Orthopedic Board Prep MCQs: Arthroplasty, Trauma & Oncology

About This Board Review Set

This is Part 72 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 72

This module focuses heavily on: Arthroplasty, Fracture, Knee, Revision, Tumor.

Sample Questions from This Set

Sample Question 1: At the time of revision total knee arthroplasty, the surgeon is trialing the knee and finds that it extends fully and is stable in flexion with a 23-mm trial spacer; however, the patella is impinging on the polyethylene spacer. No augments ...

Sample Question 2: A patient undergoes excision of a 3- x 3-cm soft-tissue sarcoma. The final histology results show tumor at the surgical margin. The surgical procedure performed is classified as...

Sample Question 3: A 68-year-old woman undergoes hemiarthroplasty for a proximal humerus fracture. What post-operative motion should be limited as it puts the most stress on the lesser tuberosity fragment fixation?...

Sample Question 4: -A 39-year-old woman jammed her long finger playing softball 24 hours ago. She is unable to actively extend the proximal interphalangeal joint; however, when the joint is brought passively into full extension, she is able to maintain that p...

Sample Question 5: What term best describes the process involved when a growth factor produced by an osteoblast stimulates the differentiation of an adjacent undifferentiated mesenchymal cell during fracture repair?...

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

At the time of revision total knee arthroplasty, the surgeon is trialing the knee and finds that it extends fully and is stable in flexion with a 23-mm trial spacer; however, the patella is impinging on the polyethylene spacer. No augments were used on the femur or the tibia because the components fit well without them. What is the most appropriate action at this time?

Explanation

DISCUSSION: The surgeon in this case is faced with a common scenario at the time of revision total knee arthroplasty and the tendency is to elevate the joint line. Elevation of the joint line is associated with deleterious effects including anterior knee pain, restricted knee flexion, and instability. The error that has been made is resting the femoral component on the bone that is left behind after removal of the prior component; this typically leads to a femoral component that is too small (leading to an enlarged flexion gap) and proximal to where it should be (enlarging the extension gap). Although the flexion and extension gaps are equivalent, joint line elevation has occurred. To correct this problem, the femoral component size should be increased or offset posteriorly (to decrease the size of the flexion gap) and distal femoral augments should be used to decrease the size of the extension gap and restore the joint line to the appropriate level.
REFERENCES: Laskin RS: Joint line position restoration during revision total knee replacement. Clin Orthop Relat Res 2002;404:169-171.
Yoshii I, Whiteside LA, White SE, et al: Influence of prosthetic joint line position on knee kinematics and patellar position. J Arthroplasty 1991;6:169-177.
Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction
Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 123-145. Question 100
A 68-year-old woman is undergoing a cementless medial/lateral tapered femoral placement during a total hip arthroplasty and the surgeon notices a small crack forming in the anteromedial femoral neck with final implant insertion. The most appropriate management should include which of the following?
Placement of a cerclage cable around the femoral neck above the lesser trochanter
Removal of the implant, placement of a cable around the femoral neck above the lesser trochanter, and reinsertion of the implant
Removal of the press-fit implant and cementing of the same femoral stem
Final seating of the cementless femoral component without additional measures
Removal of the cementless femoral component and placement of a revision modular taper- fluted femoral stem
DISCUSSION: The recognized treatment of the proximal periprosthetic fracture is first to identify its extent and then to optimize the correction. Removing the implant seems logical to accomplish the identification. Several studies indicate that proximal cerclage wiring is adequate to create a “barrel hoop” stability of the proxima l femur. The postoperative management may also include protected weight bearing and periodic radiographs.
REFERENCES: Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 475503.
Warren PJ, Thompson P, Fletcher MD: Transfemoral implantation of the Wagner SL stem: The abolition of
subsidence and enhancement of osteotomy union rate using Dall-Miles cables. Arch Orthop Trauma Surg 2002;122:557-560.
Your Source for Lifelong Orthopaedic Learning

Question 2

A patient undergoes excision of a 3- x 3-cm soft-tissue sarcoma. The final histology results show tumor at the surgical margin. The surgical procedure performed is classified as

Explanation

DISCUSSION: Surgical margins are classified according to the plane of dissection in relation to the tumor. An intralesional procedure is where the plane of dissection passes through the tumor. A marginal resection involves a resection where the plane of dissection is through the reactive zone of the tumor. A wide resection is through completely normal tissue outside of the reactive zone. A radical resection removes all of the muscles and/or bone of the compartment that are involved by the tumor.
REFERENCE: Enneking WF, Spanier SS, Goodman MA: A system for the surgical staging of musculoskeletal sarcoma. Clin Orthop 1980;153:106-120.

Question 3

A 68-year-old woman undergoes hemiarthroplasty for a proximal humerus fracture. What post-operative motion should be limited as it puts the most stress on the lesser tuberosity fragment fixation?

Explanation

DISCUSSION: Frankle et al found that passive external rotation of the shoulder placed the most stress on the lesser tuberosity fixation. The subscapularis tendon inserts on the lesser tuberosity and is the deforming force when placed under tension during external rotation. They also found that non-anatomic tuberosity reduction of 4-part proximal humerus fractures treated with hemiarthroplasty increased torque and impaired external rotation kinematics.

Question 4

A 39-year-old woman jammed her long finger playing softball 24 hours ago. She is unable to actively extend the proximal interphalangeal joint; however, when the joint is brought passively into full extension, she is able to maintain that position. Management should consist of

Explanation

Disruption of the central slip of the extensor tendon at the PIP joint with volar migration of the lateral bands will result in the so-called boutonniere deformity, which includes loss of extension at the PIP joint and compensatory hyperextension at the DIP joint. The lesion is most often secondary to closed blunt trauma with acute forceful flexion at the PIP joint. This produces avulsion of the central slip from its insertion on the dorsal base of the middle phalanx with or without fracture and/or laceration of the extensor tendon at its insertion. In closed injuries the characteristic boutonniere deformity may not be apparent at the time of injury and may not be noted until 10 to 21 days after injury. Two diagnostic tests that are useful in early recognition of this lesion are: (1) a 15 deg to 20 deg or greater loss of active extension of the PIP joint when the wrist and MP joint are fully flexed and (2) extravasation of intraarticular radiopaque dye dorsal and distal to the PIP joint. Weak extension against resistance has also been noted to be a helpful diagnostic finding. Treatment in acute cases before fixed contractures have occurred may be achieved by progressively splinting the PIP joint into full extension and at the same time performing active and passive flexion exercises of the DIP joint. In a closed boutonniere deformity operative intervention is indicated under two circumstances. (1) when the central slip has been avulsed with a bone fragment which is lying free over the PIP joint and (2) a long-standing boutonniere deformity in a young person.

Question 5

What term best describes the process involved when a growth factor produced by an osteoblast stimulates the differentiation of an adjacent undifferentiated mesenchymal cell during fracture repair?

Explanation

DISCUSSION: Growth factors are proteins secreted by cells that can act on target cells to produce certain biologic actions. These actions can be described as autocrine, paracrine, and endocrine. Autocrine actions are those in which the growth factor influences an adjacent cell of its origin or identical phenotype. Paracrine actions are those in which the protein influences an adjacent cell that is different in its origin or phenotype. Endocrine actions are those in which the factor influences a cell located at a distant anatomic site.
REFERENCES: Lieberman J, Daluiski A, Einhorn TA: The role of growth factors in the repair of bone: Biology and clinical applications. J Bone Joint Surg Am 2002;84:1032-1044.
Zuscik MJ, Drissi MH, Reynolds PR, et al: Molecular and cell biology in orthopaedics, in Einhorn TA, O’Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006,

in press.

Question 6

Which of the following is considered the most useful screening method for the evaluation of protective foot sensation in a patient with diabetes mellitus?

Explanation

DISCUSSION: Patients with diabetes mellitus should be screened for the presence of protective foot sensation. In the absence of protective foot sensation, patients are at increased risk for the development of neuropathic ulcerations and neuropathic arthropathy. The most reliable screening tool for the presence of protective sensation is the ability to feel the 5.07 Semmes-Weinstein monofilament.
REFERENCES: Pinzur MS, Shields N, Trepman E, Dawson P, Evans A: Current practice patterns in the treatment of Charcot foot. Foot Ankle Int 2000;21:916-920.
Smith KD, Emerzian GJ, Petrov O: A comparison of calibrated and non-calibrated 5.07 nylon monofilaments. Foot Ankle Int 2000;21:852-855.

Question 7

An 80-year-old African American woman who lives in a large city is scheduled for total hip arthroplasty to address primary osteoarthritis. Part of the presurgical protocol includes nasal swab screening to assess for methicillin-resistant Staphylococcus aureus (MRSA) colonization. Which demographic factor places this patient at highest risk for a positive result?

Explanation

DISCUSSION:
Demographic factors are associated with increased risk for MRSA colonization, so it is important to identify vulnerable patients. Female gender and advanced age reduce the risk for colonization, whereas African American race increases this risk. Urban environments do not influence MRSA colonization.

Question 8

A patient has pain 2 years after undergoing a metal-on-metal (MOM) left total hip arthroplasty (THA). Which test(s) best correlate with prognosis in the setting of reaction to metal debris?

Explanation

Figures 1 and 2 are the recent radiographs of an 82-year-old man with rheumatoid arthritis who underwent total knee arthroplasty (TKA) 18 years ago. These radiographs reveal osteolysis with loosening of the tibial component. Aspiration and laboratory study findings for infection are negative. During the revision TKA, treatment of tibial bone loss should consist of

Question 9

Which of the following statements regarding conus medullaris syndrome is most accurate?

Explanation

DISCUSSION: Conus medullaris syndrome most frequently occurs as a result of trauma or with a disk herniation at L1, resulting in a lower motor neuron syndrome but with a poor prognosis for recovery of bowel and bladder dysfunction. The conus region, as the termination of the spinal cord, contains the motor cell bodies of the sacral roots. The syndrome is usually a sacral level neural injury; therefore, lower extremity weakness is uncommon.
REFERENCES: Haher TR, Felmly WT, O’Brien M: Thoracic and lumbar fractures: Diagnosis and management, in Bridwell KH, Dewald RL, Hammerberg KW, et al (eds): The Textbook of Spinal Surgery, ed 2. New York, NY, Lippincott Williams & Wilkins, 1977, pp 1773-1778.
Reitman CA (ed): Management of Thoracolumbar Fractures. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 35-45.

Question 10

A 45-year-old man reports a history of a popping sensation and pain in the right shoulder while lifting boxes 6 months ago. The pain has persisted with loss of motion of the shoulder. Radiographs and MRI scans are shown in Figures 47a through 47d. Which of the following studies is likely to produce a significant positive result? Review Topic

Explanation

The patient has a neuropathic joint secondary to syringomyelia that can be seen on a cervical MRI scan. The patient sustained minimal trauma that lead to a chronic anterior glenohumeral dislocation. He did not seek treatment for several months and has a massive rotator cuff tear and hygroma on MRI in addition to the chronic dislocation. Rheumatoid arthritis does not present with a neuropathic picture, except theoretically as the result of numerous intra-articular cortisone injections. This Charcot picture is inconsistent with ankylosing spondylitis or gout. Cannabis use is not typically associated with seizures that could produce anterior as well as posterior shoulder dislocations.

Question 11

Synovitis of the MTP joints with eventual hyperextension deformity of the MTP is a common toe deformity seen with RA.

Explanation

Polymorphisms in the genes for the calcitonin receptor, estrogen receptor-1, vitamin D receptor, and the type I collagen alpha-1 chain (along with over 45 other genes) have been shown to be associated with osteoporosis. Answer 5, Cartilage oligomeric matrix protein, shows no current association with osteoporosis, but is the known genetic mutation associated with multiple epiphyseal dysplasia (a frequently tested fact). No single cause for osteoporosis has been shown at this point in time.
Jin et al conducted a meta-analysis regarding polymorphisms in the 5' flank of COL1A1 gene and the conflicting results relating to osteoporosis. They found that the COL1A1 Sp1 polymorphism is associated with a modest reduction in BMD and an increased risk of fracture.
The attached review by Huang and Kung discusses the multiple genetic and environmental determinants of osteoporosis and illustration A (from a different review by these same authors) lists the known genes currently associated with osteoporosis.
The greatest biomechanical difference between unicortical and bicortical locking screws is seen when what force is applied?
Compression
Torsion
Distraction
Bending on the side of the plate
Bending on the surface perpendicular to the plate
Torsion force has the largest biomechanical difference between unicortical locked screws and bicortical locked screws.
The first referenced article by Roberts et al noted that by replacing the farthest unicortical
screws (3 per side of the fracture) with bicortical locking screws, torsion resistance was increased by over 50%.
The second referenced article by Fulkerson et al noted decreased resistance to all applied forces with unicortical screws in a comminuted fracture model, and recommended against their use in such a fracture.

