patients (43%) treated with unnecessary fasciotomies. They conclude using a differential pressure of
30 mmHg is a more reliable indicator of compartment syndrome.
Olson et al. provide a review of compartment syndrome for the lower extremity. They discuss a variety of injuries and medical conditions that may initiate acute compartment syndrome, including fractures, bleeding disorders, and other trauma. Although the diagnosis is primarily a clinical one, they also recommend supplementation with compartment pressure measurements in equivocal cases.
Figure A shows a closed comminuted tibial shaft fracture. Incorrect Answers:

Question 51

A 13-year-old girl sustained an isolated midshaft left femoral fracture in a motor vehicle accident. The fracture was treated with a rigid, antegrade intramedullary nail placed through the piriformis fossa. The fracture healed uneventfully, as shown in Figure 46a; however, at 12 months postoperatively she now reports left hip pain. A current AP radiograph and MRI scan are shown in Figures 46b and 46c. What complication occurred in this patient? Review Topic

Explanation

The development of femoral head ischemic necrosis is the iatrogenically created complication in this skeletally immature patient. Placement of a rigid, antegrade intramedullary nail through the piriformis fossa is likely to damage the vascular supply to the femoral head as the vessels ascend the femoral neck on the way to the femoral head. The MRI scan reveals ischemic necrosis with early collapse of the femoral head. The joint space is preserved on the MRI scan, ruling out chondrolysis.

Question 52

When treating a proximal tibia fracture, the surgeon decides to (1) use blocking screws in the proximal fragment, and (2) pick the intramedullary nail based on the location of the Herzog curve. Which of the following combinations will best prevent the classic deformity associated with this fracture?

Explanation

Proximal tibial fractures develop an apex anterior (procurvatum) and valgus malalignment. Blocking (poller) screws should be placed in the concavity of the deformity, thus posterior and lateral to the nail. The Herzog curve should be proximal to the fracture site.
Up to 58% of proximal tibial fractures are malaligned. Malalignment arises because the nail fits loosely in the wide metaphyses and cannot control alignment. Without close fit of the nail at the fracture site, the nail will not align the fracture independent of a stable reduction and careful nail path. Blocking screws serve to reduce the size of the proximal metaphyseal canal and guide final nail passage.
Stinner et al. discuss strategies in proximal tibial fracture nailing. They describe an accurate starting point (using the twin peaks AP view or fibular bisector AP view, and flat plateau lateral view). They emphasize fracture reduction prior to reaming and implant placement.
Hiesterman reviewed nailing of extra-articular proximal tibial fractures. Techniques described include blocking screws, unicortical plating, using a universal distractor, nailing in flexion/locking in extension, semiextended nailing (including percutaneous suprapatellar quads-splitting approaches), multiple proximal interlocking screws (>=3).
Illustration A shows placement of a coronal blocking screw. Illustration B shows placement of a sagittal blocking screw. Illustration C shows the effect of the Herzog curve. A more distal Herzog curve leads to a "wedge" effect and fracture displacement whereas a proximal Herzog curve contains the fracture. The "wedge" effect occurs as the nail is seated and impinges on the posterior cortex of the distal segment accentuating an apex anterior deformity because of the effective widening of the nail above the bend and posterior force on the distal segment to match the nail shape.
Incorrect Answers:

Question 53

A 26-year-old ballet dancer reports posterolateral ankle pain, especially with maximal plantar flexion. Examination reveals maximal tenderness just posterior to the lateral malleolus, and symptoms are heightened with forced passive plantar flexion. Radiographs are shown in Figures 42a and 42b. What is the most likely cause of the patient’s symptoms?

Explanation

DISCUSSION: The patient has a symptomatic os trigonum caused by impingement that occurs with maximal plantar flexion of the ankle in the demi-pointe or full-pointe position. Patients frequently report posterolateral pain localized behind the lateral malleolus that may be misinterpreted as a disorder of the peroneal tendon. Pain with passive plantar flexion (the plantar flexion sign) indicates posterior impingement, not a problem with the peroneal tendon. The symptoms are not characteristic of a stress fracture, nor do the radiographs show a stress fracture or an osteochondritis dissecans lesion. The os trigonum is modest in its dimensions. The incidence or magnitude of symptoms does not correlate with the size of the fragment. Large fragments may be asymptomatic, while small lesions may create significant symptoms.
REFERENCES: Marotta JJ, Micheli LJ: Os trigonum impingement in dancers. Am J Sports Med 1992;20:533-536.
Hamilton WG: Foot and ankle injuries in dancers, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, CV Mosby, 1993, pp 1241-1276.

Question 54

A 72-year-old woman who sustained a cerebrovascular accident 9 months ago now has a fixed elbow flexion contracture of 80 degrees. Management should consist of

Explanation

DISCUSSION: A flexion contracture of the elbow is commonly seen in hemiplegic patients following cerebrovascular accidents. Spasticity and myostatic contracture of the joint are both causative factors. In patients with a flexion deformity of less than 90 degrees, musculocutaneous neurectomy is recommended, followed by serial casting to treat any residual deformity. At 9 months after injury, physical therapy will not significantly improve motion. Nerve blocks may be used in the early stages of recovery to facilitate therapy and serial casting.
REFERENCE: Waters RL, Keenan ME: Surgical treatment of the upper extremity after stroke, in Chapman MW (ed): Operative Orthopedics. Philadelphia, PA, JB Lippincott, 1988, vol 2,

pp 1449-1450.

Question 55

A 20-year-old woman sustained the closed injury shown in Figures 49a and 49b in a motor vehicle accident. Examination reveals that this is an isolated injury; however, she has a complete radial nerve palsy. Management should consist of

Explanation

DISCUSSION: Lacerated radial nerves are associated with open humeral fractures. All open humeral fractures with radial nerve palsy should be managed with radial nerve exploration and skeletal stabilization. Closed humeral fractures with associated radial nerve palsy usually have an intact nerve with neurapraxia. Most of these patients recover without surgical treatment. If the patient has multiple injuries, skeletal stabilization may be indicated to improve mobilization. For an isolated closed humeral fracture with a radial nerve palsy, the treatment of choice is splinting for 1 to 2 weeks, followed by a humeral fracture brace.
REFERENCES: Ring D, Chin K, Jupiter JB: Radial nerve palsy associated with high-energy humeral shaft fractures. J Hand Surg Am 2004;29:144-147.
Foster RJ, Swiontkowski MF, Bach AW, et al: Radial nerve palsy caused by open humeral shaft fractures. J Hand Surg Am 1993;18:121-124.

Question 56

Figure 41 shows the MRI scan of a 38-year-old weightlifter. What does the arrow on the MRI scan indicate? Review Topic

Explanation

Pectoralis major ruptures typically occur in avid weightlifters (often on supplements) and typically while bench-pressing. Clinically there is significant discoloration/bruising over the pectoralis and into the axilla. MRI helps confirm the diagnosis and may help determine if the tear is in the muscle belly or at the bone-tendon junction.

Question 57

.Figures 89a and 89b are the radiographs of an 18-year-old woman who has had elbow pain after falling on an outstretched hand. She is evaluated 5 days after the injury. Examination reveals the wrist is normal and her elbow has a limited arc of motion of 30 to 90 degrees of flexion/extension and 20 to 20 degrees of pronation and supination, with tenderness isolated to the lateral side of the elbow. What is the most appropriate treatment option?

Explanation

Question 58

A 45-year-old woman awakens with the acute onset of burning left shoulder pain that radiates toward the axilla. She denies any history of trauma. On examination, she is unable to abduct her arm but has full passive shoulder motion. Her sensation is intact. Cervical spine examination reveals full range of motion and a negative Spurling’s test. Radiographs and MRI studies are normal for the cervical spine and shoulder. What is the most likely diagnosis? Review Topic

Explanation

The definition of brachial neuritis or Parsonage-Turner syndrome is a rare disorder of unknown etiology that causes pain or weakness of the shoulder and upper extremity. The loss of active motion excludes cervical C6-7 radiculopathy and impingement. A normal MRI scan and full passive motion exclude a rotator cuff tear and adhesive capsulitis, respectively.

Question 59

Examination of a 28-year-old woman reveals a moderate hallux valgus deformity and a prominence of the medial eminence. She reports that she can participate in all activities, wear 3-inch heels with minimal discomfort, and walk in a 1-inch heel with no pain. However, she is concerned that the deformity will get worse and requests recommendations regarding surgical correction. What is the best course of action?

Explanation

DISCUSSION: Because the patient is essentially asymptomatic, the most appropriate course of action is observation. Prophylactic hallux valgus surgery is not medically indicated. Steroid injection would only risk infection, as well as joint and capsule damage. There are no data to support the use of a custom orthosis to delay the progression of a hallux valgus deformity. Special shoe wear or an extra-depth shoe is not necessary and is unlikely to be accepted by the patient.
REFERENCES: Donley BG, Tisdel CL, Sferra JJ, Hall JO: Diagnosing and treating hallux valgus: A conservative approach for a common problem. Cleve Clin J Med 1997;64:469-474.
Teitz CC, Hu SS, Arendt EA: The female athlete: Evaluation and treatment of sports-related problems. J Am Acad Orthop Surg 1997;5:87-96.

Question 60

Figures below show the radiographs obtained from a 79-year-old woman who has been experiencing increasing tibial pain 10 years after undergoing revision total knee arthroplasty. No evidence of infection is seen. What is the most appropriate treatment?

Explanation

DISCUSSION:
Stems are available for cemented and press-fit implantation. To be effective, press-fit stems should engage the diaphysis, as shown in Figures 3 and 4. They also assist in obtaining correct limb alignment. Short metaphyseal-engaging stems are associated with failure rates that range between 16% and 29%. Cemented stems may be shorter than press-fit stems, because they do not have to engage the diaphysis. Short, fully cemented stems offer the advantage of metaphyseal fixation. Hybrid stem fixation makes use of the metaphysis for cement fixation with metaphyseal cones or sleeves and diaphyseal-engaging press-fit stems.

Question 61

A 52-year-old man has pain in the sternal area after landing on his right shoulder in a fall from his bicycle. In addition, he reports that he had difficulty swallowing and breathing immediately after the fall, but the symptoms resolved. A CT scan reveals a posterior sternoclavicular dislocation. Initial management should include

Explanation

DISCUSSION: Posterior sternoclavicular dislocations require rapid treatment because of the proximity of major neurovascular structures and the airway. Initial management should consist of closed reduction under general anesthesia in the operating room with a chest surgeon available. A successful closed reduction is usually stable. Internal fixation of sternoclavicular injuries should be avoided because of the likelihood of hardware migration and possible injury to the mediastinal structures. If closed reduction is unsuccessful, open reduction is indicated. Treatment following reduction of the sternoclavicular joint includes the application of a figure-of-8 splint and a sling for 6 weeks, followed by stretching and strengthening exercises.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont IL, American Academy of Orthopaedic Surgeons, 1999, pp 287-297.
Rockwood CA Jr: Disorders of the sternoclavicular joint, in Rockwood CA Jr, Matsen FA III (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1990, vol 2, pp 1010-1017.

Question 62

A 20-year-old man has activity-related deep-seated shoulder pain in his dominant right shoulder. He has taken 3 months off training as a college javelin thrower, and management consisting of physical therapy has failed to provide relief. Shoulder arthroscopic views are shown in Figures 16a through 16c. What is the underlying association with this condition? Review Topic

Explanation

The patient is involved in overhead athletics and reports deep-seated pain. The arthroscopic views show a SLAP tear with posterior extension that is typical of internal impingement. The history lacks a component of gross instability expected in traumatic anterior dislocations or multidirectional instability associated with a connective tissue disorder, and it also lacks risk factors for osteonecrosis. The images do not show evidence of an unstable humeral cartilage flap or a supraspinatus tear.

Question 63

A 63-year-old man with type I diabetes mellitus who underwent open forefoot amputation now has a high fever, and an elevated WBC count and blood glucose levels. Repeat laboratory studies the day after surgery show a WBC count of 9,500/mm 3 , a serum albumin level of 1.9 g/dL, and a total lymphocyte count of 1,900/mm 3 . Examination reveals that he is afebrile, and his blood glucose level is now normal. An ultrasound Doppler of the dorsalis pedis artery shows an ankle-brachial index of 0.6. A transcutaneous partial pressure measurement of oxygen at the ankle joint shows a level of 38 mm Hg. What is the best course of action?

Explanation

DISCUSSION: This patient appears to have adequate blood supply to heal a Syme’s ankle disarticulation but is currently malnourished because of the systemic infection, and is likely to progress to wound failure. Therefore, the initial management of choice is culture-specific antibiotic therapy, open wound management, and nutritional supplementation. If his serum albumin rises to a minimum of 2.5 gm/dL, he can undergo elective Syme’s ankle disarticulation. If the serum albumin does not rise within a short period of time, he should undergo transtibial amputation.
REFERENCE: Pinzur MS, Stuck RM, Sage R, et al: Syme ankle disarticulation in patients with diabetes. J Bone Joint Surg Am 2003;85:1667-1672.

Question 64

The CT scan reveals a nondisplaced greater trochanteric fracture. The patient is now experiencing severe pain. What is the most appropriate treatment at this time?

Explanation

DISCUSSION
This patient presents with significant polyethylene wear, which can lead to both osteolysis and synovitis. However, synovitis usually manifests as a mild to moderate chronic ache, which should explain the discomfort. Although infection should always be ruled out with new-onset pain, no clinical parameters suggest acute hematogenous infection. Similarly, without any mention of back pain or neuropathy, radicular pain from the spine is unlikely. If this patient has a nondisplaced greater trochanteric fracture noted on MR imaging, the optimal immediate mode of treatment is to not rush into surgery despite the mild osteolysis. The patient’s severe pain is likely attributable to the nondisplaced greater trochanteric fracture rather than wear-induced synovitis, which typically presents as a mild to moderate ache. It is recommended to
allow the fracture to heal to avoid fracture displacement. Once the fracture is healed, a revision surgery with liner exchange can be recommended. Based on this clinical scenario, the acetabular component is within what is largely considered the “safe-zone” in THA. Despite this patient’s dislocations, the preferred treatment modality is to revise to a constrained liner. This patient had a well-functioning hip for longer than 15 years. Therefore, conversion to a constrained liner is the best treatment.

Question 65

A 38-year-old woman fell from a ladder onto her right hip. The radiographs and CT scan are shown in Figures 52a through 52d. What is the best surgical approach for this fracture?

Explanation

DISCUSSION: The fracture is an associated both column fracture. The best approach for this fracture is the ilioinguinal. The Kocher-Langenbeck is best for posterior injuries to the acetabulum and some transverse fractures. The iliofemoral alone is limited to high anterior column injuries. The extended iliofemoral and triradiate approaches although useful for this fracture, have a higher rate of complications.
REFERENCES: Letournel E: The treatment of acetabular fractures through the ilioinguinal approach. Clin Orthop Relat Res 1993;292:62-76.
Matta JM: Operative treatment of acetabular fractures through the ilioinguinal approach:

A 10-year perspective. Clin Orthop Relat Res 1994;305:10-19.

Question 66

An 82-year-old woman fell on her right shoulder 2 days ago. She is alert, oriented, and in mild discomfort. Prior to falling, she lived alone and functioned independently. Examination reveals extensive ecchymosis extending to the midhumeral region. Her neurovascular examination is normal. Radiographs are shown in Figures 41a and 41b. What is the most appropriate management?

