Orthopedic Board MCQs: Hip, Shoulder & Arthroplasty

About This Board Review Set

This is Part 179 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.

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Two distinct learning modes are available:

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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 179

This module focuses heavily on: Arthroplasty, Hip, Shoulder.

Sample Questions from This Set

Sample Question 1: An 18-year-old boxer sustained a blow to his right eye in a boxing match. Examination on the sideline reveals hyphema, reduced visual acuity and color vision, and a visual field cut. What is the next step in management? Review Topic...

Sample Question 2: An 18-year-old man has had an enlarging mass in his hand for the past 3 months. Radiographs, an MRI scan, and biopsy specimens are shown in Figures 54a through 54d. What is the most likely diagnosis?...

Sample Question 3: A 71-year-old man has worsening left hip pain and is indicated for a left total hip arthroplasty (THA). Figure 1 shows a preoperative plan for the patient. The patient is scheduled for a left THA using a direct anterior approach with the pi...

Sample Question 4: A unilateral "piano key" sign, indicates...

Sample Question 5: A 19-year-old college pitcher reports posterior shoulder discomfort that started recently with pitching. He is able to throw with normal velocity and control, but his pain in the early acceleration phase of throwing is getting worse. Examin...

Why Active MCQ Practice Works

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

Comprehensive 100-Question Exam

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Question 1

An 18-year-old boxer sustained a blow to his right eye in a boxing match. Examination on the sideline reveals hyphema, reduced visual acuity and color vision, and a visual field cut. What is the next step in management? Review Topic

Explanation

With the examination demonstrating reduced visual acuity and visual field changes, emergent CT is needed to look for traumatic optic neuropathy from direct or indirect trauma. The most common mechanism is blunt facial trauma (78%), but penetrating trauma is also common (22%). The most common etiologies are sports and motor vehicle accidents. Fluorescein eye stain would only be useful for corneal abrasion or corneal foreign body. CT scans are often helpful for an orbital fracture, optic nerve sheath hemorrhage, optical canal fractures, skull fractures, foreign bodies, nonorbital facial fractures, or associated brain injuries. The presence of a fracture of the optic canal on a CT scan was a poor prognostic sign in a recent series by Goldenberg and associates. The treatment is controversial. Although treatment options include high-dose corticosteroids, retrobulbar steroid injection, optic canal decompression, and optic sheath fenestration, there is no consensus as to the optimum treatment. It has been reported that treatment does not alter the prognosis in children and adolescents. Only 29% to 44% of children and adolescent patients had significant improvement in visual acuity. Hyphema is a collection of free blood in the anterior chamber of the eye. It is the most common intraocular eye injury associated with sports as reported by Denyi and associates, and occurs in 24% of injured eye cases. At the time of injury, it occurs as a haze in the anterior chamber. An eye patch and ophthalmology evaluation in 2 days is inappropriate because timely evaluation in this scenario is important. High-dose steroids are often used for this injury but not before a full evaluation including a CT scan. Observation is not appropriate because the injury needs an urgent evaluation.

Question 2

An 18-year-old man has had an enlarging mass in his hand for the past 3 months. Radiographs, an MRI scan, and biopsy specimens are shown in Figures 54a through 54d. What is the most likely diagnosis?

Explanation

DISCUSSION: Also known as Nora’s lesion, BPOP is a benign osteocartilaginous tumor that almost always occurs in the hands and feet; one occurrence each in the femur and tibia has been reported. Although local recurrence is common after excision, metastases have not been reported.
REFERENCES: Abramovici L, Steiner GC: Bizarre parosteal osteochondromatous proliferation (Nora’s lesion): A retrospective study of 12 cases, 2 arising in long bones. Hum Pathol 2002;33:1205-1210.
Nora FE, Dahlin DC, Beabout JW: Bizarre parosteal osteochondromatous proliferations of the hands and feet. Am J Surg Pathol 1983;7:245-250.

Question 3

A 71-year-old man has worsening left hip pain and is indicated for a left total hip arthroplasty (THA). Figure 1 shows a preoperative plan for the patient. The patient is scheduled for a left THA using a direct anterior approach with the pictured implants. If this plan is followed as pictured, what is the likely outcome for this patient? Figure could not be loaded

Explanation

Figure 1 is the radiograph of a 73-year-old woman who had a right hip arthroplasty one year prior. Her BMI is 48. Postoperative radiographs at 6 weeks showed early stem subsidence of 4 mm compared with intraoperative radiographs. The current radiographic findings likely resulted from the
A. spinal fusion.
B. BMI and implant size.
C. mismatch between the metaphysis and diaphysis.
D. modular neck prosthesis.

Question 4

A unilateral "piano key" sign, indicates

Explanation

EXPLANATION:
The piano key sign is a demonstration of instability at the DRUJ, typically seen after healing from a distal radius fracture with an associated ulnar styloid fracture (as in this case) or other wrist injury. The hand is pushed down against a table top, and the distal radius translates dorsally (with the distal ulna apparently moving volarly). In fact, the distal radius is the mobile segment, while the distal ulna is fixed in space. Treatment involves repair or reconstruction of the foveal insertion of the triangular fibrocartilage complex (TFCC) and distal radioulnar ligaments. This type of instability is also common in malunions of the distal radius or distal one-third of the radial shaft (Galeazzi-type fractures). In malunions, DRUJ instability can be treated with a corrective osteotomy of the distal radius to restore the anatomic relationship between the distal ulna and the distal radius at the DRUJ. Radiocarpal and midcarpal instability do not involve the DRUJ. Disruption of the interosseous membrane (in isolation, with intact distal radioulnar ligaments and an intact TFCC) does not lead to translational instability of the DRUJ. Although hypermobility syndrome may lead to ligamentous laxity, it does not lead to unilateral DRUJ instability.

Question 5

A 19-year-old college pitcher reports posterior shoulder discomfort that started recently with pitching. He is able to throw with normal velocity and control, but his pain in the early acceleration phase of throwing is getting worse. Examination reveals symmetric rotator cuff strength and no increased anterior or posterior translation of either shoulder. He has some discomfort with his shoulder in abduction and external rotation. Supine range of motion of the right shoulder in 90 degrees of abduction reveals external rotation to 100 degrees and internal rotation to 25 degrees. His left shoulder has 95 degrees of external rotation and 45 degrees of internal rotation. He is not playing the next 2 weeks and requests some exercises that he can do on his own. Which of the following exercises will most likely improve his shoulder symptoms? Review Topic

Explanation

The patient has a glenohumeral internal rotation deficit of 20 degrees. Posterior capsular stretching would be beneficial. A sleeper stretch is a common way for patients to stretch the posterior capsule on their own. It involves lying on the side with the shoulder abducted 90 degrees and the elbow flexed 90 degrees and trying to push the forearm toward the table. Closed-chain rotator cuff exercises, such as humeral head depressions while holding a ball against a wall, pectoralis minor stretching, such as lying on a rolled towel and pushing posteriorly on the shoulders, scapular
protraction, such as punches, and scapular retraction, such as row exercises, can all be helpful for the disabled throwing shoulder, but they will not restore the decreased internal rotation.

Question 6

Following total elbow arthroplasty, patients should be instructed to Review Topic

Explanation

Current recommendations are for a lifetime restriction of load bearing and avoidance of impact activities following total elbow arthroplasty (TEA). TEA is a very effective procedure in reducing pain or reconstructing previously unreconstructable fractures. However, its usage must be tempered with the limitations of currently available prostheses. Aggressive triceps strengthening must be delayed following TEA to allow healing of the triceps attachment, regardless of the surgical approach. Wrist and hand mobilization should begin immediately postoperatively to prevent stiffness. Pronation and supination should not stress a humeral ulnar arthroplasty.

Question 7

In a fatigue test, the maximum stress under which the material will not fail, regardless of how many loading cycles are applied, is defined as

Explanation

Fatigue failure occurs with repetitive loading cycles at stress below the ultimate tensile strength. Fatigue failure depends on the magnitude of the stress and number of cycles. If the stress is less than a predetermined amount of stress, called the endurance limit, the material may be loaded cyclically an infinite number of times without breaking.

Question 8

A defect in the gene coding for fibrillin-1 would lead to which diagnosis? Review Topic

Explanation

A defect in fibrillin-1 is the underlying cause of Marfan Syndrome.
Marfan Syndrome is a genetic disorder of connective tissue typically caused by a mutation in the gene coding for the fibrillin-1 protein. Affected patients are typically very tall with long limbs and thin fingers and toes. Marfan Syndrome patients have many common features including ectopic lens, aortic root dilation, scoliosis, protrusio acetabuli, and ligamentous laxity.
Shirley et al. present a review of Marfan Syndrome with emphasis on the musculoskeletal manifestations including ligamentous laxity, protrusio acetabuli, and scoliosis. They note that scoliosis in these patients, when compared to those with idiopathic scoliosis, commonly progresses faster, is more resistant to bracing, and has a higher association with dural ectasia.
Dean presents a review of Marfan Syndrome and its underlying genetic cause of a mutation in fibrillin. They state that diagnosis can be made using the Ghent nosology (see Illustration A) which can diagnose or rule out the condition in 86% of patients. They caution using these criteria in young children as some features of Marfan Syndrome may not present until later ages.
Illustration A is a summary of the 2010 Revised Ghent nosology for diagnosing Marfan Syndrome.
Incorrect Answers:

Question 9

-Assuming that the lesion can be covered appropriately and there is no drainage from the lesion, when should the patient be allowed to safely return to wrestling?

Explanation

DISCUSSION FOR QUESTIONS 48 AND 49
This patient has cellulitis, which is typically caused by group A Streptococcus or Staphylococcus. The patient’s lack of improvement with first-line antibiotics is concerning for methicillin-resistant Staphylococcus aureus (MRSA) infection. MRSA cellulitis is becoming more prevalent in young athletes,and a high index of suspicion is required to provide appropriate intervention during this
aggressive disease process. The diagnosis is typically made clinically without the use of cultures. Oral trimethoprimsulfamethoxazole (a sulfonamide-class drug) double strength twice daily for 10 to 14 days or doxycycline (a tetracycline-class drug) 100 mg twice daily for 10 to 14 days are recommended for first-line treatment of suspected MRSA cellulitis. There is no indication to proceed with irrigation and debridement; however, if the patient develops a soft-tissue abscess or the underlying joint becomes involved, this would be an appropriate intervention. Switching the athlete to an IV cephalosporin (cefazolin) is not likely to be effective against the presumed resistant bacteria.
Ciprofloxacin (a fluoroquinolone-class drug) is effective against many bacteria, but not MRSA. The current recommendation for wrestlers with cellulitis is that return to competition be allowed after 72 hours of antibiotic treatment if there has been no extension of the cellulitis for 48 hours, the lesion can be covered, and there is no drainage from the lesion. The other responses are not current recommendations for return to competition.

Question 10

Figure 21 is the radiograph of a 45-year-old woman who was severely injured in a motorcycle crash. Her injuries include a traumatic subarachnoid hemorrhage, bilateral pneumothoraces with pulmonary contusions and flail chest, fracture-dislocation of the left hip, and open fractures of the right distal femur and proximal tibia. Antibiotics and tetanus are administered in the emergency department. The patient is intubated and bilateral chest tubes are placed. A closed reduction is performed on the left hip. After appropriate resuscitation, what is the most appropriate initial management of the right knee injury?

Explanation

Although the radiographic evaluation is incomplete, the single lateral view shows a comminuted fracture of the distal femur with suspicion of intra-articular injury and an ipsilateral proximal tibia fracture. This is an open fracture that requires antibiotics, débridement , and skeletal stabilization. The fractures are complicated and the patient is polytraumatized; therefore, rapid but complete surgical débridement and simple stabilization of the knee with a spanning external fixator would be the most appropriate management. Definitive surgical stabilization will likely be complicated and is less desirable during the early post-injury period.

Question 11

What is the most anatomic location for placement of the femoral tunnel in anterior cruciate ligament reconstruction?

Explanation

DISCUSSION: It is critical for graft isometry and knee stability that the femoral tunnel be placed as far posterior as possible on the lateral femoral condyle. Superiorly, the graft should be at the one o’clock position on the left knee. Resident’s ridge is a false posterior shelf that often seems like the extreme posterior cortex. Abnormal tunnel placement results in a variety of complications, including an unstable knee, early graft failure, and joint stiffness.
REFERENCES: Johnson RJ, Beynnon BD, Nichols CE, Renstrom PA: The treatment of injuries of the anterior cruciate ligament. J Bone Joint Surg Am 1992;74:140-151.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 533-557.

Question 12

Compared with wear rates of metal-on-standard polyethylene bearings (75 to 250 m m/y), the wear rate of metal-on-metal bearings for hip arthroplasty is approximately how many micrometers per year?

Explanation

DISCUSSION: Studies on older systems, as well as newer designs, have confirmed that metal-on-metal bearing surfaces undergo linear wear of 2 to 5 mm per year. Ceramic bearing surfaces produced with recent technology perform even better, with a wear rate of 0.5 to 2.5 mm per year. Clinical wear rates of metal-on-crosslinked polyethylene have not yet been determined.
REFERENCES: McKellop H, Park SH, Chiesa R, et al: In vivo wear of three types of metal on metal hip prostheses during two decades of use. Clin Orthop 1996;329:S128-S140.
Schmalzried TP, Callaghan JJ: Wear in total hip and knee replacements. J Bone Joint Surg Am 1999;81:115-136.

Question 13

Second impact syndrome (SIS) after head injury is characterized by which of the following? Review Topic

Explanation

SIS is a devastating but preventable complication of head injury. It occurs when return to activities is allowed prior to complete resolution of the symptoms of the first head injury. A second, sometimes trivial, head injury can lead to a devastating series of events that can result in sudden death. The symptoms tend to progress rapidly and often involve the brain stem. The prognosis is poor.

Question 14

A 62-year-old man has cervical myelopathy with no evidence of cervical radiculopathy. MRI reveals stenosis at C4-5 and C5-6 with severe cord compression. Examination will most likely reveal which of the following findings?

Explanation

DISCUSSION: Cervical myelopathy involves compression of the spinal cord and presents as an upper motor neuron disorder. Patients commonly have extremity spasticity and problems with ambulation and balance. Hoffman’s sign is often present and is elicited by suddenly extending the distal interphalangeal joint of the middle finger; reflexive finger flexion represents a positive finding. The extremities are usually hyperreflexic with myelopathy. With cervical radiculopathy (lower motor neuron disorder), reflexes are hyporeflexic, and patients report pain along a dermatomal distribution. A hyperactive jaw jerk reflex indicates pathology above the foramen magnum or in some cases, systemic disease. Flaccid paraparesis suggests a lower motor neuron problem.
REFERENCES: Sachs BL: Differential diagnosis of neck pain, arm pain and myelopathy, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Raven, 1998, pp 741-742.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 673-680.

Question 15

Which of the following events is most likely to occur following a complete transection of a peripheral nerve?

Explanation

Reference-Within a few hours of injury to a nerve fiber the cell body swells and Nissl granules disappear. The axon distal to the site of injury rapidly undergoes Wallerian degeneration with the loss of the axon and breakup of the surrounding myelin.

Question 16

Figures 42a and 42b show the sagittal and axial MRI scans of a 24-year-old patient who has sciatia. Which of the following combinations of physical findings is most consistent wit the MRI studies?

Explanation

Figures 42a and 42b show a posterocentral disc herniation between L5 and S1 and will affect the S1 nerve root. This will cause sensory changes in the posterior calf and plantar foot, motor loss in the gastrocnemius/soleus complex, reflex changes in the ankle jerk, and a positive straight leg raise sign. A positive femoral nerve stretch test may indicate L2, L3, or L4 nerve root irritation. EHL function is mainly L5.

Question 17

Myositis ossificans is a recognized complication of contusion to the quadriceps muscle. During early rehabilitation, this condition is most likely to be exacerbated by

Explanation

DISCUSSION: Passive stretching is contraindicated during rehabilitation as it may potentiate the severity of the myositis ossificans. Electrical stimulation, iontophoresis, isometric exercise, and ice/heat contrast are not known to exacerbate this process.
REFERENCES: Brunet ME, Hontas RB: The thigh, in DeLee JC, Drez D (eds): Orthopaedic Sports Medicine. Philadelphia, PA, WB Saunders, 1994, pp 1086-1112.
Cushner FD, Morwessel RM: Myositis ossificans traumatica. Orthop Rev 1992;21:1319-1326.