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You are planning surgery on a 54-year-old female with the tibial plateau fracture seen in figures A and B. After reduction of the joint surface you plan to fill the void with a bone-graft substitute to prevent joint collapse. Which of the following bone-graft substitutes
disappears most quickly in vivo?
Collagen-based matrices
Calcium phosphate
Calcium sulfate
Synthetic calcium sulfate and tri-phosphate mixture
Coraline hydroxyapatite
Calcium sulfate disappears in vivo quickly, usually within 4-12 weeks. Calcium phosphate and coraline hydroxyapatite are resorbed slowly, somewhere between 1-10 years, depending on the manufacturer. Synthetics that combine calcium sulfate and phosphate
resorb quicker than calcium phosphate but slower than calcium sulfate. Collagen-based matrices show quick resorption of the collegen but slow resorption of their hydroxyapatite coating. Walsh et al. examined the in vivo response of calcium sulfate pellets alone or in combination with autogenous bone graft in a sheep model. They found excellent bone formation in defects filled with calcium sulfate pellets. Immunostaining for various cytokines (BMP-2, BMP-7, PDGF, or TGF-beta)
showed elevated levels in the newly formed bone. They proposed that the local environment acidity was responsible for breakdown of the calcium sulfate. Watson evaluated 8 patients with comminuted tibial metaphyseal fractures treated with an injectable calcium sulfate. They found that bone regrowth was observed in all patients and the bone substitute almost completely resorbed by
months. Bucholz reviewed the biochemical, biomechanical, and longevity characteristics of the common bone substitutes.
Which of the following Figures shows a fixation construct achieving absolute stability?
Figure A shows percutaneous pinning, Figure B shows locked bridge plating, Figure C shows intramedullary nailing, Figure D shows lag fixation and neutralization plating, and Figure E shows external fixation. All except Figure D show relative stability constructs.
Absolute stability is a construct seen in Figure D, where lag screws and a neutralization plate are shown in a postoperative clavicle. No micromotion is seen with this technique, and healing is by primary (Haversian) healing, as opposed to the other four constructs, which have relative stability and heal via callus formation. The first reference, the AO Principles textbook, covers this in depth.
The second reference by Claes et al notes that bone can still heal with bone (as opposed to fibrous union) with strain rates up to 15%.
Which immunoglobulin subtype does the rheumatoid factor target?
IgA
IgE
IgM
IgG
Rheumatoid factor does not target an immunoglobulin
Rheumatoid factor is an auto-antibody most commonly seen with rheumatoid arthritis. The presence of rheumatoid factor can also indicate generalized autoimmune activity unrelated to rheumatoid arthritis (e.g. tissue or organ rejection). Rheumatoid factor is itself an IgM antibody that is directed against the Fc portion of IgG antibody. Rheumatoid factor (IgM) attaches to IgG to form immune complexes which are deposited in tissues like the kidney and contribute to the overall disease process in rheumatoid arthritis.
James et al. assessed the occurrence and predictive factors for orthopaedic surgery in an cohort of patients with rheumatoid arthritis. Risk factors for surgery varied but the authors found that decreased inflammatory markers during the first year after diagnosis decreased the risk for subsequent surgery.
The positive predictive value is defined as which of the following?
True positives / (true positives + true negatives)
False negatives / (false negatives + true positives)
False positives / (false positives + false negatives)
(True positives + false positives) / (true negatives + false negatives)
True positives / (true positives + false positives) Corrent answer: 5
The positive predictive value is defined as the true positives divided by the sum of the positive results (true positive and false positive). It is also defined as the probability that a patient with a positive test actually has the disease; it is dependent on prevalence of disease.
The referenced articles by Wojtys and Kuhn et al are two of a series of medical statistics review papers.
An 85-year-old woman undergoes the treatment seen in Figure A for a displaced left femoral neck fracture. During wound closure, the patient becomes hypoxic and hypotensive. Despite aggressive resuscitation efforts, she passes away three hours later in the intensive care unit. The autopsy findings seen in
Figure B from the patient's lungs are most likely the result of which of the following
Reaming for the femoral component
Insertion of a femoral component after cement pressurization
Utilization of undersized broaches during canal preparation
Inadequate beta blockade
Use of spinal anesthesia
The clinical scenario is consistent with fat emboli syndrome. Figure A, shows a cemented bipolar hemiarthroplasty while Figure B shows marrow embolization into the lungs.
Studies have shown that intramedullary pressure and fat embolization are greatest during pressurization of cement and implant insertion.
Intramedullary pressure is influenced by size, shape, sharpness and insertion rate of an implant. Pressurization during cementing of a femoral component generates a large degree of pressure over a much wider surface area than in the other methods described of femoral canal instrumentation or preparation, as the entire femoral canal is
pressurized at one time. This results in the highest degree of marrow embolization to the lungs resulting in hypoxia.
Dobrjanski et al studied which variables affected intramedullary pressurization and found that lower implant insertion speed, lower hammering force, a
rubber- compared with steel-tipped hammer and a larger synthetic bone-to- implant radial gap reduced intramedullary pressure generated in a femur module.
Sustained compression applied to a growth plate under experimental conditions has what effect?
No effect
Accelerated longitudinal growth
Decelerated longitudinal growth
Decelerated apposition growth
Decreased bending strength of the bone
The Heuter-Volkmann Law states that compression across the growth plate slows longitudinal growth.
Stokes et al demonstrated that sustained compression across the growth plate can decrease longitudinal growth by 40%. Tension across the physis increases growth, but to a lesser degree.
A 13-year-old girl with a displaced proximal tibia fracture is brought into the emergency department by her adult cousin. The
fracture needs surgical management. The child is living with her cousin's family while her parents are in Germany. While the child speaks fluent English, her cousin and her parents are German-only speaking. How should you consent this patient?
No consent is needed given the urgent nature of the injury, proceed with surgery
Talk with the cousin, using the child as a translator
Talk with the cousin, using a German-translator
Call the parents in Germany, using the child as a translator over the phone
Call the parents in Germany, using a German-translator over the phone
This is an urgent (not emergent) clinical senario, and as such, the child needs to have
formal consent by speaking with her parents using a German- translator.
Wenger and Lieberman discuss the problems and potential solutions surrounding the process of informed consent in patients who either personally lack capacity to make decisions or in patients who require surrogates (like minors) to make treatment decisions.
Lindseth reviews the ethical issues encountered in pediatric orthopaedics and the problems associated with these decisions. Specifically pediatric consent is confounded because the person giving the consent is not the person who will bear the consequences of the treatment.
What is the primary mode of bisphosphonate excretion?
Renal
Gastrointestinal
Liver
Skin
Pulmonary
Bisphosphonates are a broad class of medicines used to treat osteoporosis and Paget's disease. They work by inhibiting osteoclast-mediated resorption after being absorbed into the inorganic phase of bone and taken up by osteoclasts. The paper by Lin et al provides a nice review of bisphosphonates and describe their appropriate use in enhancing bone density in patients with structurally
flawed bone. They describe the mechanism of action of bisphosphonates as pyrophosphate analogues and their renal mechanism of excretion, thus, prohibiting their use in patients with renal insufficiency. Rosier discusses the role of the orthopaedic surgeon in the diagnosis and treatment of patients with osteoporosis, now referred to as the "own the bone" initiative. Central to the treatment of osteoporosis are bisphosphonates and the anti-RANKL
monoclonal antibody, Denosumab.
The 2009 AAOS Clinical Guideline on prevention of pulmonary embolism in patients undergoing total hip or knee arthroplasty recommends classifying patients as having either a "standard" or "elevated" risk of bleeding complications. The presence of all of the following qualify a patient as having an "elevated" risk of major bleeding EXCEPT?
History of hemophilia
History of protein C deficiency
History of a recent gastrointestinal bleed
History of a recent hemorrhagic stroke
History of Von Willebrand's Disease
The 2009 AAOS Clinical Guideline on prevention of pulmonary embolism in patients undergoing total hip or knee arthroplasty recommends that all patients pre-operatively should be classified as either having an elevated or standard risk of bleeding and either an elevated or standard risk of pulmonary embolism.
A history of a bleeding disorder (e.g., hemophilia, Von Willebrand's Disease), recent GI bleed, or hemorrhagic stroke qualifies a patient as having an elevated risk of major bleeding.
A history of hypercoagulable state (such as protein C deficiency) or previous documented pulmonary embolism qualifies a patient as having an elevated risk of pulmonary embolism. Type of thromboembolism prophylaxis is recommended by weighing risk of major bleeding vs risk of PE. For those patients with a known contraindication to anticoagulation an IVC filter is considered. Mechanical prophylaxis is recommended across all risk (low to
high risk of either bleeding or pulmonary embolism) groups undergoing total hip or total knee arthroplasty. The detailed AAOS guidelines can be found on the AAOS website.
The evidence based clinical recommendations are presented in the reference by Johanson et al.
In consideration of a prosthetic knee, each of the following are advantages of choosing a polycentric knee with fluid control over a constant friction knee EXCEPT:
Allows variations in cadence
Flexes in a more controlled manner
Lighter in weight
Improved stance control allows less energy expenditure
Overall length of the limb is shortened during initiation of a step reducing the risk of stumbling
Single axis, constant friction knees function as a simple hinge. They are light, durable, and much cheaper prostheses making them ideal for growing children who will need multiple prostheses before reaching adulthood. This prosthesis allows only a single speed of walking, and relies solely on alignment for stance phase stability. Polycentric knees offer each of the advantages stated above making it a more ideal prosthesis for the active adult. Disadvantages of the polycentric knee include cost, weight, and more sophisticated maintenance.
Tang et al reviews the current prosthetic options for leg and foot amputees. Illustration A demonstrates a single axis knee prosthesis.
Illustration B demonstrates a polycentric knee prosthesis.
Which of the following biologic agents commonly used to treat rheumatoid arthritis (RA) DOES NOT target tumor necrosis factor- alpha (TNF-alpha)?
Infliximab
Rituximab
Etanercept
Golimumab
Adalimumab
Rituximab is a chimeric monoclonal antibody against the protein CD20, which is primarily found on the surface of immune system B cells. Rituximab is used in combination with methotrexate to treat RA that has not responded to one or more types of treatment, including anti-tumor necrosis factor (TNF) blockers.
In rheumatoid arthritis, and other chronic inflammatory conditions, cytokines produced by activated T-cells/macrophages contribute to the pro-inflammatory state. TNF-alpha is thought to be one of the major cytokines involved in rheumatoid arthritis pathology. As a result, many biologic agents used to treat RA are directed towards blocking TNF-alpha or its receptors. These drugs are able to reduce inflammation and stop disease progression.
Elliot et al. evaluated the safety and efficacy of infliximab in 20 patients with active RA in an open phase I/II trial lasting 8 weeks. They found that treatment with anti-TNFa was safe, well tolerated and resulted in significant clinical and laboratory improvements.
Illustration A depicts five commonly used anti-TNF alpha biologic agents for the treatment of rheumatoid arhtirits with their usual dosing regimens.
Incorrect Answers:
Receptor activator of nuclear-factor kappa-B ligand (RANKL) is
an important regulator of bone resorption. Which of the following cells is the MAJOR source of RANKL in bone remodelling?
Osteoclasts
Osteoblasts
Integrins
T cells
Macrophages
RANKL, a key osteoclastogenic protein, is expressed by osteoblasts and binds to the RANK receptor on osteoclast precursor cells.
The binding of RANKL to RANK on osteoclast precursor cells drives their differentiation into mature osteoclasts (multinucleated giant cells). Mature osteoclasts bind to the bone surfaces via integrins and resorb bone via their ruffled border within Howship's lacunae. Osteocytes orchestrate bone resorption and bone deposition by controlling osteoclast and osteoblast activity. Osteoblasts release RANKL to induce osteoclast differentiation, while
osteoblasts release osteoprotegerin (OPG) to downregulate osteoclastogenesis. Osteocytes also release fibroblast growth factor-23 (FGF-23), BMPs and sclerostin to regulate osteoblast activity. Antibodies to RANKL and Sclerostin have both been shown to increase bone density.
Compton et al. reviewed osteocyte function and the emerging importance of sclerostin, which is a glycoprotein. Sclerostin is predominantly secreted by osteocytes under physiologic conditions to act as an important negative regulator of bone mass through inhibition of bone formation by osteoblasts.
Illustration A demonstrates local bone milieu. It depicts the interplay between osteocytes, osteoblasts, and osteoclasts via the factors described above.
Incorrect answers:
A 45-year-old woman with rheumatoid arthritis is being scheduled for a total knee athroplasty in 2 weeks. She is currently taking sulfasalazine, Penicillamine, and etanercept, a tumor necrosis factor inhibitor (aTNF-a). What changes should be made to her medication regimen prior to surgery?
Discontinuation of all three medications 1 weeks prior to surgery
Discontinuation of sulfasalazine 1 weeks prior to surgery, continuation of etanercept and penicillamine
Continuation of sulfasalazine, penicillamine, and etanercept
Continuation of sulfasalazine and penicillamine, discontinuation of etanercept 1 week prior to surgery
Continuation of penicillamine, discontinuation of sulfasalazine and etanercept 1 week prior to surgery
Anticytokine disease-modifying antirheumatic drugs (DMARD) have become increasingly popular in the treatment of RA. Immunosuppression and the risk of infection are potential complications for all anti-TNF-alpha medications. Current recommendations for cessation of immunosuppressive therapy are when the drug concentrations are at their lowest levels which include the following: 3 days after etanercept injection; 2 weeks prior to infliximab infusion; 10 days after adalimumab injection. Medications such as sulfasalazine and penicillamine may be continued during the pre and post- operative period. Recent evidence and guidelines such as those reviewed by Keith's paper, suggest that anti-TNF-alpha medications should be stopped 4 weeks prior to surgery.
Giles et al report in their case control series an increased infection rate of RA patients undergoing an orthopaedic procedure who were on TNF-a inhibitors as opposed to patients on more traditional treatment regimens like methotrexate and prednisone.
Which of the following supplements affects blood clotting through its effect on platelets?
Ginkgo
Vitamin D
Ephedra
St. John's Wort
Selenium
Ginkgo and ginseng are two common supplements used in the general population that have inhibitory effects of platelet function. Adverse peri- operative complications consisting of increased bleeding and hematoma formation have been reported with the use of these two herbal supplements. The most commonly used supplements that could have an effect in the peri- operative period include echinacea, ephedra, garlic, ginkgo, ginseng, kava, St John's wort, and valerian. Bleeding has been shown to be effected by garlic, ginkgo, and ginseng; cardiovascular instability from ephedra; and hypoglycemia from ginseng. Kava and valerian have pharmacodynamic herb- drug interactions that can increase the sedative effect of anesthetics. St John's wort has been shown to alter the metabolism of certain drugs used in the perioperative period.
Ang-Lee et al review common supplements used today and their potential anesthesia/operative effects. The article places emphasis on proper history taking of not only medications but also supplements which is often times left out of documentation.
The femur radiograph of a healthy 25-year-old female is compared to the femur radiograph of a healthy 85-year-old female. Which of the following best describes the 25-year-old's femur?
Increased cortical thickness and a smaller medullary canal volume
Decreased cortical thickness and a larger medullary canal volume
Equivalent cortical thickness and medullary canal volume
Increased cortical thickness and larger medullary canal volume
Decreased cortical thickness and a smaller medullary canal volume
As the human body ages the cortical thickness/area decreases and subsequently the diameter/volume of the medullary canal increases. Therefore, a young healthy 25- year-old woman should have thicker cortices and a smaller medullary canal volume than her counterpart at 85 years. A decreased cortical bone area is linked to increased fracture risk.
Stein et al studied femurs from subjects aged 21-92 years of age. They found that a reduction in cortical area was seen in older specimens and this change was more
pronounced in female specimens.
Wrong Answers:
Which of the following is NOT a described complication of corticosteroid injections?
Local flare in surrounding tissues
Apoptosis of myocytes
Skin pigmentation changes
Fat atrophy
Facial flushing
Corticosteroids have not been shown to cause apoptosis of myocytes when injected extra-articularly. Each of the other answers have been described.
Cole and Schumacher provide a review of current uses of corticosteroid injections, and emphasize that how accurately the injection is placed affects the outcome.
Kumar and Newman report prospectively on 672 patients who received 1147 intra- and extra-articular injections. Their overall complication rate was low (16%) with injection site pain (mild) and bleeding constituting the majority of cases. There were 4 instances of fat atrophy in the extra-articular group, and
cases of syncope or dizziness in the intra-articular group. They did not discuss the efficacy of their injections.
A surgeon chooses a periarticular locking plate with unicortical proximal locking screws for an extra-articular distal femur fracture as seen in Figure A. Compared to an identical construct with bicortical unlocked proximal screw fixation, the periarticular locking plate with unicortical locking screws has which biomechanical properties?
Greater torsional and axial fixation strength
Less torsional but greater axial fixation strength
Equal torsional and axial fixation strength
Greater torsional but less axial fixation strength
Less torsional and axial fixation strength
Unicortical locking plates have characteristically less torsional strength than bicortical locking plates and bicortical non-locking plates. Axial strength is improved with locking plate fixation.
Zlowodzki et al studied the LISS periarticular locking plate with unicortical proximal fixation in a distal femur model and found superior axial fixation strength (134%) but worse torsional strength (68%) compared to a fixed angle blade plate with non- locking bicortical screw fixation.
Locked plating was reviewed by Haidukewych and Ricci which highlighted the added cost, unique complications, and they recommended the use of locked plating only in situations when unlocked constructs have demonstrated poor outcomes.
In rat models looking at the effect of malnutrition on fracture healing, amino acid supplementation in a nutritionally deprived rat increases all of the following EXCEPT
Serum albumin
Body mass
Quadriceps total protein content
Fracture callus mineralization
Insulin-like growth factor 1 (IGF-1) mRNA expression
The study by Hughes et al found that essential amino acid supplementation (glutamine, arginine, and taurine) following femoral fracture in a protein- malnourished rat model increases serum albumin, body mass, quadriceps total protein content, and fracture callus mineralization. Expression of IGF-1 and
IGF-2, myosin, actin, and VEGF mRNA were all significantly decreased in the amino acid supplemented group compared to the malnourished group. The malnourished group is thought to have upregulation of mRNA expression in attempt to increase the amount of protein product that is translated, however the lack of amino acid building blocks in the malnutrition group was a barrier to appropriate protein synthesis.
The study by Day et al created a malnourished rat femur fracture model by administering a 6% protein diet. They found that administering a 20% protein diet in the post-fracture period yielded a greater cross-sectional area of the
fracture callus and callus stiffness compared to the 6% protein malnourished group.
The statistical power of a study is best defined by?
1 - probability of type-II (beta) error
True positive/(true positive + false negative)
True negative/(false positive + true negative)
1 - probability of type-I (alpha) error
[True positive/(true positive + false negative)] / false-positive rate
The power of a study is an estimate of the probability of finding a significant association in a research study when one truly exists. The power is defined by
1 - probability of type-II (beta) error, and is often set at 80%. For example, a power of 80% means that if the intervention works, the study has an 80% chance of detecting this and a 20% chance of randomly missing it. A type-II or beta error occurs when one falsely concludes that there is no significant association when there actually is an association (resulting in a false-negative study that rejects a true alternative hypothesis). The type-II or beta error can be determined if Type I error rate and sample size are known. A type-I or alpha error occurs when a significant association is found when there is no true association (resulting in a false-positive study that rejects a true null hypothesis). The alpha level refers to the probability of a type-I (alpha) error and is usually set for most studies at 0.05. Answer 2 is the formula for sensitivity. Answer 3 is the formula for specificity. Answer 5 is the formula for the positive likelihood ratio. The references by
Kocher and Wojtys are excellent reviews of basic biostatistic principles.
A 55-year-old female with a history of metastatic breast cancer develops shoulder pain without any trauma. Which of the following is involved with the findings shown in Figures A and B?
IL-4
RANK
TNF-alpha
OPG
Sox-9
Osteoclastic bone resorption is the final common mechanism for osteolysis, whether due to a pathologic lytic lesion, macrophage activation in particle wear, or normal remodeling. The RANK-RANKL mechanism controls the coupling of osteoblast and osteoclast activation. Figures A and B show an osteolytic lesion in the humerus in a patient with known metastatic breast carcinoma.
RANKL is expressed from osteoblasts and bone-marrow stromal cells. When RANKL binds to the RANK receptor (receptor/activator of NF-[kappa]B) on the cell membrane of osteoclasts it stimulates differentiation from osteoclast progenitor cells to mature osteoclasts. Mature osteoclasts proceed with osteoclastic bone resporption.
Osteoprotegerin (OPG) acts as a decoy receptor by binding to RANKL and blocking the interaction between RANKL and the RANK-receptor and consequently inhibiting osteoclast formation and
activation.
Illustration A depicts the RANK/RANKL involvement in tumor metastatic spread.
Laboratory values of a normal serum calcium and parathyroid hormone can be found in which of the following disease states?
Primary hyperparathyroidism
Type I vitamin D deficient rickets
Type II vitamin D deficient rickets
X-linked hypophosphatemic rickets
Nutritional rickets
Hypophosphatemic rickets is caused by the inability of kidney proximal tubules to reabsorb phosphate due to a mutated PHEX gene, found on the X chromosome. PHEX is thought to protect extracellular matrix glycoproteins from proteolysis. Hypophosphatemic rickets shares many clinical similarities with nutritional rickets but shows PTH levels that are not elevated, even with calcium and phosphate abnormalities.
Pettifor reviews the advances in molecular genetics in the understanding and possible treatments in tumour-induced osteomalacia/rickets.
The review article by Carpenter discusses the X-linked disorder including its clinical manifestations, the wide spectrum of disease severity, and complications of the disease in adult patients.
Illustration A is a table that details the laboratory values associated with each type of rickets.
An 80 year-old female undergoes ORIF of her hip fracture without any complications. A hospitalist consult was obtained for medical clearance pre- operatively, and she was diagnosed with osteoporosis. Which of the following treatment scenarios will lead to the best management of the patient's osteoporosis?
Schedule a follow-up appointment with the patients primary care physician to initiate therapy
Order a physical therapy consult and initiate an exercise plan
Have the patient meet with a nutritionist to increase her calcium and vitamin D intake
Start bisphosphonates, and have the patient follow-up with her primary care physician
Perform a metabolic work-up as an inpatient, and set-up an appointment in an osteoporosis clinic
The initiation of appropriate osteoporosis treatment following hip fractures occurs at a surprisingly low rate. Physical therapy and dietary changes are not appropriate initial treatments for osteoporosis, and bisphosphonate therapy should be prescribed by the physician who will be following and managing the patient's osteoporosis.
Miki et al performed a prospective randomized trial where they compared the rates of osteoporosis treatment initiation. The percentage of patients who were on pharmacologic treatment at 6 months post-injury was 58% in the group whose treatment was directed by the orthopedic surgeon and osteoporosis clinic, and 29% when managed by the primary care physician alone.
The elements chromium, molybdenum, and cobalt are basic components of which of the following implant materials?
Aluminum oxide
Cobalt alloy
Stainless steel
PMMA
Tantalum
Cobalt alloys are extremely strong and are well-suited to applications requiring longevity. Strength of the implant is improved by the addition of molybdenum. Corrosion resistance is addressed by the addition of chromium, which also increases the hardness of the implant.
Incorrect Answers:
Which of the following scenarios of treatment of a humerus fracture best achieves low strain at the fracture site and high stiffness of the treatment construct?
Functional bracing of a transverse midshaft fracture
Comminuted midshaft fracture with locked bridge plating
Short oblique fracture with interfragmentary lag screw and locked neutralization plate
Uniplane external fixation of a spiral open fracture
Oblique fracture with intramedullary nail fixation
Strain in fractures is calculated by dividing the interfragmentary movement by the size of the fracture gap. Strain must be very low (2%) for primary bone healing to occur, and should be less than 10% for secondary bone healing to occur. Stiffness refers the ability of the construct to resist movement under applied loads. Answer 3 describes a situation where primary bone healing is
the goal. For this to occur, there must be no significant gapping at the fracture site, there must be low strain between fracture fragments, and the construct must be stiff.
None of the other answers would accomplish this. Functional bracing and intramedullary fixation both accomplish healing through formation of fracture callus, or secondary healing. A comminuted fracture treated with locked bridge plating relies on less stiffness to allow for secondary healing between fragments. However, since there are many fracture fragments, the strain is distributed among them and therefore remains low. A uniplane external fixator is very unlikely to accomplish low strain and high stiffness in this setting.
A 67-year-old man complains of low-grade fevers and calf pain 2 weeks following a total knee arthroplasty. What is the next appropriate step in management of this patient?
Plethysmography of lower extremity
MRI of lower extremity
CT angiography of lower extremity
Venous ultrasonography
Knee aspiration to evaluate for septic joint
Venous ultrasonography is the next best step in this patient's management, due to the clinical picture of a deep venous thrombosis. The most sensitive and specific recommended diagnostic procedure is a venous ultrasonography.
In their multi-center study, Haut et al. hypothesized that admission to trauma centers that use duplex ultrasound more frequently would independently predict increased DVT reporting for individual patients. They indeed found that trauma centers ultrasound practice was an independent predictor of DVT diagnosis for individual patients, controlling for patient-level risk factors, but concluded the elevated DVT rates at these centers were due to surveillance bias. As such, they recommend that surveillance for DVT should not be considered as a quality control measure in the care of trauma patients.
A patient undergoes closed reduction of a bimalleolar ankle fracture dislocation by the ER physician and is sent to your clinic for evaluation. You evaluate the patient and schedule him for surgery. According to the 2009 guidelines, which of the following scenarios would meet criteria for coding the encounter as a new patient?
You injected his knee in the office almost 3 years ago for osteoarthritis, and have not seen him since
He had an arthroscopic operation by your partner 4 years ago
You were consulted 1 year ago for shoulder pain when he was hospitalized for chronic renal failure
He was seen by your partner in clinic for a herniated disk 2 years ago, but had no procedures performed
You performed a hip replacement on him 12 years ago, and his last follow- up was 18 months ago at which time he was doing well
Only answer two is correct. The 2009 guidlines clarify that the patient can be defined as new only if he has not been seen by anyone in the physician's same group practice and of the same specialty in the past 3 years. Hand and sports medicine specialists with a CAQ, however, are an exception and are allowed to bill for patients already seen by other orthopedists in the same group as new
patients. This scenario would not qualify as a consultation, since the orthopedic surgeon
is taking over care of the patient's problem and is not merely offering advice to another physician who is already caring for the patient. Consultations do not have the same 3 year time qualification. However, Medicare and many other insurers no longer recognize consultation codes.
All the following medications binds reversibly to the enzyme COX-1 EXCEPT
Meloxicam
Diclofenac
Indomethacin
Naproxen sodium
Aspirin
Aspirin binds irreversibly to the cyclooxygenase enzyme. Aspirin acetylates platelet cyclooxygenase and permanently inhibits thromboxane (TX) A2 production leading to its antiplatelet effects. The other NSAID's listed above bind reversibly with COX-1.
Patrono et al discuss the pharmokinetics and platelet effect of both low dose and regular dose aspirin. Nonsteroidal anti-inflammatory drugs compete dose- dependently with arachidonate for binding to platelet cyclooxygenase.
In the treatment of patients with rheumatoid arthritis, TNF-alpha is blocked by which of the following agents?
Tocilizumab
Anakinra
Etanercept
Abatacept
Rituximab
Etanercept is a biochemically designed soluble p75 tumor necrosis factor receptor immunoglobulin G fusion protein, which blocks the downstream
effects of TNF.
Methotrexate is a chemotherapy agent used to inhibit lymphocytes. Gold inhibits monocytes, while sulfasalazine is an anti-inflammatory decreasing the production of
prostaglandins and leukotrienes. Rituximab inhibits B-cells as it
is a monoclonal antibody to CD20 antigen. Anakinra (Kineret) is a recombinant IL-1 receptor antagonist. Abatacept (Orencia) is a selective costimulation modulator that binds to CD-80 and CD-86 (inhibits T cells). Tocilizumab (Actemra)is an IL-6 receptor inhibitor (2nd line treatment for poor response to TNF-antagonist therapy).
Pisetsky wrote an editorial in NEJM discussing the development of TNF blockers through research, and the potential for the use of Etanercept in patients with juvenile RA through its inhibition of lymphotoxin-alpha.
Which of the following medications when combined with methotrexate has been shown to be more effective than methotrexate alone in the treatment of rheumatoid arthritis?
Nitrofurantoin
Rifampin
Azithromycin
Erythromycin
Doxycycline
Tetracycline was initially used in the treatment of rheumatoid arthritis (RA) because Mycoplasma was thought to be the causative agent. It was later found that tetracyclines have biologic effects on the inflammatory and immunologic cascade by inhibiting collagenase activity. Collagenase is an enzyme involved
in breaking down macromolecules in the connective tissue, contributing to the pathologic changes of RA.
In a prospective study, O'Dell et al found that initial therapy with methotrexate plus doxycycline was superior to treatment with methotrexate alone. Furthermore, similar results for low-dose and high-dose doxycycline suggested that antimetalloproteinase effects were more important than the antibacterial effects.
When using C-arm fluorocopy, patient radiation exposure will be increased with which of the following?
The extremity is positioned closer to the image intensifier
A larger body part is imaged compared to a smaller body part
Use of radiation beam collimation
Mini C-arm fluroscopy is used instead of large C-arm fluroscopy
Decreased duration of imaging
Patient radiation exposure will be increased if a larger body part is imaged compared to a smaller body part.
The first study by Giordano et al used radiation dosimeters for large and mini c-arm machines. They found that elevated exposure levels can be expected when larger body parts are imaged, when the extremity is positioned closer to the x-ray source, and when the large c-arm is used over the mini c-arm.
The second study by Giordano et al also used dosimeters for a mini c-arm and found that the surgical team is exposed to minimal radiation during routine
use of mini-c-arm fluoroscopy, except when they are in the direct path of the radiation beam. They list factors to decrease radiation exposure to patient and surgeon including: minimizing exposure time, reducing exposure factors, manipulating the x-ray beam with collimation, orienting the fluoroscopic beam in an inverted position relative to the patient, strategic positioning of the surgeon within the operative field, judicious use of protective shielding during imaging, and maximizing the distance of the surgeon from the radiation beam.
Illustration A shows that arrangement #1 has the body part half-way between the radiation source and image intensifier. Arrangement #2 has the the image intensifier acting as an arm table for the body part with the radiation source further away. Arrangement #1 has more radiation exposure than #2. The distance between the x-ray tube and the body part is doubled in arrangement
#2 compared to arrangement #1. This increased distance correlates to a reduction in exposure according to the inverse square law (reduction in radiation intensity with greater distance from the x-ray source).
You are seeing a 13-year-old girl for asymptomatic flat feet and recommend observation. In educating this patient/family about general bone health, you recommend what amount of daily dietary calcium for your patient?

Question 12

Examination of a supine patient in which the hip is abducted, externally rotated, and flexed is referred to as

Explanation

DISCUSSION: During Patrick’s test, also known as the FABER test, the flexed, abducted, and externally rotated hip is positioned to isolate sacroiliac pathology. Back pain with this test is not considered diagnostic. With Kernig’s sign, the spinal cord is placed on stretch, eliciting root or meningeal irritation by forcibly flexing the patient’s head and neck with his or her hands clasped behind the head. For Lasegue’s sign, the patient performs a straight leg raise with the immobile hip already held in flexion. The femoral stretch test can be performed in the prone position or side lying, but the hip is held in extension while the knee is flexed, testing for femoral neuritis.
REFERENCES: Watkins RG: History, physical examination, and diagnostic tests for back and lower extremity problems, in Watkins RG (ed): The Spine in Sports. St Louis, MO, Mosby, 1996, Chapter 7.
Hoppenfeld S: Physical Examination of the Spine and Extremities. East Norwalk, CT, Appleton-Century-Crofts, 1976, Chapter 9.

Question 13

A patient reports progessive bilateral hand clumsiness and ataxia. Examination reveals a positive Hoffmann’s sign and intrinsic atrophy. MRI reveals multilevel cervical spondylosis, and lateral flexion and extension radiographs show cervical kyphosis in the neutral position, with restoration of lordosis on extension. Which of the following procedures is most likely to result in poor long-term results?

Explanation

DISCUSSION: Adequate decompression of the cervical cord can be achieved in a variety of ways depending on the pathoanatomy of the compression, but kyphosis is a relative contraindication to laminectomy alone. For laminectomy to be effective, the lordosis must be maintained so the cord can displace posteriorly away from the anterior structures. In addition, removing the posterior tension band increases the probability that the kyphosis will progress, therefore increasing the force against the front of the cord as it tents across the kyphosis.
REFERENCES: Albert TJ, Vaccaro A: Postlaminectomy kyphosis. Spine 1998;23:2738-2745.
Truumees E, Herkowitz HN: Cervical spondylotic myelopathy and radiculopthy. Instr Course Lect 2000;49:339-360.
Emery SE: Cervical spondylotic myelopathy: Diagnosis and treatment. J Am Acad Orthop Surg 2001;9:376-388.

Question 14

Histologic studies of surgically resected tissue in lateral epicondylitis demonstrate which of the following findings? Review Topic

Explanation

The extensor carpi radialis brevis is most often cited as the anatomic location of pathology in lateral epicondylitis. Histologic examination demonstrates noninflammatory tissue, primarily angiofibroblastic tendinosis though normal tendon histology is also present. There is usually no evidence of acute inflammation or chondroblastic tissue, or significant calcium deposition.

Question 15

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 16

Total hip arthroplasty is most appropriate for the injury shown in Figure A for which of the following patients?

Explanation

Figure A is an AP radiograph demonstrating a displaced femoral neck fracture. Active older patients who present with a displaced femoral neck fracture should be treated with total hip arthroplasty (THA).
Displaced femoral neck fractures can present a challenge to treat. In younger patients with good bone stock a closed vs. open reduction and internal fixation should be attempted. For active older patients a total hip arthroplasty is the best option, especially if there is pre-existing arthritis in the injured hip. THA provides the best function with the least pain and less need for repeat surgery (compared to hemiarthroplasty). For low-demand or debilitated patients, for patients older than age 80, or for those who can not reliably follow hip precautions a hemiarthroplasty provides the lowest risk of dislocation, and thus would be the treatment of choice.
Macaulay et al. present a prospective randomized trial of patients with femoral neck fractures treated with THA vs hemiarthroplasty. They found that functional outcomes and patient satisfaction were higher in the THA group without significant increased risk of complications. Inclusion criteria required patients to be over age 50, be a community ambulator, and were excluded for presence of dementia.
Abboud et al. retrospectively reviewed patients treated with THA for osteoarthritis and compared them to patients treated with THA for a femoral neck fracture. They found no significant difference between the two groups for outcomes or complications.
Figure A is an AP radiograph demonstrating a displaced femoral neck fracture.
Incorrect Answers:

Question 17

Which local treatment option is most appropriate?

Explanation

DISCUSSION
This patient has a pathologic femur fracture. Her history of antecedent pain in the context of a previously well-functioning implant suggests that a new process such as dedifferentiation of a long-standing lesion may have occurred. The initial radiograph reveals a well-mineralized lesion within the intramedullary canal with punctate calcifications. This by itself suggests an enchondroma or low-grade chondrosarcoma. It is important to note that enchondromas in the long bones rarely cause pathologic fractures. This is not the case when they are present in the hands and feet, where enchondromas frequently have a more aggressive radiologic appearance and pose higher risk. Radiographic findings concerning for malignant dedifferentiation of an enchondroma
include cortical thinning or breach, a soft-tissue mass, or periosteal elevation. The pathologic fracture obscures the ability to identify these hallmarks of malignant degeneration.
Multiple myeloma, renal cell carcinoma, and osteolysis are all typically radiolucent. Implant-associated osteolysis lesions are commonly multiple and periarticular. The histopathology reveals a cartilage tumor. The chondroid tissue appears to be low grade. However, in an adjacent region there is a high-grade component seen both on the low-power view and the second higher-power sample that does not resemble cartilage. This is highly suggestive of a dedifferentiated chondrosarcoma. This component signifies that a portion of the original tumor (low-grade chondrosarcoma), which resembled the tissue of origin, converted into a different cell lineage with more aggressive properties (nearly any type of high-grade sarcoma). Dedifferentiated chondrosarcoma is a highly aggressive malignancy, with average 5-year survivals of less than 50%. As with most sarcomas, the most likely site of metastatic dissemination of chondrosarcoma is pulmonary. Consequently, standard staging entails a high-resolution CT scan of the lungs.
Serum protein electrophoresis and a skeletal survey are used for diagnosis of multiple myeloma. Positron emission tomography/CT fusion scans are used at many centers in the staging of osteosarcoma, but their role in chondrosarcoma staging is an emerging modality that is being investigated. Radiation is not typically used for local treatment of extremity chondrosarcoma. Extended curettage is not appropriate for a high-grade lesion such as this. Revision arthroplasty alone does not address the tumor. Wide resection is the local treatment of choice for high-grade chondrosarcoma; because of the fracture, this patient may require an amputation to achieve wide margins.
RECOMMENDED READINGS
Henderson ER, Pala E, Angelini A, Rimondi E, Ruggieri P. Dedifferentiated peripheral chondrosarcoma: a review of radiologic characteristics. Sarcoma. 2013;2013:505321. doi: 10.1155/2013/505321. Epub 2013 Mar 25. PubMed PMID: 23589702. View Abstract at PubMed
Grimer RJ, Gosheger G, Taminiau A, Biau D, Matejovsky Z, Kollender Y, San-Julian M, Gherlinzoni F, Ferrari C. Dedifferentiated chondrosarcoma: prognostic factors and outcome from a European group. Eur J Cancer. 2007 Sep;43(14):2060-5. Epub 2007 Aug 27. View Abstract at PubMed
Mavrogenis AF, Gambarotti M, Angelini A, Palmerini E, Staals EL, Ruggieri P, Papagelopoulos PJ. Chondrosarcomas revisited. Orthopedics. 2012 Mar 7;35(3):e379-90. doi: 10.3928/01477447-20120222-30. PubMed PMID: 22385450. View Abstract at PubMed
Flemming DJ, Murphey MD. Enchondroma and chondrosarcoma. Semin Musculoskelet Radiol. 2000;4(1):59-71. Review. PubMed PMID: 11061692. View Abstract at PubMed

Question 18

When comparing arthroscopic lavage and knee debridement with placebo in patients with chronic symptomatic osteoarthritis, what outcome has been demonstrated?

Explanation

DISCUSSION:
Excluding a diagnosis of meniscal tear, loose body, or mechanical derangement, treating knee osteoarthritis of indeterminate cause with arthroscopic lavage and debridement has been found to provide no discernable benefit to offset the risk of surgery. The effects of arthroscopy have not been clinically significant in the vast majority of patient-oriented outcomes measures for pain and function at multiple
times between 1 week and 2 years after surgery.

Question 19

Which of the following anatomic structures are in contact with internal impingement in the throwing athlete?

Explanation

DISCUSSION: Internal impingement occurs in the late cocking phase of throwing with humeral head abduction and maximal external rotation. It is a physiologic phenomenon occurring in
85% of patients undergoing arthroscopy for various indications in one study. Internal impingement is defined as impingement of the posterior-superior rotator cuff between the humerus and posterior-superior glenoid rim. Symptomatic internal impingement is felt to be due to the frequency and magnitude of the impingement in throwers.
REFERENCES: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 252.
Paley KJ, Jobe FW, Pink MM, et al: Arthroscopic findings in the overhand throwing athlete: Evidence for posterior internal impingement of the rotator cuff. Arthroscopy 2000;16:35-40.