Explanation

DISCUSSION: The patient has a displaced four-part proximal humerus fracture. Given her age and the presence of osteopenia, a cemented hemiarthroplasty is the treatment of choice. The glenoid is uninjured so a total shoulder arthroplasty is not indicated. Percutaneous pinning in younger individuals with good bone quality may be indicated but not in an 82-year-old woman with osteopenia. Sling immobilization and immediate pendulum exercises will lead to a nonunion. Sling immobilization for 6 weeks followed by active range of motion will result in a nonunion or malunion with unacceptable functional results.
REFERENCES: Neer CS II: Displaced proximal humeral fractures: I. Classification and evaluation. J Bone Joint Surg Am 1970;52:1077-1089.
Bigliani LU, Flatow EL, Pollock RG: Fractures of the proximal humerus, in Rockwood CA Jr, Matsen FA III (eds): Rockwood and Matsen The Shoulder, ed 2. Philadelphia, PA,

WB Saunders, 1998, pp 352-354.

Question 67

The images reveal T2-weighted MRI sequences with edema isolated to the infraspinatus. In the absence of a tear in the infraspinatus tendon, the edema is most likely due to compression of the suprascapular nerve in the spinoglenoid notch. As this pathology persists, progressive muscle atrophy and fatty infiltration can result. Compression of the suprascapular nerve in the suprascapular notch would have resulted in edema and weakness in both the supra- and infraspinatus muscles. Compression is commonly caused by cysts from the joint secondary to labral tears. A rotator cuff tear of the infraspinatus is not identified on these images, and there is no history of trauma provided. There is no evidence of an anteroinferior labral tear, nor would this be expected to result in external rotation weakness or MRI abnormality of the infraspinatus. Quadrilateral space syndrome results in compression of the axillary nerve, which supplies the teres minor. Correcr answer : C

Explanation

Figure 1 is the radiograph of a 12-year-old baseball player who has posterolateral elbow pain with throwing. The area of interest is designated by the black arrow. His range of motion and strength are full. No previous treatment has been provided. What is the most appropriate initial treatment?

Elbow arthroscopy with debridement

Immobilization and rest for 6 weeks

Corticosteroid injection

Open osteochondral autograft transfer

Osteochondritis dissecans of the capitellum is a painful condition that affects immature athletes who undergo repetitive compression of the radiocapitellar joint. Management is based primarily on the integrity of the articular cartilage surface and the stability of the lesion. Nonsurgical treatment is typically selected for patients

with early-grade, stable lesions, and it involves activity modification with cessation of sports participation. The duration of activity modification is dictated by symptoms, with 3 to 6 weeks of rest followed by return to sport in 3 to 6 months commonly used as a guideline. Strengthening and stretching exercises are commonly incorporated after the pain has subsided. Surgical intervention or corticosteroid injection would not be first-line treatment.

Figures 1 and 2 are the radiographs of a 69-year-old man with a history of treated prostate cancer and hemodialysis-dependent end- stage renal disease who presents to the emergency department with progressively worsening right shoulder pain and stiffness. Laboratory tests reveal a white blood cell count of 17,000, erythrocyte sedimentation rate, 75, and CRP, 10.1. He has a draining sinus located along the anterior shoulder. What is the best next step?

Question 68

What portion of the pitching phase creates forces approaching the tensile limit of the medial collateral ligament?

Explanation

DISCUSSION: The late cocking phase of the overhand throw places a marked valgus moment across the medial elbow. This repetitive force reaches the tensile limits of the medial collateral ligament.
REFERENCES: Fleisig GS, Andrews JR, Dillman CJ, et al: Kinetics of baseball pitching with implications about injury mechanisms. Am J Sports Med 1995;23:233-239.
Lynch JR, Waitayawinyu T, Hanel DP, et al: Medial collateral ligament injury in the overhand-throwing athlete. J Hand Surg 2008;33:430-437.

Figure 5a Figure 5b

Question 69

Venous thromboembolism may occur after total joint arthroplasty. The risk of this complication is elevated in patients with

Explanation

DISCUSSION:
Obesity, a prior history of venous thromboembolism, and metabolic syndrome have all been associated with an increased risk of thromboembolism. A recent meta-analysis showed that diabetes had no significant relationship with venous thromboembolism following hip or knee arthroplasty. Tranexamic acid is an antifibrinolytic agent that has been shown to reduce blood loss substantially following hip and knee arthroplasty. It has also been shown to be safe in patients with severe medial comorbidities and a prior history of venous thromboembolism.

Question 70

A 16-year-old swimmer has right shoulder pain with activity. She describes the continued sensation that her shoulder is “loose.” She has been in physical therapy for 7 months to work on strengthening the muscles around her shoulder and scapula. She denies being able to voluntarily dislocate her shoulder. Upon examination, you can feel the humeral head slide over the glenoid rim both anteriorly and posteriorly with the load and shift test. She has a grade III sulcus sign. What is the most appropriate next step?

Explanation

CLINICAL SITUATION FOR QUESTIONS 21 THROUGH 25
A 19-year-old collegiate offensive lineman injures his left elbow in a scrimmage. He reports reaching out with his left arm to prevent the defensive player from getting around him, and, as he grabbed the player, his elbow was forced into extension. He had immediate pain and weakness and heard a “pop.” He has mild swelling in the antecubital fossa and a prominent-appearing biceps muscle belly. His hook test result is abnormal at the elbow.

Question 71

A 21-year-old male construction worker fell from a roof and sustained an injury to his left foot. Radiographs and CT scans are shown in Figures 24a through 24e. Compared to nonsurgical management, surgical treatment offers which of the following advantages?

Explanation

DISCUSSION: The radiographs and CT scans show a displaced intra-articular calcaneal fracture, with loss of calcaneal height and length. Recent multicenter, randomized, prospective studies suggest that surgical treatment of displaced intra-articular calcaneal fractures is associated with an almost six-fold decrease in the risk of posttraumatic subtalar arthritis (necessitating subtalar arthrodesis) compared to nonsurgical treatment. Despite ongoing controversy, surgical treatment has not been shown to be advantageous with respect to activity, time to return to work, or subtalar joint range of motion. A nonunion of a calcaneal fracture is exceedingly rare regardless of the treatment method.
REFERENCES: Buckley R, Tough S, McCormack R, et al: Operative compared with nonoperative treatment of displaced intra-articular calcaneal fractures: A prospective, randomized, controlled multicenter trial. J Bone Joint Surg Am 2002;84:1733-1744.
Csizy M, Buckley R, Tough S, et al: Displaced intra-articular calcaneal fractures: Variables predicting late subtalar fusion. J Orthop Trauma 2003;17:106-112.

Question 72

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

Explanation

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

Question 73

What is the most common foot and ankle deformity in patients with arthrogryposis?

Explanation

DISCUSSION: Clubfoot (talipes equinovarus) in patients with arthrogryposis is a rigid and resistant deformity. However, multiple studies document limited success with nonsurgical management. Manipulation and casting are generally a preliminary treatment before surgery; successful correction will most like require a talectomy.
REFERENCES: Guidera KJ, Drennan JC: Foot and ankle deformities in arthrogryposis multiplex congenita. Clin Orthop 1985;194:93-98.
Handelsman JE, Badalamente MA: Neuromuscular studies in clubfoot. J Pediatr Orthop 1981;1:23-32.
Dias LS, Stern LS: Talectomy in the treatment of resistant talipes equinovarus deformity in myelomeningocele and arthrogryposis. J Pediatr Orthop 1987;7:39-41.

Question 74

An extended head hemiarthroplasty (rotator cuff tear arthropathy head) has what theoretic advantage when compared to a standard hemiarthroplasty?

Explanation

DISCUSSION: The theoretic advantage of a metal-to-bone articulation with the acromion is that there is a greater arc in which a smooth metal surface contacts the glenoid and acromion. This may improve pain and function, but no studies have evaluated this to date. One study showed results comparable to that of a standard hemiarthroplasty. There are no other biomechanic advantages.
REFERENCES: Visotsky JL, Basamania C, Seebauer L, et al: Cuff tear arthropathy: Pathogenesis, classification, and algorithm for treatment. J Bone Joint Surg Am 2004;86:35-40.
Zuckerman JD, Scott AJ, Gallagher MA: Hemiarthroplasty for cuff tear arthropathy. J Shoulder Elbow Surg 2000;9:169-172.

Question 75

Which of the following factors is most critical to the success of a meniscal allograft transplantation?

Explanation

Success of a meniscal allograft transplantation is strongly dependent on accurate graft sizing, typically within 5% of the native meniscus. Previous studies have established that donor cell viability is not mandatory for the survival of these grafts since they are replaced by the recipient’s cells (at least peripherally) within several weeks. Thus,
cryopreservation of the graft to ensure cell viability is not necessary. There is a limited immune response to musculoskeletal allografts; therefore, immunosuppression, as is required for visceral organ transplantation, is not indicated.

Question 76

A 40-year-old woman has local back pain and intense burning pain in her perianal region after being shot twice in the back. Motor and sensory examination of her lower extremities reveals no apparent deficit. She has present but decreased sensation in her perianal region, an intact anal wink, good rectal tone, and an intact bulbocavernosus reflex. Radiographs and CT scans are shown in Figures 3a through 3d. What is the next most appropriate step in management?

Explanation

DISCUSSION: Because the patient has an apparent compressive neuropathy secondary to the metallic fragments, removal of the fragments in this incomplete lesion at the cauda equina level can be expected to improve her sensory dysesthesias and pain. Steroids are not indicated in a root lesion secondary to a penetrating injury. MRI will have significant artifact effect and will not provide much additional information. The posterior bony elements are not significantly injured; therefore, stabilization is not indicated.
REFERENCES: Bracken MB, Shepard MJ, Holford TR: Administration of methylprednisolone for 24 or 48 hours or tirilazad mesylate for 48 hours in the treatment of acute spinal cord injury. JAMA 1997;277:1597-1604.
Waters RL, Adkins RH: The effects of removal of bullet fragments retained in the spinal canal: A collaborative study by the National Spinal Cord Injury Model Systems. Spine

1991;16:934-939.
Stauffer ES, Wood RW, Kelly EG: Gunshot wounds of the spine: The effects of laminectomy.

J Bone Joint Surg Am 1979;61:389-392.

Question 77

The condition seen in Figure 60 is attributable to

Explanation

DISCUSSION
Cephallomedullary implants for treatment of proximal femur fractures have gained in popularity over the last decade. Although these implants have improved outcomes for certain fracture types, multiple complications are associated with this implant. Failure may occur secondary to implant design (for example, mismatch of curvature of the nail to the femur, which can result in distal anterior cortical perforation).
RECOMMENDED READINGS
Bazylewicz DB, Egol KA, Koval KJ. Cortical encroachment after cephalomedullary nailing of the proximal femur: evaluation of a more anatomic radius of curvature. J Orthop Trauma. 2013 Jun;27(6):303-7. doi: 10.1097/BOT.0b013e318283f24f. PubMed PMID: 23287752.
View Abstract at PubMed
Parker MJ, Handoll HH. Gamma and other cephalocondylic intramedullary nails versus extramedullary implants for extracapsular hip fractures in adults. Cochrane Database Syst Rev. 2008 Jul 16;(3):CD000093. doi: 10.1002/14651858.CD000093.pub4. Review. Update
in: Cochrane Database Syst Rev. 2010;(9):CD000093. PubMed PMID: 18646058. View Abstract at PubMed

Question 78

The radiograph shown in Figure 54 reveals that the plate on the second metacarpal is acting in what manner?

Explanation

DISCUSSION: There are four ways in which a plate acts: compression, tension bend, bridge or spanning, and buttress. Since there is no cortical contact with the large span of comminution, this plate is acting as a bridge plate. A bridge plate is defined as when the plate is used as an extramedullary splint attached to the two main fragments, leaving the comminution untouched.
REFERENCE: Ruedi T, Murphy WM (eds): AO Principles of Fracture Management. New York, NY, Thieme, 2000, p 221.

Question 79

A 12-year-old girl is seen after tripping and twisting her ankle earlier in the morning. She had immediate pain and swelling and was unable to bear weight. Radiographs are shown in Figures 80a through 80c. Appropriate treatment should consist of which of the following? Review Topic

Explanation

Salter Harris III and IV fractures of the medial malleolus often contain a large cartilaginous portion, larger than the apparent ossified fragment seen on radiographs. Consequently, articular incongruity is common. As such, open reduction and internal fixation is often required. Growth disturbance and angular deformity are also common complications of Salter Harris III and IV fractures of the distal tibia.

Question 80

An 18-year-old man underwent open reduction and internal fixation of a tibial spine avulsion and a posterolateral corner repair. Two years later, he underwent lateral collateral ligament (LCL) and posterolateral corner reconstruction because of instability. Examination reveals a pronounced lateral varus knee thrust when ambulating. Varus stress in 30 degrees of flexion produces a 10-mm opening that is eliminated in extension. The Lachman’s test is 2 mm with a firm end point, and the posterior drawer test is negative. Standing radiographs show widening of the lateral joint space and a 5-degree mechanical varus alignment. What is the most effective course of treatment?

Explanation

DISCUSSION: The patient has chronic posterolateral instability with a varus knee alignment; therefore, the most effective treatment is a valgus-producing HTO. A repeat soft-tissue reconstruction without correction of the varus alignment will most likely fail. An ACL reconstruction is not indicated with a normal Lachman’s test. Physical therapy and bracing will have little effect.
REFERENCES: Naudie DD, Amendola A, Fowler PJ: Opening wedge high tibial osteotomy for symptomatic hyperextension-varus thrust. Am J Sports Med 2004;32:60-70.
Covey DC: Injuries of the posterolateral corner of the knee. J Bone Joint Surg Am
2001;83:106-118.

Question 81

Figures 35a through 35c show the clinical photograph and radiographs of a 15-year-old boy who stubbed his toe 1 day ago while walking barefoot in the yard. Management should consist of

Explanation

DISCUSSION: The patient has an open fracture of the physis of the distal phalanx with a portion of the nail bed interposed in the physis. Seymour initially described this injury in the distal phalanges of fingers. Optimal treatment consists of removing the interposed tissue, irrigating the fracture, and a short course of antibiotics. The nail should be preserved to provide stability.
REFERENCES: Kensinger DR, Guille JT, Horn BD, et al: The stubbed great toe: Importance of early recognition and treatment of open fractures of the distal phalanx. J Pediatr Orthop 2001;21:31-34.
Pinckney LE, Currarino G, Kennedy LA: The stubbed great toe: A cause of occult compound fracture and infection. Radiology 1981;138:375-377.
Seymour N: Juxta-epiphysial fracture of the terminal phalanx of the finger. J Bone Joint Surg Br 1966;48:347-349.

Question 82

Patient-specific instrumentation (PSI) reliably demonstrates which benefit over conventional intramedullary guidance systems?

Explanation

DISCUSSION
Cost is usually increased with PSI because the theoretical decreased number of surgical trays and shortened surgical time do not offset cost of presurgical imaging and extra cost associated with the necessary jigs. Studies do not demonstrate a reliable improvement in functional outcomes or coronal alignment when PSI is compared to standard instrumentation. Evidence reveals that PSI necessitates fewer trays than standard instrumentation.

Question 83

A 55-year-old woman with type I diabetes mellitus has a chronic ulcer over the dorsum of her right foot and reports forefoot pain. Examination reveals 1- x 2-cm nondraining ulcer over the dorsum of the foot. The patient has 1-2+ pain with compression of the foot and ankle. She has a weakly palpable posterior tibial pulse and an absent dorsalis pedis pulse. There is no erythema, cellulitis, or drainage. Radiographs are normal. Which of the following diagnostic studies should be obtained?