Question 18

Which of the following conditions is associated é the highest mortality in patients é a pelvic fracture?

Explanation

The highest rate of mortality rate after a pelvic fracture is associated with hypovolemic shock. Most of which is secondary to extensive intrapelvic arterial injuries.

Question 19

A 72-year-old man was scheduled for left total knee replacement. He has a history of hypertension and deep venous thrombosis (DVT) in his right lower extremity after an ankle fracture 2 years ago that was treated nonsurgically. The patient asked about the recommended types of DVT prophylaxis or investigations. Based on the 2011 AAOS Clinical Practice Guideline, Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty , what is an acceptable option?

Explanation

The 2011 AAOS guideline, Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty, recommends the combined use of mechanical and pharmacological prophylaxis in patients who have a history of previous thromboembolism. This recommendation is a consensus opinion of the work group that established these guidelines because there is no other reliable evidence for this clinical scenario. There is strong evidence against the use of routine duplex scans in patients undergoing hip and knee replacement. The remaining two responses are less appropriate because they do not include the use of mechanical prophylaxis immediately after surgery.

Question 20

Figure 1 is the MR image of a 36-year-old athlete who is tackled from behind and falls forward onto his left knee. He has pain, swelling, and stiffness. Examination includes a moderate effusion, positive quadriceps active test, and normal Lachman test finding. Left untreated, injury to this structure most likely will lead to degenerative changes in

Explanation

The clinical description and MR image point to an injury to the posterior cruciate ligament (PCL). This ligament is thought to be primarily composed of anterolateral and posteromedial bundles, with the former tightening in flexion and the latter in extension. Because of alterations in knee kinematics and increased varus alignment in PCL insufficiency, contact stresses and cartilage loads increase in the patellofemoral and medial compartments. Although good outcomes may be obtained with transtibial, open inlay, and arthroscopic inlay techniques, one major difference is the creation of the “killer-turn” during the transtibial approach. This sharp turn in the graft as it emerges from the tibia appears to lead to more pronounced attenuation and thinning of the graft during cyclic loading. The scenario describes a patient with chronic PCL and posterolateral corner (PLC) injury, as evidenced by the varus thrust and abnormal
Dial test finding. A valgus-producing osteotomy may be effective, and, in fact, may be the only treatment necessary to address chronic PLC injury. Accordingly, an opening lateral osteotomy would not be appropriate. Of the remaining responses, an osteotomy that increases tibial slope would also address the PCL deficiency by reducing posterior tibial sag. Vascular injury is an uncommon, but potentially devastating, complication associated with PCL surgery and may occur regardless of the technique used. Numerous strategies have been described to reduce the risk, including use of a posteromedial accessory incision to allow finger retraction of the popliteal neurovascular bundle, oscillating drills to prevent excessive soft-tissue entanglement, and tapered (rather than square) drill bits that may minimize cut-out of sharp edges as drilling reaches the posterior tibial cortex. Knee extension lessens, rather than increases, the distance between the posterior tibia and the neurovascular bundle and increases, not lessens, risk for vascular injury.

Question 21

At the time of revision knee arthroplasty, a surgeon performs a rectus snip to gain exposure to the knee. When compared with a standard parapatellar approach, what is the expected outcome?

Explanation

DISCUSSION:
Rectus snip during total knee arthroplasty has no effect on motion or strength at long-term follow-up. It has not been associated with extensor mechanism lag.

Question 22

What risk factor is most associated with progression of idiopathic scoliosis to a curve requiring surgery?

Explanation

DISCUSSION: The magnitude of the curve at the time of the peak height velocity is the most prognostic sign in relationship to surgery. More than 70% of curves that measure more than

30 degrees at this time are likely to reach surgical range.
REFERENCES: Little DG, Song KM, Katz D, et al: Relationship of peak height velocity to other maturity indicators in idiopathic scoliosis in girls. J Bone Joint Surg Am 2000;82:685-693.
Sanders JO, Moreland M, Bassett G: Idiopathic scoliosis: Prevalence and natural history, in DeWald R (ed): Spinal Deformities: The Comprehensive Text. New York, NY, Thieme Medical Publishers, 2003.

Question 23

An 18-year-old collegiate basketball player has had a 3-month history of activity-related back pain. She describes isolated low back pain without radiation that increases with training and playing basketball. Her pain resolves with rest. Physical therapy for 6 weeks has failed to provide relief. An axial CT scan is shown in Figure 17a, and Figures 17b and 17c show sagittal CT reconstructions through the right and left lumbar facets, respectively. Further management should consist of which of the following?

Explanation

DISCUSSION: The sagittal and axial CT scans show a bilateral spondylolysis at L5. The defect is in the pars interarticularis on the right side but at the base of the pedicle on the left. Having failed a trial of physical therapy with only a 3-month history of pain, the next most appropriate step in management should consist of activity modification and bracing in an antilordotic lumbosacral orthosis. Surgical intervention is reserved for patients who have failed to respond to a trial of bracing and activity restriction.
REFERENCES: Debnath UK, Freeman BJ, Grevitt MP, et al: Clinical outcome of symptomatic unilateral stress injuries of the lumbar pars interarticularis. Spine 2007;32:995-1000.
Bono CM: Low-back pain in athletes. J Bone Joint Surg Am 2004;86:382-396.

Question 24

A 57-year-old woman experiences pain 1 year after total knee arthroplasty (TKA). She reports sharp anterior pain and a painful catching sensation that is aggravated by rising from a chair or climbing stairs. Physical examination reveals a mild effusion and a range of motion of 2° to 130°, with patellar crepitus. The symptoms are reproduced by resisted knee extension. Radiographs show a well-aligned posterior-stabilized TKA without evidence of component loosening. What is the recommended treatment for this patient?

Explanation

DISCUSSION:
Patellar clunk syndrome is caused by the development of a fibrous nodule on the posterior aspect of the quadriceps tendon at its insertion into the patella. It causes a painful catching sensation when the extensor
mechanism traverses over the trochlear notch as the knee extends from 45° of flexion to 30° from full extension. It characteristically occurs in posterior stabilized total knee arthroplasties and appears to be related to femoral component design. The syndrome can usually be prevented by excising the residual synovial fold just proximal to the patella. Flexion gap instability can also cause a painful total knee arthroplasty but is less common in posterior stabilized implants. Femoral component malrotation can cause pain attributable to a flexion gap imbalance or patellar tracking problems. Polyethylene wear would be unlikely after just 1 year. Patellar clunk syndrome can usually be addressed successfully with arthroscopic synovectomy. Recurrence is uncommon. Physical therapy may help to strengthen the quadriceps following synovectomy but would not resolve the clunk syndrome symptoms. Femoral or tibial insert revision is not indicated if patellar clunk syndrome is the only problem resulting in a painful total knee arthroplasty.

Question 25

Which of the following have been found to affect the rate of perioperative infections or wound complication rates in foot and ankle surgery?

Explanation

DISCUSSION: Clinical studies have shown that smoking cessation for 4 weeks reduces the risk of infection to the level of nonsmokers. Adverse effects on wound healing caused by chemotherapy used to treat rheumatoid arthritis has not been borne out in the literature.
REFERENCES: Bibbo C, Anderson RB, Davis WH, et al: The influence of rheumatoid chemotherapy, age, and presence of rheumatoid nodules on postoperative complications in rheumatoid foot and ankle surgery: Analysis of 725 procedures in 104 patients. Foot Ankle Int 2003;24:40-44.
Bibbo C, Goldberg JW: Infections and healing complications after elective orthopaedic foot and ankle surgery during tumor necrosis factor-alpha inhibition therapy. Foot Ankle Int

2004;25:331-335.
Sorensen LT, Karlsmark T, Gottrup F: Abstinence from smoking reduces incisional wound infection: A randomized controlled trial. Ann Surg 2003;238:1-5.

Question 26

A 43-year-old woman is referred after excisional biopsy of a cutaneous soft-tissue mass from her left shoulder. Based on the biopsy specimens shown in Figures 44a and 44b, what is the best course of action?

Explanation

DISCUSSION: Dermatofibrosarcoma protuberans (DFSP) is a rare superficial sarcoma that is frequently misdiagnosed at presentation. It is frequently excised prior to suspecting that the lesion is a sarcoma and if not appropriately treated with tumor bed resection to obtain wide margins, these lesions have a high incidence of local recurrence. It is recommended that the wide excision include the deep fascia and a 2.5- to 3-cm cuff of normal-appearing skin. Distant disease spread is rare and usually occurs in the face of a multiply recurrent lesion. Despite the apparent gross circumscription of these lesions, the tumor diffusely infiltrates the dermis and subcutaneous tissues. A characteristic histologic finding can be seen in the deep margins of the tumor where it intricately interdigitates with normal fat.
REFERENCES: Lindner NJ, Scarborough MT, Powell GJ, et al: Revision surgery in dermatofibrosarcoma protuberans of the trunk and extremities. Eur J Surg Oncol

1999;25:392-397.
Weiss SW, Goldblum JR, Enzinger FM: Enzinger and Weiss’s Soft Tissue Tumors, ed 4. Philadelphia, PA, Elsevier, 2001, pp 491-505.

Question 27

below show the radiographs, MRI, and MR arthrogram obtained from a year-old collegiate soccer player who has new-onset left groin pain. He played competitive soccer from a young age and has competed or practiced 5 to 6 times per week since the age of He denies any specific hip injury that necessitated treatment, but his trainer contends that he had a groin pull. He reports groin pain with passive flexion and internal rotation of the left hip, and his hip has less internal rotation than his asymptomatic right hip. He is otherwise healthy.When counseling patients who have a cam deformity, the orthopaedic surgeon should note that

Explanation

Multiple studies have confirmed that cam or pincer anatomy is commonly present in asymptomatic hips. According to a large systematic review, cam deformities are present in approximately one-third of asymptomatic hips in young adults, and the proportion is higher than 50% in the subgroup of athletes. Ganz and associates proposed that femoral acetabular impingement is the root cause of osteoarthritis in most nontraumatic, nondysplastic hips, and functional improvement with surgical correction of the deformity has been demonstrated. Despite the link between cam deformity and hip osteoarthritis, a corresponding link between the correction of the deformity and prevention of osteoarthritis has never been proven. The results of cam deformity correction, typically including repair of the degenerative labral tear, are much poorer when substantial joint space loss is present. A typical joint space cutoff of 2 mm or less is used to recommend against hip preservation surgery.

Question 28

During placement of an external fixator for a distal radius fracture, the most commonly injured nerve is a branch of which of the following nerves? Review Topic

Explanation

Post-surgical mortality rates are significantly lower after total hip arthroplasty compared to hemiarthroplasty
Internal fixation shows better outcomes (reoperation rate, functional status, and/or complication rates) compared to arthroplasty
Bipolar hemiarthroplasty shows better outcomes (reoperation rate, functional status, and/or complication rates) compared to unipolar hemiarthroplasty
A delay in surgery greater than 48 hours is recommended if the patient has multiple medical comorbiditiesm which are not fully optimized
Dislocation rates are equivalent between total hip arthroplasty and hemiarthroplasty
Moderate evidence supports that hip fracture surgery within 48 hours of admission is associated with better outcomes. However, patients with significant medical comorbidity should be fully optimized before surgery.
Although several studies have shown a benefit to surgery within 48 hours, no definitive time frame has been elucidated. The majority of literature has shown improved outcomes in regards to pain, complications, and length of stay with early surgery. Patients with significant medical comorbidities have been shown to have the highest mortality rates.
Moran et al. aimed to determine whether a delay in surgery for hip fractures had an affect on postoperative mortality among elderly patients. In an observational study of 2660 patients, they showed that mortality following hip fracture surgery was 9% at 30-days, 19% at 90-days, and 30% at 12-months. Patients with medical comorbidities had 2.5 times the risk of death within 30-days of surgery. In addition, individuals who had surgery delayed beyond 4 days had increased mortality at 90-days and 12-months.
Papakostidis et al. examined the timing of internal fixation of intracapsular fractures of the neck of femur on the development of late complications, particularly osteonecrosis of femoral head (ONFH) and non-union. They showed no benefit of
early surgery on incidence of AVN. However, delay of internal fixation of more than
24 hours showed increased rates of non-union.
Figure A shows a displaced right femoral neck fracture. Incorrect Answers:

Question 29

Figures 142a and 142b are the current radiographs of an 89-year-old woman who had open reduction and internal fixation (ORIF) of a distal periprosthetic femur fracture 4 months ago. An examination reveals well-healed incisions, a painful range of motion from 15 to 85 degrees, and normal neurovascular function. An infection workup, including an erythrocyte sedimentation rate and C-reactive protein level, is negative. The most appropriate treatment option is

Explanation

DISCUSSION
Current periprosthetic fracture treatments after TKA include ORIF via plating, retrograde nailing, or revision using standard revision TKA components or a distal femoral arthroplasty. Locked plating has demonstrated a trend toward increased nonunion rates when compared to retrograde nailing, as evidenced in this patient. The advanced age of the patient, the presence of failed fixation, and the significant amount of bone loss preclude a trial of further nonsurgical treatment or revision ORIF. A review of 3 methods for treatment of comminuted distal periprosthetic femur fractures in patients older than age 70 demonstrated that distal femur arthroplasty should be considered in patients with advanced age and poor bone quality who require early mobilization. As a result, treatment of this patient with a revision TKA using a distal femoral arthroplasty would be the preferred response because of the bone quality and fracture pattern. Above-knee amputation is a salvage procedure and is not indicated at this time.

Question 30

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 31

Which of the following statements best describes the outcome of the routine use of continuous passive motion (CPM) machines after total knee arthroplasty (TKA)?

Explanation

DISCUSSION: Although CPM machines are used widely in the United States for patients undergoing TKA, the benefit seems to be marginal, if any. Numerous randomized trials have shown that final outcomes after total knee arthroplasty are unaffected by the use of CPM machines postoperatively. Some studies have suggested that use of CPM may improve flexion in the first few weeks, but any short-term benefit from the machine was lost by intermediate-term follow-up. Aside from potential improvement in flexion within the first few postoperative weeks, there does not appear to be any benefit from the machines. There is no improvement in pain, ambulation, or extension. The cost-effectiveness of these machines has been questioned by many authors.
REFERENCES: Pellicci PM, Tria AJ, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 287-293.
McInnes J, Larson MG, Daltroy LH, et al: A controlled evaluation of continuous passive motion in patients undergoing total knee arthroplasty. JAMA 1992;268:1423-1428.
Kumar PJ, McPherson EJ, Dorr LD, et al: Rehabilitation after total knee arthroplasty: A comparison of 2 rehabilitation techniques. Clin Orthop 1996;331:93-101.

Question 32

The essential lesion in recurrent or posterior instability following simple dislocation of the elbow typically involves which of the following structures?

Explanation

The lateral ulnar collateral ligament is the essential lesion in recurrent or persistent instability following simple dislocations of the elbow. Simple elbow dislocations are usually stable and may be managed by a short period of immobilization followed by early range of motion. Treatment of dislocations resulting in persistent instability frequently involves focusing on the lateral ulnar collateral ligament. The medial collateral ligament is repaired only if treatment of associated fractures and lateral collateral ligament injury does not restore stability.

Question 33

He is intubated and being resuscitated. The calf is very swollen with compartment pressures: anterior 25 mm Hg, lateral 24 mm Hg, deep posterior 21 mm Hg, and

Explanation

A compartment syndrome is best diagnosed with a "deltaP" (diastolic pressure minus compartment pressure) of less than or equal to 30 mm Hg. This patient is hypotensive and the "deltaPs" are all less than 30 mm Hg. Emergent fasciotomy is the preferred treatment.

Question 34

below show the clinical photograph and radiograph obtained from a year-old man who has deformity and pain 1 year after primary total hip arthroplasty. What is the reason for the observed deformity?

Explanation

DISCUSSION:
Figure 1 reveals an external rotation deformity of the right lower extremity. This deformity can have numerous causes, including extra-articular deformity. Figure 2 reveals a loose, subsided femoral component. Femoral stems typically subside into retroversion due to proximal femoral biomechanics, which cause a compensatory external rotation deformity. The combined findings from both images suggest an external rotation deformity most likely related to subsidence into retroversion.

Question 35

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

Explanation

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

Question 36

A full-term newborn has webbing at the knees, rigid clubfeet, a Buddha-like posture of the lower extremities, and no voluntary or involuntary muscle action at and below the knees. Radiographs of the spine and pelvis reveal an absence of the lumbar spine and sacrum. What maternal condition is associated with this diagnosis?