Question 20

A 14-year-old boy has an anteromedial distal thigh mass. A radiograph and MRI scan are shown in Figures 39a and 39b. An open biopsy of the mass should include

Explanation

DISCUSSION: Biopsy of the soft-tissue component is often diagnostic. Alternatively, in centers with pathologists familiar with bone tumors, needle biopsy is usually successful. The principles of biopsy of bone tumors include avoiding contamination of uninvolved structures and compartments, taking the most direct path to the tumors, making an excisable biopsy tract, and obtaining diagnostic tissue. Transverse biopsy incisions should be avoided because they hinder the definitive surgical procedure.
REFERENCES: Peabody TD, Simon MA: Making the diagnosis: Keys to a successful biopsy in children with bone and soft-tissue tumors. Orthop Clin North Am 1996;27:453-459.
Mankin HJ, Mankin CJ, Simon MA: The hazards of the biopsy, revisited. Members of the Musculoskeletal Tumor Society. J Bone Joint Surg Am 1996;78:656-663.
Skrzynski MC, Biermann JS, Montag A, Simon MA: Diagnostic accuracy and charge-savings of outpatient core needle biopsy compared with open biopsy of musculoskeletal tumors. J Bone Joint Surg Am 1996;78:644-649.

Question 21

A 9-year-old boy is injured while playing soccer. His examination reveals painful range of motion between 5° and 75°. There is tenderness on the medial side of his knee. There is no effusion, a grade 1A Lachman test, and severe pain over the medial epicondyle of the knee. Varus stress is negative and pain is elicited with valgus stress. Initial radiographs were negative for abnormality. Stress radiographs show a 2-mm medial physeal widening with valgus stress. What is the best initial treatment strategy for this patient?

Explanation

This patient likely has a physeal injury to the distal femoral physis. Stress radiographs or an MRI scan will most reliably reveal this diagnosis. The growth plate, when injured, is most commonly fractured through the hypertrophic zone of cartilage, its weakest point. This patient is optimally treated in a cylindrical or long-leg cast.

Question 22

0 sustained a subcapital fracture of her hip. She is an avid tennis player, and history reveals no previous fractures. What is the most appropriate follow-up care? Review Topic

Explanation

A DEXA scan is most appropriately used to establish a baseline score. Even if the bone mineral density is not within the osteoporotic range (T-score less than -2.5), a prior fragility fracture is a strong risk factor for a second fracture as a result of factors other than bone density, such as worsening vision or balance, confusion, or other predispositions to falls. The guidelines of the National Osteoporosis Foundation indicate that, following a fragility hip fracture, active anti-osteoporotic medication should be initiated, whether or not a DEXA scan is performed. A recent study showed that antiresorptive therapy following a hip fracture reduces not only the risk of a second fracture but also overall mortality.

Question 23

Osteochondritis dissecans of the capitellum is a source of elbow pain and most commonly occurs in what patient population?

Explanation

DISCUSSION: The etiology of osteochondritis dissecans of the capitellum is somewhat unclear. However, trauma has been implicated in this disease process. Gymnasts who load their upper extremities during tumbling and throwing athletes with repetitive trauma during the throwing motion are common patient subgroups in which osteochondritis dissecans of the elbow is seen. This often occurs in the adolescent age population.
REFERENCES: Baumgarten TE, Andrews JR, Satterwhite YE: The arthroscopic classification and treatment of osteochondritis dissecans of the capitellum. Am J Sports Med 1998;26:520-523.
Takahara M, Ogino T, Fukushima S, et al: Nonoperative treatment of osteochondritis dissecans of the humeral capitellum. Am J Sports Med 1999;27:728-732.

Question 24

What is the most common complication following metatarsal osteotomy for a bunion deformity in an adolescent?

Explanation

Hallux varus-The question does not specify proximal or distal osteotomies, however it is the most common complication with overcorrection of proximal 1st metatarsal osteotomies. Mann. Pg. 329. “Transfer” 2nd metatarsaglia-most significant, not most common, complication of the Mitchell Osteotomy.Mann pg. 319.
Physeal arrest of the first metatarsal-“While an open epiphysis cannot be considered an absolute contraindication to an osteotomy in either the proximal phalanx, or proximal first metatarsal, it is
important at surgery to determine the exact location of the metaphyseal epiphysis to avoid injury.” Pg. 307 Mann, Surgery of Foot and Ankle.
In studies performed by Blais et. Al. A females full foot growth is usually achieved by 14 years and at 12 years an average less than 1 cm of total foot growth remains with less than 50% of this growth at the proximal epiphysis. Males’ terminal growth expected at 16 years of age with 3cm left at 12 years and approximately 1.5 cm of metatarsal growth.
Most studies show recurrence of Hallux Valgus deformity after surgical correction in the juvenile as inordinately high.

Question 25

Which of the following types of ultra-high molecular weight polyethylene has been associated with the poorest clinical performance?

Explanation

DISCUSSION: Numerous studies have documented the poor performance of heat-pressed ultra-high molecular weight polyethylene used in the porous-coated anatomic tibial inserts of both total knee and unicompartmental arthroplasty. The other processing and sterilization methods have not been associated with significantly high failure rates.
REFERENCES: Wright TM, Rimnac CM, Stulberg SD, et al: Wear of polyethylene in total joint replacements: Observations from retrieved PCA knee implants. Clin Orthop 1992;276:126-134.
Landy MM, Walker PS: Wear of ultra-high molecular-weight polyethylene components of 90 retrieved knee prostheses. J Arthroplasty 1988;3:S73-S85.
Skyrme AD, Mencia MM, Skinner PW: Early failure of the porous-coated anatomic cemented unicompartmental knee arthroplasty: . A 5- to 9-year follow-up study. J Arthroplasty 2002;17:201-205.

Question 26

A healthy 16-year-old boy has had increasing pain in the right knee for the past 3 months. Examination reveals warmth and swelling around the distal femur. Radiographs and an MRI scan are shown in Figures 51a through 51c, and a biopsy specimen is shown in Figure 51d. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographs show a bone-producing lesion in the distal femoral metaphysis in this case of classic osteosarcoma presenting in the most common location, the distal femur. The coronal MRI scan reveals a marrow-occupying lesion with extension into the soft tissues. The histology shows osteoid production by pleomorphic cells consistent with an osteosarcoma. Ewing’s sarcoma is a bone tumor characterized by uniform small blue cells on histology. Rhabdomyosarcoma is the most common childhood soft-tissue sarcoma. Osteomyelitis has an inflammatory appearance on histology. Malignant fibrous histiocytoma of bone has a lytic radiographic appearance and a pleomorphic storiform pattern without osteoid on histology.
REFERENCES: Wold LE, Adler CP, Sim FH, et al: Atlas of Orthopedic Pathology, ed 2. Philadelphia, PA, WB Saunders, 2003, p 179.
McCarthy EF, Frassica FJ: Pathology of Bone and Joint Disorders with Clinical and Radiographic Correlation. Philadelphia, PA, WB Saunders, 1998, p 205.

Question 27

A right-handed 20-year-old college baseball pitcher has had a 6-month history of vague right elbow pain while pitching. Examination reveals full flexion of the elbow and a loss of only a few degrees of full extension. The elbow is stable, but palpation reveals tenderness over the olecranon. Plain radiographs are inconclusive. MRI and CT scans are shown in Figures 20a and 20b. Management should consist of

Explanation

DISCUSSION: The patient has a stress fracture of the olecranon that occurs with repetitive throwing motions. If the fracture is not displaced, the initial treatment of choice is rest and rehabilitation to maintain elbow motion, followed by aggressive strengthening at 6 to 8 weeks. A light throwing program generally can begin at 8 to 12 weeks. Complete recovery may require 3 to 6 months. If the fracture is displaced or if nonsurgical management fails, surgery is indicated for internal fixation of the stress fracture.
REFERENCES: Azar FM, Wilk KE: Nonoperative treatment of the elbow in throwers. Oper Tech Sports Med 1996;4:91-99.
Griffin LY (ed): Orthopaedic Knowledge Uupdate: Sports Medicine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 191-203.

Question 28

A 40-year-old female recreational basketball player notes pain deep within her shoulder that occurs with activity. Pain began insidiously 6 months previously. She has completed a physical therapy program, and an intra-articular corticosteroid injection provided excellent temporary relief. Physical examination shows symmetric range of motion of her shoulder. She has a positive O'Brien’s active compression test. There is no pain with cross-arm adduction or tenderness to palpation over the acromioclavicular joint. Resisted abduction is nonpainful and strong. MRI shows increased signal in the substance of the superior labrum, low-grade bursal surface fraying of the supraspinatus, and mild degenerative changes within the acromioclavicular joint. What is the best treatment option?

Explanation

A 50-year-old man sustained an external rotation traction injury to his right arm. He felt a pop in the anterior aspect of his shoulder associated with immediate pain and swelling. The MRI scan shows a tear of the subscapularis tendon, as shown in Figures 1 and 2. The arrow points to what anatomic structure?

Question 29

A toddler is brought in by his parents for evaluation of gait problems. Birth history and neurologic examination are unremarkable. After evaluating femoral torsion, tibial torsion, and foot contour, the diagnosis is excessive internal tibial torsion. The parents should be advised to expect which of the following outcomes?

Explanation

DISCUSSION: Excessive internal tibial torsion is a common cause of intoeing in toddlers. In most children, this resolves spontaneously by 3 to 4 years of age. Intoeing in elementary age children is usually the result of excessive femoral anteversion. Studies have shown that active intervention (casting, splinting, and shoe modifications) has no demonstrable effect on the natural history or resolution of tibial torsion. Surgery is rarely indicated in adolescents with severe internal tibial torsion that has not resolved and is resulting in cosmetic and functional problems.
REFERENCES: Canale ST, Beaty JH: Operative Pediatric Orthopaedics. St Louis, MO, Mosby Year Book, 1991, pp 357-385.
Lincoln TL, Suen PW: Common rotational variations in children. J Am Acad Orthop Surg 2003;11:312-320.

Question 30

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

Explanation

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

Question 31

Figures 91a through 91c are the radiographs of a 10-year-old boy who has a 6-month history of progressive heel pain. The patient is a year-round soccer player and now experiences pain with most every step. What is the most appropriate management?

Explanation

The patient has calcaneal apophysitis, an overuse syndrome common in children ages 9 to 12 years. Symptoms are usually the result of excess tension and a tight heel cord. Management includes activity modification, as well as heel cord stretching, nonsteroidal anti-inflammatory drugs, icing, and other modalities. Radiographs are typically negative; MRI is unnecessary. Custom orthotics are not indicated. The condition is self-limiting, in that the symptoms fully resolve once the apophyses fuses, such that surgery is rarely indicated.

Question 32

-Which type of cells has been implicated in the process shown inFigure?

Explanation

Question 33

Figure 72 is the MRI scan of a 61-year-old man who had left shoulder pain with a massive rotator cuff tear. Active forward elevation was 120 degrees. Arthroscopic examination revealed that the rotator cuff tear was irreparable. The articular surfaces of the glenohumeral joint have a normal appearance without significant degenerative changes. What is the most appropriate treatment option? Review Topic

Explanation

The MRI scan shows medial subluxation of the biceps tendon. Biceps tenotomy has been an effective treatment option for patients with large to massive rotator cuff tears when the tear is irreparable and pain is the main symptom. The MRI scan does not show a loose body. Patients with severe external rotation deficit and a deficient teres minor may experience a better functional result with latissimus dorsi transfer. Reverse total shoulder arthroplasty is an option in patients with cuff tear arthropathy and pseudoparalysis.

Question 34

…Giant-cell tumor of bone usually involves the epiphysis of long bones. What is the next most common type of tumor involving this anatomical location?

Explanation

CLINICAL SITUATION FOR QUESTIONS 71 THROUGH 73
Figures 71a through 71e are the radiographs, MRI scan, and CT scans of a 14-year-old-boy who has cyclical pain in his thigh. His symptoms began approximately 6 months ago. He complains of increased pain when he runs and also of pain that wakes him at night. This pain is relieved by nonsteroidal anti-inflammatory drugs (NSAIDs).

Question 35

Figure 9 is the clinical photograph of a 68-year-old woman 10 days after undergoing primary total knee replacement. She is experiencing hemarthrosis, discoloration, and bruising of the soft tissue about the knee; her history includes persistent serous drainage. This clinical appearance likely is associated with

Explanation

DISCUSSION
Certain anticoagulants are associated with an increased risk for wound complications. Two studies showed an increase in postsurgical bleeding and wound drainage following use of LMWH. Other investigators have associated use of anticoagulants such as LMWH with an increased incidence of persistent wound drainage and subsequent infection. Current evidence does not support a significant difference in complication rates with and without the use of wound drains or a tourniquet. Regional anesthesia has been associated with less blood loss than general anesthesia and is not associated with a difference in wound complication incidence.

Question 36

A 54-year-old man undergoes total shoulder arthroplasty for osteoarthritis. Despite compliance with an early passive range-of-motion exercise program, he does not regain more than 90 degrees of elevation, 10 degrees of external rotation, and has internal rotation to the fifth lumbar vertebra. At 6 months, his motion fails to improve. Radiographs are shown in Figures 18a and 18b. What is the best course of action?

Explanation

DISCUSSION: The patient has a global loss of motion that has failed to improve with 6 months of nonsurgical treatment; because he has reached a plateau, further nonsurgical management will likely be ineffective. Revision in the form of an open release is indicated to lyse intra- and extra-articular adhesions; subscapularis lengthening may be done concurrently as needed. Revising to a smaller head can be considered if adequate motion is not achieved. The radiographs reveal an adequate neck cut with appropriate seating of the component. Removing the glenoid component will decrease capsular tension but will probably increase pain because of the lack of glenoid resurfacing. Increasing humeral retroversion will not improve motion.
REFERENCES: Cuomo F, Checroun A: Avoiding pitfalls and complication in total shoulder arthroplasty. Orthop Clin North Am 1998;29:507-518.
Wirth MA, Rockwood CA Jr: Complications of shoulder arthroplasty. Clin Orthop 1994;307:47-69.

Question 37

The fracture shown in Figure 32 is strongly indicative of what diagnosis?

Explanation

DISCUSSION: Fractures that occur through the primary spongiosa at the subphyseal region of the metaphysis are highly specific for child abuse. On radiographic studies, the metaphyseal lucency in these injuries may appear as either the so-called “bucket-handle” or “metaphyseal corner” fracture. These fractures are not typical features of osteogenesis imperfecta or vitamin D-resistant rickets. The ingestion of lead may lead to thick, transverse bands of increased density at the distal metaphysis. Fractures in the subphyseal region of the metaphysis are not typically seen in children who have osteomyelitis.
REFERENCES: Kocher MS, Kasser JR: Orthopaedic aspects of child abuse. J Am Acad Orthop Surg 2000;8:10-20.
Kleinman PK, Marks SC, Blackbourne B: The metaphyseal lesion in abused infants: A radiologic-histopathologic study. Am J Roentgenol 1986;146:895-905.

Question 38

A 14-year-old boy has failed physical therapy management for Scheuermann kyphosis, and an extension thoracolumbosacral orthosis brace is recommended. The boy and his parents are told that the brace will force his thoracic spine into normal sagittal alignment and put the anterior vertebral bodies of the thoracic segment into tension, which will induce bone growth and normalization of wedge-shaped vertebrae. What name is associated with this process?

Explanation

The Heuter-Volkmann principle shows that bone placed in longitudinal tension will tend to stimulate longitudinal growth, and that compressive longitudinal forces inhibit longitudinal growth, making this response the best choice. Hooke's law relates to stress being proportional to strain and is not directly related to bone growth. Kirchhoff's laws apply to electrical circuit design. Wolff's law states that bone
remodels in response to mechanical stress, with the correlate that increased stress causes increased growth, and decreased stress leads to bone loss.

Question 39

A 50-year-old pipefitter falls from a ladder at work and dislocates his non-dominant shoulder. His MRI scan shows supraspinatus and infraspinatus tears with retraction to the glenoid. He cannot actively raise his arm away from his side. He denies prior shoulder symptoms before his fall. Three weeks of physical therapy have failed to improve his function. Which factor has been demonstrated to result in a poor clinical outcome following surgical intervention?

Explanation

Several studies have demonstrated that patients with work-related injuries do not do as well as those whose injuries are not work-related after repair of the rotator cuff. This patient’s age and gender are not negative prognostic indicators. The acute nature of the tear does not lead to an inferior outcome.

Question 40

A 45-year-old man with a painful varus knee is being considered for an upper tibial osteotomy. Which of the following factors is considered the most compelling argument against this procedure?

Explanation

DISCUSSION: Proximal tibial osteotomy is appropriate for the younger and/or athletic patient who has mild to moderate medial compartment osteoarthritis. Relative contraindications include limited range of motion (eg, flexion contracture of 15°), anatomic varus of greater than 10°, advanced patellofemoral arthritis, and tibial subluxation. Inflammatory arthritides involve all the compartments and are a contraindication to osteotomies around the knee.
REFERENCE: Kelly MA: Nonprosthetic management of the arthritic knee, 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 245-249.

Question 41

Figure 59 shows properties of a material being tested for use as an implant. What is represented by the portion of the stress-strain curve from point A to point B?

Explanation

DISCUSSION: The figure is a stress-strain diagram representing specific metal subjected to increasing tensile stress. The portion of the curve from A to B is a straight line demonstrating a proportional increase in strain for each increase in tensile stress. If the stress is removed at any point between A and C, the material will return to its original shape, returning back along the original curve without permanent deformation. This is termed elastic behavior. If the applied stress causes strain beyond point C, then permanent deformation occurs and returns along a different path to a different zero stress point. This is termed plastic behavior. The point C at which the material stops behaving in an elastic manner and begins behaving in a plastic manner is the elastic limit or yield point. Point D represents a point on the curve of plastic deformation. Point E is the fracture point when the stress on the material creates enough strain that the material fractures.
REFERENCES: Vaccaro AR (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 45-46.
El-Ghannam A, Ducheyne P: Biomaterials, in Mow VC, Huiskes R (eds): Basic Orthopaedic Biomechanics and Mechano-Biology, ed 3. Philadelphia, PA, Lippincott-Raven, 2005, pp 501-503.

Question 42

The risk of progression with congenital kyphosis is greatest with which of the following?

Explanation

DISCUSSION: The risk of neurologic compromise associated with congenital kyphosis is normally secondary to risk of progression. The classic study of the natural history of congenital spinal deformity by McMaster and Singh confirms that an anterolateral bar with contralateral quadrant vertebrae has the greatest risk.
REFERENCES: McMaster MJ, Singh H: Natural history of congenital kyphosis and kyphoscoliosis: A study of one hundred and twelve patients. J Bone Joint Surg Am 1999;81:1367-1383.
Herring JA (ed): Tachdjian’s Pediatric Orthopaedics, ed 4. Philadelphia, PA, WB Saunders, 2008, p 351.
AL-Madena Copy

Question 43

Which of the following findings is most prognostic for the ability of a young child with cerebral palsy to walk?

Explanation

DISCUSSION: Several studies have shown that sitting ability by age 2 years is highly prognostic of walking. Molnar and Gordon reported that children not sitting independently by age 2 years had a poor prognosis for walking. Wu and associates reported that children sitting without support by age 2 years had an odds ratio of 26:1 of walking compared with those unable to sit. This was far higher than the odds ratios for cerebral palsy location, motor dysfunction, crawling, creeping, scooting, or rolling.
REFERENCES: Molnar GE, Gordon SU: Cerebral palsy: Predictive value of selected clinical signs for early prognostication of motor function. Arch Phys Med Rehabil 1976;57:153-158.
Wu YW, Day SM, Strauss DJ, et al: Prognosis for ambulation in cerebral palsy: A population-based study. Pediatrics 2004;114:1264-1271.

Question 44

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 45

A “p value” of 4% (p=0.04) indicates that the

Explanation

The paper cited is an excellent review in detail about confidence intervals including the mathematical equations.
The p value is the probability that the chance selection of patients might suggest a difference in treatment that was not real. Only with a small p value are we willing to believe that the observed difference in treatment is very likely real and not simply due to chance.
The confidence interval provides a measure of the magnitude of the possible difference between two groups of patients, regardless of whether or not the p value was small. This makes the confidence interval more informative than the p value when different treatments are compared. This is much beyond the scope of this review.

Question 46

A 72-year-old man with a history of Parkinson’s disease, stable coronary artery disease, and mild renal insufficiency is seen for hip arthroplasty. Which of the following is considered the most appropriate bearing of choice?

Explanation

DISCUSSION: The most appropriate bearing of those listed would be a large diameter metal head on cross-linked polyethylene. Because of the renal insufficiency, metal-on-metal should be avoided because metal ions are renally excreted. Ceramic-on-ceramic implants are not necessary in this patient because of the patient’s limited activity and life expectancy, as well as the downside of increased cost, the small but definite risk of ceramic fracture, and the increased technical demands of inserting ceramic implants. A highly cross-linked liner is favored to allow for maximum head size as the patient may be at increased risk of dislocation because of his neurologic disorder.
REFERENCES: Bragdon CR, Greene ME, Freiberg AA, et al: Radiostereometric analysis comparison of wear of highly cross-linked polyethylene against 36- vs 28-mm femoral heads. J Arthroplasty 2007;22:125-129.
MacDonald SJ: Metal-on-metal total hip arthroplasty: The concerns. Clin Orthop Relat Res 2004;429:86- 93.

Question 47

The illustration shown in Figure 19 shows a Chamberlain line. What is the most likely diagnosis?

Explanation

DISCUSSION: Basilar invagination is best defined as vertical or compressive instability at the occiput-C1 joint. Such invaginations most commonly occur in patients with rheumatoid arthritis but also can occur secondary to trauma or tumor. A Chamberlain line is used as a method to determine basilar invagination. The odontoid tip should not be more than 5 mm above a Chamberlain line.
REFERENCES: Wiesel SW, Rothman RH: Occipito-atlantal hypermobility.

Spine 1979;4:187-191.
Clark CR: The Cervical Spine, ed 3. Philadelphia, PA, Lippincott-Raven, 1998, pp 50-51.

Question 48

When harvesting iliac crest bone graft during a posterior spinal decompression and fusion, injury to what structure can result in painful neuromas or numbness over the skin of the buttocks?

Explanation

DISCUSSION: The superior cluneal nerves (L1, L2, and L3) are most at risk when harvesting iliac crest bone graft during a posterior decompression and fusion. These nerves pierce the lumbodorsal fascia and cross the posterior iliac crest, beginning 8 cm lateral to the posterior superior iliac spine. The ilioinguinal nerve is more at risk during exposure of the anterior ilium during retraction of the iliacus and abdominal wall muscles. Iliohypogastric nerve injury may arise in a similar fashion to ilioinguinal neuralgia. The lateral femoral cutaneous nerve lies in close proximity to the anterior superior iliac spine and is also at risk with anterior iliac crest bone graft harvesting. The superior gluteal nerve courses through the sciatic notch and supplies motor branches to the gluteus medius, minimus, and tensor fascia lata muscles. Injury results in hip abduction weakness.
REFERENCES: An HS: Principles and Techniques of Spine Surgery. Baltimore, MD, Williams and Wilkins 1998, pp 770-773.
Kurz LT, Garfin SR, Booth RE Jr: Harvesting autogenous iliac bone grafts: A review of complications and techniques. Spine 1989;14:1324-1331.
Mrazik J, Amato C, Leban S, et al: The ilium as a source of autogenous bone grafting: Clinical considerations. J Oral Surg 1980;38:29-32.

Question 49

During the early swing phase of the normal gait cycle, what lower extremity muscle is primarily contracting?

Explanation

DISCUSSION: Electromyography during walking reveals the tibialis anterior muscle is active during early swing, allowing the foot to clear the ground. All of the other muscles are quiet, as the limb moves forward through space with minimal muscular effort. The other muscles are primarily active during weight acceptance or push-off.
REFERENCES: Gage JR: An overview of normal walking. Instr Course Lect 1990;39:291-303.
Wootten ME, Kadaba MP, Cochran GV: Dynamic electromyography II: Normal patterns during gait. J Orthop Res 1990;8:259-265.

Question 50

A 45-year-old man is seen in the emergency department after returning from a 2-hour airplane flight. He is reporting severe pain in his right leg but has no trouble moving his ankle, leg, or knee. Venous doppler testing reveals no evidence of deep venous thrombosis. He is placed on IV cephazolin but continues to worsen. On the third day in the hospital he has increased pain, some respiratory distress, and trouble maintaining his blood pressure. His leg takes on the appearance seen in Figure 15. An urgent MRI scan shows thickening of the subcutaneous tissues and superficial swelling in the leg but no evidence of an abscess. What is the next most appropriate step in management? Review Topic

Explanation

The patient has necrotizing fasciitis, a rare and sometimes fatal disease that has many different etiologies. Signs that this is not a normal infection are the worsening clinical symptoms despite IV antibiotics and the systemic symptoms. He needs urgent surgical care before he becomes completely septic and unstable. He needs very aggressive debridement of his tissues. Hyperbaric oxygen and immunoglobulins are only anecdotally helpful, and would only be used after surgery.

Question 51

A 22-year-old female collegiate javelin thrower has shoulder pain. She notes that her pain is primarily located in the posterior aspect of her shoulder, is exacerbated with throwing, and she experiences maximal tenderness in the extreme cocking phase of the throwing cycle. On examination, she reports deep posterior shoulder pain when the arm is abducted 90 degrees and maximally externally rotated to 110 degrees. This reproduces her symptoms precisely. Shoulder radiographs are normal. What is the most likely diagnosis? Review Topic

Explanation

The patient has internal impingement. Internal impingement is commonly seen in overhead throwing athletes. When positioned in the extreme cocking phase of the throwing cycle, the posterior glenoid impacts the articular surface of the infraspinatus and posterior fibers of the supraspinatus tendon. This impact can cause partial-thickness rotator cuff tearing and posterosuperior labral lesions. She has no evidence of anterior shoulder instability, and her range of motion is excellent which rules out adhesive capsulitis. Subacromial impingement is identified with anterolateral shoulder pain with internal rotation in the abducted position. A full-thickness rotator cuff tear in a 22-year-old individual would require significant trauma and would likely result in pain at rest and with lifting.