Explanation

DISCUSSION: The presence of a dorsal ulcer in the presence of weak or absent pulses strongly suggests the possibility of arterial insufficiency. The best initial noninvasive study to assess for ischemia is the Doppler arterial study. A determination of the vascular status is of a greater priority than an assessment for infection or neuropathy because of the location and presentation of the ulcer. If ankle pressures are less than 45 mm Hg, there is a high risk that these lesions will not heal without revascularization.
REFERENCES: Wagner FW Jr: The dysvascular foot: A system for diagnosis and treatment. Foot Ankle 1981;2:64-122.
Apelqvist J, Castenfors J, Larson J, Stenstrom A, Agardh CD: Prognostic value of systolic ankle and toe blood pressure levels in outcome of diabetic foot ulcer. Diabetes Care 1989;12:373-378.

Question 84

With the increasing availability of total hip arthroplasty (THA) to younger patients with hip osteoarthritis, there has been increased use of alternative bearing surfaces. Compared to a ceramic-on-ceramic articulation, which of the following is a specific advantage of a metal-on-metal bearing surface?

Explanation

DISCUSSION: Alternative bearing surfaces in THA have received much attention in recent years as more and more hip arthroplasties are being performed on younger patients with hip arthritis. The two most popular nonmetal-on-polyethylene bearing surfaces are metal-on-metal and ceramic-on-ceramic. There are arguments supporting the use of either, but ceramic bearings have been shown to have a theoretic increased risk of fracture compared with cobalt-chromium. This has been shown to be clinically relevant with zirconium ceramics. Newer alumina ceramics are being produced with lower porosity and grain size and with higher density and purity, resulting in lower fracture risk but still greater than that of cobalt-chromium.
REFERENCES: Heisel C, Silva M, Schmalzried TP: Bearing surface options for total hip replacement in young patients. Instr Course Lect 2004;53:49-65.
D’Antonio J, Capello W, Manley M, et al: New experience with alumina-on-alumina ceramic bearings for total hip arthroplasty. J Arthroplasty 2002;17:390-397.

Question 85

Based on the findings shown in Figures 22a and 22b, corrective surgery to obtain maximal safe correction and optimal instrumentation fixation should be performed at which of the following locations?

Explanation

DISCUSSION: The clinical photograph and radiograph show an iatrogenic flatback deformity with loss of the normal lumbar lordosis. The safest correction for this malalignment typically is performed away from the spinal cord in the midlumbar spine, most commonly at L2 or L3. The more distal the correction is performed, the more sagittal plane translation of the C7 plumb line with respect to the posterior sacrum. Performing the osteotomy too distally, however, makes it difficult to obtain adequate distal fixation.
REFERENCES: Shufflebarger HL, Clark CE: Thoracolumbar osteotomy for postsurgical sagittal imbalance. Spine 1992;17:S287-S290.
Murrey DB, Brigham CD, Kiebzak GM, et al: Transpedicular decompression and pedicle subtraction osteotomy (eggshell procedure): A retrospective review of 59 patients. Spine 2002;27:2338-2345.

Question 86

A 78-year-old man with ankylosing spondylitis sustains a minor fall. Shortly afterward he experiences sudden worsening of his chronic back pain and is brought to the emergency department by his caregiver. Radiographs and a CT scan of the spine do not show a clear fracture. What is the most appropriate next step?

Explanation

DISCUSSION
Patients with ankylosing spondylitis are at high risk for occult fractures after low-energy injuries. Although radiographs and a CT scan do not demonstrate a spinal fracture in this patient, high risk for an unstable occult fracture necessitates further imaging with MRI to ensure that no fractures are missed. Although a CT scan is typically the primary imaging modality for workup of spine injuries in similar patients, CT and MRI complement each other and each detects fractures that are missed using the other modality. A CT myelogram might detect cord or root compression but would not aid in the diagnosis of an occult fracture. Nonsteroidal anti-inflammatory drugs are first-line treatment for idiopathic low-back pain. In a patient with ankylosing spondylitis at high risk for fracture, further workup is needed to rule out an occult fracture. Flexion and extension radiographs of the spine are inferior to MRI for evaluating occult fractures and ligamentous injuries. The primary concern for this patient remains an unstable spinal fracture, which necessitates an MRI of the spine before initiating a workup for other possible causes of his back pain.
RECOMMENDED READINGS
Duane TM, Cross J, Scarcella N, Wolfe LG, Mayglothling J, Aboutanos MB, Whelan JF, Malhotra AK, Ivatury RR. Flexion-extension cervical spine plain films compared with MRI in the diagnosis of ligamentous injury. Am Surg. 2010 Jun;76(6):595-8. PubMed PMID: 20583514. View Abstract at PubMed
Hitchon PW, From AM, Brenton MD, Glaser JA, Torner JC. Fractures of the thoracolumbar spine complicating ankylosing spondylitis. J Neurosurg. 2002 Sep;97(2 Suppl):218-22. PubMed PMID: 12296682. View Abstract at PubMed
Koivikko MP, Koskinen SK. MRI of cervical spine injuries complicating ankylosing spondylitis. Skeletal Radiol. 2008 Sep;37(9):813-9. doi: 10.1007/s00256-008-0484-x. Epub 2008 Apr

Question 87

A high school distance runner reports a 3-week history of heel pain while running. Examination elicits no pain with dorsiflexion or with palpitation of the plantar fascia; however, pain is evident with palpitation over the muscular origin of the abductor hallucis. What is the most likely etiology of the pain?

Explanation

The tibial nerve gives off two branches. In the distal 1/3 of the leg, the tibial nerve curves anteroinferiorily into the sole of the foot behind the medial malleolus, deep to the flexor retinaculum and between the tendons of the flexor hallicus longus and the flexor digitorum longus muscles. Just distal to the flexor retinaculum, the tibial nerve divides into the medial and lateral plantar nerve. At this site, the lateral plantar nerve gives off its first branch which lies anterior and adjacent to the abductor hallicus.

Question 88

Which of the following factors is most commonly associated with mechanical failure of a cemented total hip arthroplasty?

Explanation

DISCUSSION: Varus position of the stem is most commonly associated with failure of the cemented femoral component because of association with an inadequate cement mantle in the proximal medial and distal lateral zones. An inadequate cement mantle and obesity have been associated with increased loosening but not as frequently as a varus deformity. The influences of gender and osteoporotic bone on the outcome of cemented femoral components have not been established.
REFERENCES: Maloney WJ III: Primary cemented total hip arthroplasty, in Callaghan JJ, Dennis DA, Paprosky WG, Rosenberg AG (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1995, pp 179-189.
Callaghan JJ, Salvati EA, Pellicci PM, Wilson PD Jr, Ranawat CS: Results of revision for mechanical failure after cemented total hip replacement, 1979 to 1982: A two- to five-year follow-up. J Bone Joint Surg Am 1985;67:1074-1085.

Question 89

During primary total knee arthroplasty, what is the maximum distance the joint line can be raised or lowered before poor motion, joint instability, and increased chance of revision occur?

Explanation

DISCUSSION: Positioning of the femoral and tibial components is a common cause of early failure of total knee arthroplasty. Two modes of possible position are raising or lowering the joint line from its anatomic level. Raising or lowering the joint line beyond an established threshold can cause limited range of motion, poor patellar function, and possible instability. It has been determined that a threshold of approximately 8 mm provides consistently good results after knee arthroplasty.
REFERENCE: Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 339-365.

Question 90

A 70-year-old woman has a preoperative anterior interscalene block prior to undergoing a total shoulder arthroplasty. After seating her in the beach chair position, she becomes acutely hypotensive. What is the most likely cause for the hypotension?

Explanation

DISCUSSION: The beach chair position may cause sudden hypotension and bradycardia as a result of the Bezold-Jarisch reflex. This reflex occurs when venous pooling and increased sympathetic tone induce a low-volume, hypercontractile ventricle, resulting in activation of the parasympathetic nervous system and sympathetic withdrawal. The reported incidence of this phenomenon associated with the sitting position is between 13% to 24%. Left untreated, the result may be cardiac arrest. Pneumothorax or central nervous system toxicity after interscalene block is rare and has an incidence of less than 0.2%. Laryngeal nerve block associated with interscalene nerve block can occur but usually results in hoarseness secondary to ipsilateral vocal cord palsy.
REFERENCES: Long T, Wass C, Burkle C: Perioperative interscalene blockade: An overview of its history and current clinical use. J Clin Anesthesia 2002;14:546-556.
Norris T (ed): Orthopaedic Knowledge Update: Shoulder and Elbow 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 433-442.

Question 91

Treatment of an atrophic nonunion of the radial diaphysis should include which of the following?

Explanation

DISCUSSION: Atrophic nonunions of the radius and ulna are fairly rare with modern techniques of fixation; the few reports that have been published have discussed the use of structural corticocancellous bone grafts for the treatment of atrophic nonunions. The referenced study by Ring et al noted a 100% healing rate and improved patient reported outcomes with 3.5-mm plate-and-screw fixation and autogenous cancellous bone-grafting for atrophic forearm nonunions.

Question 92

What complication is more likely following excessive medial retraction of the anterior covering structures during the anterolateral (Watson-Jones) approach to the hip?

Explanation

DISCUSSION: The femoral nerve is the most lateral structure in the anterior neurovascular bundle. The femoral artery and vein lie medial to the nerve. Retractors placed in the anterior acetabular lip should be safe, although neurapraxia of the femoral nerve may occur if retraction is prolonged or forceful leading to quadriceps weakness. The femoral artery and nerve are well protected by the interposed psoas muscle. Damage to the lateral femoral cutaneous nerve, causing numbness over the anterolateral thigh, can occur while developing the interval between the tensor fascia latae and sartorious in the anterior (Smith-Petersen) approach but less likely in the Watson-Jones approach. Superior gluteal injury and accompanying abductor insufficiency may occur during excessive splitting of the glutei during the direct lateral (Hardinge) approach. Foot drop secondary to sciatic injury is more common with a posterior exposure or posterior retractor placement.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, p 325.
Anderson JE: Grant’s Atlas of Anatomy, ed 7. Baltimore, MD, Lippincott Williams & Wilkins, 1978, pp 4-17, 4-18.

Question 93

Figures 27a through 27c show the AP radiograph, MRI scan, and biopsy specimen of an otherwise healthy man who has a painful wrist. Serum chemistry studies are normal. What is the most likely diagnosis?

Explanation

DISCUSSION: The osseous sites most frequently involved by giant cell tumor of bone are the distal femur, proximal tibia, and distal radius with approximately 10% of giant cell tumors involving the distal radius. The goals of treatment are to remove the tumor completely and to preserve maximum function of the extremity.
REFERENCE: Vander Griend RA, Funderburk CH: The treatment of giant-cell tumors of the distal part of the radius. J Bone Joint Surg Am 1993;75:899-908.

Question 94

03 Which of the following findings is one of the diagnostic criteria for diffuse idiopathic skeletal hyperostosis?

Explanation

back answer
Diffuse idiopathic skeletal hyperostosis is a common disease, most prevalent in those over 50 years of age. The usual presentation is a middle-aged or older patient with chronic mild pain in the middle to lower back, spinal stiffness, and typical radiographic changes in the thoracic spine. Diffuse idiopathic skeletal hyperostosis is predominantly a radiographic diagnosis with 3 major diagnostic criteria. 1. Flowing ossification along the anterolateral aspect of at least four contiguous vertebrae. 2. Preservation of disk height in the involved vertebral segment; the relative absence of significant degenterative changes, such as marginal sclerosis in vertebral bodies or vacuum phenomenon. 3.
Absence of facet-joint ankylosis; absence of sacroiliac erosion, sclerosis, or intra-articular osseous fusion. Treatment is typically non-operative, with anti-inflammatories, activity modification and PT.
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Question 95

A 13-year-old girl is diagnosed with a stage IIB osteosarcoma of the proximal tibia. Following neoadjuvant chemotherapy, local control should consist of

Explanation

DISCUSSION: Local control of osteosarcoma consists of wide resection and reconstruction. Radiation therapy is not recommended except in unresectable lesions or for palliation. Curettage and bone grafting result in intralesional resection with an unacceptable high rate of local recurrence. Chemotherapy alone is not adequate for local control.
REFERENCES: Simon M, Springfield D, et al: Osteogenic Sarcoma: Surgery for Bone and Soft Tissue. Philadelphia, PA, Lippincott Raven, 1998, p 274.
Wold LA, et al: Osteogenic Sarcoma: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990, pp 14-15.

Question 96

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

Explanation

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

Question 97

A 15-year-old girl sustained the injury shown in Figures 70a and 70b when she jumped from the back of a moving truck. She is seen in the emergency department 2 hours after her injury. She has no other injuries. Her foot is warm and she has a normal motor and sensory examination. Pulses are only evident on Doppler. What is the most appropriate management? Review Topic

Explanation

The radiographs reveal a distal femoral fracture that is often associated with a neurovascular injury at the level of the fracture. Initial treatment should be to reduce the fracture, stabilize it, and then reevaluate the extremity for neurovascular function. A CT scan, arteriogram, or MRI scan would not help and would delay treatment. A cast would not be appropriate because access to the extremity is necessary and it would not provide stabilization for vascular repair if it is required.

Question 98

What is the most likely complication after surgical treatment in this scenario?

Explanation

DISCUSSION
Posterior shoulder instability is a rare form of instability that often presents with pain rather than feelings of instability. It often occurs in young athletes during activities that put the shoulder in an “at-risk position” (flexion, adduction, and internal rotation). Repetitive microtrauma can lead to posterior shoulder instability such as seen in football linemen. Swinging a bat or golf club places the lead arm in a flexed, adducted, and internally rotated position, which can lead to posterior translation of the humeral head that is forcibly reduced in follow-through as seen in this patient.
The glenohumeral joint relies on static and dynamic stabilizers. Static stabilizers help prevent instability at the end ranges of motion when the ligaments are taut. Dynamic stabilizers work to prevent subluxation at midranges of motion at which the ligaments are lax. The rotator cuff is integral as a dynamic stabilizer of the shoulder. It works through a process called concavity compression. The 4 muscles of the rotator cuff compress the humeral head into the concavity of the glenoid-labrum. This prevents the humeral head from subluxing during the midranges of motion. Of the 4 rotator cuff muscles, the subscapularis is most important at preventing posterior subluxation.
This patient has posterior instability, and various surgical techniques may be indicated depending on findings. Arthroscopic labral repair is indicated for anterior instability. Arthroscopic posterior labral repair is indicated for this patient because he has a posterior labral tear and posterior instability. If a patient has ligamentous laxity (not seen in this scenario because sulcus and Brighton sign findings would be negative), a posterior capsular shift with rotator interval closure is indicated. If a patient has excessive glenoid retroversion, a posterior opening-wedge osteotomy is appropriate.
The most common complication seen after arthroscopic posterior labral repair is stiffness, followed by recurrent instability and degenerative joint disease.

Question 99

A 75-year-old woman has had severe shoulder pain for the past month. Her medical history includes hypertension and a total nephrectomy for renal cell carcinoma 7 years ago. Radiographs and sagittal MRI scans are shown in Figures 36a through 36d. A bone scan reveals this to be an isolated lesion. Biopsy findings are consistent with metastatic renal cell carcinoma. What is the most appropriate treatment for this patient?