Explanation

DISCUSSION: The history, physical examination, and radiographic findings are consistent with type IV sacral agenesis or caudal regression syndrome. These children are born with no lumbar spine or sacrum. The T12 vertebra is often prominent posteriorly. Popliteal webbing and knee flexion contractures are common with this diagnosis. There is a higher incidence of this diagnosis when the mother has diabetes mellitus. Maternal drug abuse and alcoholism can produce phenotypically unique children but without the findings described here. Maternal idiopathic scoliosis is not associated with caudal regression syndrome.
REFERENCES: Chan BW, Chan KS, Koide T, et al: Maternal diabetes increases the risk of caudal regression caused by retinoic acid. Diabetes 2002;51:2811-2816.
Zaw W, Stone DG: Caudal regression syndrome in twin pregnancy with type II diabetes.

J Perinatol 2002;22:171-174.

Question 37

In the setting of a proximal tibial plateau fracture and its repair, which of the following materials is an isotropic material?

Explanation

DISCUSSION: An isotropic material is one that has similar mechanical properties regardless of the orientation of the material. Examples of isotropic materials include metals, plastics, and methacrylate. Most biologic tissues are anisotropic, meaning their mechanical properties alter depending on the materials’ orientation to the applied stress.
REFERENCE: Einhorn TA, O’Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2007, pp 58-59.

Question 38

In the most common condition causing a winged scapula, which of the following nerves is affected? Review Topic

Explanation

A winged scapula is most often associated with Parsonage-Turner syndrome, a condition thought to be due to an inflammatory or immune-mediated mechanism. Certain muscles are predisposed, particularly the serratus anterior muscle innervated by the long thoracic nerve. Other less common nerve lesions (eg, the spinal accessory and dorsal scapular nerves) may also cause winged scapulae.

Question 39

An 18-year-old football player is injured after making a tackle with his left shoulder. He has decreased sensation over the lateral aspect of the left shoulder and radial aspect of the forearm. Motor examination reveals weakness to shoulder abduction and external rotation as well as elbow flexion. He has decreased reflexes of the biceps tendon on the left side but full, nontender range of motion of the cervical spine. What anatomic site has been injured?

Explanation

DISCUSSION: The athlete has symptoms referable to the axillary, musculocutaneous, and suprascapular nerves resulting from an injury to the upper trunk of the brachial plexus. This portion of the plexus is formed by contributions of the fourth through sixth cervical nerve roots. This area is often contused or stretched following a tackling maneuver that results in either depression of the shoulder from contact at Erb’s point or traction of the upper plexus from forced stretching of the neck to the contralateral side.
REFERENCES: Schenck CD: Anatomy of the innervation of the upper extremity, in Torg JS (ed): Athletic Injuries to the Head, Neck, and Face, ed 2. St Louis, MO, Mosby-Year Book, 1991.
Hershman EB: Brachial plexus injuries. Clin Sports Med 1990;9:311-329.

Question 40

Familial (Leiden) thrombophilia is of importance in joint arthroplasty because of an abnormality in the clotting cascade. Which of the following statements best describes the condition?

Explanation

Factor V Leiden is a disease caused by an abnormality of factor V in which a single amino acid substitution of glutamine for arginine in the protein C cleavage region leads to decreased inactivation of factor V and thus a greater tendency to form clots. More than half of all individuals with Factor V Leiden will develop deep venous thrombosis in the presence of a single additional risk factor such as long bone fracture or total joint arthroplasty.

Question 41

An active 36-year-old woman with rheumatoid arthritis has continued forefoot discomfort despite the use of orthotics and shoe wear modifications. A radiograph and a clinical photograph are shown in Figures 26a and 26b. Treatment at this point should consist of

Explanation

DISCUSSION: In a patient with inflammatory arthritis, advanced hallux valgus deformity in conjunction with lesser metatarsophalangeal joint destruction and subluxation warrants fusion of the first metatarsophalangeal joint and lesser metatarsal head resections. Hallux valgus correction will fail because of incompetent soft tissues. A Keller resection arthroplasty is not indicated in this age group. Synovectomy is contraindicated because of evidence of erosive changes of the lesser metatarsophalangeal joints.
REFERENCES: Ouzounian T: Rheumatoid arthritis of the foot & ankle, in Myerson MS (ed): Foot & Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, vol 2, pp 1189-1204.
Mann RA, Thompson FM: Arthrodesis of the first metatarsophalangeal joint for hallux valgus in rheumatoid arthritis. J Bone Joint Surg Am 1984;66:687-692.
Coughlin MJ: Rheumatoid forefoot reconstruction: A long-term followup study. J Bone Joint Surg Am 2000;82:322-341.

Question 42

Deep venous thromboses are primarily composed of red blood cells and fibrin. What is fibrin?

Explanation

Fibrin is the end product of the coagulation cascade that results from the cleavage of fibrinogen by thrombin (factor IIa). Platelets are a key component in arterial thromboses. Collagen initiates the intrinsic arm of the coagulation cascade. Thromboplastin is a procoagulant substance that triggers the extrinsic arm of the coagulation cascade. The fibrinolytic system is the regulatory pathway that breaks down cross-linked fibrin.

Question 43

What is the most reproducible landmark for the accurate anatomic placement of the tibial tunnel for an anterior cruciate ligament (ACL) reconstruction?

Explanation

DISCUSSION: The anterior border of the PCL is the most accurate and reproducible landmark for appropriate placement of the tibial tunnel for an ACL reconstruction. The central sagittal insertion point of the ACL is consistently 10 to 11 mm anterior to the anterior border of the PCL ligament. The anterior border of the tibia is not well visualized and does not serve as a reference point. While the posterior border of the anterior horn of the lateral meniscus could be used as a reference point, it has twice the variability of the PCL reference point. The posterior border of the tibia is difficult to identify and has greater variability than the PCL relative to the AP dimension of the proximal tibial surface. The anterior horn of the medial meniscus is also more variable than the PCL.
REFERENCES: Hutchinson MR, Bae TS: Reproducibility of anatomic tibial landmarks for anterior cruciate ligament reconstructions. Am J Sports Med 2001;29:777-780.
McGuire DA, Hendricks SD, Sanders HM: The relationship between anterior cruciate ligament reconstruction tibial tunnel location and the anterior aspect of the posterior cruciate ligament insertion. Arthroscopy 1997;13:465-473.

Question 44

A lO'/z-year-old boy sustained the injury shown in Figure 72 when he fell out of a tree. This is a closed, neurologically intact injury and the patient has no head injury or loss of consciousness. He weighs 115 pounds and is otherwise healthy. What is the optimal treatment option for this injury?

Explanation

DISCUSSION: Although flexible intramedullary nails are a good treatment alternative for femoral shaft fractures in older children, patients weighing more than 100 pounds have a higher incidence of complications that include bending of the nails. Therefore, transtrochanteric solid intramedullary nail fixation is most likely the best option for this patient. Using a greater trochanteric entry point avoids the piriformis fossa and the possibility of osteonecrosis. External fixation is not a good alternative for this patient because of the transverse nature of the fracture. External fixation of this fracture pattern has been associated with a high refracture rate. Traction and casting can be performed but results in a lengthy hospital stay and a very large cast in an overweight 10-year-old child.
REFERENCES: Flynn JM, Schwend RM: Management of pediatric femoral shaft fractures. J Am Acad Orthop Surg 2004;12:347-359.

Gordon JE, Swenning TA, Burd TA, et al: Proximal femoral radiographic changes after lateral transtrochanteric intramedullary nail placement in children. J Bone Joint Surg Am 2003;85:1295-1301.
Figure 73a Figure 73b

Question 45

You have been waiting to enroll a patient into your recent institutional review board (IRB)-approved clinical research protocol. A patient is admitted who, upon initial screening, meets all inclusion criteria. However, he has late-stage dementia, and you are told by your research coordinator that this condition is an exclusionary criterion. This scenario demonstrates the need for which aspect of proper informed consent?

Explanation

Proper informed consent for research protocols includes the same elements as consent for invasive procedures. Jurisdiction is not one of the 5 elements, although it must be recognized that the process of obtaining proper informed consent for participation in a study protocol is mandated by the local IRB. The 5 elements of informed consent are:

Question 46

Which of the following is accurate regarding low-molecular-weight heparin used for deep venous thrombosis (DVT) prophylaxis in total joint arthroplasty?

Explanation

DISCUSSION: Low-molecular-weight heparin is highly bioavailable with a half-life
to 18 hours. This is greater than the 1 hour half-life of unfractionated heparin.

Low-molecular-weight heparin offers an advantage over unfractionated heparin by selectively targeting Factor Xa while having a lesser effect on circulating thrombin (Factor IIa). Circulating thrombin Factor IIa is needed for local hemostasis at the site of the surgical wound. Clinical studies have shown a reduction by one third in the incidence of thrombocytopenia with the use of low-molecular-weight heparin. Low-molecular-weight heparin has been shown to demonstrate similar clinical results compared to warfarin with respect to preventing thromboembolic disease after total hip arthroplasty and complications such as bleeding.
REFERENCES: Zimlich RH, Fulbright BM, Friedman RJ: Current status of anticoagulation therapy after total hip and total knee arthroplasty. J Am Acad Orthop Surg 1996;4:54-62.
Colwell CW Jr, Spiro TE, Trowbridge AA, et al: Use of enoxaparin, a low-molecular-weight heparin, and unfractionated heparin for the prevention of deep venous thrombosis after elective hip replacement: A clinical trial comparing efficacy and safety. J Bone Joint Surg Am 1994;76:3-14.
Torholm C, Broeng L, Jorgensen PS, et al: Thromboprophylaxis by low-molecular-weight heparin in elective hip surgery: A placebo controlled study. J Bone Joint Surg Br 1991;73:434-438.

Question 47

They found statistically significant decreases in need for secondary intervention, hardware failure, and infection as well as faster wound healing and faster time to fracture union.

Explanation

OrthoCash 2020
A 32-year-old male is involved in a motor vehicle collision and sustains the injury seen in Figure A. What is the most common urological injury associated with this injury pattern?

Testicular torsion
Posterior urethral tear
Bladder denervation
Testicular rupture
Renal hematoma
The figure shows an anteroposterior pelvic ring injury. The most common urological injury with pelvic ring injuries remains the posterior urethral tear, followed by bladder rupture.
Watnik et al notes lower urinary tract (bladder to end of urethra) injuries in up to 25% of patients with this injury. He reports that when contaminated urine communicates with the anterior arch, the possibility of infection exists, and early repair of bladder disruptions with simultaneous anterior arch plating minimizes this risk.
Routt et al notes that even with simultaneous treatment of these injuries, complications are common (late stricture in 44%, impotence in 16%, delayed incontinence in 20% of females, anterior deep pelvic infection in 4%). Despite this, they report that early urological repairs are easily performed at the time of anterior pelvic open reduction and internal fixation.
OrthoCash 2020
A 26-year-old women, 31-weeks pregnant, presents to the emergency department with the injury shown in Figure A. She states the injury occurred while lifting a heavy vacuum five days ago. She suffers from chronic headaches and sleep disturbances. On inspection, there are multiple dorsal and volar bruising over her wrist and upper arm. She is neurologically intact. After closed reduction and immobilizing the arm, what would be the next best step in management of this patient?

Diagnostic wrist arthroscopy
Urgent MRI wrist
Skeletal survey radiographs
Request a consultation with social worker in the hospital
Urgent open reduction internal fixation Corrent answer: 4
This patient presents with classic features of domestic violence. The most appropriate next step would be consultation with a social worker at the hospital, assess for child and patient safety, and encouraging the patient to seek self-protection.
Factors suggestive of domestic violence in the patient include pregnancy, delayed presentation after injury, inconsistent history, multiple bruises and complaints of chronic headache/sleep disturbances. Victims frequently miss days of work and as a result are at risk for losing their jobs. Victims are also more likely to engage in high-risk behavior with sex, drugs, alcohol, smoking, and eating.
The AAOS published a document outlining the Orthopaedic Surgeon’s responsibilities in domestic and family violence. Musculoskeletal injuries that should raise a suspicion of a problem include (1) Multiple injuries/fractures; (2) Unusual patterns of injury/fracture; (3) Injuries/fractures of varying ages; (4)
Injuries/fractures inconsistent with or disproportional to the history; (5) Multiple injuries treated in different hospital emergency departments or by different providers.
Incorrect Answers:
OrthoCash 2020
A 45-year-old man undergoes open reduction and internal fixation for a comminuted intra-articular humerus fracture . An olecranon osteotomy is performed and subsequently fixed with an intramedullary cancellous screw. Which of the following options in the table shown in Figure A best describes the characteristics of this osteotomy?

Question 48

The findings in Brown-Sequard syndrome include loss of which of the following? Review Topic

Explanation

Brown-Séquard syndrome is most commonly seen after penetrating injuries to the spinal cord and results in ipsilateral loss of motor function and contralateral loss of pain and temperature sensation. Patients with central cord syndrome have greater weakness in the upper extremities than in the lower extremities. Loss of proprioception is typically seen in patients with posterior cord syndrome.

Question 49

Which of the following is a function of siRNA (small interfering RNA)?

Explanation

siRNA functions by causing mRNA to be broken down after transcriptions, resulting in an inability to undergo translation.
siRNA are short (usually 20 to 24-bp) double-stranded RNA (dsRNA) sequences with phosphorylated 5' ends and hydroxylated 3' ends. Because of their ability to block a gene of interest, they have been generating interest in the treatment of disease processes that involve gene expression.
Noh et al. study the affects of PD98059, an extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor, on osteosarcoma. They found that blocking the ERK1/2 pathway with PD98059 induces osteosarcoma cell death by inhibiting a potential drug-resistance mechanism.
Illustration A shows how siRNA works to block translation of mRNA. Incorrect Answers:

Question 50

A 26-year-old male underwent statically locked intramedullary nail fixation for a comminuted left femur fracture. An early post-operative computed tomography (CT) scanogram was taken to check rotational alignment, as shown in Figure A. What would be the next best step in the management of this patient?

Explanation

The CT scanogram shows the operative left femur is 8 degrees externally rotated compared to the native right femur. No correction is required unless malalignment is
>15 degrees and symptomatic. Therefore, the most appropriate next step would be to continue with postoperative observation and close follow-up.
The primary purpose of CT scanogram is to measure the angle of rotation of the femoral neck relative to the femoral condyle. To do this, the right and left femurs must be scanned together using a 5mm helical slice scanner at the hip and knee. The first slice should reveal the alignment of the femoral neck, so as to allow for measurement of the femoral neck-to-horizontal (FNH) angle. The second slice should reveal the alignment of the posterior femoral condyles. This allows measurement of the posterior condyle-to-horizontal (PCH) angle. Finally, to calculate the rotational alignment (RA), the FNH angle and PCH angles are subtracted (e.g., RA = FNH -PCH). Normal RA is usually +5 to +20 degrees, which is also referred to as 5 to 20 degrees of femoral anteversion.
Lindsey et al. reviewed femoral malrotation following intramedullary nail fixation. They showed the incidence of rotational malalignment was ~28%. Normal femoral neck anteversion (angle of the femoral neck relative to the transverse axis through the femoral condyles) is ~11-13°. However, they noted that some patients have up to 15° difference in rotation in native limbs. Therefore <15 degrees of rotational difference after fixation is considered acceptable.
Gugala et al. examined the long-term functional implications for patients with iatrogenic femoral malrotation following femoral intramedullary nail fixation. They
showed that patients can compensate for even significant femoral malrotation (up to 30 degrees) and tolerate it well. However, external femoral malrotation (more common) appears to be better compensated/tolerated than internal malrotation.
Figure A shows that the left femoral neck is externally rotated (ER) by 15° to the horizontal (ER15). The right femoral neck is externally rotated (ER) by 4° to the horizontal (ER4). The left distal fragment is ER10. The right distal fragment is internally rotated (IR) by 9°. Thus, left femur has a total (ER15)-(ER10)= (+15)-(+10)=(+5), and right femur has (ER4)-(IR9)= (+4)-(-9)=(+13) to the horizontal. Therefore, the difference is 8 degrees.
Incorrect Answers:
>15 degrees and symptomatic.