Question 52

A 58-year-old woman who underwent a successful total hip replacement for degenerative arthritis 8 years ago reports groin pain for the past 6 months. A radiograph of the hip is shown in Figure 32. At revision, severe deficiency of the posterior column is noted. What reconstructive option would be most appropriate for the acetabulum?

Explanation

DISCUSSION: The radiograph shows medial migration of the cementless acetabular component, strongly suggesting acetabular discontinuity with a combined segmental and cavitary medial deficiency. The treatment of choice is a morcellized or structural graft, supported with a reconstructive cage bridging the pelvic discontinuity, and a cemented cup.
REFERENCES: Whiteside LA: Selection of acetabular component, in Steinberg ME, Garino JP (eds): Revision Total Hip Arthroplasty. Philadelphia, PA, Lippincott Williams and Wilkins, 1999, pp 209-220.
Berry DJ, Muller ME: Revision arthroplasty using an anti-protrusio cage for massive acetabular bone deficiency. J Bone Joint Surg Br 1992;74:711-715.

Question 53

In recurrent posterior shoulder instability, what is the recommended approach to the posterior capsule? Review Topic

Explanation

Using an infraspinatus-splitting incision allows for excellent exposure of the posterior capsule and minimizes the risk of injury to the axillary nerve which lies inferior to the teres minor in the quadrilateral space.

Question 54

A 12-year-old male patient is scheduled to undergo femoral lengthening. The 2 techniques at your disposal are (1) femoral lengthening along the mechanical axis of the limb with an external fixator, and (2) femoral lengthening along the anatomical axis of the femur with a telescoping nail. What happens to the mechanical axis of the limb when performing these techniques? Review Topic

Explanation

With femoral lengthening of the limb along its mechanical axis, the goal is overall mechanical axis preservation and this is not altered. When lengthening the limb along the anatomical axis of the femur, there is lateral mechanical axis deviation (LAD).
There is a difference of approximately 7° between the mechanical axis of the limb and the anatomical axis of the femur. Lengthening along the anatomical axis of the femur leads to lateral MAD. Similarly, shortening along the anatomical axis of the femur leads to medial MAD.
Kasis et al. described limb shortening of 4cm using external fixator assistance to dial in compression before fixation with a blade plate. They claimed this allowed correction of any tendency to medialize the mechanical axis of the limb prior to plate fixation.
Burghardt et al. described femoral lengthening over a telescoping nail and found lateral shift of the mechanical axis in 26 of 27 limbs, although many were minor and inconsequential. As a rule of thumb, the mechanical axis will shift about 1 mm laterally for every 1 cm of lengthening.
Illustration A illustrates how when lengthening with an external fixator (left), the mechanical axis can be preserved. On the other hand, when lengthening over a nail
(right), the anatomical axis is preserved, but there is lateral MAD (ISKD, intramedullary skeletal kinetic distractor).
Incorrect Answers:

Question 55

A 21-year-old man has had posterior neck discomfort for the past 6 months. A whole-body bone scan and a cervical single-photon emission CT reveal increased activity at the C7 spinous process. MRI reveals multifocal involvement of the spinous process lamina and facet of C7. A CT-directed needle biopsy reveals osteoblastoma. What is the best course of action?

Explanation

DISCUSSION: En bloc excision is the recommended treatment of osteoblastoma. Treatment should consist of en bloc removal of the lamina, facet, and spinous process. Facet removal would necessitate fusion. Radiation therapy is not recommended. Intralesional curettage has a high rate of recurrence.
REFERENCES: Bridwell KH, Ogilvie JW: Primary tumors of the spine, in Bridwell KH, DeWald RL (eds): The Textbook of Spinal Surgery. Philadelphia, PA, JB Lippincott, 1991, vol 2, pp 1143-1174.
Ozaki T, Liljenquist U, Hillmann A, et al: Osteoid osteoma and osteoblastoma of the spine: Experience with 22 patients. Clin Orthop 2002;397:394-402.

Question 56

A 60-year-old man who underwent left partial knee arthroplasty 6 months earlier was doing well until he experienced left knee pain and swelling for 4 weeks following a dental procedure. The left knee aspirate was bloody, with a white blood cell count of 8,000 and 70% neutrophils. Culture grew group B Streptococcus ( Granulicatella adiacens ), and serologies were elevated, with an erythrocyte sedimentation rate of 55 mm/h (reference range: 0 to 20 mm/h) and a C-reactive protein level of 24 mg/L (reference range: 0.08 to 3.1 mg/L). What is the best next step?

Explanation

DISCUSSION:
This complication is best addressed with either a single-stage or two-stage total knee arthroplasty. A recent report suggests that a single-stage arthroplasty can be effective, although many surgeons would perform a two-stage procedure with an articulating or static spacer. Arthroscopic would be non-effective, especially given 4 weeks of symptoms. Resection arthroplasty without a spacer would leave an unstable and poorly functioning extremity. Knee fusion should be used as a salvage procedure.

Question 57

In the majority of patients with chronic anterior cruciate ligament (ACL)-deficient knees, analysis of the gait pattern during level walking will most likely reveal which of the following changes?

Explanation

DISCUSSION: Patients with chronic ACL-deficient knees typically have lower than normal net quadriceps activity during the middle portion of the stance phase; the net moment about the knee reverses from one that demands quadriceps activity to one that demands increased hamstring activity. This type of gait is termed “quadriceps avoidance.” This avoidance is believed to be a functional adaptation to reduce anterior tibial translation, and it is most prevalent as the knee moves from 45° of flexion toward full extension, the arc of motion through which the ACL is most responsible for stability.
REFERENCES: Hurwitz DE, Andriacchi TP, Bush-Joseph CA, Bach BR Jr: Functional adaptations in patients with ACL-deficient knees. Exerc Sport Sci Rev 1997;25:1-20.
Andriacchi TP, Birac D: Functional testing in the anterior cruciate ligament-deficient knee. Clin Orthop 1993;288:40-47.
Solomonow M, Baratta R, Zhou BH, et al: The synergistic action of the anterior cruciate ligament and thigh muscles in maintaining joint stability. Am J Sports Med 1987;15:207-213.

Question 58

A B D … C E F G

Explanation

DISCUSSION

Question 59

When compared with patients having a body mass index (BMI) lower than 35, patients with a BMI above 40 who undergo primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) are likely to have

Explanation

DISCUSSION:
The obesity epidemic is increasing, and the number of patients with a BMI higher than 35 undergoing THA and TKA also is growing. Controversy exists over the optimal BMI cutoff and the ability to perform joint replacements safely in patients who are morbidly obese. Several clinical series and national database analyses have shown that morbidly obese patients undergoing THA or TKA are at increased risk for wound complications as well as 30-day and 90-day readmissions. These patients’ incisions are typically larger because of the size of the soft-tissue envelope. Although the clinical scores following successful THA or TKA often are lower than the scores of controls, the overall changes in clinical function and satisfaction are equivalent in nonobese and obese patients.

Question 60

A 66-year-old woman who previously underwent hemiarthroplasty 2 years ago for a fracture continues to have severe pain and loss of motion despite undergoing physical therapy. A radiograph is shown in Figure 2. What is the most likely reason that this patient has failed to improve her motion?

Explanation

DISCUSSION: The radiograph shows tuberosity malposition. The effect of improper prosthetic placement has also been associated with poor outcomes. However, the malposition of the tuberosity seen on the radiograph clearly explains loss of motion in this patient. It has been demonstrated that the functional results after hemiarthroplasty for three- and four-part proximal humeral fractures appear to be directly associated with tuberosity osteosynthesis. The most significant factor associated with poor and unsatisfactory postoperative functional results was malposition and/or migration of the tuberosities. Factors associated with a failure of tuberosity osteosynthesis in a recent study were poor initial position of the prosthesis, poor position of the greater tuberosity, and women older than age 75 years (most likely with osteopenic bone). Greater tuberosity displacement has been identified by Tanner and Cofield as being the most common complication after prosthetic arthroplasty for proximal humeral fractures. Furthermore, Bigliani and associates examined the causes of failure after prosthetic replacement for proximal humeral fractures and found that although almost all failed cases had multiple causes, the most common single identifiable reason was greater tuberosity displacement.
REFERENCES: Bigliani LU, Flatow EL, McCluskey G, et al: Failed prosthetic replacement for displaced proximal humeral fractures. Orthop Trans 1991;15:747-748.
Boileau P, Krishnan SG, Tinsi L, et al: Tuberosity malposition and migration: Reasons for poor outcomes after hemiarthroplasty for displaced fractures of the proximal humerus. J Shoulder Elbow Surg 2002;11:401-412.
Tanner MW, Cofield RH: Prosthetic arthroplasty for fractures and fracture-dislocations of the proximal humerus. Clin Orthop Relat Res 1983;179:116-128.

Question 61

A 56-year-old man has had a 2-year history of slowly progressive neck pain and bilateral arm aching. Over the past year, he has noticed intermittent, diffuse numbness in both hands, with decreased grip strength and mild hand clumsiness. He denies any problems with balance. Examination shows a wide-based gait, intrinsic wasting, and a postive Hoffman's sign bilaterally. An MRI scan of the cervical spine is shown in Figure 16. What is the most appropriate treatment? Review Topic

Explanation

The patient has classic symptoms of myelopathy with upper motor neuron signs on examination. His symptoms have been present for years, and are getting worse. The cervical spine MRI scan shows spinal stenosis with multilevel spondylosis causing spinal cord compression at multiple levels. With the longstanding duration of the patient's signs and symptoms, combined with involvement of multiple levels in the cervical spine, posterior multilevel laminectomy and fusion is the best treatment option. Two-level anterior diskectomy and fusion would address the two areas of most severe narrowing, but it would fail to decompress the other stenotic areas which also require decompression. Posterior cervical foraminotomies would only address radicular symptoms, which are not present in this patient, and would not succeed in decompression of the spinal cord. Cervical epidural injections are not indicated for myelopathy symptoms, and may in fact place this patient at risk for neurologic deterioration.

Question 62

Varus malalignment after a talar neck fracture with medial comminution causes a decrease in what motion?

Explanation

DISCUSSION: Varus alignment at the talar neck results in a decrease in subtalar eversion before impingement occurs. Varus talar neck alignment can cause a fixed internal rotation position of the midfoot as the navicular follows the talar head. This can lead to a more rigid hindfoot which is specifically manifested as a decreased eversion range of motion.
Herscovici et al review the appropriate management of complex ankle and hindfoot injuries in this instructional course lecture.
Daniels et al performed a cadaveric study where they osteotomized the talar neck and then studied ankle motion with and without removal of a medially based wedge of bone. They found that subtalar eversion was specifically decreased.
Sanders et al found that secondary reconstructive procedures following talar neck fractures were most commonly performed to treat subtalar arthritis or misalignment.

Question 63

Figure 194 is the radiograph of a 71-year-old woman who had a right total hip arthroplasty 4 months ago; now she has tripped and fallen. She is unable to continue weight-bearing activity on her right leg, but denies pain or ambulation issues prior to her fall. She is seen in the emergency department. What is best treatment for this patient?

Explanation

DISCUSSION
This patient has sustained a periprosthetic hip fracture consistent with a Vancouver B2 pattern. The femoral stem must be revised by bypassing the fracture and simultaneously providing stability through fixation. Method of fixation is dependent upon fracture pattern, and, in this case, the medial fracture fragment is better suited for cerclage fixation. Loosening of the stem precludes simply fixing the fracture with cables, plates, or allograft struts, and there is no need to allow the fracture to heal prior to placing a new stem if the fracture is adequately stabilized with fixation.
CLINICAL SITUATION FOR QUESTIONS 195 THROUGH 197
A 67-year-old woman with osteoarthritis is scheduled for total hip arthroplasty (THA). She has a history of hypertension and stenting for coronary artery disease. She has no surgical history. Her presurgical hemoglobin level is 11.5 g/dL (reference range, 14.0-17.5 g/dL).

Question 64

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

Explanation

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

Question 65

A 19-year-old woman fell onto her nondominant hand 6 weeks ago. Radiographs are shown in Figures 37a and 37b. A decision has been made to treat this fracture surgically. What is the best approach to treat this fracture?

Explanation

DISCUSSION: Displaced fractures of the scaphoid are best treated with compression screw fixation. Proximal third fractures (as in this patient) are optimally approached via a dorsal approach to ensure proper reduction and compression. Fractures of the scaphoid waist can be approached either by a volar or a dorsal approach. Kirschner wire fixation is limited to proximal pole fractures that are too small to accommodate the trailing head of a compression screw.
REFERENCES: Retting ME, Raskin KB: Retrograde compression screw fixation of acute proximal pole fractures. J Hand Surg Am 1999;24:1206-1210.
Filan SK, Herbert TJ: Herbert screw fixation of scaphoid fractures. J Bone Joint Surg Br 1996;78:519-529.

Question 66

Which of the following statements is true regarding the posterior oblique portion of the medial collateral ligament of the elbow? Review Topic

Explanation

Addressing flexion in a post-traumatic contracture of the elbow requires releasing the posterior oblique ligament (or band) of the medial ulnar collateral complex.
The medial ulnar collateral ligament is one of the primary static stabilizers of the elbow and is composed of three parts: anterior, posterior and transverse. The MCL provides resistance to valgus and distractive stresses. The anterior oblique fibers (of the anterior bundle) are the most important against valgus stresses. The posterior bundle is involved elbow contractures and releasing it can yield significant flexion gains, without creating valgus instability.
Morrey et al. performed a pilot study on 4 specimens and found the valgus stability is equally divided among the medial collateral ligament complex, anterior capsule, and bony articulation in full extension; whereas, at 90 degrees of flexion the contribution of the anterior capsule is assumed by the medial collateral ligament which provides approximately 55% of the stabilizing contribution to valgus stress.
Regan et al. was a subsequent study by the same group that found the posterior medial collateral ligament (PMCL) was taut only when the elbow was in a flexed position. Among the collateral ligaments, the anterior (AMCL) was the strongest and stiffest. (Of note, using present terminology these would be referred to as posterior oblique and anterior oblique portions of the medial ulnar collateral complex).
Wada et al. reported a series of open medial releases for post-traumatic elbow contracture and found scarring on the posterior oblique bundle in all cases. Large increases in flexion were achieved by releasing this structure and the capsule without the need for a lateral incision in most cases.
Illustrations A and B show the posterior oblique portion of the medial collateral ligament. Illustration C shows the most recent terminology and identifies the area to be resected for stiffness.
Incorrect Answers:

Question 67

What is the most common arthroscopic finding of internal impingement in an overhead athlete?

Explanation

DISCUSSION: Internal impingement occurs when the articular side of the supraspinatus abrades against the posterior superior glenoid in the cocking position. Damage may include a posterior labral tear where the contact occurs, not anteriorly as in a Bankart lesion. Biceps fraying and acromion spurs are more commonly seen in extrinsic impingement. Loose bodies may occur from multiple lesions associated with instability and articular cartilage disorders but are uncommon in internal impingement.
REFERENCES: Jobe CM: Posterior superior impingement of the rotator cuff on the glenoid rim as a cause of shoulder pain in the overhead athlete. Arthroscopy 1993;9:697-699.
McFarland EG, Hsu C, Neir C, O’Neil O: Internal impingement of the shoulder: A clinical and arthroscopic analysis. J Shoulder Elbow Surg 1999;8:458-460.

Question 68

An 8-year-old boy with severe hemophilia A (factor VIII) and no inhibitor is averaging eight transfusions per month for bleeding into the right ankle. Examination shows synovial hypertrophy; range of motion consists of 0° of dorsiflexion and 20° of plantar flexion. The patient’s knees, elbows, and left ankle have no restriction of motion. Standing radiographs of the right ankle are shown in Figure 18. Management should consist of

Explanation

DISCUSSION: The patient has bilateral hypertrophic synovitis that is causing repeated hemarthroses and progressive arthropathy. Ankle synovectomy in patients with hemophilia is effective in significantly reducing the rate of joint bleeding and in slowing the progression of the arthropathy; therefore, bilateral synovectomies is the treatment of choice. Range of motion can be effectively maintained after ankle synovectomy. Bracing and prophylactic transfusions would be ineffective at this time. Ankle arthrodesis should be reserved for patients with severe pain. Compared with patients who have juvenile rheumatoid arthritis, patients with hemophilia generally do not have involvement of the subtalar joint and rarely require a pantalar arthrodesis.
REFERENCES: Greene WB: Synovectomy of the ankle for hemophilic arthropathy. J Bone Joint Surg Am 1994;76:812-819.
Greene WB: Chronic inflammatory arthridities and diseases related to the hematopoietic system, in Drennan JC (ed): The Child’s Foot and Ankle, New York, NY, Raven Press, 1992, pp 461-482.

Question 69

When using a two-incision approach for open reduction and internal fixation of a Hawkins III talar fracture-dislocation involving the talar neck and body, what anatomic structure must be preserved to optimize outcome?

Explanation

DISCUSSION: A Hawkins III fracture-dislocation generally presents with posteromedial displacement with the deltoid ligament intact. Therefore, the only remaining blood supply is the deltoid branch of the artery of the tarsal canal originating from the posterior tibial artery. Often, the medial malleolus is fractured, assisting in reduction and visualization of fracture reduction. If the medial malleolus is intact, a medial malleolus osteotomy allows visualization of the reduction without compromising the last remaining blood supply to the talus.
REFERENCES: Mulfinger GL, Trueta J: The blood supply of the talus. J Bone Joint Surg Br 1970;52:160-167.
Vallier HA, Nork SE, Barei DP, et al: Talar neck fractures: Results and outcomes. J Bone Joint Surg Am 2004;86:1616-1624.

Question 70

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 71

Intramembranous ossification during fracture repair is characterized by absence of which of the following elements?

Explanation

DISCUSSION: Intramembranous ossification occurs through the direct formation of bone without the formation of a cartilaginous intermediate. Clinically, both intramembranous and endochondral ossification occur simultaneously during fracture healing; however, the latter is characterized by the differentiation and maturation of chondrocytes, vascular invasion of a hypertrophic cartilage matrix, and bone formation. Collagens type II and X are cartilage specific and would be characteristic of endochondral ossification, not intramembranous ossification.
REFERENCES: Li J, Sandell LJ: Transcriptional regulation of cartilage-specific genes, in Rosier RN, Evans C (eds): Molecular Biology in Orthoapedics, Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 21-24.
Buckwalter JA, Einhorn TA, Bolander ME: Healing of the musculoskeletal tissues, in Rockwood CA Jr, Green DP, Bucholz RW, et al (eds): Rockwood and Green’s Fractures in Adults, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, pp 261-276.

Question 72

Flexion-distraction injuries of the thoracolumbar spine are most frequently associated with injury to what organ system?

Explanation

DISCUSSION: In patients with flexion-distraction injuries of the thoracolumbar spine, 50% have associated, potentially life-threatening, visceral injuries that occasionally are diagnosed hours or even days after admission. Based on these findings, consultation with a general surgeon is recommended. Blunt and penetrating injuries to the cardiopulmonary system or aorta sometimes can be seen with this type of injury, but they are no more common than with other types of thoracolumbar fractures because of the relatively mild bony injury anteriorly. Neurologic trauma with this type of fracture is also somewhat rare.
REFERENCES: Levine AM (ed): Orthopaedic Knowledge Update: Trauma. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1996, pp 351-360.
Inaba K, Kirkpatrick AW, Finkelstein J, et al: Blunt abdominal aortic trauma in association with thoracolumbar spine fractures. Injury 2001;32:201-207.

Question 73

What is the most appropriate orthosis for hallux rigidus?

Explanation

DISCUSSION: A Morton’s extension limits excursion of the first metatarsophalangeal joint. It also functions as a ground reaction stabilizer during the toe-off phase of gait and thus reduces torque and joint reaction force at the first metatarsophalangeal joint. The metatarsal arch pad and full-length semi-rigid longitudinal arch support may help by dorsiflexing the first metatarsal relative to the phalanx and thus decompress the first metatarsophalangeal joint. However, they are not as biomechanically effective as the Morton’s extension. Both medial hindfoot and lateral forefoot posting are contraindicated because they increase ground reaction at the first metatarsophalangeal joint.
REFERENCES: Coughlin MJ: Arthritides, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, p 611.
Watson AD, Wapner KL: Foot and ankle reconstruction, in Baratz ME, Watson AD, Imbriglia JE (eds): Orthopaedic Surgery: The Essentials. New York, NY, Thieme, 1999, p 635.

Question 74

Figure 1 is the radiograph of a 21-year-old college lacrosse player who has a 2-year history of progressive left groin pain that is exacerbated by activity. Pain is preventing him from participating with his team. Examination reveals a fit man without tenderness to palpation around the hip. No clicking or popping occurs with hip range of motion. Strength of all muscles about the hip is normal, but there is some mild pain with resisted hip flexion and hip adduction. While lying supine, progressive hip flexion with internal rotation and adduction reproduces his groin pain. Further workup confirms an anterosuperior tear of the acetabular labrum and prominence of the acetabulum. What is the most likely location of a chondral injury associated with these findings?

Explanation

This clinical scenario describes a patient with FAI attributable to pincer (acetabular) deformity. This form of FAI, which involves prominence of the anterosuperior acetabular lip, may be more common among women. Decreased range of motion and pain occur secondary to the abutment of the femoral head against the acetabular labrum and rim. Hip flexion, combined with adduction and internal rotation, recreates this contact and causes pain, but CAM or pincer etiology remains unknown. The differential diagnosis of hip pain in a young athlete includes femoral neck stress reaction/fracture, sacroiliac arthritis, intra-articular loose body, trochanteric bursitis, osteitis pubis, and hernia. No information presented in this scenario suggests any of these causes. Diagnosis of FAI is best performed via MR imaging, with an arthrogram increasing the sensitivity and specificity for labral pathology. Ultrasonography may be useful in the diagnosis of dysplasia or for dynamic assessment of a snapping hip, but ultrasonography is not commonly used to diagnose labral pathology. Although concomitant chondral lesions of the femoral head are uncommon, the forced leverage of the anterosuperior femoral neck upon the anterior acetabulum may result in a “contra-coup” chondral injury on the posteroinferior acetabulum. This is the most common location of chondral lesions in this scenario. Without bony resection to prevent further impingement, this patient will continue to experience symptoms. Because there is no evidence of femoral neck prominence (CAM lesion), there is no indication for osteoplasty of the femoral neck; resection of the pincer lesion is necessary. This will often require take-down of the labrum in this location. If possible, iatrogenic or traumatic labral tears should subsequently be repaired after pincer debridement because the labrum has important functions for hip stability and maintenance of the suction seal of the joint.

Question 75

A 14-year-old boy has a midshaft fibular lesion. Biopsy results are consistent with Ewing’s sarcoma. Following induction chemotherapy, local control typically consists of

Explanation

DISCUSSION: Current treatment regimens for Ewing’s sarcoma typically involve induction chemotherapy followed by local control and further chemotherapy. Local control consists of surgery alone, radiation therapy alone, or a combination of the two. In bones that are easily resectable (or expendable) with wide margins, surgery alone is usually recommended. For areas that are unresectable (ie, large, bulky pelvic tumors), radiation therapy alone is sometimes the preferred method of local control. If surgery is chosen and margins are close, radiation therapy can be used as an adjuvant. Amputation rarely is required for an isolated fibular lesion. Observation without adequate local therapy results in local recurrence.
REFERENCES: Nesbit ME Jr, Gehan EA, Burgert EO Jr, et al: Multimodal therapy for the management of primary, nonmetastatic Ewing’s sarcoma of bone: A long-term follow-up of the First Intergroup study. J Clin Oncol 1990;8:1664-1674.
Simon MA, Springfield DS, et al: Ewing’s Sarcoma: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 287-297.

Question 76

A 79-year-old woman with a massive rotator cuff tear presents to the emergency department with pain and difficulty moving her arm 7 weeks after undergoing reverse TSA for a displaced 4-part proximal humerus fracture.

Explanation

DISCUSSION
The complication rate is high after surgical treatment of proximal humerus fractures, particularly in elderly patients with osteoporotic bone. In patients treated with ORIF, common complications include varus malunion (16%), avascular necrosis (10%), screw penetration (8%), and infection (4%). In cases involving a dislocation of the humeral head, avascular necrosis is more common. In patients treated with hemiarthroplasty or TSA, complications include component loosening, infection, and dislocation. TSA is associated with
glenoid loosening in patients with rotator cuff incompetence and should be avoided in these patients. Reverse TSA is a potential solution for this population. Dislocation and postoperative infection are potential complications after reverse TSA.
RECOMMENDED READINGS
Krappinger D, Bizzotto N, Riedmann S, Kammerlander C, Hengg C, Kralinger FS. Predicting failure after surgical fixation of proximal humerus fractures. Injury. 2011 Nov;42(11):1283-

Question 77

A year-old patient fell 3 weeks after undergoing a total hip arthroplasty using cementless fixation of the femoral component. She sustained a comminuted Vancouver type B-2 fracture with displacement of the calcar fragment. What is the best treatment option?

Explanation

DISCUSSION:
The patient has an acute postoperative fracture of the proximal femur with subsidence. It is also common that the stem retroverts relative to the femur. It is most often seen in proximally porous coated stems within 90 days of surgery, one paper found it to occur 0.7% of the time in modern implants. There is always a debate whether this is a missed intraoperative fracture, or a new fracture that has resulted from an event of increased hoop stresses. Removal of the primary stem, placement of a diaphyseal engaging
stem (most frequently a tapered-fluted stem), and cabling of the fracture is the most successful treatment.

Question 78

An 83-year-old woman with a long history of her foot slowly and progressively “turning out” now reports significant ankle pain. History reveals that she has significant cardiac disease and exercise-induced angina. Examination reveals a deficiency in the posterior tibial tendon; however, the hindfoot remains moderately supple. Radiographs reveal a valgus tilt of the tibiotalar joint and early arthrosis. What is the most appropriate orthotic management?

Explanation

DISCUSSION: The patient will continue to have pain secondary to the ankle arthrosis with both the UCBL and the molded articulated ankle-foot orthosis. The total contact orthotic does not provide enough hindfoot control to support the progressive collapse of the ankle into valgus positioning. A molded leather gauntlet will not only control tibiotalar motion but also control hindfoot motion and allow support of the longitudinal arch.
REFERENCE: Augustin JF, Lin SS, Berberian WS, et al: Nonoperative treatment of adult acquired flat foot with the Arizona brace. Foot Ankle Clin 2003;8:491-502.