Explanation

DISCUSSION: Resection and reconstruction of this very proximal lesion provides the best chance to avoid hardware complications that may be associated with stabilization procedures. Wide resection of isolated renal cell carcinoma metastasis, which presents distant to the nephrectomy, may improve long-term survival.
REFERENCES: Fuchs B, Trousdale RT, Rock MG: Solitary bony metastasis from renal cell carcinoma: Significance of surgical treatment. Clin Orthop Relat Res 2005;431:187-192.
Jung ST, Ghert MA, Harrelson JM, et al: Treatment of osseous metastases in patients with renal cell carcinoma. Clin Orthop Relat Res 2003;409:223-231.

Question 100

In the treatment of intra-articular calcaneal fractures, surgical reduction and fixation has been shown to have improved outcomes over nonoperative treatment in all of the following patient groups EXCEPT:

Explanation

DISCUSSION: The referenced study by Buckley et al is a prospective study of intra-articular calcaneus fractures at several trauma centers. They found that overall, the outcomes after nonoperative treatment were not different from those after operative treatment. However, when stratifying groups, women who were managed operatively scored significantly higher on the SF-36 than did women who were managed nonoperatively. Also, patients who were less than twenty-nine years old, had a Böhler angle of 0 degrees to 14 degrees, a comminuted fracture, or a light workload did better after surgery compared with those who were treated nonoperatively.

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

Acute tendon repair
DIP joint extension splinting for 6 weeks
DIP and proximal interphalangeal joint extension splinting for 6 weeks
Buddy taping to the middle finger for 2 weeks
Early range-of-motion exercises and return to play as pain permits

Correct Answer: Acute tendon repair

Explanation:

Question 2:

One year after undergoing anterior cervical decompression and fusion, what percentage of patients still have dysphagia?

Options:

10% to 15%
30% to 35%
50% to 55%
70% to 75%

Correct Answer: 10% to 15%

Explanation:

DISCUSSION
Dysphagia after anterior cervical diskectomy and fusion is a common, usually transient finding after anterior cervical approaches to the spine. While it has been reported to occur in up to 70% of patients 2 weeks following surgery, in most cases the symptoms quickly resolve. There is, however, a small subset of patients for whom symptoms of dysphagia will persist. Lee and associates prospectively studied the rate of dysphagia after anterior cervical diskectomy and fusion, reporting a 15% rate of dysphagia at 12 months, and 12% at 24 months. Phillips and associates analyzed the 2-year data from the PCM FDE clinical trial and found a 12.1% incidence of dysphagia in the ACDF arm.
RECOMMENDED READINGS
Lee MJ, Bazaz R, Furey CG, Yoo J. Risk factors for dysphagia after anterior cervical spine surgery: a two-year prospective cohort study. Spine J. 2007 Mar-Apr;7(2):141-7. Epub 2007 Jan 22. PubMed PMID: 17321961.
View Abstract at PubMed
Smith-Hammond CA, New KC, Pietrobon R, Curtis DJ, Scharver CH, Turner DA. Prospective analysis of incidence and risk factors of dysphagia in spine surgery patients: comparison of anterior cervical, posterior cervical, and lumbar procedures. Spine (Phila Pa 1976). 2004 Jul 1;29(13):1441-6. PubMed PMID: 15223936.
View
Abstract at PubMed
Edwards CC 2nd, Karpitskaya Y, Cha C, Heller JG, Lauryssen C, Yoon ST, Riew KD. Accurate identification of adverse outcomes after cervical spine surgery. J Bone Joint Surg Am. 2004 Feb;86-A(2):251-6. PubMed PMID: 14960668.
View Abstract at PubMed
Phillips FM, Lee JY, Geisler FH, Cappuccino A, Chaput CD, DeVine JG, Reah C, Gilder KM, Howell KM, McAfee PC. A prospective, randomized, controlled clinical investigation comparing PCM cervical disc arthroplasty with anterior cervical discectomy and fusion. 2-year results from the US FDA IDE clinical trial. Spine (Phila Pa 1976). 2013 Jul 1;38(15):E907-18. doi: 10.1097/BRS.0b013e318296232f.
Rihn JA, Kane J, Albert TJ, Vaccaro AR, Hilibrand AS. What is the incidence and severity of dysphagia after anterior cervical surgery? Clin Orthop Relat Res. 2011 Mar;469(3):658-65. PMID: 21140251.
View Abstract at PubMed

Question 3:

Options:

metacarpophalangeal (MP) joint extension.
proximal interphalangeal (PIP) joint extension.
MP flexion.
PIP joint flexion.

Correct Answer: proximal interphalangeal (PIP) joint extension.

Explanation:

EXPLANATION:
This is a transverse proximal phalanx fracture with apex volar angulation. The fracture displaces into an apex volar angulated position under the pull of the central slip on the distal fragment and the interossei insertions at the base of proximal phalanx. Although it is possible to lose motion in flexion or extension of the MP or PIP joints, the biomechanics will not allow full extension of the PIP joint. If allowed to heal in apex palmar malunion, the predicted corresponding extensor lags are for a 10-degree lag at 16 degrees of angular deformity, a 24-degree lag at 27 degrees of deformity, and a 66-degree lag at 46 degrees of deformity. These fractures usually can be treated with closed reduction with or without percutaneous
pinning. With surgical treatment, there may be loss of motion both at the MP and PIP joints.

Question 4:

A patient who underwent total knee arthroplasty now reports a loss of sensation in the area circled in Figure 38. This area is innervated by which of the following nerves?

Options:

Infrapateller branch of the saphenous
Ascending branch of the peroneal
Anterior branch of the femoral
Posterior cutaneous of the thigh
Lateral cutaneous of the thigh

Correct Answer: Infrapateller branch of the saphenous

Explanation:

Question 5:

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 6:

Options:

Neurophysiologic test to evaluate the posterior interosseous nerve
Transfer of the extensor indicis proprius to the extensor pollicis longus tendon
Interphalangeal joint arthrodesis of the thumb
Extension splinting of the thumb
Fine cut CT of the distal radius to evaluate Lister’s tubercle

Correct Answer: Transfer of the extensor indicis proprius to the extensor pollicis longus tendon

Explanation:

Question 7:

Options:

open reduction and plate fixation.
a figure-of-8 bandage for 4 to 6 weeks.
a sling for comfort, followed by physical therapy when pain-free.
excision of the outer end of the clavicle.
a tension band and Kirschner wires.

Correct Answer: a sling for comfort, followed by physical therapy when pain-free.

Explanation:

Question 8:

Options:

Valgus osteotomy
Removal of the hardware
Intramedullary fixation after removal of the hardware
Conversion to total hip arthroplasty with a long cementless stem
Conversion to total hip arthroplasty with a primary tapered stem

Correct Answer: Conversion to total hip arthroplasty with a long cementless stem

Explanation:

Question 9:

The blood supply to the anterior cruciate ligament is primarily derived from what artery?

Options:

Anterior tibial artery
Superolateral geniculate
Middle geniculate
Inferolateral geniculate
Inferomedial geniculate

Correct Answer: Middle geniculate

Explanation:

Question 10:

Options:

Hip instability
Abductor weakness
Adductor weakness
Quadriceps weakness
Leg-length discrepancy

Correct Answer: Abductor weakness

Question 11:

A 34-year-old woman who is a professional skier (Figure 42)

Options:

Ligamentous reconstruction
Meniscal repair
Meniscectomy
Immobilization

Correct Answer: Meniscectomy

Question 12:

- A 25-year-old patient who was wearing a seat belt in the back chair of a car involved in a head-on collision undergoes a laparotomy. During surgery, an injury to the sigmoid colon is identified and treated. Two days later the patient has back pain when sitting in a chair. What is the most likely diagnosis?

Options:

Sacral fracture
Burst fracture of L5
Cauda equina syndrome
Distraction-flexion injury at L3
Distraction-extension injury at L3

Correct Answer: Distraction-flexion injury at L3

Explanation:

Question 13:

Options:

custom orthotics.
a below-knee non-weight-bearing cast.
exploration and resection of the calcaneocuboid joint.
exploration and resection of the talocalcaneal joint.
triple arthrodesis.

Correct Answer: triple arthrodesis.

Explanation:

Question 14:

Options:

Physical therapy to improve hip stability
Use of an abduction brace to limit the patient’s range of motion
Conversion to a constrained acetabular liner
Cobalt and chromium serum metal ion level testing

Correct Answer: Cobalt and chromium serum metal ion level testing

Explanation:

Question 15:

What percent of adult patients with rheumatoid arthritis test positive for rheumatoid factor?

Options:

Less than 20%
20% to 40%
50%
80% to 90%
More than 95%

Correct Answer: 80% to 90%

Explanation:

Question 16:

During particle-induced osteolysis around implants, what cell secretes most of the interleukin-6 (IL-6)?

Options:

Osteoblasts from surrounding bone
B-lymphocytes in the bone marrow
Fibroblastic cells in the periprosthetic lining
T-lymphocytes in the circulating blood
Macrophages in the granuloma

Correct Answer: Fibroblastic cells in the periprosthetic lining

Explanation:

Question 17:

Options:

What dominant intracellular proteins become directly phosphorylated as a result of bone morphogenetic protein (BMP) binding to its receptors?
Myc
SMADs
Beta-catenin (ß-catenin)
Adenylate cyclase

Correct Answer: SMADs

Explanation:

BMP proteins, which are part of the larger transforming growth factor-beta super family, bind to serine/threonine receptors on the cell surface. This binding causes phosphorylation of SMAD proteins, which in turn forms a complex that enters the nucleus and initiates the transcription of several genes involved in osteoblastic differentiation. Adenylate cyclase is
a transmembrane protein that acts intracellularly to activate the G protein pathways. Myc is a proto-oncogene that encodes for a transcription factor involved in numerous cell- activation pathways, but is not directly phosphorylated by BMP receptor.
ß-catenin is an intracellular molecule that plays a key role in the Wnt signaling pathway. This pathway is also involved in osteoblastic differentiation, but differs in target proteins within the cell.
A 45-year-old previously healthy woman has experienced weakness and fatigability for 2 months. She states she feels best in the morning, but tires easily with exertion. If she sits and rests her strength improves, but she easily tires with each activity. When her fatigue is most severe, she has double vision. Physical examination is
positive for ptosis with upward gaze after 20 seconds. When she holds her arms out straight she shows good initial strength, but rapidly decreasing strength with time. What is the pathologic cause of her muscle weakness?
Ig antibodies at the neuromuscular (NM) junction
Decreased release of acetylcholine at the NM junction
Decrease in myelin sheath of axonal nerves with loss of NM junction
Absence of dystrophin with excess calcium at sarcolemma
The patient has myasthenia gravis, which has its onset in middle age and causes progressive weakness because of the loss of acetylcholine receptors secondary to autoimmune antibodies at the NM junction. Rest periods allow uptake of acetylcholine and initial strength, but easy fatigability. Treatment is aimed at immunomodulation; acetyl cholinesterase inhibitors often coupled with thymectomy can control symptoms.
Decreased release of acetylcholine at the NM junction is the effect of a nondepolarizing drug or toxin botulinum. Patients with muscular dystrophy lack dystrophin that acts at the sarcolemma to regulate calcium channels, and onset of this condition occurs at a younger age. The decrease in myelin indicates Charcot-Marie-Tooth disease and is
often seen with long axon degeneration, such as in the feet and lower legs.
You are studying a single continuous variable after administration of a defined treatment intervention. Your statistician informs you the data are not normally distributed. What is the best test to analyze the data?
Analysis of variance (ANOVA)
Regression analysis
Student t test
Mann-Whitney U test
The Mann-Whitney U test is used when data are nonparametric, meaning either not normally distributed or variances are not equal among groups. Both the Student t test and ANOVA are used with parametric, normally distributed data. A regression analysis is a
statistical model that allows for control of potentially confounding variables. It is used to assess the relationship between a dependent variable and (usually) multiple independent variables.
Which of the following is the mechanism of action of aspirin?
Inhibition of vitamin K-dependent carboxylation
Inhibition of factor Xa through antithrombin binding
Binding of cyclooxygenase (COX)-1 and COX-2
Direct thrombin inhibition
Glycoprotein IIIb agonist binding
Aspirin works by the irreversible binding of cycloxygenase (COX). This effect inhibits platelet generation of thromboxane A2, resulting in an antithrombotic effect. In addition, there is a decrease in the level of prostaglandin production due to the COX-1 binding.
Aspirin's effects and respective mechanisms of action vary with dose:
Low doses (typically 75 to 81 mg/day) are sufficient to irreversibly acetylate serine 530 of cyclooxygenase (COX)-1. This effect inhibits platelet generation of thromboxane A2, resulting in an antithrombotic effect.
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Intermediate doses (650 mg to 4 g/day) inhibit COX-1 and COX-2, blocking prostaglandin (PG) production, and have analgesic and antipyretic effects. Illustration A shows the mechanism of action of aspirin.
InCORRECT Answers: 1,2,4,5: Aspirin does not have any of these mechanisms of action.
A study is proposed in which 2 groups of patients are randomized to treatment with bisphosphonates or placebo. This is an example of what study type?
Crossover design trial
Parallel design trial
Cohort study
Case series
In a parallel design trial, participants are randomized to 2 or more groups, each of which receives a different treatment or intervention. For example, Group A receives the drug and Group B receives the placebo. This type of
design allows for comparison between groups. In a crossover design clinical trial, both groups receive both interventions over a defined time period. For example, Groups A and B both receive the drug as well as the placebo. This allows for within-participant comparisons. In a cohort study, patient groups are followed over time on the basis of having or not having received an exposure. Cohort studies are not randomized. In a case series, patients often receive a particular treatment and the outcomes are then examined.
An otherwise healthy 50-year-old man who is a smoker undergoes a posterior spine fusion with instrumentation for spondylolisthesis. What can the patient do to minimize his risk for pseudarthrosis?
Increase calcium and vitamin D intake
Avoid all nonsteroidal anti-inflammatory drugs (NSAIDs)
Maintain smoking cessation
Engage in early physical therapy to strengthen the trunk musculature
Smoking is the biggest risk factor for nonunion and should be strictly avoided. NSAIDs interfere with bone healing, but not as strongly as smoking. Early mobilization would potentially stress the construct, inducing movement that leads to nonunion. Without history of calcium and vitamin D deficiency, increasing intake would not decrease the risk of nonunion.
When making a comparison to autograft incorporation, the inflammatory process in allograft tissue anterior cruciate ligament (ACL) reconstruction
occurs earlier.
occurs later.
is prolonged.
is shortened.
Compared to similar autograft, allograft tissue demonstrates a prolonged inflammatory response, slower rate of biological incorporation and remodeling, and a higher proportion of large-diameter collagen fibrils. Native ACL inserts
into bone through a transition of 4 distinct zones: tendon, unmineralized fibrocartilage, mineralized fibrocartilage, and bone. This transition is not reproduced with tendon grafts, which instead heal with interposed fibrovascular scar at the graft-tunnel interface. The scar rapidly remodels to form perpendicular fibers resembling Sharpey fibers and, eventually, mature bone growth into the outer portion of the graft. The intra- articular portion of allograft undergoes an initial phase of necrosis followed by repopulation by host synovial cells into the acellular collagen scaffold.
Revascularization and maturation complete the ligamentization of graft tissue.
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?
Correlation coefficient of MRSA
Prevalence of MRSA
Incidence of MRSA
Relative risk of MRSA
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.
A 48-year-old man who is scheduled to undergo total knee replacement has an X-linked clotting disorder that leads to abnormal bleeding and recurrent, spontaneous hemarthrosis. Before undergoing surgery, he should have replacement therapy of
protein C and S.
vitamin K.
von Willebrand factor.
factor VIII.
Hemophilia A is an X-linked recessive deficiency of factor VIII that can lead to significant bleeding problems including recurrent spontaneous hemarthroses that can lead to synovitis and joint destruction. von Willebrand disease is a lack of von Willebrand factor that leads to decreased platelet aggregation; more commonly patients have mucosal bleeding and not hemarthroses. Vitamin K deficiency is not hereditary; it is typically attributable to inadequate dietary intake, malabsorption, and loss of storage sites from hepatocellular disease. Protein C and S deficiencies are autosomal-dominant diseases that lead to thrombosis, not bleeding, as protein C and S shut off thrombin formation.
What is the recommended optimal timing of presurgical antibiotic administration to prevent infection in patients undergoing total joint replacement surgery?
Within 1 hour before incision
Within 2 hours before incision
Immediately after incision
Within 1 hour after incision
The current recommendation for antibiotic prophylaxis for major orthopaedic surgical procedures is to administer intravenous antibiotics within 1 hour of surgical incision. Redosing of antibiotics should occur 3 to 4 hours after the initial dose for procedures that extend beyond 3 to 4 hours. Little evidence supports postsurgical antibiotic use beyond 24 hours. As you move beyond 1 hour from time of administration of antibiotics, risk for infection increases and rates of bacterial cell death decline. It is not acceptable to
administer presurgical antibiotics after incision.
Bacterial resistance to antibiotics in biofilm is an example of
avoidance.
decreased susceptibility.
inactivation.
mutation.
CORRECT answer: 1
Three basic mechanisms of antibiotic resistance have been identified: avoidance, decreased susceptibility, and inactivation. Biofilm formation is a classic example of avoidance, whereby the biofilm creates a physical barrier to the antibiotic. Bacteria can decrease their susceptibility to antibiotics by mutating the antibiotic target or generating a mechanism to inactivate the antibiotic. Biofilm formation develops when a sufficient mass of bacteria forms on a surface. The cell-to-cell signaling becomes sufficient to activate transcription of genes needed for biofilm formation in a process known as quorum sensing. Once the bacteria produce a mature biofilm, they enter a greatly reduced or stationary phase of growth. Lastly, high-shear
environments seem to stimulate biofilm production.
A patient with Paget disease who is intolerant of bisphosphonates is given calcitonin. What is the mechanism of action of calcitonin?
Promotes reabsorption of phosphate in the renal tubules
Interferes with osteoclast maturation
Interferes with intestinal absorption of calcium
Upregulates osteoblast formation
Calcitonin is a hormone that reduces serum calcium concentration by directly interfering with osteoclast maturation via receptors. Calcitonin inhibits phosphate reabsorption and decreases calcium reabsorption in the kidneys. By attenuating cartilage breakdown and stimulating cartilage formation via inhibitory pathways of matrix metalloproteinases, calcitonin also has a
chondro-protective effect on articular cartilage. Calcitonin has no major effects on intestinal absorption of calcium, but may aid in small-bowel secretion of sodium, potassium, chloride, and water. Calcitonin also has no receptor effect on osteoblasts.
A cartilage water content increase is the hallmark of which
osteoarthritis stage?
Prearthritis
Early
Late
Terminal
The first stage of osteoarthritis is marked by an increase in water content secondary to disruption of the matrix framework. This is followed by an increase in chondrocyte anabolic and catabolic activity in response to tissue damage. Wnt-induced signal protein 1 increases chondrocyte protease expression. Failure to restore tissue balance ultimately leads to continued destruction and osteoarthritis. One hallmark of osteoarthritic cartilage is a reduced repair mechanism attributable to decreased chondrocyte response to growth factor stimulation (transforming growth factor-alpha and insulin-like growth factor-1).
Mitochondrial dysfunction and increased production of reactive oxygen species may promote cell senescence, a progressive slowing of cellular activity. Microscopic evidence of cartilage degeneration begins with fibrillation of the superficial and transition zones, followed by disruption of the tidemark by subchondral blood vessels and eventual subchondral bone remodeling. This process ultimately leads to cartilage degradation with decreased water content in the late and terminal phases of osteoarthritis.
What is the plasma half-life of warfarin?
1 to 2 hours
4 to 6 hours
12 to 18 hours
36 to 42 hours
Warfarin, which is dosed daily, can take 72 to 96 hours to reach therapeutic levels. It has a plasma half-life of 36 to 42 hours. Low-molecular heparins have a plasma half-life of 4 to 5 hours, and fondaparinux has a half-life of 17 to 21 hours. Warfarin will not affect the International Normalized Ratio (INR) until 2 to 3 days after it is given. Patients on chronic warfarin therapy should
have treatment stopped 3 to 5 days before elective surgery to allow the INR to normalize.
A 70-year-old woman with a body mass index (BMI) of 34 and a history of hypercholesterolemia has elected to undergo total hip arthroplasty. Her son recently learned he has Factor V Leiden following an episode of pulmonary embolism. What are this patient's risk factors for thromboembolic disease?
Type of surgery, age, and BMI
Type of surgery, hypercholesterolemia, and age
Age, BMI, and hypercholesterolemia
BMI, type of surgery, and hypercholesterolemia
Risk stratification is one of the most critical clinical evaluations before undergoing total joint arthroplasty. Many factors have been identified to increase risk for venous thromboembolism (VTE). The major factors include previous VTE, obesity, type of surgery (such as total joint arthroplasty), hypercoagulable states, myocardial infarction, congestive heart failure, family history of VTE, and hormonal replacement therapy.
Hypercholesterolemia is not a risk factor for thromboembolic disease.
DNA replication occurs during which phase of the cell cycle?
M
S
R
G1
G2
The cell cycle consists of four distinct phases: initial growth (G1), DNA replication/synthesis (S), a gap (G2), and mitosis (M) (see illustration).
The G1 and G2 phases of the cell cycle represent the “gaps” or growth phases in the cell cycle that occur between DNA synthesis and mitosis. G0 cells are in a stable state and have not entered the cell cycle. During the S phase, the DNA is synthesized and replicated. During the M phase or mitosis, all genetic material divides into two daughter cells.
The cells are diploid (2N) in the G0 and G1 phases. The cells become tetraploid (4N) at the end of S and for the entire G2 phases. There is no R phase in the cell cycle.
What antithrombotic agent is a selective factor I0a inhibitor?
Warfarin
Low-molecular-weight heparin
Rivaroxaban
Aspirin
Rivaroxaban is a selective factor I0a inhibitor. Aspirin is a cyclooxygenase inhibitor. Low-molecular-weight heparin is a nonspecific anticoagulant. Warfarin is a vitamin K antagonist and reduces production of clotting factors II, VII, IX, and X.
A 68-year-old woman had advanced right knee arthritis and total knee replacement was planned. She learned she had primary biliary cirrhosis at age 41 and now has advancing liver failure. Preoperative coagulation tests show a baseline International Normalized Ratio (INR) of 1.36. Appropriate methods to prevent thromboembolic
disease as recommended by the 2011 AAOS Clinical Practice Guideline,
Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee
Arthroplasty
, include
use of mechanical prophylaxis (eg, pneumatic calf compressors) while in the hospital.
oral warfarin with a goal INR between 2.0 and 3.0.
low-dose warfarin for 3 weeks postsurgically beginning 48 hours after surgery.
no prophylaxis because this patient already is partially anticoagulated secondary to her liver disease.
The 2011 AAOS Clinical Practice Guideline,
Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty
, recommends the use of mechanical prophylaxis for patients at increased risk
for bleeding (including those with liver disease or hemophilia). This recommendation is the consensus of the workgroup that established these guidelines because there was insufficient evidence to justify a stronger recommendation in this clinical scenario. The other responses use no prophylaxis or pharmacological prophylaxis. Pharmacological prophylaxis is not recommended in patients who are at increased risk for bleeding.
The pharmacokinetics of which deep venous thrombosis (DVT) prophylactic agent are affected by liver function and dietary intake?
Dalteparin
Warfarin
Fondaparinux
Enoxaparin
Warfarin is an oral vitamin K antagonist that is rapidly absorbed from the gastrointestinal tract. It accumulates in the liver, where it is metabolized and excreted. The pharmacokinetics of warfarin can be affected by certain drugs or disease states that influence liver function. Fondaparinux is a synthetic factor Xa inhibitor that is eliminated through the kidneys. Both Dalteparin and Enoxaparin are low-molecular-weight heparins that activate antithrombin and inhibit factors Xa and IIa. Like Fondaparinux, they are eliminated through the kidneys and should be used with caution in patients with kidney disease.
What infection-control measure has been shown to have the most notable impact in reducing surgical-site infections?
Intravenous antibiotic administration within 1 hour of surgical incision
Screening and decolonization of patients colonized with methicillin-resistant
Staphylococcus aureus
Horizontal laminar flow
Use of enclosed body exhaust suits
Timely administration of prophylactic antibiotics is the most important factor shown to decrease surgical-site infections. The use of horizontal laminar flow and body exhaust suits has not been shown to significantly affect infection rates.
The resistance to pullout of a screw in osteoporotic bone is increased by all of the following EXCEPT?
Placement parallel to the trabecular pattern
Purchase in cortical bone
Use of a fixed angle (locking screw construct)
Tapping prior to screw placement
Augmentation with polymethylmethacrylate
Of the options listed, tapping prior to screw placement is the only variable that does not increase the pullout strength of a screw in osteoporotic bone.
Cornell reviews internal fixation in osteoporotic bone. According to this article, the quality of the bone is the primary determinant of the holding power of an individual screw. Other factors that increase the pullout strength include fixation in cortical bone (cortical bone has greater mineral density and, therefore, greater resistance to screw pullout than trabecular bone), screws placed parallel to the trabecular pattern, and screw fixation augmented with PMMA. The addition of a locking plate will also increase the resistance to failure by creating a fixed angle construct. Tapping prior to placement of the screw has not been shown to increase resistance to pullout, on the contrary studies have shown
this decreases resistance to pullout.
Turner et al examined the holding strength of small and large diameter screws in healthy bovine and diseased human bone. They found the screw diameter, trabecular orientation of the bone, and mineral content of the bone all affect the holding strength. A larger diameter screw, parallel placement to the trabecular pattern, and purchase in bone with a higher density all increase the holding strength.
Gigantism affects which region of the growth plate labeled in Figure A?
A
B
C
D
E
Gigantism, like achondroplasia, affects the proliferative zone (Region C of Figure A) of the growth plate. In Figure A, Region A is the epiphysis, Region B is the resting zone, Region D is the hypertrophic zone, and Region E is the metaphysis. Illustration A is another depiction of the physis which is labeled. Gigantism is typically caused by a pituitary adenoma which over secretes growth hormone. Its effect on the proliferative zone results in bone overgrowth and excessive height and limb length. Acromegaly may also be
caused by a pituitary adenoma that over secretes growth hormone, but has its effect once the physis has closed.
Plain radiographs do not provide an accurate assessment of bone mineral density (BMD) until what percentage of mineral has been lost?

Question 18:

Which of the following nerves is most commonly injured during revision surgery following a Bristow procedure?

Options:

Dorsal scapular
Suprascapular
Axillary
Musculocutaneous
Ulnar

Correct Answer: Musculocutaneous

Explanation:

DISCUSSION: Because of the previously transferred bone block of coracoid and short arm flexors, the musculocutaneous nerve often scars along the anteroinferior glenohumeral capsule. Mobilization of this tissue places the nerve at greatest risk. The axillary nerve is also potentially at risk, but this is nonspecific to prior surgery, particularly the Bristow procedure.
REFERENCES: Norris TR: Complications following anterior instability repairs, in Bigliani LU (ed): Complications of Shoulder Surgery. Baltimore, MD, Williams and Wilkins, 1993,
pp 98-116.
Flatow EL, Bigliani LU, April EW: An anatomic study of the musculocutaneous nerve and its relationship to the coracoid process. Clin Orthop 1989;244:166-171.

Question 19:

Embolic material generated during total knee arthroplasty (TKA) shown in Figure 29 is composed of which of the following substances?

Options:

Fat only
Fat and air
Fat and marrow
Fat and cement
Fat and bone

Correct Answer: Fat and marrow

Explanation:

DISCUSSION: Emboli are created during TKA. Usually there is an increased incidence with the use of intramedullary rods that disrupt the marrow contents. These are not fat emboli per se. They are material composed of fat cells and marrow that act like pulmonary emboli to obstruct small arterioles in the lung. They are different from free fat emboli that are seen in fractures and that lead to chemical injury to the lung rather than obstructive injury.
REFERENCES: Markel DC, Femino JE, Farkas P, et al: Analysis of lower extremity embolic material after total knee arthroplasty in a canine model. J Arthroplasty 1999;14:227-232.
Pell AC, Christie J, Keating JF, et al: The detection of fat embolism by transoesophageal echocardiography during reamed intramedullary nailing: A study of 24 patients with femoral and tibial fractures. J Bone Joint Surg Br 1993;75:921-925.
McGrath BJ, Hsia J, Boyd A, et al: Venous embolization after deflation of lower extremity tourniquets. Anesth Analg 1994;78:349-353.

Question 20:

Options:

Chemotherapy and radiation therapy
Neoadjuvant chemotherapy followed by wide resection and reconstruction
Curettage and bone grafting
Curettage and intravenous antibiotics
Above-knee amputation

Correct Answer: Neoadjuvant chemotherapy followed by wide resection and reconstruction

Explanation:

Question 21:

A college basketball player is struck in the eye by a player’s hand while driving to the basket. Fluorescein evaluation reveals the injury shown in Figure 18. Management should consist of

Options:

administration of ophthalmic corticosteroids and antibiotics with application of an eye patch.
evaluation of intact visual fields and pupillary responses prior to a return to play.
consultation with an ophthalmologist prior to emergent repair of the damaged structure.
measurement of ocular pressure and fundoscopic examination in a properly lit examination room.
strict bed rest with the head elevated, minimizing head motion during the healing process.

Correct Answer: administration of ophthalmic corticosteroids and antibiotics with application of an eye patch.

Explanation:

Question 22:

- Which of the following is considered an advantage of an unreamed intramedullary nail over a reamed intramedullary nail?

Options:

Avoids the risk of marrow emboli
Avoids injury to the intramedullary nutrient vessels
Results in faster healing of fractures
Results in more secure fixation
Results in faster regeneration of the endosteal blood supply

Correct Answer: Results in faster regeneration of the endosteal blood supply

Explanation:

Question 23:

The radiographic finding in Figure 58 is indicative of what type of acetabular fracture?