Question 51

Figure 199 is the clinical photograph of a 68-year-old man with a history of atrial fibrillation who was treated with warfarin. Nine days after undergoing elective total hip arthroplasty, he has a swollen left thigh. His wound remains dry and he is afebrile. His erythrocyte sedimentation rate (ESR) is 25 mm/h (reference range [rr], 0-20 mm/h) and C-reactive protein (CRP) level is 6.1 mg/L (rr, 0.08-3.1 mg/L). Aspiration reveals 3246 white blood cells (WBCs)/µL with 47% polymorphonucleocytes. Treatment at this time should consist of

Explanation

DISCUSSION
This patient has a large postsurgical hematoma. Although his ESR and CRP level are elevated, they are not considered elevated given his recent surgery. Additionally, the hip aspiration reveals a synovial cell count lower than 10000 WBC/µL along with a low percentage of polymorphonucleocytes. Treatment at this time should consist of observation. The hematoma is likely attributable to postsurgical anticoagulation, considering his history of atrial fibrillation.

Question 52

A 15-year-old girl reports popping and clicking at the sternoclavicular joint and an intermittent asymmetrical prominence of the medial head of the clavicle. She denies any history of trauma or other symptoms. Management should consist of

Explanation

DISCUSSION: Atraumatic subluxation or dislocation of the sternoclavicular joint typically occurs in individuals with generalized ligamentous laxity. It is generally not painful, has no long-term sequelae, and needs no treatment. In fact, it is more likely to be painful following surgery than if managed nonsurgically.
REFERENCES: Rockwood CA Jr, Odor JM: Spontaneous atraumatic anterior subluxation of the sternoclavicular joint. J Bone Joint Surg Am 1989;71:1280-1288.
Rockwood CA, Matsen FA (eds): The Shoulder, ed 2. Philadelphia, PA, WB Saunders, 1998,

p 583.

Question 53

During the approach to the lumbar spine for an L4-L5 anterior lumbar interbody fusion, which structure generally is found overlying the anterior surface of the L4 vertebra?

Explanation

DISCUSSION
During an anterior approach to the L4-L5 disk space for anterior lumbar interbody fusion, meticulous exposure is paramount to allow for safe preparation of the disk space and subsequent arthrodesis. Although all of these structures can come into play during the exposure, the aorta lies anterior to the L4 vertebral body and bifurcates at this level. The vena cava bifurcates just distal to this. The ureters lie to both sides of the anterior spine. The right common iliac artery and the left common iliac vein originate after the bifurcation of the great vessels and lie caudal to the L4 vertebra.
RECOMMENDED READINGS
Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2003:226-235.
Agur AMR, Lee MJ, eds. Grant's Atlas of Anatomy. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999:89.

Question 54

The Injury Severity Score (ISS), using point scores from five different body systems, is a method that aids in predicting the chances of mortality in a patient with multiple injuries by

Explanation

The Abbreviated Injury Scale (AIS) is made up of scores from 5 body systems (head/neck, face, chest, abdomen, extremity/pelvis) graded from 1 minor to 5 critical. The ISS is the sum of the squares of the highest AIS grade in each of the three most severely injured areas. The AIS pertains to individual injuries. The ISS is used for multiple injuries. Using the ISS dramatically increased the correlation between severity of injury and mortality.

Question 55

Following spinal cord injury (SCI), methylprednisolone (a bolus of 30 mg/kg plus 5.4 mg/kg per hour over 24 hours) initiated within 8 hours of injury has been associated with which of the following MRI findings? Review Topic

Explanation

MRI findings following SCI treated with high dose steroids have demonstrated that the steroids are associated with a lower extent of cord hemorrhage. No difference in cord edema was found. The decreased cord hemorrhage seen with use of high dose steroid adminstration in this setting has not correlated with improved clinical outcomes.

Question 56

Figure 12 shows the lumbar CT scan of a 24-year-old man who was injured in a snowmobile accident. What is the mechanism of injury?

Explanation

DISCUSSION: A true compression fracture is a single-column injury that does not create canal compromise. A burst fracture is a two- or three-column injury that disrupts the middle column and thereby narrows the spinal canal. This patient has a burst fracture. The mechanism of injury is usually vertical compression or flexion compression.
REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.
Spivak JM, Vaccaro AR, Cotler JM: Thoracolumbar spine trauma: Principles of management. J Am Acad Orthop Surg 1995;3:353-360.

Question 57

A 28-year-old woman has left shoulder pain and a tender soft-tissue mass. Based on the MRI scan and biopsy specimens shown in Figures 74a through 74c, what is the most likely diagnosis?

Explanation

DISCUSSION: Schwannomas (neurilemomas) occur at all ages but are most frequently seen in persons between the ages of 20 and 50 years. MRI features of schwannomas are fairly nonspecific, but when they are associated with a large named nerve, the identification of a mass in continuity with that nerve is highly suggestive of a schwannoma. Most have a fairly homogeneous appearance with a high water content and often fusiform shape. Classically, the histology shows alternating Antoni A (dense spindle cell region) areas and Antoni B (loose myxoid tissue) areas. They also demonstrate uniform intense immunostaining with S-100 protein.
REFERENCES: Damron TA, Sim FH: Soft-tissue tumors about the knee. J Am Acad Orthop Surg 1997;5:141-152.
Weiss SW, Goldblum JR, Enzinger FM: Enzinger and Weiss’s Soft Tissue Tumors, ed 4. Philadelphia, PA, Elsevier, 2001, pp 1146-1167.

Question 58

Which of the following findings helps to distinguish between stress fractures of the tibia and shin splints? Review Topic

Explanation

Anterior tibial pain can often be difficult to diagnose. A bone scan showing the tibial cortex in a diffuse, longitudinal orientation is consistent with shin splints compared to a more discreet, localized uptake more commonly seen with a stress fracture. Bone stress injuries are due to cyclical overuse of the bone. They are relatively common in athletes and military recruits but are also seem in otherwise healthy people who have recently started new or intensive physical activity. Diagnosis of bone stress injuries is based on the patient's history of increased physical activity and on imaging findings.
The general symptom of a bone stress injury is stress-related pain. Bone stress injuries are difficult to diagnose based only on a clinical examination because the clinical symptoms may vary depending on the phase of the pathophysiological spectrum in the bone stress injury. Imaging studies are needed to ensure an early and exact diagnosis. If the diagnosis is made early, most bone stress injuries heal well without complications.

Question 59

A 21-year-old college student fell from a balcony and landed on his outstretched right hand. He is seen in the emergency department 4 hours later and reports wrist pain and diffuse hand numbness. The volar forearm compartment is soft and there is no pain with passive finger extension. Radiographs are shown in Figures 25a and 25b. Definitive treatment should consist of

Explanation

DISCUSSION: A spectrum of perilunate injury patterns exists, with the dorsal trans-scaphoid perilunate fracture-dislocation being the most common. Perilunate injuries are highly unstable complex carpal disruptions that are not amenable to closed treatment. Open reduction and internal fixation is necessary to accurately restore carpal alignment via fracture reduction and fixation and intercarpal ligament repair. Controversy exists regarding the need for dorsal or combined dorsal and volar approaches. Based on the radiographic findings of a volar dislocation of the lunate and the associated median nerve injury, the patient requires open reduction and internal fixation via combined dorsal and volar approaches with a concomitant carpal tunnel release.
REFERENCES: Herzberg G, Forissier D: Acute dorsal trans-scaphoid perilunate fracture-dislocations: Medium-term results. J Hand Surg Br 2002;27:498-502.
Melone CP Jr, Murphy MS, Raskin KB: Perilunate injuries: Repair by dual dorsal and volar approaches. Hand Clin 2000;16:439-448.
Herzberg G, Comtet JJ, Linscheid RL, et al: Perilunate dislocations and fracture-dislocations:

A multicenter study. J Hand Surg Am 1993;18:768-779.

Question 60

A 47-year-old man has acute right shoulder pain after falling off a ladder. The MRI scan shown in Figure 9 reveals

Explanation

DISCUSSION: The MRI scan reveals a full-thickness rotator cuff tear with retraction and increased signal in the subacromial space indicating joint fluid.
REFERENCES: Herzog RJ: Magnetic resonance imaging of the shoulder. Instr Course Lect 1998;47:3-20.
Iannotti JP, Zlatkin MB, Esterhai JL, et al: Magnetic resonance imaging of the shoulder: Sensitivity, specificity, and predictive value. J Bone Joint Surg Am 1991;73:17-29.

Question 61

A 20-year-old elite college football player has ecchymosis, swelling, and pain on the lateral side of his foot after a game. Radiographs are shown in Figures 31a through 31c. Management should consist of

Explanation

DISCUSSION: Metaphyseal-diaphyseal junction fractures of the fifth metatarsal require careful evaluation. In athletes, early intervention with a 4.5-mm intramedullary screw correlates with an earlier return to activity. One study examining the failure of surgically managed Jones fractures revealed that use of anything other than a 4.5-mm malleolar screw for internal fixation correlated with failure.
REFERENCES: Glasgow MT, Naranja RJ Jr, Glasgow SG, et al: Analysis of failed surgical management of fractures of the base of the fifth metatarsal distal to the tuberosity: The Jones fracture. Foot Ankle Int 1996;17:449-457.
Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 243-252.

Question 62

Figure 40 shows the radiographs of a 2-year-old boy who has a deformed leg. The patient is ambulatory and has no pain. What is the most appropriate management?

Explanation

DISCUSSION: The patient has a prefractured stage of congenital pseudarthrosis of the tibia and is at risk for fracture. The PTB orthosis may prevent or delay the fracture. Osteotomy is frequently complicated by nonunion. When established nonunion does not respond to intramedullary nailing and bone grafting, vascularized grafting may succeed. Amputation is a salvage procedure.
REFERENCES: Murray HH, Lovell WW: Congenital pseudarthrosis of the tibia: A long-term follow-up study. Clin Orthop 1982;166:14-20.
Crossett LS, Beaty JH, Betz RR, et al: Congenital pseudarthrosis of the tibia: Long-term

follow-up study. Clin Orthop 1989;245:16-18.

Question 63

Which of the following anatomic structures is labeled 6 in Figure 27?

Explanation

DISCUSSION: The line labeled 6 points to the A2 pulley. This structure is the condensation of the digital flexor tendon sheath corresponding to the proximal aspect of the proximal phalanx. Grayson’s ligament is volar to the digital nerve and artery. Cleland’s ligament is dorsal to the digital nerve and artery. The sagittal band anchors the extensor tendons over the metacarpophalangeal joints. The triangular ligament connects the lateral bands just proximal to the terminal tendon inserting onto the base of the distal phalanx.
REFERENCES: Hollinshead WH: Anatomy for Surgeons: The Back and Limbs, ed 3. Philadelphia, PA, Harper and Row, 1982, p 467.
Tubiana R, McCullough CJ, Masquelet AC: An Atlas of Surgical Exposures of the Upper Extremity. Philadelphia, PA, JB Lippincott, 1990, p 309.

Question 64

Figure 13 is the photograph of 18-month-old triplets with a lower-limb condition. What is the best initial treatment? Review Topic

Explanation

Brodie's Abscess
Osteomyelitis of the humeral metaphysis
Subperiosteal abscess of the humerus
Presence of subcutaneous air
High risk of proximal humeral growth arrest
This patient has osteomyelitis of the humerus with a large subperiosteal abscess. The presence of subperiosteal abscess necessitates surgical intervention for irrigation and debridement (I&D).
The diagnosis of acute osteomyelitis in children is made based upon a constellation of findings including pain, systemic signs of infection, elevated serum inflammatory markers, and imaging studies demonstrative of osseous infection. It is most commonly hematogenously spread to the metaphysis of immature bone, which is highly vascular prior to skeletal maturity. Treatment involves obtaining specimen for culture, empiric antibiotic treatment, and surgical irrigation and debridement of known abscesses. The end-point of treatment is return of pain-free functionality and the resolution of local/systemic signs of infection.
Conrad reviewed the management of acute hematogenous osteomyelitis and emphasized that surgical intervention in the presence of abscess can be both therapeutic and diagnostic: I&D can obtain culture and narrow the antibiotic plan.
Jones et. al. reviewed chronic pediatric osteomyelitis and report that surgery is the mainstay of treatment because removal of dead bone is essential for resolution of infection. This may be performed with sequestrectomy and curettage, with an emphasis on prevention of pathologic fracture, growth disturbances, bone loss, joint involvement, and permanent loss of function.
Figure A is a coronal STIR MRI image of the humerus demonstrating osteomyelitis
with extensive subperiosteal abscess.
Incorrect Answers:
Brodie's abscess is a type of subacute osteomyelitis which remains indolent and creates a focal intra-osseous abscess. This is not demonstrated in the clinical image.
The patient does have osteomyelitis of the humeral metaphysis, but this alone is not the indication for surgery. Uncomplicated osteomyelitis may be treated effectively with antibiotics alone.
Presence of subcutaneous air is suggestive of necrotizing fasciitis, which is a surgical emergency. The MRI however does not demonstrate this finding.
The infection and its surgical management both increase risk of injury to the proximal humeral physis and has the potential for growth arrest or angular deformity.
(SBQ13PE.3) Figure A demonstrates a physical examination maneuver in a 1 month old infant. What is this maneuver? Review Topic

Ortolani Test
Barlow Test
Galeazzi Sign
Patrick test
Teratologic Sign
Figure A shows a schematic image of the Ortalani test.
The Ortolani test, or Ortolani maneuver, is part of the physical examination for developmental dysplasia of the hip. It is used alongside the Barlow test to detect subluxated hips that are either reducible or irreducible. A positive sign is a distinctive 'clunk' which can be heard and felt as the femoral head relocates anteriorly into the acetabulum.
Guille et al. showed that the use of Pavlik harness has become the mainstay of initial treatment for the infant who has not yet begun to stand. If concentric reduction of the hip cannot be obtained, surgical reduction of the dislocated hip is the next step before they are able to stand.
Video V is a lecture discussing the hip examination of the infant. Incorrect Answers:
pressure on the knee, directing the force the femoral head posteriorly. A positive Barlow test would result in posterior subluxation/dislocation of the hip. Answer 3: Galeazzi test is performed by flexing an infant's knees in the supine position so that the ankles touch the buttocks. If the knees are not level then the test is positive, which indicates a potential congenital hip issue (e.g. DDH). Answer 4: Patrick or Faber test (flexion, abduction, external rotation) has been described both for stressing the SI joint and for isolating symptoms to the hip Answer 5: Teratologic dislocation of the hip is a term used to imply that the hip joint did not develop normally in utero, thus the hip is in a fixed dislocated position at birth.

Question 65

A patient who underwent a total knee arthroplasty for osteoarthritis 18 months ago now reports the sudden development of pain in the ipsilateral knee. Radiographs and examination of the knee are unremarkable. Aspiration of the synovial fluid 3 days later reveals a WBC count of 1,500/mm 3 . The cells consist of 30% neutrophils and 70% monocytes. Culture results will not be available for several days. The patient has not been on antibiotics prior to this point. Based on these findings, what is the most appropriate management?

Explanation

DISCUSSION: Synovial fluid analysis is a very sensitive tool for detecting infection in total knee arthroplasties. Several studies have demonstrated that an absolute leukocyte count in the synovial fluid of less than 1,700 to 2,500/mm³ is an accurate predictor of absence of infection. Similarly, a differential cell count of the WBCs demonstrating less than 50% to 60% neutrophils is an accurate predictor of absence of infection. If both parameters are normal, it is unlikely that the patient has an infection. The three surgical options are contraindicated based on the normal examination findings and laboratory parameters. Similarly, antibiotics should be avoided. The work-up should include tests to evaluate noninfectious sources of knee pain and sources of referred knee pain.
REFERENCES: Trampuz A, Hanssen AD, Osmon DR, et al: Synovial fluid leukocyte count and differential for the diagnosis of prosthetic knee infection. Am J Med 2004;117:556-562.
Mason JB, Fehring TK, Odum SM, et al: The value of white blood cell counts before revision total knee arthroplasty. J Arthroplasty 2003;18:1038-1043.
Kersey R, Benjamin J, Mason B: White blood cell counts and differential in synovial fluid of aseptically failed total knee arthroplasty. J Arthroplasty 2000;15:301-304.

Question 66

Which of the following tissues used for anterior cruciate ligament (ACL) reconstruction has the highest maximum load to failure?