Question 79

A 47-year-old male tennis player has pain in his nondominant shoulder that has failed to respond to 4 months of nonsurgical management. Examination reveals acromial tenderness and pain at the supraspinatus tendon insertion. He has a positive impingement sign, pain on forward elevation, and minimal cuff weakness. The MRI scans are shown in Figures 30a and 30b. To completely resolve his symptoms, treatment should consist of

Explanation

DISCUSSION: The MRI scans show a mesoacromion with tendonopathy of the supraspinatus. The history and physical findings indicate that the patient has a symptomatic os acromiale. Simple excision of the unstable os acromiale has not yielded consistently good results. Meticulous internal fixation using tension banding with cannulated screws and autologous bone grafting has shown good results for this problem.
REFERENCES: Hutchinson MR, Veenstra MA: Arthroscopic decompression of shoulder impingement secondary to os acromiale. Arthroscopy 1993;9:28-32.
Warner JJ, Beim GM, Higgins L: The treatment of symptomatic os acromiale. J Bone Joint Surg Am 1998;80:1320-1326.

Question 80

Ulnar collateral ligament (UCL) reconstruction using a modified Jobe technique

Explanation

DISCUSSION
Certain complications are more strongly associated with the approach and surgical procedure for elbow pathology. With a 2-incision distal biceps repair, heterotopic ossification
with a radial-ulnar synostosis is a concern. This complication can be minimized through irrigation of bone debris and care to avoid dissection between the radius and ulna. With a single-incision distal biceps repair, the lateral antebrachial cutaneous nerve is retracted during the procedure. Numbness on the lateral side of the forearm is common, although often temporary. During arthroscopic debridement for lateral epicondylitis, injury to the radial UCL can occur, leading to posterolateral rotatory instability of the elbow. The modified Jobe technique for UCL reconstruction typically involves an ulnar nerve transposition during the procedure. Numbness and tingling in the fourth and fifth digits are concerns when this procedure is performed.

Question 81

A 56-year-old man who underwent a left total hip arthroplasty 8 years ago is seen following a fall from a standing height. A radiograph obtained at 2 years postoperatively is shown in Figure 55a and a current radiograph obtained in the emergency department is shown in Figure 55b. On further questioning, he reports pain in this thigh for the past 3 years that has been increasing in intensity. Appropriate management at this time includes which of the following?

Explanation

DISCUSSION: The patient has a Vancouver type B2 periprosthetic femoral fracture with a loose, cementless femoral component. Radiographs show subsidence of the femoral component and the patient reports pain in the thigh for several years prior to the fall. When the femoral component is loose, revision is mandated to treat both the loose component and the fracture. Nonsurgical management is associated with a high risk of medical complications related to extended recumbency as well as a high rate of malunion and nonunion. Cementless femoral component revision has been shown to fare better than cemented femoral components, particularly for treating periprosthetic fractures of the femur.
REFERENCES: Masri BA, Meek RM, Duncan CP: Periprosthetic fractures evaluation and treatment. Clin Orthop Relat Res 2004;420:80-95.
Springer BD, Berry DJ, Lewallen DB: Treatment of periprosthetic femoral fractures following total hip
arthroplasty with femoral component revision. J Bone Joint Surg Am 2003;85:2156-2162. Question 56
A 62-year-old woman who underwent a primary total knee arthroplasty under a combined spinal-epidural anesthetic presents 5 hours postoperatively with severe pain in the extremity that is unresponsive to narcotic pain medication. A tourniquet was used during the procedure. On examination, the patient is unable to dorsiflex or plantar flex the foot and the pulses appear to be asymmetric. What is the next most appropriate step in management?
Discontinuation of the epidural and serial neurologic exams
Loosening of the surgical bandages and elevation of the extremity
MRI of the spine to evaluate for an epidural hematoma
Return to the operating room for angiography and vascular bypass
Return to the operating room for angiography, vascular bypass, and four-compartment fasciotomy PREFERRED RESPONSE: 5
DISCUSSION: The patient has clinical evidence of vascular injury and compartment syndrome. An emergent
vascular consult and a return to the operating room for an angiogram and revascularization are needed. In these situations, thrombectomy alone is often not sufficient and a bypass is typically required. A four-compartment fasciotomy should be done following revascularization of the extremity.
REFERENCES: Calligaro KD, Dougherty MJ, Ryan S, et al: Acute arterial complications associated with total hip and knee arthroplasty. J Vase Surg 2003;38:1170-1177.
Smith DE, McGraw RW, Taylor DC, et al: Arterial complications and total knee arthroplasty. J Am Acad Orthop Surg 2001;9:253-257.
Ninomiya JT, Dean JC, Goldberg VM: Injury to the popliteal artery and its anatomic location in total knee
arthroplasty. J Arthroplasty 1999;14:803-809.

Question 82

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

Explanation

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

Question 83

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

Explanation

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

Question 84

While performing long fusion with osteotomies for a patient with adult scoliosis and sagittal plane deformity, the neurophysiologist reports a change in motor-evoked potentials in the lower extremities. What is the most appropriate next step?

Explanation

DISCUSSION
The use of intraoperative neuromonitoring is expanding, especially in the setting of deformity surgery. Changes in monitoring are concerning for the possibility of a neurologic injury; however, several other factors can alter signals. These include hypotension, changes in anesthesia depth and medications, the use of paralytic agents, and technical issues such as leads falling out or becoming disconnected. If a change in neuromonitoring signals is noted, these factors should be checked first to rule out false-positive findings. If this does not correct the problem, the wound should be explored to ensure there is no compression on the neural elements. Finally, if the deformity has been corrected, some of the correction can be released in an attempt to improve the signals. A wake-up test is difficult to perform and does not provide specific information regarding the location of the problem or how to correct it. Steroids may be used depending on surgeon preference, but should not be used until neurologic injury is ruled out. Any neuromonitoring changes always necessitate immediate investigation.
RECOMMENDED READINGS
Ziewacz JE, Berven SH, Mummaneni VP, Tu TH, Akinbo OC, Lyon R, Mummaneni PV. The design, development, and implementation of a checklist for intraoperative neuromonitoring changes. Neurosurg Focus. 2012 Nov;33(5):E11. doi: 10.3171/2012.9.FOCUS12263. PubMed PMID: 23116091. View Abstract at PubMed
Malhotra NR, Shaffrey CI. Intraoperative electrophysiological monitoring in spine surgery. Spine (Phila Pa 1976). 2010 Dec 1;35(25):2167-79. doi: 10.1097/BRS.0b013e3181f6f0d0.
Review. PubMed PMID: 21102290. View Abstract at PubMed

Question 85

The dorsal (Thompson) approach to the proximal forearm uses which of the following intermuscular intervals?

Explanation

DISCUSSION: The Thompson posterior approach is used in treatment of fractures of the proximal radius. Dissection is carried out through the interval between the extensor carpi radialis brevis (radial nerve) and the extensor digitorum communis (posterior interosseous nerve). To identify this interval, the forearm is pronated and the mobile lateral wad of muscles (the ulnar-most belly is the extensor carpi radialis brevis) is grasped with the thumb and finger and pulled from the much less mobile mass of the extensor digitorum communis. The furrow created is marked with a skin marker for subsequent skin incision. The skin incision follows a line from the lateral epicondyle of the humerus to a point corresponding to the middle of the posterior aspect of the wrist. Distally, the intermuscular plane is between the extensor carpi radialis brevis and the extensor pollicis longus.
REFERENCES: Crenshaw AH Jr: Surgical techniques and approaches, in Canale ST (ed): Campbell’s Operative Orthopaedics, ed 9. St Louis, MO, Mosby-Year Book, 1998, vol 1, pp 128-129.
Hoppenfeld S, deBoer P: Posterior approach to the radius, in Surgical Exposures in Orthopaedics: The Anatomic Approach, ed 2. Philadelphia, PA, Lippincott-Raven, 1992, pp 136-146.
Thompson JE: Anatomical methods of approach in operations on the long bones of the extremities. Ann Surg 1918;68:309-316.

Question 86

A 13-year-old boy has a mild deformity of the left sternoclavicular joint after being involved in a rollover accident while riding an all-terrain vehicle. Examination in the emergency department reveals that he is hemodynamically stable, and his neurovascular examination is normal. The CT scan shown in Figure 22 was obtained because radiographs were inconclusive. Management should consist of

Explanation

DISCUSSION: The CT scan reveals a completely displaced physeal fracture of the medial clavicle with marked posterior displacement of the distal fragment. This fracture pattern is associated with potential injury to the vascular structures of the mediastinum. Reduction should be performed for this fracture and generally can be done closed with shoulder retraction and upward pull on the clavicle with a towel clip. Once reduced, the fracture is relatively stable and typically will heal in good position. Reduction should be performed in the operating room in the event that a vascular injury is detected once compression is removed from the clavicle. Open reduction may be necessary if closed reduction is not possible; however, pinning or ligament reconstruction usually is not necessary.
REFERENCES: Rockwood CA, Matsen FA (eds): The Shoulder, ed 2. Philadelphia, PA,

WB Saunders, 1998, p 581.
Wirth MA, Rockwood CA Jr: Acute and chronic traumatic injuries of the sternoclavicular joint. J Am Acad Orthop Surg 1996;4:268-278.

Question 87

Acetaminophen is an antipyretic medication. It exerts its pharmacologic effects by inhibiting which of the following enzymes?

Explanation

DISCUSSION: Acetaminophen inhibits prostaglandin E2 production via IL-1 β, without affecting cyclooxygenase-2 enzymatic activity. The therapeutic concentrations of acetaminophen induce an inhibition of IL-1 β-dependent NF-kappa β nuclear translocation. The selectivity of this effect suggests the existence of an acetaminophen-specific activity at the transcriptional level that may be one of the mechanisms through which the drug exerts its pharmacologic effects. Acetaminophen does not affect any of the other enzymes named above.
REFERENCE: Mancini F, Landolfi C, Muzio M, et al: Acetaminophen down-regulates interleukin-1beta-induced nuclear factor-kappaB nuclear translocation in a human astrocytic cell line. Neurosci Lett 2003;353:79-82.

Question 88

When performing an inside-out lateral meniscal repair, capsule exposure is provided by developing the Review Topic

Explanation

Capsular exposure for an inside-out lateral meniscal repair is performed by developing the interval between the iliotibial band and biceps tendon. Posterior retraction of the biceps tendon exposes the lateral head of the gastrocnemius. Posterior retraction of the gastrocnemius provides access to the posterolateral capsule.

Question 89

Following an acute dislocation of the patella, the risk of a recurrent dislocation is greater if the patient has which of the following findings?

Explanation

DISCUSSION: Recurrent dislocations may follow an earlier dislocation. One study found that in patients who had a patellar dislocation between the ages of 11 to 14 years, 60% had a recurrent dislocation. The incidence of recurrent dislocation dropped to 33% in patients who had a patellar dislocation between the ages of 15 to 18 years. The authors also found that the incidence of recurrence was greater in patients who demonstrated a predisposition to dislocation as determined by evaluation of the unaffected knee. Predisposing signs included passive lateral hypermobility of the patella, a dysplastic distal third of the vastus medialis obliquis muscle, and a high and/or lateral position of the patella. A second study found that the risk of redislocation was considerably higher in patients who were in their teens at the first episode of dislocation compared to older patients. There are no studies linking either a patella baja or a bipartite patella to an increased risk of redislocation.
REFERENCES: Cash JD, Hughston JC: Treatment of acute patellar dislocation. Am J Sports Med 1988;16:244-249.
Larsen E, Lauridsen F: Conservative treatment of patellar dislocations: Influence of evident factors on the tendency to redislocation and the theraputic result. Clin Orthop

1982;171:131-136.

Question 90

A 17-year-old boy is shot in the left side of the neck at the C5-6 level and sustains an incomplete spinal cord injury that is called a Brown-Sequard syndrome. Which of the following best describes the expected deficits? Review Topic

Explanation

Brown-Sequard syndrome is an incomplete spinal cord injury that involves damage unilaterally to the cord, most commonly from penetrating trauma. The motors fibers of the cord decussate within the brainstem so the motor deficit is ipsilateral to the injury; whereas, the pain and temperature fibers cross midline immediately on entering the cord so that the sensory deficit is contralateral to the injury. This patient was shot in the left side, thus he would have weakness of the left upper and lower extremity with diminished pain and temperature sensation on the right side of the body. Response 3 describes opposite symptoms that would result from a right-sided injury. Response 1 describes a central syndrome with greater upper than lower extremity involvement. Response 2 is an anterior cord syndrome with only preservation of the posterior columns of the cord. Response 4 describes a C6 root injury.

Question 91

Early postoperative infections following primary total hip arthroplasty are most likely caused by which organism?

Explanation

DISCUSSION:
S aureus is the most common organism cultured in early (fewer than 4 weeks postoperative) periprosthetic infections. Methicillin-resistant S aureus is becoming a more common pathogen in certain patient populations. B hemolytic Streptococcus and some gram-negative infections can also be found in early postoperative infections. S epidermidis, S viridans, and P acnes are more commonly found in late (more than 4 weeks postoperative) infections.

Question 92

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

Explanation

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

Question 93

Arthritic change in cartilage is characterized by which of the following findings?

Explanation

Experimental models of late-stage arthritis in animals demonstrated lower compressive modulus, higher permeability, and higher water content. There is proteoglycan loss within the matrix. A significant and progressive decrease in the tensile and shear modulus has been observed.

Question 94

A collegiate football player who sustained an injury to his neck has significant neck pain and weakness in his extremities. Following immobilization, which of the following steps should be taken prior to transport?

Explanation

DISCUSSION: Prior to transport, the face mask should be removed so that the airway can be easily accessible. If serious injury is suspected, the helmet and shoulder pads should be left in place until he is assessed at the hospital and radiographs are obtained. Leaving the helmet and shoulder pads in place helps to keep the spine in the most neutral alignment. Removal of the helmet will result in extension of the neck, whereas removal of the shoulder pads will most likely result in flexion of the neck.
REFERENCES: Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Williams & Wilkins, 1998, p 376.
Thomas B, McCullen GM, Yuan HA: Cervical spine injuries in football players. J Am Acad Orthop Surg 1999;7:338-347.
Waninger KN, Richards JG, Pan WT, et al: An evaluation of head movement in backboard-immobilized helmeted football, lacrosse, and ice hockey players. Clin J Sport Med

2001;11:82-86.
Donaldson WF III, Lauerman WC, Heil B, et al: Helmet and shoulder pad removal from a player with suspected cervical spine injury: A cadaveric model. Spine 1998;23:1729-1732.
Peris MD, Donaldson WF III, Towers J, et al: Helmet and shoulder pad removal in suspected cervical spine injury: Human control model. Spine 2002;27:995-998.

Question 95

A 67-year-old man with right shoulder osteoarthritis (OA) remains symptomatic despite a course of nonsurgical treatment. A CT scan of the shoulder shows eccentric posterior glenoid wear with 10° of retroversion. What is the appropriate management of this glenoid bone loss during surgery for an anatomic total shoulder arthroplasty?

Explanation

Total shoulder arthroplasty (TSA) is superior to hemiarthroplasty for primary OA. The most common complication of TSA is glenoid loosening and malposition, which are common causes of glenoid failure. Glenoid malposition decreases the glenohumeral contact area and subsequently increases contact pressures. Altering the stem version to accommodate glenoid retroversion does not appropriately address soft-tissue balancing. A retroversion of <12° to 15° can be corrected with eccentric reaming without excessively compromising glenoid bone stock and risking glenoid vault penetration by the glenoid component. Posterior
glenoid bone grafting may be considered for glenoid retroversion >15°.

Question 96

A 62-year-old runner injured his right ankle 8 weeks ago. He has ongoing lateral ankle pain and swelling that did not improve with 4 weeks of immobilization and 4 weeks of physical therapy. MR images demonstrate a longitudinal tear of the peroneus brevis tendon. Treatment should involve

Explanation

DISCUSSION
Additional nonsurgical treatment is not beneficial for peroneal tendon tears. Early repair of longitudinal tears reduces risk for progression to a full-thickness tear that would necessitate peroneus brevis to peroneus longus tenodesis. Platelet-rich plasma has no role in peroneal tendon tears.
RECOMMENDED READINGS
Arbab D, Tingart M, Frank D, Abbara-Czardybon M, Waizy H, Wingenfeld C. Treatment of isolated peroneus longus tears and a review of the literature. Foot Ankle Spec. 2014 Apr;7(2):113-8. doi: 10.1177/1938640013514273. Epub 2013 Dec 30. Review. PubMed
PMID: 24381076.View Abstract at PubMed
Coughlin MJ, Schon LC. Disorders of tendons. In: Coughlin MJ, Saltzman CL, Anderson RB, eds. Mann's Surgery of the Foot and Ankle. 9th ed. Philadelphia, PA: Elsevier-Saunders; 2014: 1188-1291.
RESPONSES FOR QUESTIONS 71 THROUGH 75
Lapidus procedure
First metatarsophalangeal (MTP) joint arthrodesis and lesser metatarsal head resection
Proximal first metatarsal osteotomy
Distal first metatarsal chevron osteotomy
Biplanar distal first metatarsal osteotomy
Match the appropriate surgical procedure listed above with the clinical scenario described below.

Question 97

A patient undergoes anterior spinal decompression through a left retroperitoneal approach as treatment of an L2 burst fracture. Following surgery, examination reveals the temperature of the right foot is cool when compared with the left foot. Which of the following neurologic structures has most likely been disrupted?

Explanation

Chapter 6, p. 240: “The sympathetic chain lies in the lateral aspect of the vertebral body and on the most medial aspect of the psoas muscle. It is easy to identify as the tissue is cleared from the front of the vertebrae.”
Chapter 60, p. 777: “[After sympathetic denervation], at first the blood flow rises markedly because of lost vascular tone, but over a period of says to weeks the blood flow returns to almost normal because of progressive increase tone of the vascular musculature itself, thus compensating for the loss of sympathetic tone.”

Question 98

A 41-year-old woman with diabetes mellitus fell onto her outstretched arm and sustained an injury to the right elbow. Radiographs are shown in Figures 53a and 53b. What is the most appropriate management?

Explanation

The radiographs reveal a capitellum fracture with anterior displacement. To regain concentric and stable joint motion, this fragment requires reduction and stabilization. Without a joint dislocation, the ligaments are unlikely to be damaged and do not require further assessment with MRI. Closed reduction may be considered, but is unlikely to be successful. Without anatomic reduction of the fracture fragment, immobilization in either a long arm cast or a splint will not provide optimal outcomes. Based on the radiographs, the radial head is intact and does not require replacement.

Question 99

Figure 20 shows the resting and stress radiographs of a patient who has had pain and feelings of instability after undergoing a total knee arthroplasty 1 year ago. Which of the following ligaments is not functional and is therefore responsible for the patient’s symptoms?

Explanation

DISCUSSION: The radiographs show posterior instability caused by an absent posterior cruciate ligament. The tibia is significantly displaced posteriorly with respect to the femur. This can be demonstrated with a lateral radiograph obtained with the knee in flexion. The anterior cruciate ligament has been resected but is not responsible for the instability shown.
REFERENCE: Incavo SJ, Churchill DL: The role of the posterior cruciate ligament in total knee arthroplasty. Techniques Orthop 1999;14:267-273.

Question 100

An 8-year-old boy reports ankle pain after striking the ground with the medial aspect of his foot while attempting to kick a soccer ball. Radiographs reveal slight distal tibial physeal widening but no other abnormalities. In treating this injury, which of the following associated conditions is most likely present but may be missed without careful evaluation?

Explanation

DISCUSSION: Malrotation of the foot is frequently overlooked in this clinical setting. This can be judged by evaluating and comparing the transmalleolar axes of the affected and unaffected legs. The rotation occurs through the physis and frequently is not recognized until the patient has been walking for a few months. The other conditions are not expected to occur in the clinical setting described.
REFERENCES: Phan VC, Wroten E, Yngve DA: Foot progression angle after distal tibial physeal fractures. J Pediatr Orthop 2002;22:31-35.
Brook GJ, Greer RB: Traumatic rotational displacements of the distal tibial growth plate. J Bone Joint Surg Am 1970;52:1666-1668.

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

Proceed with implantation of the final components.
Perform a Z-lengthening of the patellar tendon.
Increase the size of the femoral component and use posterior femoral augments to decrease the size of the flexion gap.
Increase the size of the femoral component and use augments both distally and posteriorly to lower the joint line and decrease the size of the flexion gap.
Place distal femoral augments on the femoral component to lower the joint line.

Correct Answer: Perform a Z-lengthening of the patellar tendon.

Explanation:

Question 2:

A patient undergoes excision of a 3- x 3-cm soft-tissue sarcoma. The final histology results show tumor at the surgical margin. The surgical procedure performed is classified as

Options:

intralesional.
marginal.
wide.
wide contaminated.
radical.

Correct Answer: intralesional.

Explanation:

Question 3:

A 68-year-old woman undergoes hemiarthroplasty for a proximal humerus fracture. What post-operative motion should be limited as it puts the most stress on the lesser tuberosity fragment fixation?

Options:

pendulums
active-assisted internal rotation of the shoulder
active finger flexion
passive external rotation of the shoulder
passive internal rotation of the shoulder

Correct Answer: pendulums

Explanation:

Question 4:

- A 39-year-old woman jammed her long finger playing softball 24 hours ago. She is unable to actively extend the proximal interphalangeal joint; however, when the joint is brought passively into full extension, she is able to maintain that position. Management should consist of

Options:

Open repair of the central slip of the extensor mechanism
Open repair of the terminal tendon of the extensor mechanism
Closed splinting with the proximal interphalangeal joint
Closed splinting with the proximal interphalangeal joint in 30 degrees of flexion
Closed splinting with the proximal interphalangeal joint in 45 degrees of flexion

Correct Answer: Closed splinting with the proximal interphalangeal joint

Explanation:

Question 5:

What term best describes the process involved when a growth factor produced by an osteoblast stimulates the differentiation of an adjacent undifferentiated mesenchymal cell during fracture repair?

Options:

Mechanical
Autocrine
Paracrine
Endocrine
Systemic

Correct Answer: Paracrine

Explanation:

Question 6:

Which of the following is considered the most useful screening method for the evaluation of protective foot sensation in a patient with diabetes mellitus?

Options:

Sharp two-point discrimination
Light touch sensation
Hot and cold sensation
Vibratory sensation
07 Semmes-Weinstein monofilament sensation

Correct Answer: 07 Semmes-Weinstein monofilament sensation

Explanation:

Question 7:

Options:

Gender
Age
Race
Environment

Correct Answer: Race

Explanation:

Question 8:

A patient has pain 2 years after undergoing a metal-on-metal (MOM) left total hip arthroplasty (THA). Which test(s) best correlate with prognosis in the setting of reaction to metal debris?

Options:

Erythrocyte sedimentation rate, C-reactive protein, and white blood cell count
Serum cobalt and chromium ion levels
MRI with metal artifact reduction sequence (MARS)
CT of pelvis Painful MOM THA and taper corrosion can cause substantial damage to a patient's hip if left untreated. In this case, the workup for a painful MOM THA starts the same as a workup for a painful metal-on-polyethylene bearing couple. Infection must be ruled out in every case with a set of inflammatory markers. If these markers are remotely elevated, this is an indication for joint aspiration. In patients with metal debris, the pathology report often indicates too many cells to count or cellular debris. Metal ion levels do not seem to correlate with prognosis. There are well-functioning patients with high ion levels and poor-functioning patients with low ion levels. Advanced imaging with MARS MRI to evaluate for peritrochanteric fluid collection, a soft-tissue mass, or synovial/capsular hypertrophy will reveal signs of a metal reaction that indicate the need for a revision discussion. A CT scan can show more advanced bony destruction as an indicator of poor prognosis. These films can be used to determine the need for a structural graft or augments for reconstruction of bone loss attributable to metal debris.

Correct Answer: MRI with metal artifact reduction sequence (MARS)

Explanation:

Question 9:

Which of the following statements regarding conus medullaris syndrome is most accurate?

Options:

Conus medullaris syndrome most commonly accompanies injuries at the T12-L2 region.
Conus medullaris injury is a lower motor neuron injury, resulting in an excellent prognosis for recovery of bowel and bladder dysfunction.
The conus medullaris houses the motor cell bodies for the lumbar roots.
Lower extremity weakness is a common sign of conus medullaris syndrome.
Autonomic dysreflexia is common.

Correct Answer: Conus medullaris syndrome most commonly accompanies injuries at the T12-L2 region.

Explanation:

DISCUSSION: Conus medullaris syndrome most frequently occurs as a result of trauma or with a disk herniation at L1, resulting in a lower motor neuron syndrome but with a poor prognosis for recovery of bowel and bladder dysfunction. The conus region, as the termination of the spinal cord, contains the motor cell bodies of the sacral roots. The syndrome is usually a sacral level neural injury; therefore, lower extremity weakness is uncommon.
REFERENCES: Haher TR, Felmly WT, O’Brien M: Thoracic and lumbar fractures: Diagnosis and management, in Bridwell KH, Dewald RL, Hammerberg KW, et al (eds): The Textbook of Spinal Surgery, ed 2. New York, NY, Lippincott Williams & Wilkins, 1977, pp 1773-1778.
Reitman
CA
(ed): Management of Thoracolumbar Fractures. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 35-45.

Question 10:

Options:

Rheumatoid factor
HLA-B27
Synovial fluid analysis
MRI of the upper cervical spine
Urine screen for tetrahydrocannabinol (THC)

Correct Answer: MRI of the upper cervical spine

Explanation:

Question 11:

Synovitis of the MTP joints with eventual hyperextension deformity of the MTP is a common toe deformity seen with RA.