Options:

Anterior column
Posterior column
Associated both column
Transverse
Associated transverse plus posterior wall

Correct Answer: Transverse

Explanation:

The radiographic image is an obturator oblique view of the left acetabulum and demonstrates a "spur" sign. It represents a spike of bone from the intact hemipelvis and no articular surface remains with the hemipelvis, which defines the associated both column fracture. The weight-bearing surface of the acetabulum is displaced with the femoral head. In all other patterns, at least part of the articular surface remains with the intact hemipelvis.
(SBQ12TR.58) A 35-year-old male was involved in a high speed motorcycle accident. He has a closed head injury, bilateral pulmonary contusions and splenic rupture. His orthopaedic injuries are shown in Figure A. He has a blood pressure of 90/50 mm Hg and a heart rate of 115, despite aggressive resuscitation. An arterial blood gas reveals that his blood lactate is 3.5 and base deficit is -6 mmol/L. Following successful closed reduction of the right hip in the operating room with a percutaneous inserted Schantz pin, what is the next most appropriate treatment for his orthopaedic injuries?
Review
Topic
Bilateral open reduction and internal fixation
Open reduction internal fixation on the right, reamed intramedullary nailing on the left
Temporizing external fixation on the right, open reduction and internal fixation on the left
Bilateral reamed intramedullary nailing
Bilateral temporizing external fixation
This patient presents with features of hemodynamic instability and a high injury severity score. The next most appropriate treatment would be temporizing external fixation bilaterally. This patient meets the criteria for damage control orthopaedics.
Damage control orthopaedics is an approach that contains and stabilizes orthopaedic injuries so that the patient's overall physiology does not undergo further inflammatory insult. As a result, external fixation of femoral shaft fracture and pelvic stabilization is an effective treatment under this strategy. Other indications include vascular injury and severe open fracture.
Pallister et al. reviewed the effects of surgical fracture fixation on the systemic inflammatory response to major trauma. They show that early stabilization of major long bone fractures is beneficial in reducing the incidence of acute respiratory distress syndrome and multiple organ failure. However, early fracture surgery increases the post-traumatic inflammatory response, which carries a higher complication rate compared to temporary fixation.
Tisherman et al. created clinical guidelines for the endpoints of resuscitation. Level I data found that standard hemodynamic parameters do not adequately quantify the degree of physiologic derangement in trauma patients. The initial base deficit, lactate level, or gastric pH should be used to stratify patients with regard to the need for ongoing fluid resuscitation.
Pape et al. retrospectively reviewed the impact of early total care vs. damage control orthopaedics in the treatment of femoral shaft fractures in polytrauma patients. They found a significantly higher incidence of acute respiratory distress syndrome (ARDS) with intramedullary nailing (15.1%) compared to external fixation (9.1%) when DCO subgroups were compared.
Figure A is a pelvic AP radiograph showing a right hip fracture-dislocation with an ipsilateral femoral shaft fracture. On the left side there is a displaced pertrochanteric hip fracture.
Incorrect Answers:

Question 24:

Anaerobic weight training has what effect in a prepubescent 10-year-old male athlete? Review Topic

Options:

It can induce muscle hypertrophy.
It can increase efficiency of muscle action.
It has no effect on muscle performance.
It can cause injury to the growth plate.
It can lead to a higher risk of osteochondritis dissecans.

Correct Answer: It can increase efficiency of muscle action.

Explanation:

Question 25:

Options:

immobilization of the wrist until the fracture heals.
excision of the hook of the hamate.
internal fixation of the fractured hook of the hamate.
ultrasound therapy to promote fracture healing.
limited intercarpal arthrodesis.

Correct Answer: immobilization of the wrist until the fracture heals.

Explanation:

Question 26:

- Figure 16 shoes the AP radiograph of a 32-year-old man with a fracture cephalad to the fovea of the femoral head. A CT scan shows a single head fragment. After closed reduction of the hip, there is 5 mm of residual articular incongruity. Management should now include

Options:

Hybrid total hip arthroplasty
Noncemental hemiarthroplasty of the hip
Closed reduction and percutaneous pin fixation
Open reduction through an anterior approach to the hip
Excision of the head fragment

Correct Answer: Open reduction through an anterior approach to the hip

Explanation:

Question 27:

Options:

Anesthesia in the first dorsal web space
Inability to extend the fingers
Inability to abduct the fingers
Inability to flex the thumb interphalangeal (IP) joint

Correct Answer: Inability to flex the thumb interphalangeal (IP) joint

Explanation:

Question 28:

-In the shoulder position of 90-degree forward flexion and internal rotation, what is the most important static stabilizer of the glenohumeral joint?

Options:

Rotator interval
Infraspinatus
Anterior band of the inferior glenohumeral ligament
Posterior band of the inferior glenohumeral ligament DISCUSSION -In the position of 90 degrees forward flexion and internal rotation, the most important static stabilizer of the glenohumeral joint is the posterior band of the inferior glenohumeral ligament. This position places the posterior-inferior glenohumeral ligament in an anterior-posterior direction and under tension. The superior glenohumeral ligament and the middle glenohumeral ligament provide static stability in the fully adducted and midrange-adducted positions, respectively. The subscapularis and infraspinatus provide primarily dynamic stability to the glenohumeral joint. Though not fully clear, the rotator interval appears to provide more static stability with the arm adducted, limiting inferior and posterior translation, and less so in the forward flexion and internal rotation position.

Correct Answer: Posterior band of the inferior glenohumeral ligament DISCUSSION -In the position of 90 degrees forward flexion and internal rotation, the most important static stabilizer of the glenohumeral joint is the posterior band of the inferior glenohumeral ligament. This position places the posterior-inferior glenohumeral ligament in an anterior-posterior direction and under tension. The superior glenohumeral ligament and the middle glenohumeral ligament provide static stability in the fully adducted and midrange-adducted positions, respectively. The subscapularis and infraspinatus provide primarily dynamic stability to the glenohumeral joint. Though not fully clear, the rotator interval appears to provide more static stability with the arm adducted, limiting inferior and posterior translation, and less so in the forward flexion and internal rotation position.

Explanation:

CLINICAL SITUATION FOR QUESTIONS 48 AND 49
A 17-year-old high school wrestler sustains an abrasion over the posterior aspect of his right elbow during a match. During the next few days the abrasion becomes erythematous and he is placed on oral cephalexin 500 mg four times per day. The erythema extends proximally despite the antibiotic regimen. The patient is afebrile, there is no fluid collection associated with the lesion, and his elbow joint is not involved.

Question 29:

Options:

Continued physical therapy
Alteration of medication to include an anti-epileptic
Tarsal tunnel release
Sympathetic blocks
Neurostimulation

Correct Answer: Sympathetic blocks

Explanation:

Question 30:

What anatomic site is considered at highest risk for pathologic fracture?

Options:

Humeral neck
Humeral diaphysis
Subtrochanteric femur
Femoral diaphysis
Pelvis

Correct Answer: Subtrochanteric femur

Explanation:

Question 31:

A study is proposed in which 2 groups of patients are randomized to treatment with bisphosphonates or placebo. This is an example of what study type?

Options:

Crossover design trial
Parallel design trial
Cohort study
Case series

Correct Answer: Parallel design trial

Explanation:

Question 32:

Which of the following is a recognized predictor of mortality after hip fracture?

Options:

American Society of Anesthesiologist (ASA) classification
Post-operative weight bearing status
Fracture comminution
Fixation device used
Hip fracture type

Correct Answer: American Society of Anesthesiologist (ASA) classification

Explanation:

Question 33:

When reconstructing the anterior cruciate ligament (ACL), what is the most common source of potential autograft failure? Review Topic

Options:

Graft choice
Tunnel position
Tibial fixation
Femoral fixation

Correct Answer: Tunnel position

Explanation:

Question 34:

Which of the following factors increases the risk of sciatic nerve injury in primary total hip arthroplasty (THA)?

Options:

Male gender
Anterolateral approach
Posterior superior quadrant acetabular screw placement
Osteonecrosis
Developmental dysplasia of the hip

Correct Answer: Developmental dysplasia of the hip

Explanation:

DISCUSSION: Injury to the sciatic nerve is a relatively rare but serious complication of THA. Dissection of the sciatic nerve is not typically done during primary THA, although the nerve can be identified during the surgical approach. An anterolateral approach to THA would not necessarily be associated with any greater incidence of sciatic nerve injury than other approaches. Screw fixation for the acetabular component is often a matter of surgeon preference. Provided that the anatomic safe zones for screw fixation (posterior inferior and posterior superior) are recognized, injury to the sciatic nerve from acetabular screws can be minimized. Restoration of anatomic length is important in primary THA. Overlengthening can result in sciatic nerve palsy. Developmental dysplasia of the hip can lead to a congenitally shortened extremity with concomitant congenital shortening of the associated neurovascular structures. Overlengthening of the extremity during THA for developmental dysplasia of the hip can lead to sciatic palsy. Osteonecrosis is not an associated risk factor for sciatic nerve palsy.
REFERENCES: DeHart MM, Riley LH Jr: Nerve injuries in total hip arthroplasty. J Am Acad Orthop Surg 1999;7:101-111.
Anas P, Felix B: Evaluation and prevention of postoperative complications, in Neurologic Injury in Revision THA. New York, NY, Springer Verlag, 1999, pp 361-371.

Question 35:

Options:

Medial collateral ligament
Annular ligament
Lateral ulnar collateral ligament
Extensor carpi radialis brevis
Extensor carpi radialis longus

Correct Answer: Lateral ulnar collateral ligament

Explanation:

DISCUSSION: The patient has an iatrogenic injury to the lateral ulnar collateral ligament following the arthroscopic procedure. Failure to adhere to known anatomic landmarks can lead to this devastating complication. The examination findings are classic for posterolateral elbow instability.
REFERENCES: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 318.
O’ Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73:440-446.

Question 36:

Which of the following nerves is most commonly injured during arthroscopy of the ankle?

Options:

Sural
Saphenous and its branches
Posterior tibial and its branches
Deep peroneal and its branches
Superficial peroneal and its branches

Correct Answer: Superficial peroneal and its branches

Explanation:

Question 37:

Options:

observation.
antibiotic therapy.
irrigation and debridement.
aspiration and compression.
excision.

Correct Answer: aspiration and compression.

Explanation:

Question 38:

Options:

Injury to the recurrent laryngeal nerve
Injury to the superior laryngeal nerve
Esophageal trauma at the time of the fracture or at the time of the reduction
Retropharyngeal edema or hematoma from the fracture
Halo vest placement

Correct Answer: Halo vest placement

Explanation:

Question 39:

A 13-year-old girl presents with back pain for 6 months. Figures A and B are SPECT scan and CT images taken at the time of presentation. What is the most likely diagnosis? Review Topic

Options:

Osteoid osteoma
Bone island
Spondylolysis
Osteoblastic metastases
Aneurysmal bone cyst

Correct Answer: Osteoid osteoma

Explanation:

Question 40:

Options:

myelography with CT.
spinal cord-evoked potentials.
repeat physical examinations.
MRI.
electromyography and nerve conduction velocity studies.

Correct Answer: repeat physical examinations.

Explanation:

DISCUSSION: The patient has spinal shock. Steroid administration and MRI are appropriate therapeutic and diagnostic procedures. Myelography with CT is of little value unless there is an unusual skeletal variant. Spinal cord-evoked potentials have no value. The best method to determine the patient’s neurologic recovery is repeated physical examinations over the first 48 to 72 hours.
REFERENCES: Spivak JM, Connolly PF (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 183-184.
Herkowitz HN, Garfin SR, Eismont FJ: Rothman-Simone The Spine, ed 5. Philadelphia, PA, Saunders Elsevier, 2006, pp 1185-1194.

Question 41:

Options:

ipsilateral weakness of the tibialis anterior.
ipsilateral weakness of the peroneus longus and brevis.
ipsilateral weakness of the extensor hallucis longus.
a positive Beevor’s sign.
a positive ipsilateral Gaenslen’s sign.

Correct Answer: ipsilateral weakness of the tibialis anterior.

Explanation:

Question 42:

Iliosacral screws placed for stabilization of posterior pelvic ring injuries (eg, sacroiliac dislocation) that exit the sacrum anteriorly are most likely to injure which of the following structures?

Options:

L4 nerve root
L5 nerve root
S1 nerve root
Internal iliac artery
External iliac artery

Correct Answer: L5 nerve root

Explanation:

Question 43:

Figures 26a and 26b show the radiograph and MRI scan of a 22-year-old man with knee pain. What is the most likely diagnosis?

Options:

Osteochondroma
Osteoblastoma
Osteosarcoma
Chondrosarcoma
Malignant fibrous histiocytoma of bone

Correct Answer: Osteochondroma

Explanation:

DISCUSSION: The lesion is an osteochondroma. This is demonstrated by a pedunculated bone-forming lesion where the medullary space of the lesion communicates with the medullary space of the host bone. The cortex of the exostosis is in continuity with the cortex of the underlying bone. The MRI scan reveals that there is no significant cartilage cap, alleviating concern for malignant conversion to a chondrosarcoma. Osteoblastoma and osteosarcoma typically have mixed areas of bone formation and bone destruction. Malignant fibrous histiocytoma of bone is usually purely lytic.
REFERENCES: Vaccaro AR (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 197-215.
Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 103-111.

Question 44:

Options:

tenolysis of the biceps.
repair of the subscapularis using suture anchors.
repair of the subscapularis tendon and biceps tenodesis.
repair of the subscapularis tendon and removal of the loose body.
observation.

Correct Answer: repair of the subscapularis tendon and biceps tenodesis.

Explanation:

DISCUSSION: Dislocation of the long head of the biceps tendon is the result of a defect in the region of the rotator cuff interval, coracohumeral ligament-superior glenohumeral ligament pulley, or an associated tear of the medial insertion of the subscapularis tendon. In the case of an intra-articular dislocation of the long head of the biceps tendon associated with a tear of the subscapularis tendon, stabilization of the biceps tendon is difficult in this situation; therefore, biceps release or tenodesis and repair of the subscapularis tendon is the treatment of choice.
REFERENCES: Eakin CL, Faber KJ, Hawkins RJ, et al: Biceps tendon disorders in athletes.
J Am Acad Orthop Surg 1999;7:300-310.
Sethi N, Wright R, Yamaguchi K: Disorders of the long head of the biceps tendon. J Shoulder Elbow Surg 1999;8:644-654.
Walch G, Boileau P: Subluxations and dislocations of the tendon of the long head of the biceps. J Shoulder Elbow Surg 1998;7:100-108.

Question 45:

What phase of overhead throwing puts the rotator cuff at most risk of injury from internal impingement?

Options:

Wind up
Late cocking
Deceleration
Follow through

Correct Answer: Follow through

Explanation:

Question 46:

Options:

group A Streptococcus.
Methicillin-resistant staphylococcus aureus.
Clostridium.
polymicrobial infection.

Correct Answer: polymicrobial infection.

Explanation:

Question 47:

Options:

pre-debridement cultures.
post-debridement cultures.
neither debridement culture.
anaerobic specimens.

Correct Answer: neither debridement culture.

Explanation:

Question 48:

During spinal deformity surgery, which of the following is the most specific early indicator of an intraoperative injury to the spinal cord? Review Topic

Options:

Somatosensory-evoked potentials
Transcranial motor-evoked potential monitoring
Transcutaneous electroencephalogram neuromonitoring
Stimulus-evoked transpedicular electromyography (EMG)
Brainstem auditory-evoked responses (BAERs)

Correct Answer: Transcranial motor-evoked potential monitoring

Explanation:

Question 49:

What mechanism of injury is most likely to cause a fracture of the anteromedial facet of the coronoid?