Explanation

DISCUSSION: While the patellar tendon ligament is considered by many to be the tissue of choice for ACL reconstruction, more recent studies have shown that the quadruple semitendinosus and gracilis tendon graft has the greatest stiffness and offers the highest maximum load to failure.
REFERENCES: Hamner DL, Brown CH Jr, Steiner ME, Hecker AT, Hayes WC: Hamstring tendon grafts for reconstruction of the anterior cruciate ligament: Biomechanical evaluation of the use of multiple strands and tensioning techniques. J Bone Joint Surg Am 1999;81:549-557.
Cooper DE, Deng XH, Burstein AL, Warren RF: The strength of the central third patellar tendon graft: A biomechanical study. Am J Sports Med 1993;21:8l8-823.
Brown CH Jr, Steiner ME, Carson EW: The use of hamstring tendons for anterior cruciate ligament reconstruction: Technique and results. Clin Sports Med 1993;12:723-756.
Engebretsen L, Lewis JL: Graft selection and biomechanical considerations in ACL reconstruction. Sports Med Arthroscopy Rev 1996;4:336-341.

Question 67

A diskectomy is performed in which the disk space is not aggressively debrided. When compared to techniques that involve aggressive debridement of the disk space, this results in

Explanation

DISCUSSION
This patient has disk herniation at the left L5-S1 level. This will generally affect the traversing S1 nerve. The S1 dermatome is on the lateral aspect and sole of the foot.
Surgical treatment generally involves a diskectomy with removal of the herniated fragment. This can be performed via a conventional open approach or minimally invasive endoscopic technique. Several recent meta-analyses have demonstrated equivalent outcomes with regard to leg pain and clinical outcomes. Although minimally invasive techniques have been associated with an increased rate of dural tear, the overall complication rate between the 2 techniques is not significantly different. Several studies have demonstrated a substantial learning curve associated with minimally invasive techniques, and the rate of complications decreases significantly with surgeon experience.
When performing a diskectomy, the herniated fragment alone can be removed (sequestrectomy) or some of the disk that remains in the disk space can be removed (complete diskectomy). Studies have shown no change in surgical time, blood loss, length of stay, or surgical complications when performing a sequestrectomy (compared to a more complete diskectomy). A sequestrectomy is associated with a higher rate of recurrent disk herniation at the surgical level.
RECOMMENDED READINGS
Kamper SJ, Ostelo RW, Rubinstein SM, Nellensteijn JM, Peul WC, Arts MP, van Tulder MW. Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis.
Eur Spine J. 2014 May;23(5):1021-43. doi: 10.1007/s00586-013-3161-2. Epub 2014 Jan 18.
PubMed PMID: 24442183. View Abstract at PubMed
Dasenbrock HH, Juraschek SP, Schultz LR, Witham TF, Sciubba DM, Wolinsky JP, Gokaslan ZL, Bydon A. The efficacy of minimally invasive discectomy compared with open discectomy: a meta-analysis of prospective randomized controlled trials. J Neurosurg Spine. 2012 May;16(5):452-62. doi: 10.3171/2012.1.SPINE11404. Epub 2012 Mar 9. PubMed PMID:

Question 68

A 17-year-old high school football player reports wrist pain after being tackled. Radiographs are shown in Figures 22a through 22c. What is the recommended intervention?

Explanation

DISCUSSION: The patient has an acute fracture of the proximal pole. A 100% healing rate has been reported for open reduction and internal fixation of proximal pole fractures via a dorsal approach. This allows for direct viewing of the fracture line, facilitates reduction, and bone grafting can be done through the same incision if necessary. A vascularized or corticocancellous graft is reserved for nonunions. Proximal fractures are very slow to heal with a cast, if they heal at all. As a small fragment, percutaneous fixation is very difficult and has been reported for waist fractures.
REFERENCES: Rettig ME, Raskin KB: Retrograde compression screw fixation of acute proximal pole scaphoid fractures. J Hand Surg Am 1999;24:1206-1210.
Raskin KB, Parisi D, Baker J, et al: Dorsal open repair of proximal pole scaphoid fractures. Hand Clin 2001;17:601-610.

Question 69

A 25-year-old motorcyclist has a knee dislocation that is reduced by the trauma surgeon in the emergency department. Radiographs show no fracture and a reduced knee joint. What is the most appropriate initial step for evaluation of a potential arterial injury?

Explanation

A high index of suspicion should exist for an arterial injury after any knee dislocation. Due to collateral circulation around the knee, pulses may still be present, as well as normal capillary refill. Though angiography is the gold standard for assessment of both major and minor (intimal) injury to the arterial system, it is invasive and not always readily available. Assessment of the ABI can be done without specialized equipment and personnel. When the ABI (systolic BP distal to injury/systolic BP of uninjured upper extremity) is less than 0.9, consideration of invasive testing or surgical exploration is recommended.

Question 70

What method of spinal fixation requires the largest force to disrupt the bone-implant interface?

Explanation

Pedicle screws have been established to produce a superior bone-implant interface in the nonosteoporotic spine according to numerous studies, but, interestingly, clinical outcomes using the varied implants have not been different.

Question 71

A 44-year-old man sustains the injury shown in Figures 1 through 3. What is the most appropriate treatment?

Explanation

EXPLANATION:
Reduction, either open or closed, with internal fixation (pinning) is the recommended treatment for the majority of these injuries. Closed reduction with pinning is most often performed for acute injuries. Open reduction with pinning is performed for those injuries that cannot be reduced by closed means or those with a delayed presentation. Four cases of successful closed reduction and splinting, all performed upon presentation in the emergency department, have been described by Storken and associates, but the authors note that their review of three prior reports uncovered cases of secondary dislocation, which required surgical stabilization. One of the dislocations occurred 4 months after the reduction. They assert that an indication for primary ORIF is a CMC dislocation associated with major fractures. Primary arthrodesis can be considered in cases with severe intra-articular comminution, but this procedure substantially limits the ability of the hand to increase and decrease the transverse metacarpal arch, which is an important functional movement. It can also lead to osteoarthritis of the triquetrohamate joint. Suspension arthroplasty has been described for old fracture-dislocations of the fifth CMC joint, using a partial slip of the extensor carpi ulnaris.

Question 72

Hip pain of month duration has developed in a year-old man with a previous total hip arthroplasty. He underwent dental work 6 weeks ago. Aspiration shows a white blood cell count of more than 6,000 cells/μL (reference range 4,500 to 11,000 cells/μL) and the presence of gram-positive cocci in clusters on Gram stain. The orthopaedic surgeon recommends urgent debridement and irrigation. Fixation of the components is judged to be stable, and the surgeon elects to retain the implants. The patient has a final culture that reveals methicillin-resistant Staphylococcus aureus (MRSA). If the attending physician recommends the two-stage protocol, including the use of an antibiotic-cement spacer, what is the most likely prognosis for this patient?

Explanation

DISCUSSION:
The patient has a late infection of at least 4 weeks symptomatic duration that most likely is hematogenous in etiology. This infection is not an acute hematogenous infection that can successfully be treated with irrigation and debridement. Retention of the implants with debridement and irrigation alone has been associated with a poor prognosis. In a recent study, the success rate was only 44% in a series of 104 patients at a mean 5.7-year follow-up. In one study of 50 infections attributable to MRSA or methicillin- resistant Staphylococcus epidermidis organisms treated with a two-stage protocol, the failure rate was
21%. Patients who experienced successful infection treatment had lower functional outcome measures using the Western Ontario and McMaster Universities Osteoarthritis Index, the University of California
Los Angeles Activity Score, and the 12-item Oxford Knee Score, however.

Question 73

Figures 34a and 34b show the axial and sagittal MRI scans of a 36-year-old man who reports the insidious onset of pain in the right shoulder. What is the most appropriate description of the acromial morphology?

Explanation

DISCUSSION: The MRI scans reveal a meso os acromiale with edema at the site in a skeletally mature patient.
REFERENCES: Sher JS: Anatomy, biomechanics, and pathophysiology of rotator cuff disease, in Iannotti JP, Williams GR (eds): Disorders of the Shoulder: Diagnosis and Management. Philadelphia, PA, Lippincott Williams & Wilkins, 1999, p 23.
Sammarco VJ: Os acromiale: Frequency, anatomy, and clinical implications. J Bone Joint Surg Am 2000;82:394-400.

Question 74

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 75

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 76

Figure 1 is the MRI scan of a 19-year-old man who has an acute anterior shoulder dislocation. The bony fragment occupies 10% of the glenoid articular surface. What is the most appropriate treatment?

Explanation

The MRI scan shows a bony Bankart lesion involving <20% of the glenoid joint surface. A recent series reported high success rates after arthroscopic treatment when the defect is incorporated into the repair. Anterior bony deficiencies occupying >25% to >30% of the glenoid joint surface treated with soft-tissue repair only are associated with high recurrence rates. In these patients, an open or arthroscopic coracoid transfer or structural iliac crest graft should be considered. Open reduction and internal fixation has been reported for treatment of large acute glenoid rim fractures but is not recommended for recurrent anterior shoulder instability in the setting of a 10% glenoid rim fracture.

Question 77

A 58-year-old woman with rheumatoid arthritis and a severe hindfoot valgus deformity now reports recurrent lateral ankle pain. Examination reveals pain over the fibula and sinus tarsi, with a valgus hindfoot that is passively correctable. Despite the use of an ankle-foot orthosis, this is the second time this problem has occurred. Radiographs and a clinical photograph are shown in Figures 28a through 28c. What is the next most appropriate step in treatment?

Explanation

DISCUSSION: Excessive hindfoot valgus can lead to abutment between the calcaneus and fibula. This valgus force can lead to a stress fracture of the distal fibula. Surgery may be required if an insufficiency fracture recurs despite orthotic management. Of the choices listed, a subtalar arthrodesis is most likely to achieve rebalancing of the foot at the level of the deformity.
REFERENCES: Stephens HM, Walling AK, Solmen JD, Tankson CJ: Subtalar repositional arthrodesis for adult acquired flatfoot. Clin Orthop 1999;365:69-73
Easley ME, Trnka HJ, Schon LC, Myerson MS: Isolated subtalar arthrodesis. J Bone Joint Surg Am 2000;82:613-624.

Question 78

What is the most common diagnosis in a patient older than age 40 years with a destructive bony lesion?

Explanation

DISCUSSION: The most common destructive lesions in a patient older than age 40 years are, in decreasing incidence, metastatic carcinoma, multiple myeloma, lymphoma, and chondrosarcoma. Osteosarcoma is found primarily in younger patients.
REFERENCE: CA, January/February 2000, vol 50, no. 1 (Cancer Statistics).

Question 79

A player on a professional football team sustains a knee injury and is diagnosed with an anterior cruciate ligament rupture. When employed as the team physician, your ethical obligation is to inform

Explanation

When you are employed as a team physician, you are obligated to inform the players and the team organization of all athletically relevant medical issues. This differs significantly from the normal rule of patient confidentiality. If the player came to see you and you were not the team physician, you may not inform the team unless the player so desires. As the team physician, you are not obligated to inform the media.

Question 80

5 mm of change in the atlanto-dens interval (ADI) between flexion and extension views

Explanation

The patient has been treated with agents for rheumatoid arthritis (RA) and is developing symptoms concerning for rheumatoid cervical spondylitis. All of the answers are indications for surgical intervention EXCEPT >3.5 mm change in ADI on flexion/extension views.
With the introductions of disease-modifying antirheumatic agents (DMARDs), the incidence of RA patients undergoing cervical spine surgery has decreased significantly. Basilar invagination, atlantoaxial instability, and subaxial subluxation are the three most common manifestations of cervical disease. Multiple studies in RA patients with untreated or poorly controlled disease have led to the development of a set of measurements that identify patients who require surgical intervention and predict outcome after surgery. Additionally, progressive neurological compromise and
refractory
pain
are
indications
for
intervention.
Kim and Hilibrand reviewed management of the rheumatoid cervical spine and outline parameters for surgical intervention. These include a PADI < 14 mm, cervicomedullary angle <135 degrees, progressive neurological deficit, refractory pain, atlantoaxial impaction as determined by migration >5 mm rostral to McGregor's line, and subaxial canal diameter < 14 mm.
Boden et al. analyzed 73 patients followed for rheumatoid cervical spine disease with an average follow up of 7 years. They found that the PADI correlated with paralysis. Patients with PADI less than 10 mm had no recovery, and all patients with PADI greater than 14 mm had full recovery.
Illustration A demonstrates the measurement of the ADI and PADI. Illustration B demonstrates how to measure the cervicomedullary angle (as marked by A), which is typically determined on MRI
Incorrect

Question 81

A 34-year-old woman has had painful snapping and popping in the elbow since falling while in-line skating 6 months ago. The popping also occurs when she pushes off with her hands to rise from a seated position. Initial radiographs were normal, and she was told that she had sprained her elbow. Examination reveals few findings except that she is very apprehensive when the forearm is forcefully supinated with the elbow extended or partially flexed. A radiograph taken in that position is shown in Figure 24. Treatment should consist of

Explanation

DISCUSSION: The radiograph reveals posterolateral rotatory subluxation of the radiohumeral and ulnohumeral joints. The space between the ulna and trochlea is enlarged, particularly posteriorly at the olecranon. These findings are diagnostic of posterolateral rotatory instability, which causes recurrent subluxation and reduction as the elbow is flexed from an extended and supinated position with valgus load. The posterolateral rotatory instability apprehension test was performed on this patient and the result was positive. The lateral pivot-shift test causes a clunk as the elbow reduces but is more difficult to perform, even under general anesthesia. The patient does not have isolated subluxation of the radial head, although these findings can be mistakenly diagnosed as such. The radial head is normally shaped and does not represent a congenital dislocation. There are no findings here to suggest osteochondritis dissecans or loose bodies.
REFERENCES: O’Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73:440-446.
Burgess RC, Sprague HH: Post-traumatic posterior radial head subluxation: Two case reports. Clin Orthop 1984;186:192-194.
Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 345-354.

Question 82

Figure below shows the standing AP radiograph obtained from a 55-year-old man who has a 5-year history of daily left knee medial joint line pain with weight-bearing activities. He denies night pain or symptoms of instability. On examination, his range of motion is 0° to 140°. He has a mild, fully correctable varus deformity and a negative Lachman test result. Nonsurgical treatment has failed. What is the UKA survivorship for a 55-year-old patient, compared with the survivorship for total knee arthroplasty?

Explanation

DISCUSSION:
A patient with medial compartment arthritis and a correctable varus deformity with no clinical or examination findings of knee instability most likely has an intact anterior cruciate ligament (ACL). The pattern of medial compartment osteoarthritis most commonly associated with an intact ACL is that of anteromedial osteoarthritis. An incompetent ACL is commonly associated with a fixed varus deformity and radiographic signs of posteromedial wear. An incompetent ACL is a relative contraindication to a mobile-bearing UKA. When evaluating patients for a mobile-bearing UKA, a stress radiograph aids the orthopaedic surgeon in determining the correction of the varus deformity and assessing the lateral compartment. An inability to fully correct the deformity or narrowing of the lateral compartment with valgus stress should influence the surgeon against UKA. Joint registries across the world have shown decreased survivorship associated with TKA and UKA in men compared with other age groups, but survivorship is lower for UKA than for TKA. No studies to date have shown any differences in survivorship between fixed-bearing and mobile-bearing UKAs. The complication that is unique to mobile-bearing UKA is bearing spinout, which occurs in less than 1% of mobile-bearing UKA procedures. In vivo and in vitro polyethylene wear in mobile-bearing UKA are low. Arthritis may progress faster in patients with mobile-bearing UKAs than in those with fixed-bearing UKAs.

Question 83

When elevating the arm, the ratio of scapulothoracic to glenohumeral motion over the total range of motion is best described as

Explanation

DISCUSSION: The ratio of scapulothoracic to glenohumeral motion with elevation has been shown to vary depending on what portion of elevation is examined, how much load is on the arm, and the technique used to measure increments of elevation. However, almost every study shows that the ratio of scapulothoracic to glenohumeral motion is 1:2 for the contributions over a full range of elevation to 170 degrees. In the first 30 degrees of elevation, there is significant variability in the ratio, and there may be significant variability up to around 60 degrees.
REFERENCES: Inman VT, Saunders JR, Abbott LC: Observations of the function of the shoulder joint. Clin Orthop 1996;330:3-12.
Freedman L, Munro RH: Abduction of the arm in the scapular plane: Scapular and glenohumeral movements. J Bone Joint Surg Am 1966;18:1503.

Question 84

Figures 20a and 20b show the radiographs of a 14-year-old boy who sustained a twisting injury to his ankle. If attempted closed reduction is unsuccessful, what is the primary reason to proceed with surgical treatment?