Options:

Genetic polymorphisms in all of the following genes are associated with osteoporosis EXCEPT?
Calcitonin receptor
Estrogen receptor-1
Vitamin D receptor
Type I collagen alpha-1 chain
Cartilage oligomeric matrix protein (COMP)

Correct Answer: Calcitonin receptor

Explanation:

Polymorphisms in the genes for the calcitonin receptor, estrogen receptor-1, vitamin D receptor, and the type I collagen alpha-1 chain (along with over 45 other genes) have been shown to be associated with osteoporosis. Answer 5, Cartilage oligomeric matrix protein, shows no current association with osteoporosis, but is the known genetic mutation associated with multiple epiphyseal dysplasia (a frequently tested fact). No single cause for osteoporosis has been shown at this point in time.
Jin et al conducted a meta-analysis regarding polymorphisms in the 5' flank of COL1A1 gene and the conflicting results relating to osteoporosis. They found that the COL1A1 Sp1 polymorphism is associated with a modest reduction in BMD and an increased risk of fracture.
The attached review by Huang and Kung discusses the multiple genetic and environmental determinants of osteoporosis and illustration A (from a different review by these same authors) lists the known genes currently associated with osteoporosis.
The greatest biomechanical difference between unicortical and bicortical locking screws is seen when what force is applied?
Compression
Torsion
Distraction
Bending on the side of the plate
Bending on the surface perpendicular to the plate
Torsion force has the largest biomechanical difference between unicortical locked screws and bicortical locked screws.
The first referenced article by Roberts et al noted that by replacing the farthest unicortical
screws (3 per side of the fracture) with bicortical locking screws, torsion resistance was increased by over 50%.
The second referenced article by Fulkerson et al noted decreased resistance to all applied forces with unicortical screws in a comminuted fracture model, and recommended against their use in such a fracture.
FOR ALL MCQS CLICK THE LINK ORTHO
MCQ BANK
You are planning surgery on a 54-year-old female with the tibial plateau fracture seen in figures A and B. After reduction of the joint surface you plan to fill the void with a bone-graft substitute to prevent joint collapse. Which of the following bone-graft substitutes
disappears most quickly in vivo?
Collagen-based matrices
Calcium phosphate
Calcium sulfate
Synthetic calcium sulfate and tri-phosphate mixture
Coraline hydroxyapatite
Calcium sulfate disappears in vivo quickly, usually within 4-12 weeks. Calcium phosphate and coraline hydroxyapatite are resorbed slowly, somewhere between 1-10 years, depending on the manufacturer. Synthetics that combine calcium sulfate and phosphate
resorb quicker than calcium phosphate but slower than calcium sulfate. Collagen-based matrices show quick resorption of the collegen but slow resorption of their hydroxyapatite coating. Walsh et al. examined the in vivo response of calcium sulfate pellets alone or in combination with autogenous bone graft in a sheep model. They found excellent bone formation in defects filled with calcium sulfate pellets. Immunostaining for various cytokines (BMP-2, BMP-7, PDGF, or TGF-beta)
showed elevated levels in the newly formed bone. They proposed that the local environment acidity was responsible for breakdown of the calcium sulfate. Watson evaluated 8 patients with comminuted tibial metaphyseal fractures treated with an injectable calcium sulfate. They found that bone regrowth was observed in all patients and the bone substitute almost completely resorbed by
months. Bucholz reviewed the biochemical, biomechanical, and longevity characteristics of the common bone substitutes.
Which of the following Figures shows a fixation construct achieving absolute stability?
Figure A shows percutaneous pinning, Figure B shows locked bridge plating, Figure C shows intramedullary nailing, Figure D shows lag fixation and neutralization plating, and Figure E shows external fixation. All except Figure D show relative stability constructs.
Absolute stability is a construct seen in Figure D, where lag screws and a neutralization plate are shown in a postoperative clavicle. No micromotion is seen with this technique, and healing is by primary (Haversian) healing, as opposed to the other four constructs, which have relative stability and heal via callus formation. The first reference, the AO Principles textbook, covers this in depth.
The second reference by Claes et al notes that bone can still heal with bone (as opposed to fibrous union) with strain rates up to 15%.
Which immunoglobulin subtype does the rheumatoid factor target?
IgA
IgE
IgM
IgG
Rheumatoid factor does not target an immunoglobulin
Rheumatoid factor is an auto-antibody most commonly seen with rheumatoid arthritis. The presence of rheumatoid factor can also indicate generalized autoimmune activity unrelated to rheumatoid arthritis (e.g. tissue or organ rejection). Rheumatoid factor is itself an IgM antibody that is directed against the Fc portion of IgG antibody. Rheumatoid factor (IgM) attaches to IgG to form immune complexes which are deposited in tissues like the kidney and contribute to the overall disease process in rheumatoid arthritis.
James et al. assessed the occurrence and predictive factors for orthopaedic surgery in an cohort of patients with rheumatoid arthritis. Risk factors for surgery varied but the authors found that decreased inflammatory markers during the first year after diagnosis decreased the risk for subsequent surgery.
The positive predictive value is defined as which of the following?
True positives / (true positives + true negatives)
False negatives / (false negatives + true positives)
False positives / (false positives + false negatives)
(True positives + false positives) / (true negatives + false negatives)
True positives / (true positives + false positives)
Corrent answer: 5
The positive predictive value is defined as the true positives divided by the sum of the positive results (true positive and false positive). It is also defined as the probability that a patient with a positive test actually has the disease; it is dependent on prevalence of disease.
The referenced articles by Wojtys and Kuhn et al are two of a series of medical statistics review papers.
An 85-year-old woman undergoes the treatment seen in Figure A for a displaced left femoral neck fracture. During wound closure, the patient becomes hypoxic and hypotensive. Despite aggressive resuscitation efforts, she passes away three hours later in the intensive care unit. The autopsy findings seen in
Figure B from the patient's lungs are most likely the result of which of the following
Reaming for the femoral component
Insertion of a femoral component after cement pressurization
Utilization of undersized broaches during canal preparation
Inadequate beta blockade
Use of spinal anesthesia
The clinical scenario is consistent with fat emboli syndrome. Figure A, shows a cemented bipolar hemiarthroplasty while Figure B shows marrow embolization into the lungs.
Studies have shown that intramedullary pressure and fat embolization are greatest during pressurization of cement and implant insertion.
Intramedullary pressure is influenced by size, shape, sharpness and insertion rate of an implant. Pressurization during cementing of a femoral component generates a large degree of pressure over a much wider surface area than in the other methods described of femoral canal instrumentation or preparation, as the entire femoral canal is
pressurized at one time. This results in the highest degree of marrow embolization to the lungs resulting in hypoxia.
Dobrjanski et al studied which variables affected intramedullary pressurization and found that lower implant insertion speed, lower hammering force, a
rubber- compared with steel-tipped hammer and a larger synthetic bone-to- implant radial gap reduced intramedullary pressure generated in a femur module.
Sustained compression applied to a growth plate under experimental conditions has what effect?
No effect
Accelerated longitudinal growth
Decelerated longitudinal growth
Decelerated apposition growth
Decreased bending strength of the bone
The Heuter-Volkmann Law states that compression across the growth plate slows longitudinal growth.
Stokes et al demonstrated that sustained compression across the growth plate can decrease longitudinal growth by 40%. Tension across the physis increases growth, but to a lesser degree.
A 13-year-old girl with a displaced proximal tibia fracture is brought into the emergency department by her adult cousin. The
fracture needs surgical management. The child is living with her cousin's family while her parents are in Germany. While the child speaks fluent English, her cousin and her parents are German-only speaking. How should you consent this patient?
No consent is needed given the urgent nature of the injury, proceed with surgery
Talk with the cousin, using the child as a translator
Talk with the cousin, using a German-translator
Call the parents in Germany, using the child as a translator over the phone
Call the parents in Germany, using a German-translator over the phone
This is an urgent (not emergent) clinical senario, and as such, the child needs to have
formal consent by speaking with her parents using a German- translator.
Wenger and Lieberman discuss the problems and potential solutions surrounding the process of informed consent in patients who either personally lack capacity to make decisions or in patients who require surrogates (like minors) to make treatment decisions.
Lindseth reviews the ethical issues encountered in pediatric orthopaedics and the problems associated with these decisions. Specifically pediatric consent is confounded because the person giving the consent is not the person who will bear the consequences of the treatment.
What is the primary mode of bisphosphonate excretion?
Renal
Gastrointestinal
Liver
Skin
Pulmonary
Bisphosphonates are a broad class of medicines used to treat osteoporosis and Paget's disease. They work by inhibiting osteoclast-mediated resorption after being absorbed into the inorganic phase of bone and taken up by osteoclasts. The paper by Lin et al provides a nice review of bisphosphonates and describe their appropriate use in enhancing bone density in patients with structurally
flawed bone. They describe the mechanism of action of bisphosphonates as pyrophosphate analogues and their renal mechanism of excretion, thus, prohibiting their use in patients with renal insufficiency. Rosier discusses the role of the orthopaedic surgeon in the diagnosis and treatment of patients with osteoporosis, now referred to as the "own the bone" initiative. Central to the treatment of osteoporosis are bisphosphonates and the anti-RANKL
monoclonal antibody, Denosumab.
The 2009 AAOS Clinical Guideline on prevention of pulmonary embolism in patients undergoing total hip or knee arthroplasty recommends classifying patients as having either a "standard" or "elevated" risk of bleeding complications. The presence of all of the following qualify a patient as having an "elevated" risk of major bleeding EXCEPT?
History of hemophilia
History of protein C deficiency
History of a recent gastrointestinal bleed
History of a recent hemorrhagic stroke
History of Von Willebrand's Disease
The 2009 AAOS Clinical Guideline on prevention of pulmonary embolism in patients undergoing total hip or knee arthroplasty recommends that all patients pre-operatively should be classified as either having an elevated or standard risk of bleeding and either an elevated or standard risk of pulmonary embolism.
A history of a bleeding disorder (e.g., hemophilia, Von Willebrand's Disease), recent GI bleed, or hemorrhagic stroke qualifies a patient as having an elevated risk of major bleeding.
A history of hypercoagulable state (such as protein C deficiency) or previous documented pulmonary embolism qualifies a patient as having an elevated risk of pulmonary embolism. Type of thromboembolism prophylaxis is recommended by weighing risk of major bleeding vs risk of PE. For those patients with a known contraindication to anticoagulation an IVC filter is considered. Mechanical prophylaxis is recommended across all risk (low to
high risk of either bleeding or pulmonary embolism) groups undergoing total hip or total knee arthroplasty. The detailed AAOS guidelines can be found on the AAOS website.
The evidence based clinical recommendations are presented in the reference by Johanson et al.
In consideration of a prosthetic knee, each of the following are advantages of choosing a polycentric knee with fluid control over a constant friction knee EXCEPT:
Allows variations in cadence
Flexes in a more controlled manner
Lighter in weight
Improved stance control allows less energy expenditure
Overall length of the limb is shortened during initiation of a step reducing the risk of stumbling
Single axis, constant friction knees function as a simple hinge. They are light, durable, and much cheaper prostheses making them ideal for growing children who will need multiple prostheses before reaching adulthood. This prosthesis allows only a single speed of walking, and relies solely on alignment for stance phase stability. Polycentric knees offer each of the advantages stated above making it a more ideal prosthesis for the active adult. Disadvantages of the polycentric knee include cost, weight, and more sophisticated maintenance.
Tang et al reviews the current prosthetic options for leg and foot amputees. Illustration A demonstrates a single axis knee prosthesis.
Illustration B demonstrates a polycentric knee prosthesis.
Which of the following biologic agents commonly used to treat rheumatoid arthritis (RA) DOES NOT target tumor necrosis factor- alpha (TNF-alpha)?
Infliximab
Rituximab
Etanercept
Golimumab
Adalimumab
Rituximab is a chimeric monoclonal antibody against the protein CD20, which is primarily found on the surface of immune system B cells. Rituximab is used in combination with methotrexate to treat RA that has not responded to one or more types of treatment, including anti-tumor necrosis factor (TNF) blockers.
In rheumatoid arthritis, and other chronic inflammatory conditions, cytokines produced by activated T-cells/macrophages contribute to the pro-inflammatory state. TNF-alpha is thought to be one of the major cytokines involved in rheumatoid arthritis pathology. As a result, many biologic agents used to treat RA are directed towards blocking TNF-alpha or its receptors. These drugs are able to reduce inflammation and stop disease progression.
Elliot et al. evaluated the safety and efficacy of infliximab in 20 patients with active RA in an open phase I/II trial lasting 8 weeks. They found that treatment with anti-TNFa was safe, well tolerated and resulted in significant clinical and laboratory improvements.
Illustration A depicts five commonly used anti-TNF alpha biologic agents for the treatment of rheumatoid arhtirits with their usual dosing regimens.
Incorrect Answers:
Receptor activator of nuclear-factor kappa-B ligand (RANKL) is
an important regulator of bone resorption. Which of the following cells is the MAJOR source of RANKL in bone remodelling?
Osteoclasts
Osteoblasts
Integrins
T cells
Macrophages
RANKL, a key osteoclastogenic protein, is expressed by osteoblasts and binds to the RANK receptor on osteoclast precursor cells.
The binding of RANKL to RANK on osteoclast precursor cells drives their differentiation into mature osteoclasts (multinucleated giant cells). Mature osteoclasts bind to the bone surfaces via integrins and resorb bone via their ruffled border within Howship's lacunae. Osteocytes orchestrate bone resorption and bone deposition by controlling osteoclast and osteoblast activity. Osteoblasts release RANKL to induce osteoclast differentiation, while
osteoblasts release osteoprotegerin (OPG) to downregulate osteoclastogenesis. Osteocytes also release fibroblast growth factor-23 (FGF-23), BMPs and sclerostin to regulate osteoblast activity. Antibodies to RANKL and Sclerostin have both been shown to increase bone density.
Compton et al. reviewed osteocyte function and the emerging importance of sclerostin, which is a glycoprotein. Sclerostin is predominantly secreted by osteocytes under physiologic conditions to act as an important negative regulator of bone mass through inhibition of bone formation by osteoblasts.
Illustration A demonstrates local bone milieu. It depicts the interplay between osteocytes, osteoblasts, and osteoclasts via the factors described above.
Incorrect answers:
A 45-year-old woman with rheumatoid arthritis is being scheduled for a total knee athroplasty in 2 weeks. She is currently taking sulfasalazine, Penicillamine, and etanercept, a tumor necrosis factor inhibitor (aTNF-a). What changes should be made to her medication regimen prior to surgery?
Discontinuation of all three medications 1 weeks prior to surgery
Discontinuation of sulfasalazine 1 weeks prior to surgery, continuation of etanercept and penicillamine
Continuation of sulfasalazine, penicillamine, and etanercept
Continuation of sulfasalazine and penicillamine, discontinuation of etanercept 1 week prior to surgery
Continuation of penicillamine, discontinuation of sulfasalazine and etanercept 1 week prior to surgery
Anticytokine disease-modifying antirheumatic drugs (DMARD) have become increasingly popular in the treatment of RA. Immunosuppression and the risk of infection are potential complications for all anti-TNF-alpha medications. Current recommendations for cessation of immunosuppressive therapy are when the drug concentrations are at their lowest levels which include the following: 3 days after etanercept injection; 2 weeks prior to infliximab infusion; 10 days after adalimumab injection. Medications such as sulfasalazine and penicillamine may be continued during the pre and post- operative period. Recent evidence and guidelines such as those reviewed by Keith's paper, suggest that anti-TNF-alpha medications should be stopped 4 weeks prior to surgery.
Giles et al report in their case control series an increased infection rate of RA patients undergoing an orthopaedic procedure who were on TNF-a inhibitors as opposed to patients on more traditional treatment regimens like methotrexate and prednisone.
Which of the following supplements affects blood clotting through its effect on platelets?
Ginkgo
Vitamin D
Ephedra
St. John's Wort
Selenium
Ginkgo and ginseng are two common supplements used in the general population that have inhibitory effects of platelet function. Adverse peri- operative complications consisting of increased bleeding and hematoma formation have been reported with the use of these two herbal supplements. The most commonly used supplements that could have an effect in the peri- operative period include echinacea, ephedra, garlic, ginkgo, ginseng, kava, St John's wort, and valerian. Bleeding has been shown to be effected by garlic, ginkgo, and ginseng; cardiovascular instability from ephedra; and hypoglycemia from ginseng. Kava and valerian have pharmacodynamic herb- drug interactions that can increase the sedative effect of anesthetics. St John's wort has been shown to alter the metabolism of certain drugs used in the perioperative period.
Ang-Lee et al review common supplements used today and their potential anesthesia/operative effects. The article places emphasis on proper history taking of not only medications but also supplements which is often times left out of documentation.
The femur radiograph of a healthy 25-year-old female is compared to the femur radiograph of a healthy 85-year-old female. Which of the following best describes the 25-year-old's femur?
Increased cortical thickness and a smaller medullary canal volume
Decreased cortical thickness and a larger medullary canal volume
Equivalent cortical thickness and medullary canal volume
Increased cortical thickness and larger medullary canal volume
Decreased cortical thickness and a smaller medullary canal volume
As the human body ages the cortical thickness/area decreases and subsequently the diameter/volume of the medullary canal increases. Therefore, a young healthy 25- year-old woman should have thicker cortices and a smaller medullary canal volume than her counterpart at 85 years. A decreased cortical bone area is linked to increased fracture risk.
Stein et al studied femurs from subjects aged 21-92 years of age. They found that a reduction in cortical area was seen in older specimens and this change was more
pronounced in female specimens.
Wrong Answers:
Which of the following is NOT a described complication of corticosteroid injections?
Local flare in surrounding tissues
Apoptosis of myocytes
Skin pigmentation changes
Fat atrophy
Facial flushing
Corticosteroids have not been shown to cause apoptosis of myocytes when injected extra-articularly. Each of the other answers have been described.
Cole and Schumacher provide a review of current uses of corticosteroid injections, and emphasize that how accurately the injection is placed affects the outcome.
Kumar and Newman report prospectively on 672 patients who received 1147 intra- and extra-articular injections. Their overall complication rate was low (16%) with injection site pain (mild) and bleeding constituting the majority of cases. There were 4 instances of fat atrophy in the extra-articular group, and
cases of syncope or dizziness in the intra-articular group. They did not discuss the efficacy of their injections.
A surgeon chooses a periarticular locking plate with unicortical proximal locking screws for an extra-articular distal femur fracture as seen in Figure A. Compared to an identical construct with bicortical unlocked proximal screw fixation, the periarticular locking plate with unicortical locking screws has which biomechanical properties?
Greater torsional and axial fixation strength
Less torsional but greater axial fixation strength
Equal torsional and axial fixation strength
Greater torsional but less axial fixation strength
Less torsional and axial fixation strength
Unicortical locking plates have characteristically less torsional strength than bicortical locking plates and bicortical non-locking plates. Axial strength is improved with locking plate fixation.
Zlowodzki et al studied the LISS periarticular locking plate with unicortical proximal fixation in a distal femur model and found superior axial fixation strength (134%) but worse torsional strength (68%) compared to a fixed angle blade plate with non- locking bicortical screw fixation.
Locked plating was reviewed by Haidukewych and Ricci which highlighted the added cost, unique complications, and they recommended the use of locked plating only in situations when unlocked constructs have demonstrated poor outcomes.
In rat models looking at the effect of malnutrition on fracture healing, amino acid supplementation in a nutritionally deprived rat increases all of the following EXCEPT
Serum albumin
Body mass
Quadriceps total protein content
Fracture callus mineralization
Insulin-like growth factor 1 (IGF-1) mRNA expression
The study by Hughes et al found that essential amino acid supplementation (glutamine, arginine, and taurine) following femoral fracture in a protein- malnourished rat model increases serum albumin, body mass, quadriceps total protein content, and fracture callus mineralization. Expression of IGF-1 and
IGF-2, myosin, actin, and VEGF mRNA were all significantly decreased in the amino acid supplemented group compared to the malnourished group. The malnourished group is thought to have upregulation of mRNA expression in attempt to increase the amount of protein product that is translated, however the lack of amino acid building blocks in the malnutrition group was a barrier to appropriate protein synthesis.
The study by Day et al created a malnourished rat femur fracture model by administering a 6% protein diet. They found that administering a 20% protein diet in the post-fracture period yielded a greater cross-sectional area of the
fracture callus and callus stiffness compared to the 6% protein malnourished group.
The statistical power of a study is best defined by?
1 - probability of type-II (beta) error
True positive/(true positive + false negative)
True negative/(false positive + true negative)
1 - probability of type-I (alpha) error
[True positive/(true positive + false negative)] / false-positive rate
The power of a study is an estimate of the probability of finding a significant association in a research study when one truly exists. The power is defined by
1 - probability of type-II (beta) error, and is often set at 80%. For example, a power of 80% means that if the intervention works, the study has an 80% chance of detecting this and a 20% chance of randomly missing it. A type-II or beta error occurs when one falsely concludes that there is no significant association when there actually is an association (resulting in a false-negative study that rejects a true alternative hypothesis). The type-II or beta error can be determined if Type I error rate and sample size are known. A type-I or alpha error occurs when a significant association is found when there is no true association (resulting in a false-positive study that rejects a true null hypothesis). The alpha level refers to the probability of a type-I (alpha) error and is usually set for most studies at 0.05. Answer 2 is the formula for sensitivity. Answer 3 is the formula for specificity. Answer 5 is the formula for the positive likelihood ratio. The references by
Kocher and Wojtys are excellent reviews of basic biostatistic principles.
A 55-year-old female with a history of metastatic breast cancer develops shoulder pain without any trauma. Which of the following is involved with the findings shown in Figures A and B?
IL-4
RANK
TNF-alpha
OPG
Sox-9
Osteoclastic bone resorption is the final common mechanism for osteolysis, whether due to a pathologic lytic lesion, macrophage activation in particle wear, or normal remodeling. The RANK-RANKL mechanism controls the coupling of osteoblast and osteoclast activation. Figures A and B show an osteolytic lesion in the humerus in a patient with known metastatic breast carcinoma.
RANKL is expressed from osteoblasts and bone-marrow stromal cells. When RANKL binds to the RANK receptor (receptor/activator of NF-[kappa]B) on the cell membrane of osteoclasts it stimulates differentiation from osteoclast progenitor cells to mature osteoclasts. Mature osteoclasts proceed with osteoclastic bone resporption.
Osteoprotegerin (OPG) acts as a decoy receptor by binding to RANKL and blocking the interaction between RANKL and the RANK-receptor and consequently inhibiting osteoclast formation and
activation.
Illustration A depicts the RANK/RANKL involvement in tumor metastatic spread.
Laboratory values of a normal serum calcium and parathyroid hormone can be found in which of the following disease states?
Primary hyperparathyroidism
Type I vitamin D deficient rickets
Type II vitamin D deficient rickets
X-linked hypophosphatemic rickets
Nutritional rickets
Hypophosphatemic rickets is caused by the inability of kidney proximal tubules to reabsorb phosphate due to a mutated PHEX gene, found on the X chromosome. PHEX is thought to protect extracellular matrix glycoproteins from proteolysis. Hypophosphatemic rickets shares many clinical similarities with nutritional rickets but shows PTH levels that are not elevated, even with calcium and phosphate abnormalities.
Pettifor reviews the advances in molecular genetics in the understanding and possible treatments in tumour-induced osteomalacia/rickets.
The review article by Carpenter discusses the X-linked disorder including its clinical manifestations, the wide spectrum of disease severity, and complications of the disease in adult patients.
Illustration A is a table that details the laboratory values associated with each type of rickets.
An 80 year-old female undergoes ORIF of her hip fracture without any complications. A hospitalist consult was obtained for medical clearance pre- operatively, and she was diagnosed with osteoporosis. Which of the following treatment scenarios will lead to the best management of the patient's osteoporosis?
Schedule a follow-up appointment with the patients primary care physician to initiate therapy
Order a physical therapy consult and initiate an exercise plan
Have the patient meet with a nutritionist to increase her calcium and vitamin D intake
Start bisphosphonates, and have the patient follow-up with her primary care physician
Perform a metabolic work-up as an inpatient, and set-up an appointment in an osteoporosis clinic
The initiation of appropriate osteoporosis treatment following hip fractures occurs at a surprisingly low rate. Physical therapy and dietary changes are not appropriate initial treatments for osteoporosis, and bisphosphonate therapy should be prescribed by the physician who will be following and managing the patient's osteoporosis.
Miki et al performed a prospective randomized trial where they compared the rates of osteoporosis treatment initiation. The percentage of patients who were on pharmacologic treatment at 6 months post-injury was 58% in the group whose treatment was directed by the orthopedic surgeon and osteoporosis clinic, and 29% when managed by the primary care physician alone.
The elements chromium, molybdenum, and cobalt are basic components of which of the following implant materials?
Aluminum oxide
Cobalt alloy
Stainless steel
PMMA
Tantalum
Cobalt alloys are extremely strong and are well-suited to applications requiring longevity. Strength of the implant is improved by the addition of molybdenum. Corrosion resistance is addressed by the addition of chromium, which also increases the hardness of the implant.
Incorrect Answers:
Which of the following scenarios of treatment of a humerus fracture best achieves low strain at the fracture site and high stiffness of the treatment construct?
Functional bracing of a transverse midshaft fracture
Comminuted midshaft fracture with locked bridge plating
Short oblique fracture with interfragmentary lag screw and locked neutralization plate
Uniplane external fixation of a spiral open fracture
Oblique fracture with intramedullary nail fixation
Strain in fractures is calculated by dividing the interfragmentary movement by the size of the fracture gap. Strain must be very low (2%) for primary bone healing to occur, and should be less than 10% for secondary bone healing to occur. Stiffness refers the ability of the construct to resist movement under applied loads. Answer 3 describes a situation where primary bone healing is
the goal. For this to occur, there must be no significant gapping at the fracture site, there must be low strain between fracture fragments, and the construct must be stiff.
None of the other answers would accomplish this. Functional bracing and intramedullary fixation both accomplish healing through formation of fracture callus, or secondary healing. A comminuted fracture treated with locked bridge plating relies on less stiffness to allow for secondary healing between fragments. However, since there are many fracture fragments, the strain is distributed among them and therefore remains low. A uniplane external fixator is very unlikely to accomplish low strain and high stiffness in this setting.
A 67-year-old man complains of low-grade fevers and calf pain 2 weeks following a total knee arthroplasty. What is the next appropriate step in management of this patient?
Plethysmography of lower extremity
MRI of lower extremity
CT angiography of lower extremity
Venous ultrasonography
Knee aspiration to evaluate for septic joint
Venous ultrasonography is the next best step in this patient's management, due to the clinical picture of a deep venous thrombosis. The most sensitive and specific recommended diagnostic procedure is a venous ultrasonography.
In their multi-center study, Haut et al. hypothesized that admission to trauma centers that use duplex ultrasound more frequently would independently predict increased DVT reporting for individual patients. They indeed found that trauma centers ultrasound practice was an independent predictor of DVT diagnosis for individual patients, controlling for patient-level risk factors, but concluded the elevated DVT rates at these centers were due to surveillance bias. As such, they recommend that surveillance for DVT should not be considered as a quality control measure in the care of trauma patients.
A patient undergoes closed reduction of a bimalleolar ankle fracture dislocation by the ER physician and is sent to your clinic for evaluation. You evaluate the patient and schedule him for surgery. According to the 2009 guidelines, which of the following scenarios would meet criteria for coding the encounter as a new patient?
You injected his knee in the office almost 3 years ago for osteoarthritis, and have not seen him since
He had an arthroscopic operation by your partner 4 years ago
You were consulted 1 year ago for shoulder pain when he was hospitalized for chronic renal failure
He was seen by your partner in clinic for a herniated disk 2 years ago, but had no procedures performed
You performed a hip replacement on him 12 years ago, and his last follow- up was 18 months ago at which time he was doing well
Only answer two is correct. The 2009 guidlines clarify that the patient can be defined as new only if he has not been seen by anyone in the physician's same group practice and of the same specialty in the past 3 years. Hand and sports medicine specialists with a CAQ, however, are an exception and are allowed to bill for patients already seen by other orthopedists in the same group as new
patients. This scenario would not qualify as a consultation, since the orthopedic surgeon
is taking over care of the patient's problem and is not merely offering advice to another physician who is already caring for the patient. Consultations do not have the same 3 year time qualification. However, Medicare and many other insurers no longer recognize consultation codes.
All the following medications binds reversibly to the enzyme COX-1 EXCEPT
Meloxicam
Diclofenac
Indomethacin
Naproxen sodium
Aspirin
Aspirin binds irreversibly to the cyclooxygenase enzyme. Aspirin acetylates platelet cyclooxygenase and permanently inhibits thromboxane (TX) A2 production leading to its antiplatelet effects. The other NSAID's listed above bind reversibly with COX-1.
Patrono et al discuss the pharmokinetics and platelet effect of both low dose and regular dose aspirin. Nonsteroidal anti-inflammatory drugs compete dose- dependently with arachidonate for binding to platelet cyclooxygenase.
In the treatment of patients with rheumatoid arthritis, TNF-alpha is blocked by which of the following agents?
Tocilizumab
Anakinra
Etanercept
Abatacept
Rituximab
Etanercept is a biochemically designed soluble p75 tumor necrosis factor receptor immunoglobulin G fusion protein, which blocks the downstream
effects of TNF.
Methotrexate is a chemotherapy agent used to inhibit lymphocytes. Gold inhibits monocytes, while sulfasalazine is an anti-inflammatory decreasing the production of
prostaglandins and leukotrienes. Rituximab inhibits B-cells as it
is a monoclonal antibody to CD20 antigen. Anakinra (Kineret) is a recombinant IL-1 receptor antagonist. Abatacept (Orencia) is a selective costimulation modulator that binds to CD-80 and CD-86 (inhibits T cells). Tocilizumab (Actemra)is an IL-6 receptor inhibitor (2nd line treatment for poor response to TNF-antagonist therapy).
Pisetsky wrote an editorial in NEJM discussing the development of TNF blockers through research, and the potential for the use of Etanercept in patients with juvenile RA through its inhibition of lymphotoxin-alpha.
Which of the following medications when combined with methotrexate has been shown to be more effective than methotrexate alone in the treatment of rheumatoid arthritis?
Nitrofurantoin
Rifampin
Azithromycin
Erythromycin
Doxycycline
Tetracycline was initially used in the treatment of rheumatoid arthritis (RA) because Mycoplasma was thought to be the causative agent. It was later found that tetracyclines have biologic effects on the inflammatory and immunologic cascade by inhibiting collagenase activity. Collagenase is an enzyme involved
in breaking down macromolecules in the connective tissue, contributing to the pathologic changes of RA.
In a prospective study, O'Dell et al found that initial therapy with methotrexate plus doxycycline was superior to treatment with methotrexate alone. Furthermore, similar results for low-dose and high-dose doxycycline suggested that antimetalloproteinase effects were more important than the antibacterial effects.
When using C-arm fluorocopy, patient radiation exposure will be increased with which of the following?
The extremity is positioned closer to the image intensifier
A larger body part is imaged compared to a smaller body part
Use of radiation beam collimation
Mini C-arm fluroscopy is used instead of large C-arm fluroscopy
Decreased duration of imaging
Patient radiation exposure will be increased if a larger body part is imaged compared to a smaller body part.
The first study by Giordano et al used radiation dosimeters for large and mini c-arm machines. They found that elevated exposure levels can be expected when larger body parts are imaged, when the extremity is positioned closer to the x-ray source, and when the large c-arm is used over the mini c-arm.
The second study by Giordano et al also used dosimeters for a mini c-arm and found that the surgical team is exposed to minimal radiation during routine
use of mini-c-arm fluoroscopy, except when they are in the direct path of the radiation beam. They list factors to decrease radiation exposure to patient and surgeon including: minimizing exposure time, reducing exposure factors, manipulating the x-ray beam with collimation, orienting the fluoroscopic beam in an inverted position relative to the patient, strategic positioning of the surgeon within the operative field, judicious use of protective shielding during imaging, and maximizing the distance of the surgeon from the radiation beam.
Illustration A shows that arrangement #1 has the body part half-way between the radiation source and image intensifier. Arrangement #2 has the the image intensifier acting as an arm table for the body part with the radiation source further away. Arrangement #1 has more radiation exposure than #2. The distance between the x-ray tube and the body part is doubled in arrangement
#2 compared to arrangement #1. This increased distance correlates to a reduction in exposure according to the inverse square law (reduction in radiation intensity with greater distance from the x-ray source).
You are seeing a 13-year-old girl for asymptomatic flat feet and recommend observation. In educating this patient/family about general bone health, you recommend what amount of daily dietary calcium for your patient?