Options:

Extension and axial load
Varus and posteromedial rotation
Valgus and posteromedial rotation
Varus and posterolateral rotation
Valgus and posterolateral rotation

Correct Answer: Extension and axial load

Explanation:

The mechanism of injury in a fracture of the anteromedial facet of the coronoid is typically a varus and posteromedial rotation force on the forearm which is the opposite of a terrible triad injury. First, the lateral collateral ligament is injured and then the medial coronoid is compressed against and then under the medial trochlea.
(SBQ12TR.86) Figure A shows intraoperative radiographs of a 45-year-old patient with a left elbow injury. What would be the next most appropriate step in this patients care?
Early range of motion
Hinged elbow brace for 4 weeks
Repair lateral collateral ligament
Remove and upsize implant
Remove and downsize implant
The intraoperative images are consistent with overstuffing of the ulnohumeral joint during a radial head replacement. The most appropriate next step would be removing and downsizing the implant.
Overstuffing the radiohumeral joint by >2.5 mm can significantly alter elbow kinematics. It has also shown to lead to pain and early joint disease. The most sensitive method to assess for overstuffing of the joint is by direct visualisation intraoperatively. This can be performed by visualising the lateral aspect of the ulnohumeral joint when the radial head is resected and comparing this to when the trial radial head is reduced in place. In comparison, radiographic asymmetry of the medial ulnohumeral joint has been shown to be less sensitive. Radiographic findings of incongruity of ulnohumeral joint only occurs when significant overlengthening of the radius occurs.
Frank et al. examined the effect of radial head thickness in seven cadaver specimens. They found that incongruity of the medial ulnohumeral joint would only become apparent radiographically after overlengthening of the radius by >or=6 mm.
Doornberg et al. examined seventeen computed tomography scans of the elbow to investigate the height of the radial head relative to the lateral edge and central ridge of the coronoid process. They found that the radial head was on average only 0.9 mm more proximal than the lateral edge of the coronoid process.
Figure A shows intraoperative radiographs of a patient that has undergone a radial head arthroplasty. There is significant widening of the medial ulnohumeral joint on an AP radiograph as well as widening of the ulnohumeral joint on the lateral radiograph,
Incorrect Answers:

Question 50:

Options:

both a and b
a, b and c

Correct Answer: both a and b

Explanation:

Question 51:

Options:

Chondrolysis
Ischemic necrosis of the femoral head
Ischemic necrosis of the greater trochanter
Femoral neck fracture
Trochanteric overgrowth

Correct Answer: Ischemic necrosis of the femoral head

Explanation:

Question 52:

Options:

Place blocking screws medial and posterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.
Place blocking screws medial and posterior to the nail. Use a nail with a Herzog curve distal to the fracture site.
Place blocking screws lateral and posterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.
Place blocking screws lateral and posterior to the nail. Use a nail with a Herzog curve distal to the fracture site.
Place blocking screws lateral and anterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.

Correct Answer: Place blocking screws medial and posterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.

Explanation:

Question 53:

Options:

Posterior impingement of the os trigonum
Subluxation of the peroneal tendon
Posterior tibial stress fracture
Osteochondritis dissecans of the lateral dome of the talus
Stenosis of the peroneal tendon sheath

Correct Answer: Posterior impingement of the os trigonum

Explanation:

Question 54:

A 72-year-old woman who sustained a cerebrovascular accident 9 months ago now has a fixed elbow flexion contracture of 80 degrees. Management should consist of

Options:

passive physical therapy.
musculocutaneous neurectomy and serial casting.
musculocutaneous nerve block.
lengthening of the biceps tendon.
distraction arthroplasty.

Correct Answer: musculocutaneous neurectomy and serial casting.

Explanation:

Question 55:

Options:

splinting for 1 to 2 weeks, followed by a humeral fracture brace.
intramedullary nailing.
exploration of the radial nerve and intramedullary nailing.
exploration of the radial nerve and a humeral fracture brace.
exploration of the radial nerve and open reduction and internal fixation with plates and screws.

Correct Answer: splinting for 1 to 2 weeks, followed by a humeral fracture brace.

Explanation:

Question 56:

Figure 41 shows the MRI scan of a 38-year-old weightlifter. What does the arrow on the MRI scan indicate? Review Topic

Options:

Biceps tear
Pectoralis minor tear
Pectoralis major tear
Subscapularis tear
Abscess formation

Correct Answer: Pectoralis major tear

Explanation:

Question 57:

Options:

Cast for 2 weeks
Initiate mobilization
Radial head excision
Radial head replacement
Open reduction and internal fixation

Correct Answer: Initiate mobilization

Question 58:

Options:

Cervical C6-7 radiculopathy
Impingement
Rotator cuff tear
Brachial neuritis
Adhesive capsulitis

Correct Answer: Brachial neuritis

Explanation:

Question 59:

Options:

Hallux valgus correction
Custom orthosis to prevent further deformity
Observation only
Steroid injection to decrease inflammation
Extra-depth shoes

Correct Answer: Observation only

Explanation:

Question 60:

Options:

Retain the components, and implant a tibial strut allograft.
Revise the tibial component with a metaphyseal cone and metaphyseal uncemented stem.
Revise the tibial component with a metaphyseal cone and a press-fit diaphyseal-engaging stem.
Revise the tibial component with a long cemented diaphyseal-engaging stem.

Correct Answer: Revise the tibial component with a metaphyseal cone and a press-fit diaphyseal-engaging stem.

Explanation:

Question 61:

Options:

a snug figure-of-8 splint and observation for spontaneous reduction.
closed reduction under general anesthesia.
closed reduction under general anesthesia and percutaneous pinning.
open reduction and capsuloligamentous repair.
open reduction and wire stabilization of the joint.

Correct Answer: closed reduction under general anesthesia.

Explanation:

Question 62:

Options:

Ehlers-Danlos syndrome
Traumatic anterior instability
Humeral head osteonecrosis
Internal impingement
Partial-thickness supraspinatus tear

Correct Answer: Internal impingement

Explanation:

Question 63:

Options:

Guillotine transtibial amputation
Standard transtibial amputation with a posterior myocutaneous flap and immediate prosthetic limb fitting
Culture-specific antibiotic therapy, open wound management, and metabolic/nutritional therapy
Culture-specific antibiotic therapy and Syme ankle disarticulation
Two-stage Syme ankle disarticulation

Correct Answer: Culture-specific antibiotic therapy, open wound management, and metabolic/nutritional therapy

Explanation:

Question 64:

The CT scan reveals a nondisplaced greater trochanteric fracture. The patient is now experiencing severe pain. What is the most appropriate treatment at this time?

Options:

Liner exchange
Revision of the entire acetabular component
Revision of both the femoral and acetabular components
Partial weight-bearing activity for 4 to 6 weeks

Correct Answer: Partial weight-bearing activity for 4 to 6 weeks

Explanation:

Question 65:

A 38-year-old woman fell from a ladder onto her right hip. The radiographs and CT scan are shown in Figures 52a through 52d. What is the best surgical approach for this fracture?

Options:

Kocher-Langenbeck
Iliofemoral
Ilioinguinal
Extended iliofemoral
Triradiate approach

Correct Answer: Ilioinguinal

Explanation:

DISCUSSION: The fracture is an associated both column fracture. The best approach for this fracture is the ilioinguinal. The Kocher-Langenbeck is best for posterior injuries to the acetabulum and some transverse fractures. The iliofemoral alone is limited to high anterior column injuries. The extended iliofemoral and triradiate approaches although useful for this fracture, have a higher rate of complications.
REFERENCES: Letournel E: The treatment of acetabular fractures through the ilioinguinal approach. Clin Orthop Relat Res 1993;292:62-76.
Matta JM: Operative treatment of acetabular fractures through the ilioinguinal approach:
A 10-year perspective. Clin Orthop Relat Res 1994;305:10-19.

Question 66:

Options:

Surgical fixation with percutaneous pins
Surgical fixation with a hemiarthroplasty with tuberosity repair
Surgical fixation with a total shoulder arthroplasty
Sling immobilization for 6 weeks followed by active range of motion
Sling immobilization with daily pendulum exercises

Correct Answer: Surgical fixation with a hemiarthroplasty with tuberosity repair

Explanation:

DISCUSSION: The patient has a displaced four-part proximal humerus fracture. Given her age and the presence of osteopenia, a cemented hemiarthroplasty is the treatment of choice. The glenoid is uninjured so a total shoulder arthroplasty is not indicated. Percutaneous pinning in younger individuals with good bone quality may be indicated but not in an 82-year-old woman with osteopenia. Sling immobilization and immediate pendulum exercises will lead to a nonunion. Sling immobilization for 6 weeks followed by active range of motion will result in a nonunion or malunion with unacceptable functional results.
REFERENCES: Neer CS II: Displaced proximal humeral fractures: I. Classification and evaluation. J Bone Joint Surg Am 1970;52:1077-1089.
Bigliani LU, Flatow EL, Pollock RG: Fractures of the proximal humerus, in Rockwood CA Jr, Matsen FA III (eds): Rockwood and Matsen The Shoulder, ed 2. Philadelphia, PA,
WB Saunders, 1998, pp 352-354.

Question 67:

Options:

A 41-year-old right-hand-dominant man has been treated nonsurgically for right elbow arthritis. His radiographs reveal end-stage ulnohumeral arthritis with complete loss of the joint space. He reports pain during the mid-arc of elbow flexion and extension. During the last 8 years, he has attempted activity modification, medication, physical therapy, and multiple cortisone injections. His symptoms have progressed, resulting in constant pain, loss of a functional range of motion, and an inability to perform many activities of daily living. Secondary to his age and activity demands, he undergoes a soft-tissue interposition arthroplasty of his elbow with an Achilles allograft. Which presurgical finding correlates with elevated risk for postsurgical complications?
Inflammatory elbow arthritis
A presurgical flexion-extension elbow arc of approximately 50°
Retained distal humerus hardware on presurgical radiographs
Evidence of presurgical elbow instability End-stage posttraumatic or inflammatory elbow arthritis in active, high-demand patients remains difficult to treat. Traditional total elbow arthroplasty is discouraged in this demographic secondary to concerns about implant longevity. Soft-tissue interposition arthroplasty does not necessitate the same activity and weight restrictions for patients after surgery and remains a reasonable salvage procedure. Larson and Morrey published their findings on 38 patients with a mean age of 39 years following soft-tissue interposition arthroplasty for posttraumatic and inflammatory end-stage elbow arthritis. These investigators reported a significant improvement in Mayo Elbow Performance Score in addition to improvement in the flexion-extension arc from 51° to 97° after surgery. They reported worse results and elevated incidence of complications for patients with presurgical elbow instability. Retained hardware from prior surgery was not deemed a contraindication.

Correct Answer: Inflammatory elbow arthritis

Explanation:

Figure 1 is the radiograph of a 12-year-old baseball player who has posterolateral elbow pain with throwing. The area of interest is designated by the black arrow. His range of motion and strength are full. No previous treatment has been provided. What is the most appropriate initial treatment?
Elbow arthroscopy with debridement
Immobilization and rest for 6 weeks
Corticosteroid injection
Open osteochondral autograft transfer
Osteochondritis dissecans of the capitellum is a painful condition that affects immature athletes who undergo repetitive compression of the radiocapitellar joint. Management is based primarily on the integrity of the articular cartilage surface and the stability of the lesion. Nonsurgical treatment is typically selected for patients
with early-grade, stable lesions, and it involves activity modification with cessation of sports participation. The duration of activity modification is dictated by symptoms, with 3 to 6 weeks of rest followed by return to sport in 3 to 6 months commonly used as a guideline. Strengthening and stretching exercises are commonly incorporated after the pain has subsided. Surgical intervention or corticosteroid injection would not be first-line treatment.
Figures 1 and 2 are the radiographs of a 69-year-old man with a history of treated prostate cancer and hemodialysis-dependent end- stage renal disease who presents to the emergency department with progressively worsening right shoulder pain and stiffness. Laboratory tests reveal a white blood cell count of 17,000, erythrocyte sedimentation rate, 75, and CRP, 10.1. He has a draining sinus located along the anterior shoulder. What is the best next step?

Question 68:

What portion of the pitching phase creates forces approaching the tensile limit of the medial collateral ligament?

Options:

Early cocking phase
Late cocking phase
Early acceleration phase
Follow-through phase
Deceleration phase

Correct Answer: Late cocking phase

Explanation:

Question 69:

Venous thromboembolism may occur after total joint arthroplasty. The risk of this complication is elevated in patients with

Options:

a BMI lower than 30.
diabetes mellitus, with a hemoglobin A1c test result less than 7.
tranexamic acid use.
metabolic syndrome.

Correct Answer: metabolic syndrome.

Explanation:

Question 70:

Options:

Arthroscopic superior labrum anterior to superior repair
Arthroscopic Bankart repair
Latarjet procedure
Capsulorrhaphy

Correct Answer: Capsulorrhaphy

Explanation:

DISCUSSION
Nonsurgical treatment with activity modification and physical therapy is generally considered the first-line approach for young athletes with multidirectional instability (MDI) of the shoulder. Physical therapy focuses on exercises to strengthen the scapular stabilizers and rotator cuff muscles and restore scapulohumeral rhythm. Although a definitive length of time
to assess physical therapy failure is not known, many surgeons believe that a patient with MDI should undergo at least 6 months of physical therapy and activity modification before considering surgery. Although an open inferior capsular shift has historically been considered the gold standard for surgical treatment for MDI, studies have shown good success rates for arthroscopic capsulorrhaphy. Arthroscopy can allow a surgeon to assess all intra-articular structures and address a patient’s particular problem based on arthroscopic findings.
CLINICAL SITUATION FOR QUESTIONS 21 THROUGH 25
A 19-year-old collegiate offensive lineman injures his left elbow in a scrimmage. He reports reaching out with his left arm to prevent the defensive player from getting around him, and, as he grabbed the player, his elbow was forced into extension. He had immediate pain and weakness and heard a “pop.” He has mild swelling in the antecubital fossa and a prominent-appearing biceps muscle belly. His hook test result is abnormal at the elbow.

Question 71:

Options:

Quicker return to activities
Quicker return to work
Increased subtalar joint range of motion
Decreased risk of nonunion
Decreased risk of posttraumatic arthritis

Correct Answer: Decreased risk of posttraumatic arthritis

Explanation:

DISCUSSION: The radiographs and CT scans show a displaced intra-articular calcaneal fracture, with loss of calcaneal height and length. Recent multicenter, randomized, prospective studies suggest that surgical treatment of displaced intra-articular calcaneal fractures is associated with an almost six-fold decrease in the risk of posttraumatic subtalar arthritis (necessitating subtalar arthrodesis) compared to nonsurgical treatment. Despite ongoing controversy, surgical treatment has not been shown to be advantageous with respect to activity, time to return to work, or subtalar joint range of motion. A nonunion of a calcaneal fracture is exceedingly rare regardless of the treatment method.
REFERENCES: Buckley R, Tough S, McCormack R, et al: Operative compared with nonoperative treatment of displaced intra-articular calcaneal fractures: A prospective, randomized, controlled multicenter trial. J Bone Joint Surg Am 2002;84:1733-1744.
Csizy M, Buckley R, Tough S, et al: Displaced intra-articular calcaneal fractures: Variables predicting late subtalar fusion. J Orthop Trauma 2003;17:106-112.

Question 72:

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

Options:

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

Correct Answer: greater direct costs.

Explanation:

Question 73:

What is the most common foot and ankle deformity in patients with arthrogryposis?

Options:

Talipes eqinovarus
Metatarsus adductus
Brachymetatarsia
Pes planus
Tarsal coalition

Correct Answer: Talipes eqinovarus

Explanation:

Question 74:

An extended head hemiarthroplasty (rotator cuff tear arthropathy head) has what theoretic advantage when compared to a standard hemiarthroplasty?