Explanation

DISCUSSION: Triplane fractures generally occur in children who are near skeletal maturity. The injury is generally caused by a supination external rotation mechanism. The number of fracture fragments present (two or three) depends on what part of the physes is closed at the time of injury. Articular congruity is the major concern in the management of these injuries since the patient has almost reached skeletal maturity. The goal is to restore articular congruity to minimize the development of posttraumatic arthritis.
REFERENCES: Vaccaro A (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 757-765.
Kling TF Jr, Bright RW, Hensinger RN: Distal tibial physeal fractures in children that may require open reduction. J Bone Joint Surg Am 1984;66:647-657.
Spiegel PG, Mast JW, Cooperman DR, et al: Triplane fractures of the distal tibial epiphysis.

Clin Orthop Relat Res 1984;188:74-89.

Question 85

A 26-year-old woman who noted right-sided lumbosacral pain 10 days ago while vacuuming now reports that the pain has intensified. She denies any history of back problems. No radicular component is present, and her neurologic examination is normal. The next most appropriate step in management should consist of

Explanation

DISCUSSION: The initial management of a lumbar strain should consist of 2 to 3 days of bed rest when symptoms are severe, activity restrictions, and nonsteroidal anti-inflammatory drugs. It has been estimated that 60% to 80% of the adult population experiences back pain, with 2% to 5% affected yearly. Spontaneous improvement generally will occur within 4 weeks. Further study is indicated by the presence of radiculopathy, weakness, trauma, or suspicion of malignancy.
REFERENCES: Bigos S, Boyer O, Braen GR, et al: Acute low back pain in adults: Clinical practice guideline No. 14. AHCPR Publication No. 95-0642. Rockville, MD, Agency for Health Care Policy and Research, Public Health Service, US Department of Health and Human Services, December, 1994.
Deyo RA: Conservative therapy for low back pain: Distinguishing useful from useless therapy. JAMA 1983;250:1057-1062.

Question 86

A 50-year-old man with no history of trauma reports new-onset back pain after doing some yard work the previous day. He reports pain radiating down his leg posteriorly and into the first dorsal web space of his foot. MRI scans are shown in Figures 3a through 3c. What nerve root is affected?

Explanation

DISCUSSION: The MRI scans clearly show an extruded L4-5 disk that is affecting the L5 nerve root on the left side. In addition, the L5 nerve root has a cutaneous distribution in the first dorsal web space. S1 affects the lateral foot. L4 affects the medial calf.
REFERENCE: An HS: Principles and Techniques of Spine Surgery. Baltimore, MD,

Williams and Wilkins, 1998, pp 98-100.

Question 87

CLINICAL SITUATION Figures 1 and 2 are the radiographs of a 35-year-old man who has elbow pain after falling from a ladder onto an outstretched hand. Examination reveals elbow pain, swelling, limited motion, and normal neurologic function. A pathognomonic radiographic feature of this injury is a

Explanation

Discussion: Coronal shear fractures of the distal end of the humerus are rare. Failure to recognize the fracture pattern can lead to poor patient outcomes secondary to poor surgical decision making. The double arc sign is considered a pathognomonic finding on the lateral elbow radiograph seen in Figure 2. This is created by the subchondral bone of the capitellum and lateral trochlear ridge. Excessive internal rotation of the fracture fragment or a subpar lateral radiograph can make recognition of this sign difficulty
Ideal visualization of the fragment during surgery is provided through a laterally based elbow approach (Kaplan or Kocher) with the patient in the supine position. Extension of the approach can be accomplished by releasing the lateral collateral ligament origin, which must be repaired to prevent post-operative instability. Posterior comminution and lateral column impaction are occasionally seen. When present, a posterior approach with an olecranon osteotomy is considered an alternative, but still does not allow ideal visualization of the anterior articular cartilage or safe angles for anterior to posterior screw placement. Therefore, the posterior approach not the preferred approach.
Headless screws are useful because this is typically a partial articular injury and screw orientation is ideally from anterior to posterior. The anterior entry of the screw should be buried beneath the articular cartilage margin.

Question 88

Figure 1 shows the radiograph obtained from a 67-year-old man recently diagnosed with osteoarthritis, 8 years after receiving a left metal-on-metal total hip arthroplasty (THA). The acetabular component has a modular cobalt alloy acetabular liner. The patient states that he did very well postoperatively, but for the last 6 months has noted worsening pain and swelling in his left hip. Serum metal ion testing reveals a chromium level of 12.4 ng/mL, compared with a normal level of less than 0.3 ng/mL, and a cobalt level of 11.8 ng/mL, compared with a normal level less than 0.7 ng/mL. An MRI with metal artefact reduction sequence (MARS) was performed and is shown in Figure 2. What is the most appropriate management at this time?

Explanation

DISCUSSION:
Metal-on-metal THA was initially introduced in the 1990s, with the proposed advantages of decreased wear and improved stability. However, catastrophic adverse local tissue reactions associated with their use has raised numerous concerns. The work-up of a patient with a prior metal-on-metal total hip arthroplasty involves a thorough history and physical examination; blood analysis, including the erythrocyte sedimentation rate, C-reactive protein, and metal ion levels; and secondary imaging, including ultrasonography, CT, and MRI. In a patient with clinical symptoms, elevated metal ion levels, and a large fluid collection seen on MRI, the most appropriate treatment would be removal of the metal-on-metal bearing. Given the presence of an adverse reaction involving cobalt and chromium, a revision ceramic head may be most appropriate to avoid the potential of trunnion-associated corrosion.

Question 89

A patient with a transverse femur fracture undergoes statically locked antegrade intramedullary nailing. Postoperatively, the patient appears to have a

Explanation

To establish negligence, certain criteria must be met. 1) A duty was owed by the surgeon (in this case, yes, a relationship was established). 2) The duty was breached, where the provider failed to meet the standard of care (there was a technical error, but it was corrected). 3) The breach caused an injury. In this case, the patient had an outcome that was very acceptable, as documented with outcome studies, for femur fractures. Also, the rotational error and locking distally would have had little impact on the hip, whereas antegrade nailing itself is expected to result in some objective impairment of the hip in some patients. 4) Damages were incurred as a result. In this case, the patient returned to work and could not rock climb which could be reasonably expected with a femur fracture in some patients, and cannot be causally linked to the corrective surgery. For all practical purposes, the patient had a very acceptable outcome. Thus, settling the case for an error would be rather permissive and the important issue is that the surgeon recognized the problem, addressed it, and fulfilled his or her postoperative responsibility. The case is very defendable, and thus it is unlikely to be lost. Defending the case and alleging no error is incorrect because there was an error. The surgeon should never function outside of his or her legal counsel once a suit is filed.

Question 90

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

Explanation

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

Question 91

Spondyloepiphyseal dysplasia congenita and tarda, precocious osteoarthropathy, and Stickler syndrome are caused by a mutation in the gene coding for

Explanation

Precocious osteoarthropathy is due to a mutation at 12q13.11-q13.2. It causes type-II collagen disorders. Spondyloepiphyseal dysplasia congenita and tarda are autosomal dominant and recessive disorders, respectively. They also affect the gene site for coding for type-II collagen (12q13.11-q13.2). Stickler syndrome, or hereditary arthro-ophthalmopathy, is secondary to changes in type-II collagen. Stickler syndrome without eye involvement is due to mutations in type-XI collagen. Achondroplasia involves a mutation in FGFR3. Alpert syndrome is due to defects with FGFR2. Ehler-Danlos is an example of type-I collagen mutations. Type I Multiple epiphyseal dysplasia and Pseudoachondroplasia involves a defect in cartilage oligomeric protein.

Question 92

Figure 9 shows a cross-sectional view of the spinal cord at the lower cervical level. Injury to the structure indicated by the black arrow will lead to what neurologic deficit?

Explanation

DISCUSSION: The arrow is pointing to the posterior columns of the spinal cord that transmit position sense, vibratory sense, and proprioception. There are no motor tracts in the posterior columns.
REFERENCES: Bohlman H, Ducker T, Levine A: Spine trauma in adults, in Herkowitz HH (ed): The Spine, ed 4. Philadelphia, PA, WB Saunders, 1992, p 911.
Northrup B: Evaluation and early treatment of acute injuries to the spine and spinal cord, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Raven, 1998, p 545.

Question 93

The fracture seen in Figure 1 is most likely associated with injury to what ligamentous structure?

Explanation

What is the most common organism implicated in periprosthetic infection of the shoulder?
A. Methicillin-resistant Staphylococcus aureus (MRSA)
B. Cutibacterium acnes
C. Enterococcus species
D. Staphylococcus epidermidis
C acnes is the most common organism recovered in prosthetic shoulder infections (33%), Coagulase-negative Staphylococcus is second (21%), Methicillin-sensitive S aureus (13%), and S epidermidis (10%). MRSA accounts for 5% and Enterococcus species, 1.5%.

Question 94

Figures 80a and 80b are the radiographs of a 21-year-old football player who underwent anterior cruciate ligament (ACL) reconstruction with patellar tendon autograft 1 year ago. He reports mild stiffness in his knee. Upon examination, he has a negative Lachman test result, trace effusion, and range of motion from 0 to 85 degrees of knee flexion. Which factor is most contributory to his examination findings?

Explanation

DISCUSSION
Technical failure is the most common reason for ACL reconstruction failure. Tunnel position is the most frequent cause of technical failure. Malpositioning of the tunnel affects the length of the graft, causing either decreased range of motion or increased graft laxity. This patient has anterior and vertical placement of his femoral tunnel, which has been shown to cause stiffness in knee flexion. Although graft choice is an important factor when planning ACL reconstruction, overall outcomes with autograft tissues are fairly similar. Fixation of the graft at the femoral or tibial end is not as important as tunnel position. Fixing the graft in flexion can cause extension loss when isometry is not achieved, but this condition is not touched upon in this scenario.

CLINICAL SITUATION FOR QUESTIONS 81 THROUGH 84
Figures 81a through 81d are the MR images of a 25-year-old man with left knee pain after a motorcycle collision. He has palpable pedal pulses with an ankle-brachial index of 0.95. Neurologic examination findings of the injured extremity are normal.

Question 95

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

Explanation

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

Question 96

What is the primary mechanism of injury for the fracture shown in Figures 33a and 33b?

Explanation

DISCUSSION: The radiographs show a triplane fracture of the ankle. In adolescence, closure of the distal tibial physis starts peripherally at the anteromedial aspect of the medial malleolus and extends posteriorly and laterally. The anterolateral quadrant of the physis is the last to close, making this region the most susceptible to separation. When the foot is twisted into external rotation, the anterolateral portion of the epiphysis is avulsed by the pull of the anterior tibiofibular ligament. When this fragment alone is avulsed, the result is a juvenile Tillaux fracture. When the fracture extends to involve the remainder of the physis and posterior metaphysis, as in this patient, the result is a triplane fracture.
REFERENCES: Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 267-272.
Dias LS, Giegerich CR: Fractures of the distal tibial epiphysis in adolescence. J Bone Joint Surg Am 1983;65:438-444.
Kling TF Jr: Operative treatment of ankle fractures in children. Orthop Clin North Am 1990;21:381-392.

Question 97

-Figures 55a and 55b are the radiograph and CT scan of a 61-year-old woman who has had neck pain after being involved in a high-speed motor vehicle collision. Examination reveals normal strength and sensation in both upper and lower extremities, normal rectal tone, and no other injuries. The C1-C2 lateral mass overhang measures 8.5 mm. What is the most appropriate treatment option?

Explanation

Question 98

-What do the T2-weighted, fat-saturated MRI scans shown in Figures 76a through 76d reveal?

Explanation

DISCUSSION--The MRI scans show that edema is noted on the femoral insertion of the ACL consistent with a high-grade or complete ACL tear. The ACL is not visualized on the sagittal view, although the torn meniscus can be seen in the notch. On the coronal image, there is an empty lateral wall sign indicating proximal disruption of the ACL. The medial meniscus images show a disruption of normal meniscus morphology consistent with a bucket handle medial meniscus tear. Note the appearance on the sagittal MRI scan of what appears to be a second soft-tissue density in line with the PCL. This “double PCL” sign is highly indicative of a displaced medial meniscus tear rather than a displaced lateral meniscus tear.

Question 99

A 24-year-old former high school wrestler had anterior cruciate ligament (ACL) reconstruction with hamstring autograft 6 years ago. He now experiences daily instability of his knee with routine activities including walking. Examination reveals a grade 3+ Lachman test with a soft endpoint, varus laxity at 30°, and a positive dial test at 30° that dissipates at 90° of knee flexion. He has mild medial joint line tenderness. When walking, there is a slight varus thrust. What treatment is most likely to lead to a successful outcome?

Explanation

This patient underwent an ACL reconstruction that has now failed. Based on his examination, he also has a posterolateral corner injury. Because this concomitant injury was not treated, the patient had undue strain on his graft, resulting in ultimate failure. Hamstring grafts are as effective as other graft types for ACL reconstruction. The medial meniscus provides secondary stabilization to the knee; however, this patient has a missed lateral ligamentous injury, and meniscus tears do not result in the development of a varus thrust. An unrecognized PCL tear likely results in mild-to-moderate medial and patellofemoral osteoarthritis without significant lateral laxity and thrust.

Question 100

A 30-year-old man undergoes arthroscopic Bankart repair for recurrent anterior dislocation. He continues to experience instability postoperatively. Examination reveals a positive apprehension test. Radiographs of both shoulders are seen in Figure A. CT scan of his left shoulder is seen in Figure B. What is the best treatment option? Review Topic

Explanation

This patient has anterior glenoid bone deficiency (inverted pear glenoid) from a large bony Bankart lesion that was not adequately addressed in the index procedure. This is best treated with bony augmentation using the Latarjet vascularized coracoid transfer.
Patients with glenoid bone defects >20-30% have a high recurrence rate (>60%) after Bankart repair alone. Bone grafting is necessary to offer containment. Autograft options include coracoid transfer (such as the Latarjet procedure which extends the articular arc and creates a conjoined tendon sling) and iliac crest bone grafting.
Burkhart et al. addressed glenohumeral bone defects. They advise that significant bone deficits cannot be adequately addressed via arthroscopic Bankart repair alone. The Latarjet transfer creates an extra-articular platform to extend the articular arc of the glenoid.
Hantes et al. assessed Latarjet repairs using CT. They found that there is almost
complete repair of a 25% to 30% glenoid defect when using the Latarjet procedure.
Figure A comprises comparison Bernageau view glenoid profile radiographs of both shoulders. Figure B is a 3D reconstruction CT with showing glenoid bone deficiency (inverted pear deformity) with a large bony Bankart lesion. Illustration A shows the method of obtaining a Bernageau glenoid profile view. Illustration B shows the "cliff sign" of anterior glenoid bone loss. Illustration C depicts the Latarjet procedure. Illustration D depicts reduction in the articular arc with anterior glenoid loss.
Incorrect Answers:

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

Eye patch and ophthalmology evaluation in 2 days
Fluorescein eye stain
Emergent CT
High-dose systemic steroids
Observation

Correct Answer: Emergent CT

Explanation:

Question 2:

An 18-year-old man has had an enlarging mass in his hand for the past 3 months. Radiographs, an MRI scan, and biopsy specimens are shown in Figures 54a through 54d. What is the most likely diagnosis?

Options:

Bizarre parosteal osteochondromatous proliferation (BPOP)
Osteosarcoma
Ewing’s sarcoma
Enchondroma
Infection

Correct Answer: Bizarre parosteal osteochondromatous proliferation (BPOP)

Explanation:

Question 3:

Options:

Successful THA with significant shortening of the operative limb
Compromised THA with a high likelihood of persistent trochanteric bursitis
Successful THA with significant lengthening of the operative limb
Compromised THA with a Trendelenburg gait and hip instability The focus should be on the pictured plan. This shows a medialized cup and a stem that has insufficient offset (distance between the center of rotation and a line down the center of the femoral shaft) to recreate the patient’s anatomy. The cup sets the hip center of rotation (dot in the middle of the cup), and the femoral head reduces to this point. In this patient, inadequate offset could lead to a decrease in abductor efficiency and a Trendelenburg gait and even worse dislocation due to component impingement and/or muscular insufficiency. Compromised THA with a high likelihood of persistent trochanteric bursitis would be accurate if too much offset was restored for the patient. Regarding limb lengths, it appears the height of the implant is sufficient and as it stands would likely not change the leg lengths much at all. The concepts of limb length and offset restoration are critical to performing a successful THA and limiting adverse events and poor outcomes from an acquired limb length discrepancy, limb instability or persistent trochanteric bursitis.