Question 12:

Examination of a supine patient in which the hip is abducted, externally rotated, and flexed is referred to as

Options:

Beevor’s sign.
Lasegue’s sign.
Kernig’s sign.
femoral stretch test.
Patrick’s test.

Correct Answer: Patrick’s test.

Explanation:

Question 13:

Options:

Multilevel anterior cervical diskectomy with fusion
Anterior and posterior decompression with fusion
Anterior corpectomy and fusion with a fibula strut
Laminectomy and bilateral foraminotomies
Laminectomy and posterior fusion with lateral mass plating

Correct Answer: Laminectomy and bilateral foraminotomies

Explanation:

Question 14:

Histologic studies of surgically resected tissue in lateral epicondylitis demonstrate which of the following findings? Review Topic

Options:

Chondroblastic proliferation
Angiofibroblastic tendinosis
Significant active inflammation
Primarily calcium deposition
No normal tendon histology

Correct Answer: Angiofibroblastic tendinosis

Explanation:

Question 15:

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 16:

Total hip arthroplasty is most appropriate for the injury shown in Figure A for which of the following patients?

Options:

year-old female golf instructor
year-old female with Parkinsons dementia
year-old male household ambulator
year-old male alcoholic with hepatic encephalopathy
year-old male laborer

Correct Answer: year-old female with Parkinsons dementia

Explanation:

Question 17:

Which local treatment option is most appropriate?

Options:

Radiation and wide surgical resection
Extended curettage with adjuvants
Wide surgical resection
Revision knee arthroplasty

Correct Answer: Wide surgical resection

Explanation:

DISCUSSION
This patient has a pathologic femur fracture. Her history of antecedent pain in the context of a previously well-functioning implant suggests that a new process such as dedifferentiation of a long-standing lesion may have occurred. The initial radiograph reveals a well-mineralized lesion within the intramedullary canal with punctate calcifications. This by itself suggests an enchondroma or low-grade chondrosarcoma. It is important to note that enchondromas in the long bones rarely cause pathologic fractures. This is not the case when they are present in the hands and feet, where enchondromas frequently have a more aggressive radiologic appearance and pose higher risk. Radiographic findings concerning for malignant dedifferentiation of an enchondroma
include cortical thinning or breach, a soft-tissue mass, or periosteal elevation. The pathologic fracture obscures the ability to identify these hallmarks of malignant degeneration.
Multiple myeloma, renal cell carcinoma, and osteolysis are all typically radiolucent. Implant-associated osteolysis lesions are commonly multiple and periarticular. The histopathology reveals a cartilage tumor. The chondroid tissue appears to be low grade. However, in an adjacent region there is a high-grade component seen both on the low-power view and the second higher-power sample that does not resemble cartilage. This is highly suggestive of a dedifferentiated chondrosarcoma. This component signifies that a portion of the original tumor (low-grade chondrosarcoma), which resembled the tissue of origin, converted into a different cell lineage with more aggressive properties (nearly any type of high-grade sarcoma). Dedifferentiated chondrosarcoma is a highly aggressive malignancy, with average 5-year survivals of less than 50%. As with most sarcomas, the most likely site of metastatic dissemination of chondrosarcoma is pulmonary. Consequently, standard staging entails a high-resolution CT scan of the lungs.
Serum protein electrophoresis and a skeletal survey are used for diagnosis of multiple myeloma. Positron emission tomography/CT fusion scans are used at many centers in the staging of osteosarcoma, but their role in chondrosarcoma staging is an emerging modality that is being investigated. Radiation is not typically used for local treatment of extremity chondrosarcoma. Extended curettage is not appropriate for a high-grade lesion such as this. Revision arthroplasty alone does not address the tumor. Wide resection is the local treatment of choice for high-grade chondrosarcoma; because of the fracture, this patient may require an amputation to achieve wide margins.
RECOMMENDED READINGS
Henderson ER, Pala E, Angelini A, Rimondi E, Ruggieri P. Dedifferentiated peripheral chondrosarcoma: a review of radiologic characteristics. Sarcoma. 2013;2013:505321. doi: 10.1155/2013/505321. Epub 2013 Mar 25. PubMed PMID: 23589702.
View Abstract at PubMed
Grimer RJ, Gosheger G, Taminiau A, Biau D, Matejovsky Z, Kollender Y, San-Julian M, Gherlinzoni F, Ferrari C. Dedifferentiated chondrosarcoma: prognostic factors and outcome from a European group. Eur J Cancer. 2007 Sep;43(14):2060-5. Epub 2007 Aug 27.
View Abstract at PubMed
Mavrogenis AF, Gambarotti M, Angelini A, Palmerini E, Staals EL, Ruggieri P, Papagelopoulos PJ. Chondrosarcomas revisited. Orthopedics. 2012 Mar 7;35(3):e379-90. doi: 10.3928/01477447-20120222-30. PubMed PMID: 22385450.
View Abstract at PubMed
Flemming DJ, Murphey MD. Enchondroma and chondrosarcoma. Semin Musculoskelet Radiol. 2000;4(1):59-71. Review. PubMed PMID: 11061692.
View Abstract at PubMed

Question 18:

When comparing arthroscopic lavage and knee debridement with placebo in patients with chronic symptomatic osteoarthritis, what outcome has been demonstrated?

Options:

Reliable and durable pain relief
No significant benefit for chronic osteoarthritis
Up to 75% pain relief for 2 months, then variable response
Three-month measurable pain relief, followed by recurrence

Correct Answer: No significant benefit for chronic osteoarthritis

Explanation:

Question 19:

Which of the following anatomic structures are in contact with internal impingement in the throwing athlete?

Options:

Humerus and posterior-superior glenoid
Humerus and anterior inferior glenoid
Humerus and acromion
Biceps and acromion
Rotator cuff and acromion

Correct Answer: Humerus and posterior-superior glenoid

Explanation:

Question 20:

A 14-year-old boy has an anteromedial distal thigh mass. A radiograph and MRI scan are shown in Figures 39a and 39b. An open biopsy of the mass should include

Options:

bone obtained through a knee arthrotomy with creation of a portal that will be used for retrograde femoral nailing.
bone obtained by going through the mass.
bone obtained through a posterior approach, dissecting out and protecting the sciatic nerve and popliteal artery.
soft tissue obtained through a longitudinal incision centered over the mass.
soft tissue obtained through a transverse incision on the medial thigh.

Correct Answer: soft tissue obtained through a longitudinal incision centered over the mass.

Explanation:

Question 21:

Options:

Femoral medial collateral ligament repair, extraphyseal
Arthroscopically assisted medial collateral ligament repair
Crutch ambulation without immobilization and weight bearing as tolerated
Protected weight bearing with cast immobilization

Correct Answer: Protected weight bearing with cast immobilization

Explanation:

Question 22:

0 sustained a subcapital fracture of her hip. She is an avid tennis player, and history reveals no previous fractures. What is the most appropriate follow-up care? Review Topic

Options:

Antiresorptive bisphosphonate medication
A repeat dual-energy x-ray absorptiometry scan (DEXA) and treatment if the T-score is less than -2.5
A repeat DEXA scan and treatment if the T-score is greater than -1.5
No treatment since the BMD is not in osteoporotic range
(PTH) taraparatide hormone followed by surgery

Correct Answer: Antiresorptive bisphosphonate medication

Explanation:

Question 23:

Osteochondritis dissecans of the capitellum is a source of elbow pain and most commonly occurs in what patient population?

Options:

Swimmers and divers
Football lineman
Rugby players
Gymnasts and throwing athletes
Cyclists

Correct Answer: Gymnasts and throwing athletes

Explanation:

DISCUSSION: The etiology of osteochondritis dissecans of the capitellum is somewhat unclear. However, trauma has been implicated in this disease process. Gymnasts who load their upper extremities during tumbling and throwing athletes with repetitive trauma during the throwing motion are common patient subgroups in which osteochondritis dissecans of the elbow is seen. This often occurs in the adolescent age population.
REFERENCES: Baumgarten TE, Andrews JR, Satterwhite YE: The arthroscopic classification and treatment of osteochondritis dissecans of the capitellum. Am J Sports Med 1998;26:520-523.
Takahara M, Ogino T, Fukushima S, et al: Nonoperative treatment of osteochondritis dissecans of the humeral capitellum. Am J Sports Med 1999;27:728-732.

Question 24:

What is the most common complication following metatarsal osteotomy for a bunion deformity in an adolescent?

Options:

Hallux varus
Osteonecrosis
Recurrence of the hallux valgus
“Transfer” second metatarsalgia
Physeal arrest of the first metatarsal

Correct Answer: Recurrence of the hallux valgus

Explanation:

Question 25:

Which of the following types of ultra-high molecular weight polyethylene has been associated with the poorest clinical performance?

Options:

Compression molded
Heat pressed
Ram extruded
Gamma irradiated
Ethylene oxide sterilized

Correct Answer: Heat pressed

Explanation:

Question 26:

Options:

Ewing’s sarcoma
Osteosarcoma
Rhabdomyosarcoma
Osteomyelitis
Malignant fibrous histiocytoma

Correct Answer: Osteosarcoma

Explanation:

DISCUSSION: The radiographs show a bone-producing lesion in the distal femoral metaphysis in this case of classic osteosarcoma presenting in the most common location, the distal femur. The coronal MRI scan reveals a marrow-occupying lesion with extension into the soft tissues. The histology shows osteoid production by pleomorphic cells consistent with an osteosarcoma. Ewing’s sarcoma is a bone tumor characterized by uniform small blue cells on histology. Rhabdomyosarcoma is the most common childhood soft-tissue sarcoma. Osteomyelitis has an inflammatory appearance on histology. Malignant fibrous histiocytoma of bone has a lytic radiographic appearance and a pleomorphic storiform pattern without osteoid on histology.
REFERENCES: Wold LE, Adler CP, Sim FH, et al: Atlas of Orthopedic Pathology, ed 2. Philadelphia, PA, WB Saunders, 2003, p 179.
McCarthy EF, Frassica FJ: Pathology of Bone and Joint Disorders with Clinical and Radiographic Correlation. Philadelphia, PA, WB Saunders, 1998, p 205.

Question 27:

Options:

repair of a triceps tendon avulsion.
arthroscopy of the elbow for removal of loose bodies.
arthroscopic removal of a posteromedial olecranon osteophyte.
internal fixation of an olecranon stress fracture.
rest, rehabilitation, and resumption of pitching when the fracture is healed.

Correct Answer: rest, rehabilitation, and resumption of pitching when the fracture is healed.

Explanation:

Question 28:

Options:

Biceps tenodesis
Superior labrum anterior to posterior (SLAP) repair
Rotator cuff repair
Distal clavicle excision The patient has a clinical history and physical examination consistent with degenerative superior labral pathology, which is supported by the MRI scan. She has failed appropriate nonoperative treatment, and surgical intervention would be indicated. In a middle-aged patient with a degenerative superior labral tear, biceps tenodesis has been shown to have better outcomes and return to sport than SLAP repair. In a young patient with a traumatic superior labral tear, repair would be indicated. The other MRI findings noted are incidental and asymptomatic in this patient. As a result, rotator cuff repair or distal clavicle excision is not indicated.

Correct Answer: Biceps tenodesis

Explanation:

Question 29:

Options:

Resolution by age 3 or 4 years without active treatment in most patients
Resolution by age 8 or 9 years without active treatment in most patients
Resolution with casting as the most effective treatment
Resolution with bracing and shoe modification as the most effective treatment
Resolution with surgery as the most effective treatment

Correct Answer: Resolution by age 3 or 4 years without active treatment in most patients

Explanation:

DISCUSSION: Excessive internal tibial torsion is a common cause of intoeing in toddlers. In most children, this resolves spontaneously by 3 to 4 years of age. Intoeing in elementary age children is usually the result of excessive femoral anteversion. Studies have shown that active intervention (casting, splinting, and shoe modifications) has no demonstrable effect on the natural history or resolution of tibial torsion. Surgery is rarely indicated in adolescents with severe internal tibial torsion that has not resolved and is resulting in cosmetic and functional problems.
REFERENCES: Canale ST, Beaty JH: Operative Pediatric Orthopaedics. St Louis, MO, Mosby Year Book, 1991, pp 357-385.
Lincoln TL, Suen PW: Common rotational variations in children. J Am Acad Orthop Surg 2003;11:312-320.

Question 30:

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

Options:

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

Correct Answer: Confidence interval

Explanation:

Question 31:

Options:

MRI
Custom orthotics
Activity modification
Calcaneal epiphysiodesis
Percutaneous Achilles tendon lengthening

Correct Answer: Activity modification

Explanation:

Question 32:

-Which type of cells has been implicated in the process shown inFigure?

Options:

Monocytes
Histiocytes
Leukocytes
Neutrophils
Macrophages

Correct Answer: Macrophages

Question 33:

Options:

Biceps tenotomy
Loose body removal
Latissimus dorsi transfer
Reverse total shoulder arthroplasty

Correct Answer: Biceps tenotomy

Explanation:

Question 34:

…Giant-cell tumor of bone usually involves the epiphysis of long bones. What is the next most common type of tumor involving this anatomical location?

Options:

Conventional chondrosarcoma
Aneurysmal bone cyst
Chondroblastoma
Osteoblastoma DISCUSSION.. Giant-cell tumor is the most common lesion involving the epiphysis, although its epicenter is usually in the metaphysis, and in the rare case of giant-cell tumor occurring in a skeletally immature patient, giant-cell tumor is located in the metaphysis. It also can involve the flat bone of the pelvis and sacrum. Chondroblastoma exclusively occurs in the epiphysis of skeletally immature patients. It is more common than the other responses. Although conventional chondrosarcoma does not involve the epiphysis, clear-cell chondrosarcoma involves the epiphysis as well; however, it is rare and less common than chondroblastoma. Aneurysmal bone may occur in the epiphysis; however, it is often seen with other benign tumors such as chondroblastoma or giant-cell tumor. It is less common in this location than chondroblastoma. Osteoblastoma does not classically appear at the epiphysis. It is more commonly seen in the spine or the diaphysis of long bones.

Correct Answer: Chondroblastoma

Explanation:

Question 35:

Options:

failure to use a tourniquet.
failure to use a drain.
use of low-molecular-weight heparin (LMWH).
use of regional anesthesia.

Correct Answer: use of low-molecular-weight heparin (LMWH).

Explanation:

Question 36:

Options:

Continue with a more aggressive passive range-of-motion exercise program.
Perform an open release.
Revise the humeral component and increase retroversion.
Revise the humeral component alone after osteotomizing more of the humeral neck and seating the component lower.
Remove the glenoid component to decrease tension in the rotator cuff.

Correct Answer: Perform an open release.

Explanation:

Question 37:

The fracture shown in Figure 32 is strongly indicative of what diagnosis?

Options:

Osteogenesis imperfecta
Vitamin D-resistant rickets
Lead toxicity
Child abuse
Osteomyelitis

Correct Answer: Child abuse

Explanation:

Question 38:

Options:

Hooke's law
Kirchhoff's law
Wolff's law
Heuter-Volkmann principle

Correct Answer: Heuter-Volkmann principle

Explanation:

Question 39:

Options:

The patient's age
he patient's gender
Work-related injury
Acute nature of the tear

Correct Answer: Work-related injury

Explanation:

Question 40:

A 45-year-old man with a painful varus knee is being considered for an upper tibial osteotomy. Which of the following factors is considered the most compelling argument against this procedure?

Options:

Flexion contracture of 5°
Subchondral cyst in the medial tibial condyle
Lateral meniscal degeneration seen in an MRI scan
Rheumatoid arthropathy
Previous medial meniscectomy

Correct Answer: Rheumatoid arthropathy

Explanation:

Question 41:

Figure 59 shows properties of a material being tested for use as an implant. What is represented by the portion of the stress-strain curve from point A to point B?

Options:

Elastic limit
Nonproportional behavior
Plastic behavior
Elastic behavior
Fracture point

Correct Answer: Elastic behavior

Explanation:

Question 42:

The risk of progression with congenital kyphosis is greatest with which of the following?

Options:

Anterior unsegmented bar
Block vertebra
Posterior hemivertebra
Anterolateral bar and contralateral quadrant vertebrae
Butterfly vertebra

Correct Answer: Anterolateral bar and contralateral quadrant vertebrae

Explanation:

Question 43:

Which of the following findings is most prognostic for the ability of a young child with cerebral palsy to walk?

Options:

Ability to sit independently by age 2 years
Ability to creep by age 2 years
Ability to roll by age 2 years
Pattern of cerebral palsy (quadriplegia, diplegia, hemiplegia)
Type of motor dysfunction (spastic, ataxic, dyskinetic, hypotonic)

Correct Answer: Ability to sit independently by age 2 years

Explanation:

DISCUSSION: Several studies have shown that sitting ability by age 2 years is highly prognostic of walking. Molnar and Gordon reported that children not sitting independently by age 2 years had a poor prognosis for walking. Wu and associates reported that children sitting without support by age 2 years had an odds ratio of 26:1 of walking compared with those unable to sit. This was far higher than the odds ratios for cerebral palsy location, motor dysfunction, crawling, creeping, scooting, or rolling.
REFERENCES: Molnar GE, Gordon SU: Cerebral palsy: Predictive value of selected clinical signs for early prognostication of motor function. Arch Phys Med Rehabil 1976;57:153-158.
Wu YW, Day SM, Strauss DJ, et al: Prognosis for ambulation in cerebral palsy: A population-based study. Pediatrics 2004;114:1264-1271.

Question 44:

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 45:

A “p value” of 4% (p=0.04) indicates that the

Options:

hypothesis is incorrect or invalid
interobserver error rate is 4%.
Standard deviation is 4% higher or lower than the mean.
Sample size is 4% larger than required to be clinically significant.
Probability that the differences noted between two study groups were due to chance alone is 4%.

Correct Answer: Probability that the differences noted between two study groups were due to chance alone is 4%.

Explanation:

Question 46:

Options:

Ceramic-on-ceramic
Large diameter metal head on highly cross-linked polyethylene liner
Ceramic head on metal liner
Large diameter metal-on-metal total hip arthroplasty
Metal on conventional polyethylene liner (noncross-linked)

Correct Answer: Large diameter metal head on highly cross-linked polyethylene liner

Explanation:

Question 47:

The illustration shown in Figure 19 shows a Chamberlain line. What is the most likely diagnosis?

Options:

Anterior atlanto-occipital dislocation
Basilar invagination
C1-C2 dislocation
Transverse ligament injury
Normal findings

Correct Answer: Normal findings

Explanation:

DISCUSSION: Basilar invagination is best defined as vertical or compressive instability at the occiput-C1 joint. Such invaginations most commonly occur in patients with rheumatoid arthritis but also can occur secondary to trauma or tumor. A Chamberlain line is used as a method to determine basilar invagination. The odontoid tip should not be more than 5 mm above a Chamberlain line.
REFERENCES: Wiesel SW, Rothman RH: Occipito-atlantal hypermobility.
Spine 1979;4:187-191.
Clark CR: The Cervical Spine, ed 3. Philadelphia, PA, Lippincott-Raven, 1998, pp 50-51.

Question 48:

When harvesting iliac crest bone graft during a posterior spinal decompression and fusion, injury to what structure can result in painful neuromas or numbness over the skin of the buttocks?

Options:

Ilioinguinal nerve
Superior gluteal nerve
Superior cluneal nerves
Iliohypogastric nerves
Lateral femoral cutaneous nerve

Correct Answer: Superior cluneal nerves

Explanation:

Question 49:

During the early swing phase of the normal gait cycle, what lower extremity muscle is primarily contracting?

Options:

Tibialis posterior
Tibialis anterior
Vastus medialis
Adductor longus
Gastrocnemius

Correct Answer: Tibialis anterior

Explanation:

DISCUSSION: Electromyography during walking reveals the tibialis anterior muscle is active during early swing, allowing the foot to clear the ground. All of the other muscles are quiet, as the limb moves forward through space with minimal muscular effort. The other muscles are primarily active during weight acceptance or push-off.
REFERENCES: Gage JR: An overview of normal walking. Instr Course Lect 1990;39:291-303.
Wootten ME, Kadaba MP, Cochran GV: Dynamic electromyography II: Normal patterns during gait. J Orthop Res 1990;8:259-265.