Options:

Improved superior stability
Fixed fulcrum kinematics
Creates a metal-to-bone articulation with the acromion
Increased deltoid moment arm
Increased glenohumeral offset

Correct Answer: Creates a metal-to-bone articulation with the acromion

Explanation:

DISCUSSION: The theoretic advantage of a metal-to-bone articulation with the acromion is that there is a greater arc in which a smooth metal surface contacts the glenoid and acromion. This may improve pain and function, but no studies have evaluated this to date. One study showed results comparable to that of a standard hemiarthroplasty. There are no other biomechanic advantages.
REFERENCES: Visotsky JL, Basamania C, Seebauer L, et al: Cuff tear arthropathy: Pathogenesis, classification, and algorithm for treatment. J Bone Joint Surg Am 2004;86:35-40.
Zuckerman JD, Scott AJ, Gallagher MA: Hemiarthroplasty for cuff tear arthropathy. J Shoulder Elbow Surg 2000;9:169-172.

Question 75:

Which of the following factors is most critical to the success of a meniscal allograft transplantation?

Options:

Accurate graft size
Donor cell viability
Reestablishment of the central meniscal blood supply
Suppression of the immune response
Cryopreservation of the donor graft

Correct Answer: Accurate graft size

Explanation:

Question 76:

Options:

Initiation of spinal cord injury steroid protocol
MRI of the lumbar spine
Immobilization in a thoracolumbosacral orthosis
Removal of the metallic fragments via laminectomy
Removal of the metallic fragments and posterior fusion with instrumentation

Correct Answer: Removal of the metallic fragments via laminectomy

Explanation:

DISCUSSION: Because the patient has an apparent compressive neuropathy secondary to the metallic fragments, removal of the fragments in this incomplete lesion at the cauda equina level can be expected to improve her sensory dysesthesias and pain. Steroids are not indicated in a root lesion secondary to a penetrating injury. MRI will have significant artifact effect and will not provide much additional information. The posterior bony elements are not significantly injured; therefore, stabilization is not indicated.
REFERENCES: Bracken MB, Shepard MJ, Holford TR: Administration of methylprednisolone for 24 or 48 hours or tirilazad mesylate for 48 hours in the treatment of acute spinal cord injury. JAMA 1997;277:1597-1604.
Waters RL, Adkins RH: The effects of removal of bullet fragments retained in the spinal canal: A collaborative study by the National Spinal Cord Injury Model Systems. Spine
1991;16:934-939.
Stauffer ES, Wood RW, Kelly EG: Gunshot wounds of the spine: The effects of laminectomy.
J Bone Joint Surg Am 1979;61:389-392.

Question 77:

The condition seen in Figure 60 is attributable to

Options:

- improper nail placement.
- wrong implant choice.
- patient noncompliance.
- radius of the curvature of the implant.

Correct Answer: - radius of the curvature of the implant.

Explanation:

Question 78:

The radiograph shown in Figure 54 reveals that the plate on the second metacarpal is acting in what manner?

Options:

Compression plate
Tension band plate
Bridge plate
Buttress plate
Spring plate

Correct Answer: Bridge plate

Explanation:

DISCUSSION: There are four ways in which a plate acts: compression, tension bend, bridge or spanning, and buttress. Since there is no cortical contact with the large span of comminution, this plate is acting as a bridge plate. A bridge plate is defined as when the plate is used as an extramedullary splint attached to the two main fragments, leaving the comminution untouched.
REFERENCE: Ruedi T, Murphy WM (eds): AO Principles of Fracture Management. New York, NY, Thieme, 2000, p 221.

Question 79:

Options:

Short leg cast with no weight bearing for the first 3 weeks
Short leg cast with immediate weight bearing
Long leg cast with no weight bearing for the first 3 weeks
Open reduction and internal fixation, avoiding the physeal growth plate and joint
CAM walker with immediate weight bearing

Correct Answer: Open reduction and internal fixation, avoiding the physeal growth plate and joint

Explanation:

Question 80:

Options:

Physical therapy for quadriceps strengthening
Functional bracing
Anterior cruciate ligament (ACL) reconstruction
Revision reconstruction of the LCL and posterolateral corner
Valgus-producing high tibial osteotomy (HTO)

Correct Answer: Valgus-producing high tibial osteotomy (HTO)

Explanation:

Question 81:

Figures 35a through 35c show the clinical photograph and radiographs of a 15-year-old boy who stubbed his toe 1 day ago while walking barefoot in the yard. Management should consist of

Options:

buddy taping of the great toe to the second toe for 3 weeks and use of a hard-soled shoe.
buddy taping of the great toe to the second toe for 3 weeks and application of a short leg cast.
buddy taping of the great toe to the second toe for 3 weeks, use of a hard-soled shoe, and a short course of antibiotics.
nail removal in the emergency department, buddy taping of the great toe to the second toe for 3 weeks, and use of a hard-soled shoe.
irrigation and open reduction, with or without fixation, and a short course of antibiotics.

Correct Answer: irrigation and open reduction, with or without fixation, and a short course of antibiotics.

Explanation:

DISCUSSION: The patient has an open fracture of the physis of the distal phalanx with a portion of the nail bed interposed in the physis. Seymour initially described this injury in the distal phalanges of fingers. Optimal treatment consists of removing the interposed tissue, irrigating the fracture, and a short course of antibiotics. The nail should be preserved to provide stability.
REFERENCES: Kensinger DR, Guille JT, Horn BD, et al: The stubbed great toe: Importance of early recognition and treatment of open fractures of the distal phalanx. J Pediatr Orthop 2001;21:31-34.
Pinckney LE, Currarino G, Kennedy LA: The stubbed great toe: A cause of occult compound fracture and infection. Radiology 1981;138:375-377.
Seymour N: Juxta-epiphysial fracture of the terminal phalanx of the finger. J Bone Joint Surg Br 1966;48:347-349.

Question 82:

Patient-specific instrumentation (PSI) reliably demonstrates which benefit over conventional intramedullary guidance systems?

Options:

Lower cost
Improved functional outcomes
Better coronal alignment
Fewer trays

Correct Answer: Fewer trays

Explanation:

Question 83:

Options:

MRI
Doppler arterial study
Arteriography
Electromyography
Triple phase bone scan (technetium Tc 99m)

Correct Answer: Doppler arterial study

Explanation:

Question 84:

Options:

Increased wettability
Increased hardness
Increased fracture toughness
Decreased surface roughness
Lower coefficient of friction

Correct Answer: Increased fracture toughness

Explanation:

DISCUSSION: Alternative bearing surfaces in THA have received much attention in recent years as more and more hip arthroplasties are being performed on younger patients with hip arthritis. The two most popular nonmetal-on-polyethylene bearing surfaces are metal-on-metal and ceramic-on-ceramic. There are arguments supporting the use of either, but ceramic bearings have been shown to have a theoretic increased risk of fracture compared with cobalt-chromium. This has been shown to be clinically relevant with zirconium ceramics. Newer alumina ceramics are being produced with lower porosity and grain size and with higher density and purity, resulting in lower fracture risk but still greater than that of cobalt-chromium.
REFERENCES: Heisel C, Silva M, Schmalzried TP: Bearing surface options for total hip replacement in young patients. Instr Course Lect 2004;53:49-65.
D’Antonio J, Capello W, Manley M, et al: New experience with alumina-on-alumina ceramic bearings for total hip arthroplasty. J Arthroplasty 2002;17:390-397.

Question 85:

Based on the findings shown in Figures 22a and 22b, corrective surgery to obtain maximal safe correction and optimal instrumentation fixation should be performed at which of the following locations?

Options:

Lower cervical spine
Midthoracic spine
Thoracolumbar junction
Midlumbar spine
Lumbosacral junction

Correct Answer: Midlumbar spine

Explanation:

Question 86:

Options:

Nonsteroidal anti-inflammatory drugs
MRI of the spine
CT myelography
Flexion-extension plain films

Correct Answer: MRI of the spine

Explanation:

DISCUSSION
Patients with ankylosing spondylitis are at high risk for occult fractures after low-energy injuries. Although radiographs and a CT scan do not demonstrate a spinal fracture in this patient, high risk for an unstable occult fracture necessitates further imaging with MRI to ensure that no fractures are missed. Although a CT scan is typically the primary imaging modality for workup of spine injuries in similar patients, CT and MRI complement each other and each detects fractures that are missed using the other modality. A CT myelogram might detect cord or root compression but would not aid in the diagnosis of an occult fracture. Nonsteroidal anti-inflammatory drugs are first-line treatment for idiopathic low-back pain. In a patient with ankylosing spondylitis at high risk for fracture, further workup is needed to rule out an occult fracture. Flexion and extension radiographs of the spine are inferior to MRI for evaluating occult fractures and ligamentous injuries. The primary concern for this patient remains an unstable spinal fracture, which necessitates an MRI of the spine before initiating a workup for other possible causes of his back pain.
RECOMMENDED READINGS
Duane TM, Cross J, Scarcella N, Wolfe LG, Mayglothling J, Aboutanos MB, Whelan JF, Malhotra AK, Ivatury RR. Flexion-extension cervical spine plain films compared with MRI in the diagnosis of ligamentous injury. Am Surg. 2010 Jun;76(6):595-8. PubMed PMID: 20583514.
View Abstract at PubMed
Hitchon PW, From AM, Brenton MD, Glaser JA, Torner JC. Fractures of the thoracolumbar spine complicating ankylosing spondylitis. J Neurosurg. 2002 Sep;97(2 Suppl):218-22. PubMed PMID: 12296682.
View Abstract at PubMed
Koivikko MP, Koskinen SK. MRI of cervical spine injuries complicating ankylosing spondylitis. Skeletal Radiol. 2008 Sep;37(9):813-9. doi: 10.1007/s00256-008-0484-x. Epub 2008 Apr

Question 87:

- A high school distance runner reports a 3-week history of heel pain while running. Examination elicits no pain with dorsiflexion or with palpitation of the plantar fascia; however, pain is evident with palpitation over the muscular origin of the abductor hallucis. What is the most likely etiology of the pain?

Options:

Heel spur
Plantar fascitis
Dysfunction of the tibialis posterior tendon
Compression of the first branch of the lateral plantar nerve
Compression of the calcaneal nerve

Correct Answer: Compression of the first branch of the lateral plantar nerve

Explanation:

Question 88:

Which of the following factors is most commonly associated with mechanical failure of a cemented total hip arthroplasty?

Options:

Increased stem offset
Varus position of the stem
Osteoporotic bone
Patient weight of greater than 154 lb
Gender

Correct Answer: Varus position of the stem

Explanation:

Question 89:

During primary total knee arthroplasty, what is the maximum distance the joint line can be raised or lowered before poor motion, joint instability, and increased chance of revision occur?

Options:

4 mm
8 mm
12 mm
16 mm
20 mm

Correct Answer: 8 mm

Explanation:

Question 90:

Options:

Tension pneumothorax
Inadvertent epidural injection
Inadvertent intravascular injection
Laryngeal nerve block
Bezold-Jarisch reflex

Correct Answer: Bezold-Jarisch reflex

Explanation:

Question 91:

Treatment of an atrophic nonunion of the radial diaphysis should include which of the following?

Options:

Ilizarov fixation
Electrical stimulation
Ultrasound bone stimulator
Plate exchange with autogenous cancellous grafting
Plate exchange with ulnar shortening osteotomy

Correct Answer: Ilizarov fixation

Explanation:

Question 92:

What complication is more likely following excessive medial retraction of the anterior covering structures during the anterolateral (Watson-Jones) approach to the hip?

Options:

Numbness over the anterolateral thigh
Ischemia to the leg
Quadriceps weakness
Abductor insufficiency
Foot drop

Correct Answer: Quadriceps weakness

Explanation:

DISCUSSION: The femoral nerve is the most lateral structure in the anterior neurovascular bundle. The femoral artery and vein lie medial to the nerve. Retractors placed in the anterior acetabular lip should be safe, although neurapraxia of the femoral nerve may occur if retraction is prolonged or forceful leading to quadriceps weakness. The femoral artery and nerve are well protected by the interposed psoas muscle. Damage to the lateral femoral cutaneous nerve, causing numbness over the anterolateral thigh, can occur while developing the interval between the tensor fascia latae and sartorious in the anterior (Smith-Petersen) approach but less likely in the Watson-Jones approach. Superior gluteal injury and accompanying abductor insufficiency may occur during excessive splitting of the glutei during the direct lateral (Hardinge) approach. Foot drop secondary to sciatic injury is more common with a posterior exposure or posterior retractor placement.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, p 325.
Anderson JE: Grant’s Atlas of Anatomy, ed 7. Baltimore, MD, Lippincott Williams & Wilkins, 1978, pp 4-17, 4-18.

Question 93:

Options:

Aneurysmal bone cyst
Giant cell tumor
Renal cell carcinoma
Osteomyelitis
Brown tumor

Correct Answer: Giant cell tumor

Explanation:

Question 94:

03 Which of the following findings is one of the diagnostic criteria for diffuse idiopathic skeletal hyperostosis?

Options:

Flowing ossification along the anterolateral aspect of at least four contiguous vertebrae
Disk space collapse in the involved vertebral segments
Marginal syndesmophytes over four contiguous vertebrae
Sacroiliac erosion or sclerosis
Facet joint ankylosis Question 64.03

Correct Answer: Flowing ossification along the anterolateral aspect of at least four contiguous vertebrae

Explanation:

Question 95:

A 13-year-old girl is diagnosed with a stage IIB osteosarcoma of the proximal tibia. Following neoadjuvant chemotherapy, local control should consist of

Options:

wide resection and reconstruction.
wide resection and radiation therapy.
radiation therapy.
curettage and bone grafting.
observation.

Correct Answer: wide resection and reconstruction.

Explanation:

Question 96:

Options:

Deltoid
Supraspinatus
Subscapularis Infraspinatus
Infraspinatus
Infraspinatus and teres minor

Correct Answer: Infraspinatus

Explanation:

Question 97:

Options:

MRI scan of the knee
CT scan of the distal femur
Application of a long-leg cast
Arteriogram of the extremity
Reduction and fixation of the fracture

Correct Answer: Reduction and fixation of the fracture

Explanation:

Question 98:

What is the most likely complication after surgical treatment in this scenario?

Options:

Recurrent instability
Degenerative joint disease
Shoulder stiffness
Axillary nerve injury

Correct Answer: Shoulder stiffness

Explanation:

Question 99:

Options:

Prophylactic stabilization with an intramedullary rod
Radiation therapy alone
Embolization alone
Wide resection and prosthetic reconstruction
Prophylactic stabilization with a locking plate and polymethylmethacrylate cement

Correct Answer: Wide resection and prosthetic reconstruction

Explanation:

DISCUSSION: Resection and reconstruction of this very proximal lesion provides the best chance to avoid hardware complications that may be associated with stabilization procedures. Wide resection of isolated renal cell carcinoma metastasis, which presents distant to the nephrectomy, may improve long-term survival.
REFERENCES: Fuchs B, Trousdale RT, Rock MG: Solitary bony metastasis from renal cell carcinoma: Significance of surgical treatment. Clin Orthop Relat Res 2005;431:187-192.
Jung ST, Ghert MA, Harrelson JM, et al: Treatment of osseous metastases in patients with renal cell carcinoma. Clin Orthop Relat Res 2003;409:223-231.

Question 100:

Options:

Sedentary job
Sanders IIb fractures
Women
Younger age (<29 years old)
Previous calcaneus fracture

Correct Answer: Sedentary job

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

OITE & ABOS Orthopedic Board Prep: Spine, Hand & Knee Arthroplasty MCQs | Part 260

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 260

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index