Correct Answer: Compromised THA with a Trendelenburg gait and hip instability The focus should be on the pictured plan. This shows a medialized cup and a stem that has insufficient offset (distance between the center of rotation and a line down the center of the femoral shaft) to recreate the patient’s anatomy. The cup sets the hip center of rotation (dot in the middle of the cup), and the femoral head reduces to this point. In this patient, inadequate offset could lead to a decrease in abductor efficiency and a Trendelenburg gait and even worse dislocation due to component impingement and/or muscular insufficiency. Compromised THA with a high likelihood of persistent trochanteric bursitis would be accurate if too much offset was restored for the patient. Regarding limb lengths, it appears the height of the implant is sufficient and as it stands would likely not change the leg lengths much at all. The concepts of limb length and offset restoration are critical to performing a successful THA and limiting adverse events and poor outcomes from an acquired limb length discrepancy, limb instability or persistent trochanteric bursitis.

Explanation:

Question 4:

A unilateral "piano key" sign, indicates

Options:

distal radioulnar joint (DRUJ) instability.
interosseous membrane disruption.
midcarpal instability.
physiologic motion of hypermobility syndrome.

Correct Answer: distal radioulnar joint (DRUJ) instability.

Explanation:

Question 5:

Options:

Standard and low rowing exercises
Lying on his side with the shoulder abducted 90 degrees, elbow flexed 90 degrees, and pushing his forearm toward the table
Humeral head depressions while holding a ball against a wall
Scapular `punches` in many directions
Putting a rolled towel between his shoulder blades while lying supine and having a teammate push posteriorly on the shoulders

Correct Answer: Lying on his side with the shoulder abducted 90 degrees, elbow flexed 90 degrees, and pushing his forearm toward the table

Explanation:

Question 6:

Following total elbow arthroplasty, patients should be instructed to Review Topic

Options:

return to impact activities such as golf or tennis.
permanently limit the load bearing of that arm to 5 pounds or less.
aggressively strengthen the triceps immediately following surgery.
immobilize the wrist and hand for 4 weeks postoperatively to minimize stress on the surgical site.
avoid pronation and supination to reduce torsional stress on the implant.

Correct Answer: permanently limit the load bearing of that arm to 5 pounds or less.

Explanation:

Question 7:

- In a fatigue test, the maximum stress under which the material will not fail, regardless of how many loading cycles are applied, is defined as

Options:

Endurance limit
Failure stress
Critical stress
Yield stress
Elastic limit

Correct Answer: Endurance limit

Explanation:

Question 8:

A defect in the gene coding for fibrillin-1 would lead to which diagnosis? Review Topic

Options:

Osteogenesis Imperfecta
Neurofibromatosis
Achondroplasia
Pseudoachondroplasia
Marfan Syndrome

Correct Answer: Osteogenesis Imperfecta

Explanation:

Question 9:

-Assuming that the lesion can be covered appropriately and there is no drainage from the lesion, when should the patient be allowed to safely return to wrestling?

Options:

When the absence of pain is reported by the wrestler for 3 consecutive days
When 72 hours of antibiotics have been administered and there is no extension of the lesion for 48 hours
When laboratory values are within defined limits and the patient remains afebrile for 3 days
When the lesion has decreased in size by 50%

Correct Answer: When 72 hours of antibiotics have been administered and there is no extension of the lesion for 48 hours

Explanation:

DISCUSSION FOR QUESTIONS 48 AND 49
This patient has cellulitis, which is typically caused by group A Streptococcus or Staphylococcus. The patient’s lack of improvement with first-line antibiotics is concerning for methicillin-resistant Staphylococcus aureus (MRSA) infection. MRSA cellulitis is becoming more prevalent in young athletes,and a high index of suspicion is required to provide appropriate intervention during this
aggressive disease process. The diagnosis is typically made clinically without the use of cultures. Oral trimethoprimsulfamethoxazole (a sulfonamide-class drug) double strength twice daily for 10 to 14 days or doxycycline (a tetracycline-class drug) 100 mg twice daily for 10 to 14 days are recommended for first-line treatment of suspected MRSA cellulitis. There is no indication to proceed with irrigation and debridement; however, if the patient develops a soft-tissue abscess or the underlying joint becomes involved, this would be an appropriate intervention. Switching the athlete to an IV cephalosporin (cefazolin) is not likely to be effective against the presumed resistant bacteria.
Ciprofloxacin (a fluoroquinolone-class drug) is effective against many bacteria, but not MRSA. The current recommendation for wrestlers with cellulitis is that return to competition be allowed after 72 hours of antibiotic treatment if there has been no extension of the cellulitis for 48 hours, the lesion can be covered, and there is no drainage from the lesion. The other responses are not current recommendations for return to competition.

Question 10:

Options:

Skeletal traction
Irrigation and débridement of the open fractures
Irrigation and débridement and spanning external fixation of the knee
Open reduction and internal fixation of the proximal tibia and distal femur
Percutaneous screw fixation of the articular fragments with retrograde femoral nailing and antegrade tibial nailing

Correct Answer: Irrigation and débridement and spanning external fixation of the knee

Explanation:

Question 11:

What is the most anatomic location for placement of the femoral tunnel in anterior cruciate ligament reconstruction?

Options:

As far superior in the notch as possible
As far posterior as possible on the lateral femoral condyle
As far posterior as possible on the medial femoral condyle
Directly across from the posterior cruciate femoral insertion
At resident’s ridge

Correct Answer: As far posterior as possible on the lateral femoral condyle

Explanation:

Question 12:

Compared with wear rates of metal-on-standard polyethylene bearings (75 to 250 m m/y), the wear rate of metal-on-metal bearings for hip arthroplasty is approximately how many micrometers per year?

Options:

Less than 0.5
2 to 5
5 to 20
20 to 50
50 to 150

Correct Answer: 2 to 5

Explanation:

DISCUSSION: Studies on older systems, as well as newer designs, have confirmed that metal-on-metal bearing surfaces undergo linear wear of 2 to 5
m
m per year. Ceramic bearing surfaces produced with recent technology perform even better, with a wear rate of 0.5 to 2.5
m
m per year. Clinical wear rates of metal-on-crosslinked polyethylene have not yet been determined.
REFERENCES: McKellop H, Park SH, Chiesa R, et al: In vivo wear of three types of metal on metal hip prostheses during two decades of use. Clin Orthop 1996;329:S128-S140.
Schmalzried TP, Callaghan JJ: Wear in total hip and knee replacements. J Bone Joint Surg Am 1999;81:115-136.

Question 13:

Second impact syndrome (SIS) after head injury is characterized by which of the following? Review Topic

Options:

Gradual progression of neurologic symptoms
Preventable by restricting return to play until symptom-free
Excellent prognosis for full recovery
Rarely involves brain stem compromise
CT rarely shows brain edema

Correct Answer: Preventable by restricting return to play until symptom-free

Explanation:

Question 14:

Options:

Spastic gait and a positive Hoffman’s sign
Severe arm pain with upper extremity hyporeflexia
Normal neurologic findings
Hyperactive jaw jerk reflex with extremity numbness
Flaccid paraparesis

Correct Answer: Spastic gait and a positive Hoffman’s sign

Explanation:

Question 15:

- Which of the following events is most likely to occur following a complete transection of a peripheral nerve?

Options:

The cell body nucleus migrates centrally
Schwann cells distal to the transection die
Axoplasm in the proximal stump drains out
Myelin distal to the transection is phagocytized
Cell body protein synthesis decreases for the first 10 to 14 days

Correct Answer: Myelin distal to the transection is phagocytized

Explanation:

Question 16:

- Figures 42a and 42b show the sagittal and axial MRI scans of a 24-year-old patient who has sciatia. Which of the following combinations of physical findings is most consistent wit the MRI studies?

Options:

Decreased ankle jerk and positive femoral nerve stretch test
Decreased knee jerk and positive straight-leg raising sign
Gastrocnemius-soleus complex weakness and positive straight-leg raising sign
Weakness of the extensor hallucis longus and positive straight-leg raising sign
Weakness of the extensor hallucis longus and positive femoral nerve stretch test

Correct Answer: Gastrocnemius-soleus complex weakness and positive straight-leg raising sign

Explanation:

Question 17:

Myositis ossificans is a recognized complication of contusion to the quadriceps muscle. During early rehabilitation, this condition is most likely to be exacerbated by

Options:

electrical stimulation.
iontophoresis.
isometric exercise.
ice/heat contrast.
passive stretching.

Correct Answer: passive stretching.

Explanation:

Question 18:

- Which of the following conditions is associated é the highest mortality in patients é a pelvic fracture?

Options:

Shock from hypovolemia
Associated rupture of the bladder
Arterial bleeding on pelvic angiogram
Presence of a hematoma in the perineum and scrotum
Fractures of both the anterior and posterior pelvic ring

Correct Answer: Shock from hypovolemia

Explanation:

The highest rate of mortality rate after a pelvic fracture is associated with hypovolemic shock. Most of which is secondary to extensive intrapelvic arterial injuries.

Question 19:

Options:

Six weeks of acetylsalicylic acid postsurgically beginning the evening of surgery
Six weeks of low-molecular-weight heparin beginning the morning after surgery
Routine duplex scans of both lower extremities before hospital discharge to ensure the patient has not developed another DVT
Use of pneumatic calf compressors on both lower extremities while in the hospital and 4 weeks of warfarin starting the evening of surgery

Correct Answer: Use of pneumatic calf compressors on both lower extremities while in the hospital and 4 weeks of warfarin starting the evening of surgery

Explanation:

The 2011 AAOS guideline,
Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty
, recommends the combined use of mechanical and pharmacological prophylaxis in patients who have a history of previous thromboembolism. This recommendation is a consensus opinion of the work group that established these guidelines because there is no other reliable evidence for this clinical scenario. There is strong evidence against the use of routine duplex scans in patients undergoing hip and knee replacement. The remaining two responses are less appropriate because they do not include the use of mechanical prophylaxis immediately after surgery.

Question 20:

Options:

medial and lateral compartments.
medial and patellofemoral compartments.
lateral and patellofemoral compartments.
the patellofemoral compartment only.

Correct Answer: medial and patellofemoral compartments.

Explanation:

Question 21:

At the time of revision knee arthroplasty, a surgeon performs a rectus snip to gain exposure to the knee. When compared with a standard parapatellar approach, what is the expected outcome?

Options:

Improvement in range of motion
Reduction in range of motion
Increase in extensor mechanism lag
No differences in motion and strength

Correct Answer: No differences in motion and strength

Explanation:

DISCUSSION:
Rectus snip during total knee arthroplasty has no effect on motion or strength at long-term follow-up. It has not been associated with extensor mechanism lag.

Question 22:

What risk factor is most associated with progression of idiopathic scoliosis to a curve requiring surgery?

Options:

Curve magnitude of more than 20 degrees at menarche
Curve magnitude of more than 30 degrees at the peak height velocity
Curve magnitude of more than 30 degrees at skeletal age 12 years
Curve magnitude of more than 30 degrees at Risser grade 2
Curve flexibility of less than 50% at Risser grade 2

Correct Answer: Curve magnitude of more than 30 degrees at the peak height velocity

Explanation:

DISCUSSION: The magnitude of the curve at the time of the peak height velocity is the most prognostic sign in relationship to surgery. More than 70% of curves that measure more than
30 degrees at this time are likely to reach surgical range.
REFERENCES: Little DG, Song KM, Katz D, et al: Relationship of peak height velocity to other maturity indicators in idiopathic scoliosis in girls. J Bone Joint Surg Am 2000;82:685-693.
Sanders JO, Moreland M, Bassett G: Idiopathic scoliosis: Prevalence and natural history, in DeWald R (ed): Spinal Deformities: The Comprehensive Text. New York, NY, Thieme Medical Publishers, 2003.

Question 23:

Options:

CT-guided needle biopsy followed by radiation therapy
L5-S1 fusion with instrumentation
L5-S1 hemilaminotomy and partial diskectomy
Activity restriction and bracing
L5-S1 total disk arthroplasty

Correct Answer: Activity restriction and bracing

Explanation:

DISCUSSION: The sagittal and axial CT scans show a bilateral spondylolysis at L5. The defect is in the pars interarticularis on the right side but at the base of the pedicle on the left. Having failed a trial of physical therapy with only a 3-month history of pain, the next most appropriate step in management should consist of activity modification and bracing in an antilordotic lumbosacral orthosis. Surgical intervention is reserved for patients who have failed to respond to a trial of bracing and activity restriction.
REFERENCES: Debnath UK, Freeman BJ, Grevitt MP, et al: Clinical outcome of symptomatic unilateral stress injuries of the lumbar pars interarticularis. Spine 2007;32:995-1000.
Bono CM: Low-back pain in athletes. J Bone Joint Surg Am 2004;86:382-396.

Question 24:

Options:

Physical therapy
Arthroscopic synovectomy
Tibial insert revision
Femoral component revision

Correct Answer: Arthroscopic synovectomy

Explanation:

Question 25:

Which of the following have been found to affect the rate of perioperative infections or wound complication rates in foot and ankle surgery?

Options:

Methotrexate
Gold
Hydroxychloroquine
TNF-a inhibitors
Smoking

Correct Answer: Smoking

Explanation:

DISCUSSION: Clinical studies have shown that smoking cessation for 4 weeks reduces the risk of infection to the level of nonsmokers. Adverse effects on wound healing caused by chemotherapy used to treat rheumatoid arthritis has not been borne out in the literature.
REFERENCES: Bibbo C, Anderson RB, Davis WH, et al: The influence of rheumatoid chemotherapy, age, and presence of rheumatoid nodules on postoperative complications in rheumatoid foot and ankle surgery: Analysis of 725 procedures in 104 patients. Foot Ankle Int 2003;24:40-44.
Bibbo C, Goldberg JW: Infections and healing complications after elective orthopaedic foot and ankle surgery during tumor necrosis factor-alpha inhibition therapy. Foot Ankle Int
2004;25:331-335.
Sorensen LT, Karlsmark T, Gottrup F: Abstinence from smoking reduces incisional wound infection: A randomized controlled trial. Ann Surg 2003;238:1-5.

Question 26:

Options:

Marginal resection
Observation
Wide tumor bed resection
Radiation therapy
Chemotherapy

Correct Answer: Wide tumor bed resection

Explanation:

DISCUSSION: Dermatofibrosarcoma protuberans (DFSP) is a rare superficial sarcoma that is frequently misdiagnosed at presentation. It is frequently excised prior to suspecting that the lesion is a sarcoma and if not appropriately treated with tumor bed resection to obtain wide margins, these lesions have a high incidence of local recurrence. It is recommended that the wide excision include the deep fascia and a 2.5- to 3-cm cuff of normal-appearing skin. Distant disease spread is rare and usually occurs in the face of a multiply recurrent lesion. Despite the apparent gross circumscription of these lesions, the tumor diffusely infiltrates the dermis and subcutaneous tissues. A characteristic histologic finding can be seen in the deep margins of the tumor where it intricately interdigitates with normal fat.
REFERENCES: Lindner NJ, Scarborough MT, Powell GJ, et al: Revision surgery in dermatofibrosarcoma protuberans of the trunk and extremities. Eur J Surg Oncol
1999;25:392-397.
Weiss SW, Goldblum JR, Enzinger FM: Enzinger and Weiss’s Soft Tissue Tumors, ed 4. Philadelphia, PA, Elsevier, 2001, pp 491-505.

Question 27:

Options:

osteoarthritis of the hip is likely to occur later in life.
correction prevents later development of osteoarthritis.
most acetabular tears are symptomatic, and surgical treatment will be necessary.
this is an inherited deformity.

Correct Answer: osteoarthritis of the hip is likely to occur later in life.