Question 50:

Options:

Triple antibiotic coverage
Transfer to the ICU and a consult with infectious disease
Urgent irrigation and debridement with gentle skin closure
Urgent hyperbaric oxygen treatments and immunoglobulin
Urgent aggressive debridement of skin, subcutaneous fat, and fascia

Correct Answer: Urgent aggressive debridement of skin, subcutaneous fat, and fascia

Explanation:

Question 51:

Options:

Anterior shoulder instability
Early adhesive capsulitis
Internal impingement
Subacromial impingement
Full-thickness rotator cuff tear

Correct Answer: Internal impingement

Explanation:

Question 52:

Options:

Cementless cup without graft
Cemented cup without graft
Cemented cup with structural bone graft
Bone graft, reconstruction cage, and cemented cup
Bilobed cementless acetabular component

Correct Answer: Bone graft, reconstruction cage, and cemented cup

Explanation:

Question 53:

In recurrent posterior shoulder instability, what is the recommended approach to the posterior capsule? Review Topic

Options:

A teres minor-splitting approach
An infraspinatus-splitting approach
Between the infraspinatus and teres minor
Between the supraspinatus and infraspinatus
In the rotator interval

Correct Answer: An infraspinatus-splitting approach

Explanation:

Question 54:

Options:

There is no mechanical axis deviation in (1), and medial mechanical axis deviation in (2).
There is lateral mechanical axis deviation in (1) and medial mechanical axis deviation in (2).
There is no fixed direction of mechanical axis deviation in either technique.
There is medial mechanical axis deviation in (1) and lateral mechanical axis deviation in (2).
There is no mechanical axis deviation in (1), and lateral mechanical axis deviation in (2).

Correct Answer: There is no mechanical axis deviation in (1), and medial mechanical axis deviation in (2).

Explanation:

Question 55:

Options:

Observation
Radiation therapy
Curettage
En bloc excision with stabilization
En bloc excision followed by radiation therapy

Correct Answer: En bloc excision with stabilization

Explanation:

Question 56:

Options:

Arthroscopic debridement
Two-stage total knee revision arthroplasty
Resection arthroplasty without an antibiotic impregnated cement spacer
Knee fusion

Correct Answer: Two-stage total knee revision arthroplasty

Explanation:

DISCUSSION:
This complication is best addressed with either a single-stage or two-stage total knee arthroplasty. A recent report suggests that a single-stage arthroplasty can be effective, although many surgeons would perform a two-stage procedure with an articulating or static spacer. Arthroscopic would be non-effective, especially given 4 weeks of symptoms. Resection arthroplasty without a spacer would leave an unstable
and poorly functioning extremity. Knee fusion should be used as a salvage procedure.

Question 57:

In the majority of patients with chronic anterior cruciate ligament (ACL)-deficient knees, analysis of the gait pattern during level walking will most likely reveal which of the following changes?

Options:

No significant differences in gait from the contralateral knee
No change in knee flexion-extension moment with balancing of quadriceps and hamstring activity
A change in knee flexion-extension moment with decreased hamstring activity
A change in knee flexion-extension moment with decreased demand on the quadriceps and a net increase in hamstring activity
A change in knee flexion-extension moment with increased demand on the quadriceps

Correct Answer: A change in knee flexion-extension moment with decreased demand on the quadriceps and a net increase in hamstring activity

Explanation:

Question 58:

A B D … C E F G

Options:

Normal foot
Calcaneonavicular (CN) coalition
Talocalcaneal (TC) middle facet coalition
TC posterior facet coalition

Correct Answer: Talocalcaneal (TC) middle facet coalition

Explanation:

DISCUSSION

Question 59:

Options:

smaller incisions.
more wound complications.
fewer 30-day and 90-day readmissions.
lower rates of patient satisfaction.

Correct Answer: more wound complications.

Explanation:

Question 60:

Options:

She was noncompliant in physical therapy.
The original surgery should have included resurfacing the glenoid.
The humeral head was too large.
The humeral component was placed too proud.
The tuberosities are malpositioned.

Correct Answer: The tuberosities are malpositioned.

Explanation:

DISCUSSION: The radiograph shows tuberosity malposition. The effect of improper prosthetic placement has also been associated with poor outcomes. However, the malposition of the tuberosity seen on the radiograph clearly explains loss of motion in this patient. It has been demonstrated that the functional results after hemiarthroplasty for three- and four-part proximal humeral fractures appear to be directly associated with tuberosity osteosynthesis. The most significant factor associated with poor and unsatisfactory postoperative functional results was malposition and/or migration of the tuberosities. Factors associated with a failure of tuberosity osteosynthesis in a recent study were poor initial position of the prosthesis, poor position of the greater tuberosity, and women older than age 75 years (most likely with osteopenic bone). Greater tuberosity displacement has been identified by Tanner and Cofield as being the most common complication after prosthetic arthroplasty for proximal humeral fractures. Furthermore, Bigliani and associates examined the causes of failure after prosthetic replacement for proximal humeral fractures and found that although almost all failed cases had multiple causes, the most common single identifiable reason was greater tuberosity displacement.
REFERENCES: Bigliani LU, Flatow EL, McCluskey G, et al: Failed prosthetic replacement for displaced proximal humeral fractures. Orthop Trans 1991;15:747-748.
Boileau P, Krishnan SG, Tinsi L, et al: Tuberosity malposition and migration: Reasons for poor outcomes after hemiarthroplasty for displaced fractures of the proximal humerus. J Shoulder Elbow Surg 2002;11:401-412.
Tanner MW, Cofield RH: Prosthetic arthroplasty for fractures and fracture-dislocations of the proximal humerus. Clin Orthop Relat Res 1983;179:116-128.

Question 61:

Options:

Anterior diskectomy without fusion at C4-C5
Epidural injections
Anterior diskectomy and fusion at C4-C5 and C5-C6
Multilevel laminectomy and fusion
Multilevel posterior foraminotomies

Correct Answer: Multilevel laminectomy and fusion

Explanation:

Question 62:

Varus malalignment after a talar neck fracture with medial comminution causes a decrease in what motion?

Options:

Tibiotalar dorsiflexion
Tibiotalar plantarflexion
Subtalar eversion
Subtalar inversion
Internal rotation

Correct Answer: Tibiotalar dorsiflexion

Explanation:

Question 63:

Options:

Open reduction and internal fixation (ORIF) of the femur with cerclage cables
Removal of the femoral stem, fracture repair, and stage reimplantation after the fracture has healed
Revise the femoral stem bypassing the fracture by 2 cortical widths and ORIF the fracture
Fix the fracture with allograft strut and cables, but leave the stem alone

Correct Answer: Revise the femoral stem bypassing the fracture by 2 cortical widths and ORIF the fracture

Explanation:

Question 64:

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

Options:

Superficial
Transitional
Deep
Calcified
Tidemark

Correct Answer: Deep

Explanation:

Question 65:

Options:

Percutaneous pinning of the fracture with Kirschner wires
Open reduction and pinning with Kirschner wires
Arthroscopic in situ compression screw fixation
Reduction and compression screw fixation via a volar approach
Reduction and compression screw fixation via a dorsal approach

Correct Answer: Reduction and compression screw fixation via a dorsal approach

Explanation:

DISCUSSION: Displaced fractures of the scaphoid are best treated with compression screw fixation. Proximal third fractures (as in this patient) are optimally approached via a dorsal approach to ensure proper reduction and compression. Fractures of the scaphoid waist can be approached either by a volar or a dorsal approach. Kirschner wire fixation is limited to proximal pole fractures that are too small to accommodate the trailing head of a compression screw.
REFERENCES: Retting ME, Raskin KB: Retrograde compression screw fixation of acute proximal pole fractures. J Hand Surg Am 1999;24:1206-1210.
Filan SK, Herbert TJ: Herbert screw fixation of scaphoid fractures. J Bone Joint Surg Br 1996;78:519-529.

Question 66:

Which of the following statements is true regarding the posterior oblique portion of the medial collateral ligament of the elbow? Review Topic

Options:

Can be released to gain flexion in patients with post-traumatic contracture
Has the highest tensile strength of any elbow ligament
Is reconstructed in the Tommy John procedure
Is the primary ligamentous restraint to valgus force during throwing
Is responsible for the pivot shift of the elbow

Correct Answer: Is responsible for the pivot shift of the elbow

Explanation:

Question 67:

What is the most common arthroscopic finding of internal impingement in an overhead athlete?

Options:

Loose body
Type III acromion
Bankart lesion
Rotator cuff articular side tear
Biceps tendon fraying

Correct Answer: Rotator cuff articular side tear

Explanation:

Question 68:

Options:

prophylactic transfusions three times per week.
application of ankle-foot orthoses.
ankle synovectomy.
ankle arthrodesis performed with physeal protection.
pantalar arthrodesis.

Correct Answer: ankle synovectomy.

Explanation:

Question 69:

Options:

Deltoid branch of the artery of the tarsal canal
Dorsalis pedis artery
Tarsal sinus artery
Perforating peroneal artery
Navicular artery

Correct Answer: Deltoid branch of the artery of the tarsal canal

Explanation:

DISCUSSION: A Hawkins III fracture-dislocation generally presents with posteromedial displacement with the deltoid ligament intact. Therefore, the only remaining blood supply is the deltoid branch of the artery of the tarsal canal originating from the posterior tibial artery. Often, the medial malleolus is fractured, assisting in reduction and visualization of fracture reduction. If the medial malleolus is intact, a medial malleolus osteotomy allows visualization of the reduction without compromising the last remaining blood supply to the talus.
REFERENCES: Mulfinger GL, Trueta J: The blood supply of the talus. J Bone Joint Surg Br 1970;52:160-167.
Vallier HA, Nork SE, Barei DP, et al: Talar neck fractures: Results and outcomes. J Bone Joint Surg Am 2004;86:1616-1624.

Question 70:

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 71:

Intramembranous ossification during fracture repair is characterized by absence of which of the following elements?

Options:

Alkaline phosphatase
Osteonectin
Osteopontin
Collagen type I expression
Collagen type II expression

Correct Answer: Collagen type II expression

Explanation:

Question 72:

Flexion-distraction injuries of the thoracolumbar spine are most frequently associated with injury to what organ system?

Options:

Neurologic
Pulmonary
Gastrointestinal
Vascular
Lymphatic

Correct Answer: Gastrointestinal

Explanation:

Question 73:

What is the most appropriate orthosis for hallux rigidus?

Options:

Morton’s extension
Metatarsal arch pad
Full-length semi-rigid longitudinal arch support
Full-length semi-rigid longitudinal arch support with medial hindfoot posting
Full-length semi-rigid longitudinal arch support with lateral forefoot posting

Correct Answer: Morton’s extension

Explanation:

Question 74:

Options:

Posterosuperior acetabulum
Posteroinferior acetabulum
Femoral head above the fovea
Femoral head below the fovea

Correct Answer: Posteroinferior acetabulum

Explanation:

This clinical scenario describes a patient with FAI attributable to pincer (acetabular) deformity. This form of FAI, which involves prominence of the anterosuperior acetabular lip, may be more common among women. Decreased range of motion and pain occur secondary to the abutment of the femoral head against the acetabular labrum and rim. Hip flexion, combined with adduction and internal rotation, recreates this contact and causes pain, but CAM or pincer etiology remains unknown. The differential diagnosis of hip pain in a young athlete includes femoral neck stress reaction/fracture, sacroiliac arthritis, intra-articular loose body, trochanteric bursitis, osteitis pubis, and hernia. No information presented in this scenario suggests any of these causes. Diagnosis of FAI is best performed via MR imaging, with an arthrogram increasing the sensitivity and specificity for labral pathology. Ultrasonography may be useful in the diagnosis of dysplasia or for dynamic assessment of a snapping hip, but ultrasonography is not commonly used to diagnose labral pathology. Although concomitant chondral lesions of the femoral head are uncommon, the forced leverage of the anterosuperior femoral neck upon the anterior acetabulum may result in a “contra-coup” chondral injury on the posteroinferior acetabulum. This is the most common location of chondral lesions in this scenario. Without bony resection to prevent further impingement, this patient will continue to experience symptoms. Because there is no evidence of femoral neck prominence (CAM lesion), there is no indication for osteoplasty of the femoral neck; resection of the pincer lesion is necessary. This will often require take-down of the labrum in this location. If possible, iatrogenic or traumatic labral tears should subsequently be repaired after pincer debridement because the labrum has
important functions for hip stability and maintenance of the suction seal of the joint.

Question 75:

A 14-year-old boy has a midshaft fibular lesion. Biopsy results are consistent with Ewing’s sarcoma. Following induction chemotherapy, local control typically consists of

Options:

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

Correct Answer: wide excision.

Explanation:

Question 76:

Options:

- Avascular necrosis, head collapse, and screw penetration
- Fixation failure and varus collapse
- Humeral stem loosening
- Glenoid component loosening
- Hardware failure (breakage of plate or screws)
- Shoulder dislocation

Correct Answer: - Avascular necrosis, head collapse, and screw penetration

Explanation:

Question 77:

Options:

Revision using a proximal femoral replacement prosthesis
Revision using a diaphyseal engaging femoral prosthesis along with cerclage fixation
Open reduction internal fixation using a locking plate with strut graft
Protected weight bearing with abduction bracing

Correct Answer: Revision using a diaphyseal engaging femoral prosthesis along with cerclage fixation

Explanation:

Question 78:

Options:

Total contact orthotic
UCBL orthotic
Molded articulated ankle-foot orthosis
Molded ankle gauntlet (Arizona brace)
Lateral heel flare

Correct Answer: Molded ankle gauntlet (Arizona brace)

Explanation:

Question 79:

Options:

rigid open reduction and internal fixation of the os acromiale with autologous bone graft.
arthroscopic repair of the rotator cuff and acromioplasty.
arthroscopic excision of the os acromiale.
arthroscopic decompression of the supraglenoid cyst.
open distal clavicle excision (Mumford procedure).

Correct Answer: rigid open reduction and internal fixation of the os acromiale with autologous bone graft.

Explanation:

Question 80:

Ulnar collateral ligament (UCL) reconstruction using a modified Jobe technique

Options:

Paresthesias in the fourth and fifth digits
Numbness on the lateral side of the forearm
Heterotopic ossification
Posterolateral rotatory instability of the elbow
Medial antebrachial cutaneous neuroma

Correct Answer: Paresthesias in the fourth and fifth digits

Explanation:

Question 81:

Options:

Nonsurgical management with the use of a cast-brace
Nonsurgical management with skeletal traction
Open treatment with a locked plate with or without strut allograft
Revision of the femoral component to a cemented femoral component that bypasses the fracture site by two cortical diameters
Revision of the femoral component to a cementless femoral component that bypasses the fracture site by at least two cortical diameters

Correct Answer: Revision of the femoral component to a cementless femoral component that bypasses the fracture site by at least two cortical diameters

Explanation:

Question 82:

Options:

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

Correct Answer: Prevalence of MRSA

Explanation:

Question 83:

Options:

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

Correct Answer: non-weight bearing bilateral lower extremities and right upper extremity

Explanation:

Question 84:

Options:

Perform an immediate wake-up test
Continue with the surgery and reassess in 5 minutes
Administer intravenous methylprednisolone
Ensure that mean arterial blood pressure is 80 or higher

Correct Answer: Ensure that mean arterial blood pressure is 80 or higher

Explanation:

DISCUSSION
The use of intraoperative neuromonitoring is expanding, especially in the setting of deformity surgery. Changes in monitoring are concerning for the possibility of a neurologic injury; however, several other factors can alter signals. These include hypotension, changes in anesthesia depth and medications, the use of paralytic agents, and technical issues such as leads falling out or becoming disconnected. If a change in neuromonitoring signals is noted, these factors should be checked first to rule out false-positive findings. If this does not correct the problem, the wound should be explored to ensure there is no compression on the neural elements. Finally, if the deformity has been corrected, some of the correction can be released in an attempt to improve the signals. A wake-up test is difficult to perform and does not provide specific information regarding the location of the problem or how to correct it. Steroids may be used depending on surgeon preference, but should not be used until neurologic injury is ruled out. Any neuromonitoring changes always necessitate immediate investigation.
RECOMMENDED READINGS
Ziewacz JE, Berven SH, Mummaneni VP, Tu TH, Akinbo OC, Lyon R, Mummaneni PV. The design, development, and implementation of a checklist for intraoperative neuromonitoring changes. Neurosurg Focus. 2012 Nov;33(5):E11. doi: 10.3171/2012.9.FOCUS12263. PubMed PMID: 23116091.
View
Abstract at PubMed
Malhotra NR, Shaffrey CI. Intraoperative electrophysiological monitoring in spine surgery. Spine (Phila Pa 1976). 2010 Dec 1;35(25):2167-79. doi: 10.1097/BRS.0b013e3181f6f0d0.
Review. PubMed PMID: 21102290.
View Abstract at PubMed

Question 85:

The dorsal (Thompson) approach to the proximal forearm uses which of the following intermuscular intervals?

Options:

Extensor carpi radialis longus and the extensor carpi radialis brevis
Extensor pollicis longus and the extensor pollicis brevis
Extensor digitorum communis and the extensor carpi radialis brevis
Extensor carpi ulnaris and the extensor carpi radialis brevis
Abductor pollicis longus and the extensor carpi radialis brevis

Correct Answer: Extensor digitorum communis and the extensor carpi radialis brevis

Explanation:

Question 86:

Options:

ice, analgesics, and symptomatic treatment, with delayed reconstruction if necessary.
closed reduction in the emergency department.
closed reduction in the operating room under anesthesia.
open reduction and temporary stabilization with a threaded pin.
open reduction and reconstruction of the sternoclavicular joint ligaments.

Correct Answer: closed reduction in the operating room under anesthesia.

Explanation:

DISCUSSION: The CT scan reveals a completely displaced physeal fracture of the medial clavicle with marked posterior displacement of the distal fragment. This fracture pattern is associated with potential injury to the vascular structures of the mediastinum. Reduction should be performed for this fracture and generally can be done closed with shoulder retraction and upward pull on the clavicle with a towel clip. Once reduced, the fracture is relatively stable and typically will heal in good position. Reduction should be performed in the operating room in the event that a vascular injury is detected once compression is removed from the clavicle. Open reduction may be necessary if closed reduction is not possible; however, pinning or ligament reconstruction usually is not necessary.
REFERENCES: Rockwood CA, Matsen FA (eds): The Shoulder, ed 2. Philadelphia, PA,
WB Saunders, 1998, p 581.
Wirth MA, Rockwood CA Jr: Acute and chronic traumatic injuries of the sternoclavicular joint. J Am Acad Orthop Surg 1996;4:268-278.

Question 87:

Acetaminophen is an antipyretic medication. It exerts its pharmacologic effects by inhibiting which of the following enzymes?

Options:

Cyclooxygenase-2 (COX-2)
Interleukin-1 beta (IL-1 β)
Tumor necrosis factor alpha (TNF-α)
Hydroxytryptamine (5-HT)
Metalloproteinases (MMPs)

Correct Answer: Interleukin-1 beta (IL-1 β)

Explanation:

Question 88:

When performing an inside-out lateral meniscal repair, capsule exposure is provided by developing the Review Topic

Options:

iliotibial band and biceps tendon interval, then retracting the lateral head of the gastrocnemius anteriorly.
iliotibial band and biceps tendon interval, then retracting the lateral head of the gastrocnemius posteriorly.
iliotibial band and biceps tendon interval, then retracting the lateral collateral ligament posteriorly.
iliotibial band and biceps tendon interval, then splitting the lateral head of the gastrocnemius.
lateral head of the gastrocnemius and biceps tendon interval, then retracting the biceps tendon anteriorly.

Correct Answer: iliotibial band and biceps tendon interval, then retracting the lateral head of the gastrocnemius posteriorly.

Explanation:

Question 89:

Following an acute dislocation of the patella, the risk of a recurrent dislocation is greater if the patient has which of the following findings?

Options:

Bipartite patella
Age greater than 15 years at the time of the initial dislocation
Persistent atrophy of the vastus lateralis
Low-lying position of the patella (patella baja)
Passive lateral hypermobility of the unaffected knee

Correct Answer: Passive lateral hypermobility of the unaffected knee

Explanation:

Question 90:

Options:

Profound bilateral wrist extensor, finger flexor, and intrinsic weakness with good preservation of lower extremity motor function
Severe bilateral upper and lower extremity weakness, pain and temperature sensory deficit but preservation of deep pressure and proprioception
Weakness of the right upper and lower extremity with diminished pain and temperature sensation on the left side of the body
Left wrist extensor weakness and numbness along the radial border of the left forearm extending into the thumb and index finger
Weakness of the left upper and lower extremity with diminished pain and temperature sensation on the right side of the body

Correct Answer: Weakness of the left upper and lower extremity with diminished pain and temperature sensation on the right side of the body

Explanation:

Question 91:

Early postoperative infections following primary total hip arthroplasty are most likely caused by which organism?

Options:

Staphylococcus epidermidis
Streptococcus viridans
Propionibacterium acnes
Staphylococcus aureus

Correct Answer: Staphylococcus aureus

Explanation:

DISCUSSION:
S aureus
is the most common organism cultured in early (fewer than 4 weeks postoperative) periprosthetic infections. Methicillin-resistant
S aureus
is becoming a more common pathogen in certain patient populations. B hemolytic
Streptococcus
and some gram-negative infections can also be found in early postoperative infections.
S epidermidis
,
S viridans
, and
P acnes
are more commonly found in late (more than 4 weeks postoperative) infections.

Question 92:

Options:

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

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

Explanation:

Question 93:

Arthritic change in cartilage is characterized by which of the following findings?

Options:

Proteoglycan loss in the cartilage matrix
Increased compressive modulus compared to normal cartilage
Increased tensile modulus
Decreased water content
Increase in the shear modulus

Correct Answer: Proteoglycan loss in the cartilage matrix

Explanation:

Question 94:

Options:

His helmet should be removed.
His helmet and shoulder pads should be removed.
His face mask should be removed.
All equipment should be removed.
No equipment should be removed.

Correct Answer: His face mask should be removed.

Explanation:

DISCUSSION: Prior to transport, the face mask should be removed so that the airway can be easily accessible. If serious injury is suspected, the helmet and shoulder pads should be left in place until he is assessed at the hospital and radiographs are obtained. Leaving the helmet and shoulder pads in place helps to keep the spine in the most neutral alignment. Removal of the helmet will result in extension of the neck, whereas removal of the shoulder pads will most likely result in flexion of the neck.
REFERENCES: Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Williams & Wilkins, 1998, p 376.
Thomas B, McCullen GM, Yuan HA: Cervical spine injuries in football players. J Am Acad Orthop Surg 1999;7:338-347.
Waninger KN, Richards JG, Pan WT, et al: An evaluation of head movement in backboard-immobilized helmeted football, lacrosse, and ice hockey players. Clin J Sport Med
2001;11:82-86.
Donaldson WF III, Lauerman WC, Heil B, et al: Helmet and shoulder pad removal from a player with suspected cervical spine injury: A cadaveric model. Spine 1998;23:1729-1732.
Peris MD, Donaldson WF III, Towers J, et al: Helmet and shoulder pad removal in suspected cervical spine injury: Human control model. Spine 2002;27:995-998.

Question 95:

Options:

In situ glenoid component implantation
Hemiarthroplasty
Eccentric reaming of glenoid
Posterior glenoid bone graft

Correct Answer: Eccentric reaming of glenoid

Explanation:

Question 96:

Options:

peroneus brevis tendon repair.
peroneus longus to peroneus brevis tenodesis.
6 weeks in short-leg cast.
platelet-rich plasma injection.

Correct Answer: peroneus brevis tendon repair.

Explanation:

DISCUSSION
Additional nonsurgical treatment is not beneficial for peroneal tendon tears. Early repair of longitudinal tears reduces risk for progression to a full-thickness tear that would necessitate peroneus brevis to peroneus longus tenodesis. Platelet-rich plasma has no role in peroneal tendon tears.
RECOMMENDED READINGS
Arbab D, Tingart M, Frank D, Abbara-Czardybon M, Waizy H, Wingenfeld C. Treatment of isolated peroneus longus tears and a review of the literature. Foot Ankle Spec. 2014 Apr;7(2):113-8. doi: 10.1177/1938640013514273. Epub 2013 Dec 30. Review. PubMed
PMID: 24381076.
View Abstract at PubMed
Coughlin MJ, Schon LC. Disorders of tendons. In: Coughlin MJ, Saltzman CL, Anderson RB, eds. Mann's Surgery of the Foot and Ankle. 9th ed. Philadelphia, PA: Elsevier-Saunders; 2014: 1188-1291.
RESPONSES FOR QUESTIONS 71 THROUGH 75
Lapidus procedure
First metatarsophalangeal (MTP) joint arthrodesis and lesser metatarsal head resection
Proximal first metatarsal osteotomy
Distal first metatarsal chevron osteotomy
Biplanar distal first metatarsal osteotomy
Match the appropriate surgical procedure listed above with the clinical scenario described below.

Question 97:

Options:

Cauda equina
Conus medullaris
Genitofemoral nerve
Lumbar sympathetic plexus
Lumbar parasympathetic plexus

Correct Answer: Lumbar sympathetic plexus

Explanation:

Question 98:

Options:

Open reduction and internal fixation
MRI of the elbow to assess the integrity of the collateral ligaments
Immobilization in a long arm cast for 3 weeks
Short-term immobilization in a splint, followed by early motion exercises
Radial head replacement

Correct Answer: Open reduction and internal fixation

Explanation:

Question 99:

Options:

Anterior cruciate
Posterior cruciate
Medial collateral
Lateral collateral
Patellar tendon/ligament

Correct Answer: Posterior cruciate

Explanation:

Question 100:

Options:

Malrotation of the foot
Neurologic injury
Vascular injury
Knee meniscal injury
Hip fracture

Correct Answer: Malrotation of the foot

OITE & ABOS Orthopedic Exam MCQs: Trauma, Foot & Knee Board Review Part 132

Orthopedic Board Prep MCQs: Arthroplasty, Trauma & Oncology | Part 72

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 72

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index