Explanation:

Question 28:

During placement of an external fixator for a distal radius fracture, the most commonly injured nerve is a branch of which of the following nerves? Review Topic

Options:

Ulnar
Median
Superficial radial
Lateral antebrachial cutaneous
Medial antebrachial cutaneous

Correct Answer: Superficial radial

Explanation:

Pin track infections and sensory injuries are among the most common complications of external fixation for distal radius fractures. The proximal pins of most distal radius external fixators are placed in the “bare area” of the distal radius, about four finger-breadths above the radial styloid. This corresponds to the area where the dorsal sensory branch of the radial nerve penetrates the fascia dorsal to the brachioradialis tendon to become a subcutaneous structure. Injury to the superficial radial nerve may produce painful dysesthesias and neuromas.
(SBQ12TR.106) A 67-year-old female sustains the injury shown in Figure A after a trip and fall. When discussing the outcomes of surgery with the patient, which of the following statements is true?
Post-surgical mortality rates are significantly lower after total hip arthroplasty compared to hemiarthroplasty
Internal fixation shows better outcomes (reoperation rate, functional status, and/or complication rates) compared to arthroplasty
Bipolar hemiarthroplasty shows better outcomes (reoperation rate, functional status, and/or complication rates) compared to unipolar hemiarthroplasty
A delay in surgery greater than 48 hours is recommended if the patient has multiple medical comorbiditiesm which are not fully optimized
Dislocation rates are equivalent between total hip arthroplasty and hemiarthroplasty
Moderate evidence supports that hip fracture surgery within 48 hours of admission is associated with better outcomes. However, patients with significant medical comorbidity should be fully optimized before surgery.
Although several studies have shown a benefit to surgery within 48 hours, no definitive time frame has been elucidated. The majority of literature has shown improved outcomes in regards to pain, complications, and length of stay with early surgery. Patients with significant medical comorbidities have been shown to have the highest mortality rates.
Moran et al. aimed to determine whether a delay in surgery for hip fractures had an affect on postoperative mortality among elderly patients. In an observational study of 2660 patients, they showed that mortality following hip fracture surgery was 9% at 30-days, 19% at 90-days, and 30% at 12-months. Patients with medical comorbidities had 2.5 times the risk of death within 30-days of surgery. In addition, individuals who had surgery delayed beyond 4 days had increased mortality at 90-days and 12-months.
Papakostidis et al. examined the timing of internal fixation of intracapsular fractures of the neck of femur on the development of late complications, particularly osteonecrosis of femoral head (ONFH) and non-union. They showed no benefit of
early surgery on incidence of AVN. However, delay of internal fixation of more than
24 hours showed increased rates of non-union.
Figure A shows a displaced right femoral neck fracture. Incorrect Answers:

Question 29:

Options:

hinge knee bracing with restricted weight bearing.
revision ORIF.
revision total knee arthroplasty (TKA).
above-knee amputation.

Correct Answer: revision total knee arthroplasty (TKA).

Explanation:

Question 30:

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 31:

Which of the following statements best describes the outcome of the routine use of continuous passive motion (CPM) machines after total knee arthroplasty (TKA)?

Options:

CPM is likely to improve early range of motion and final range of motion.
CPM may improve early range of motion but is unlikely to improve final range of motion.
CPM is likely to decrease postoperative pain.
CPM is likely to improve extension but not flexion.
CPM is likely to restore quicker ambulatory ability.

Correct Answer: CPM may improve early range of motion but is unlikely to improve final range of motion.

Explanation:

DISCUSSION: Although CPM machines are used widely in the United States for patients undergoing TKA, the benefit seems to be marginal, if any. Numerous randomized trials have shown that final outcomes after total knee arthroplasty are unaffected by the use of CPM machines postoperatively. Some studies have suggested that use of CPM may improve flexion in the first few weeks, but any short-term benefit from the machine was lost by intermediate-term follow-up. Aside from potential improvement in flexion within the first few postoperative weeks, there does not appear to be any benefit from the machines. There is no improvement in pain, ambulation, or extension. The cost-effectiveness of these machines has been questioned by many authors.
REFERENCES: Pellicci PM, Tria AJ, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 287-293.
McInnes J, Larson MG, Daltroy LH, et al: A controlled evaluation of continuous passive motion in patients undergoing total knee arthroplasty. JAMA 1992;268:1423-1428.
Kumar PJ, McPherson EJ, Dorr LD, et al: Rehabilitation after total knee arthroplasty: A comparison of 2 rehabilitation techniques. Clin Orthop 1996;331:93-101.

Question 32:

The essential lesion in recurrent or posterior instability following simple dislocation of the elbow typically involves which of the following structures?

Options:

Medial collateral ligament
Lateral ulnar collateral ligament
Coracohumeral ligament
Anterior joint capsule
Posterior joint capsule

Correct Answer: Lateral ulnar collateral ligament

Explanation:

Question 33:

He is intubated and being resuscitated. The calf is very swollen with compartment pressures: anterior 25 mm Hg, lateral 24 mm Hg, deep posterior 21 mm Hg, and

Options:

Observation
Splinting and limb elevation above the heart
Splinting and no limb elevation
Immediate fasciotomy
Continuous pressure monitoring with an indwelling catheter

Correct Answer: Immediate fasciotomy

Explanation:

Question 34:

below show the clinical photograph and radiograph obtained from a year-old man who has deformity and pain 1 year after primary total hip arthroplasty. What is the reason for the observed deformity?

Options:

A Vancouver type B1 fracture
Residual leg-length discrepancy
Loosening and subsidence of the femoral stem into anteversion
Loosening and subsidence of the femoral stem into retroversion

Correct Answer: Loosening and subsidence of the femoral stem into retroversion

Explanation:

Question 35:

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

Options:

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

Correct Answer: Annulus fibrosis

Explanation:

Question 36:

Options:

Alcoholism
Drug abuse
Down syndrome
Diabetes mellitus
Idiopathic scoliosis

Correct Answer: Diabetes mellitus

Explanation:

DISCUSSION: The history, physical examination, and radiographic findings are consistent with type IV sacral agenesis or caudal regression syndrome. These children are born with no lumbar spine or sacrum. The T12 vertebra is often prominent posteriorly. Popliteal webbing and knee flexion contractures are common with this diagnosis. There is a higher incidence of this diagnosis when the mother has diabetes mellitus. Maternal drug abuse and alcoholism can produce phenotypically unique children but without the findings described here. Maternal idiopathic scoliosis is not associated with caudal regression syndrome.
REFERENCES: Chan BW, Chan KS, Koide T, et al: Maternal diabetes increases the risk of caudal regression caused by retinoic acid. Diabetes 2002;51:2811-2816.
Zaw W, Stone DG: Caudal regression syndrome in twin pregnancy with type II diabetes.
J Perinatol 2002;22:171-174.

Question 37:

In the setting of a proximal tibial plateau fracture and its repair, which of the following materials is an isotropic material?

Options:

Proximal tibial cortical bone
Articular cartilage of the tibial plateau
Stainless steel tibial plate
Medial or lateral meniscus
Calcium phosphate cement

Correct Answer: Stainless steel tibial plate

Explanation:

DISCUSSION: An isotropic material is one that has similar mechanical properties regardless of the orientation of the material. Examples of isotropic materials include metals, plastics, and methacrylate. Most biologic tissues are anisotropic, meaning their mechanical properties alter depending on the materials’ orientation to the applied stress.
REFERENCE: Einhorn TA, O’Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2007, pp 58-59.

Question 38:

In the most common condition causing a winged scapula, which of the following nerves is affected? Review Topic

Options:

Long thoracic nerve
Spinal accessory nerve
Suprascapular nerve
Dorsal scapular nerve
Thoracodorsal nerve

Correct Answer: Long thoracic nerve

Explanation:

Question 39:

Options:

Fourth cervical nerve root
Upper trunk of the brachial plexus
Middle trunk of the brachial plexus
Lateral cord of the brachial plexus
Axillary nerve

Correct Answer: Upper trunk of the brachial plexus

Explanation:

Question 40:

Familial (Leiden) thrombophilia is of importance in joint arthroplasty because of an abnormality in the clotting cascade. Which of the following statements best describes the condition?

Options:

It is a disease caused by an abnormality of platelets that leads to increased blood clotting.
It is a disease caused by an abnormality of vascular endothelium that leads to increased blood clotting.
It is a disease caused by an abnormality of hepatic metabolism that leads to decreased production of factor V and decreased blood clotting.
It is a disease caused by an abnormality of factor V that leads to decreased inactivation of factor Va by activated protein C (aPC) and increased blood clotting.
It is a familial, genetic disease that requires placement of a Greenfield filter in all individuals who have the abnormality, prior to surgery.

Correct Answer: It is a disease caused by an abnormality of factor V that leads to decreased inactivation of factor Va by activated protein C (aPC) and increased blood clotting.

Explanation:

Question 41:

Options:

hallux valgus correction and lesser metatarsophalangeal joint synovectomies.
hallux valgus correction and lesser metatarsal head resections.
first metatarsophalangeal joint fusion and lesser metatarsal head resections.
first metatarsophalangeal joint fusion and lesser metatarsophalangeal joint synovectomies.
Keller resection arthroplasty and lesser metatarsal head resections.

Correct Answer: first metatarsophalangeal joint fusion and lesser metatarsal head resections.

Explanation:

Question 42:

Deep venous thromboses are primarily composed of red blood cells and fibrin. What is fibrin?

Options:

Platelet cytoskeletons
Fragmented collagen
A type of thromboplastin
A product of the coagulation cascade
A product of the fibrinolytic system

Correct Answer: A product of the coagulation cascade

Explanation:

Question 43:

What is the most reproducible landmark for the accurate anatomic placement of the tibial tunnel for an anterior cruciate ligament (ACL) reconstruction?

Options:

Anterior border of the tibia
Anterior border of the posterior cruciate ligament (PCL)
Posterior border of the tibia
Posterior border of the anterior horn of the lateral meniscus
Posterior border of the anterior horn of the medial meniscus

Correct Answer: Anterior border of the posterior cruciate ligament (PCL)

Explanation:

Question 44:

Options:

Immediate spica casting
Flexible intramedullary nail placement
Traction and casting
External fixation
Solid intramedullary nail fixation via the greater trochanter

Correct Answer: Solid intramedullary nail fixation via the greater trochanter

Explanation:

Question 45:

Options:

Provision of information
Competency
Understanding
Jurisdiction

Correct Answer: Competency

Explanation:

Question 46:

Which of the following is accurate regarding low-molecular-weight heparin used for deep venous thrombosis (DVT) prophylaxis in total joint arthroplasty?

Options:

The incidence of thrombocytopenia is lower with low-molecular-weight heparin than with unfractionated heparin.
The half-life of low-molecular-weight heparin is less than that of unfractionated heparin.
Low-molecular-weight heparin affects circulating thrombin (Factor IIa) to a greater extent than unfractionated heparin.
The mechanism of action of low-molecular-weight heparin is primarily by targeting Factor Xa.
There is a significant decrease in postoperative bleeding with the use of low-molecular-weight heparin compared to warfarin.

Correct Answer: The mechanism of action of low-molecular-weight heparin is primarily by targeting Factor Xa.

Explanation:

DISCUSSION: Low-molecular-weight heparin is highly bioavailable with a half-life
to 18 hours. This is greater than the 1 hour half-life of unfractionated heparin.
Low-molecular-weight heparin offers an advantage over unfractionated heparin by selectively targeting Factor Xa while having a lesser effect on circulating thrombin (Factor IIa). Circulating thrombin Factor IIa is needed for local hemostasis at the site of the surgical wound. Clinical studies have shown a reduction by one third in the incidence of thrombocytopenia with the use of low-molecular-weight heparin. Low-molecular-weight heparin has been shown to demonstrate similar clinical results compared to warfarin with respect to preventing thromboembolic disease after total hip arthroplasty and complications such as bleeding.
REFERENCES: Zimlich RH, Fulbright BM, Friedman RJ: Current status of anticoagulation therapy after total hip and total knee arthroplasty. J Am Acad Orthop Surg 1996;4:54-62.
Colwell CW Jr, Spiro TE, Trowbridge AA, et al: Use of enoxaparin, a low-molecular-weight heparin, and unfractionated heparin for the prevention of deep venous thrombosis after elective hip replacement: A clinical trial comparing efficacy and safety. J Bone Joint Surg Am 1994;76:3-14.
Torholm C, Broeng L, Jorgensen PS, et al: Thromboprophylaxis by low-molecular-weight heparin in elective hip surgery: A placebo controlled study. J Bone Joint Surg Br 1991;73:434-438.

Question 47:

They found statistically significant decreases in need for secondary intervention, hardware failure, and infection as well as faster wound healing and faster time to fracture union.

Options:

Wei et al. provide a meta analysis regarding use of rhBMP-2 in open tibia fractures. Due to decreased rates of secondary interventions they estimated a net savings of $6,000 per case when rh-BMP2 was used. They found no significant difference in rates of infection, postoperative pain, hardware failure, or fracture healing at 20 weeks.
Incorrect answers:

Correct Answer: Wei et al. provide a meta analysis regarding use of rhBMP-2 in open tibia fractures. Due to decreased rates of secondary interventions they estimated a net savings of $6,000 per case when rh-BMP2 was used. They found no significant difference in rates of infection, postoperative pain, hardware failure, or fracture healing at 20 weeks.

Explanation:

OrthoCash 2020
A 76-year old patient underwent partial foot amputation through the talonavicular and calcaneocuboid joints. Besides Achilles tendon lengthening, what additional procedure(s) may be required to prevent the most common post-operative deformity?
Posterior capsule release
Anterior tibialis transfer to the talar neck
Anterior tibialis transfer to cuboid
Flexor hallucis longus transfer to calcaneus
Peroneus brevis transfer to calcaneus
Corrent answer: 2
Achilles tendon lengthening AND anterior tibialis transfer to the talar neck would be required to prevent equinovarus deformity.
Partial foot amputation through the talonavicular and calcaneocuboid joints is also known as the Chopart amputation. Chopart amputation alone is known to result in significant equinovarus deformity. This deformity results in excessive pressure on the anterior wound during gait, causing pain and wound complications. Transfer of the tibialis anterior tendon to talar neck will provide force, and muscle tone, that promotes ankle dorsiflexion. Lengthening of the Achilles tendon will also reduce the equinus moment force across the ankle joint.
Dillion et al. examined the gait patterns of partial foot amputees. They found that amputations proximal to the metatarsal heads compromised the normal propulsive function of the foot and ankle. The ideal level of amputation to maintain normal propulsive function was distal to the metatarsal heads (i.e., disarticulating the metatarsophalangeal (MTP) joint).
Illustration A is a lateral radiograph showing a Chopart amputation. Incorrect Answers:
prevent the equinovarus deformity.
OrthoCash 2020
A 32-year-old male is involved in a motor vehicle collision and sustains the injury seen in Figure A. What is the most common urological injury associated with this injury pattern?
Testicular torsion
Posterior urethral tear
Bladder denervation
Testicular rupture
Renal hematoma
The figure shows an anteroposterior pelvic ring injury. The most common urological injury with pelvic ring injuries remains the posterior urethral tear, followed by bladder rupture.
Watnik et al notes lower urinary tract (bladder to end of urethra) injuries in up to 25% of patients with this injury. He reports that when contaminated urine communicates with the anterior arch, the possibility of infection exists, and early repair of bladder disruptions with simultaneous anterior arch plating minimizes this risk.
Routt et al notes that even with simultaneous treatment of these injuries, complications are common (late stricture in 44%, impotence in 16%, delayed incontinence in 20% of females, anterior deep pelvic infection in 4%). Despite this, they report that early urological repairs are easily performed at the time of anterior pelvic open reduction and internal fixation.
OrthoCash 2020
A 26-year-old women, 31-weeks pregnant, presents to the emergency department with the injury shown in Figure A. She states the injury occurred while lifting a heavy vacuum five days ago. She suffers from chronic headaches and sleep disturbances. On inspection, there are multiple dorsal and volar bruising over her wrist and upper arm. She is neurologically intact. After closed reduction and immobilizing the arm, what would be the next best step in management of this patient?
Diagnostic wrist arthroscopy
Urgent MRI wrist
Skeletal survey radiographs
Request a consultation with social worker in the hospital
Urgent open reduction internal fixation
Corrent answer: 4
This patient presents with classic features of domestic violence. The most appropriate next step would be consultation with a social worker at the hospital, assess for child and patient safety, and encouraging the patient to seek self-protection.
Factors suggestive of domestic violence in the patient include pregnancy, delayed presentation after injury, inconsistent history, multiple bruises and complaints of chronic headache/sleep disturbances. Victims frequently miss days of work and as a result are at risk for losing their jobs. Victims are also more likely to engage in high-risk behavior with sex, drugs, alcohol, smoking, and eating.
The AAOS published a document outlining the Orthopaedic Surgeon’s responsibilities in domestic and family violence. Musculoskeletal injuries that should raise a suspicion of a problem include (1) Multiple injuries/fractures; (2) Unusual patterns of injury/fracture; (3) Injuries/fractures of varying ages; (4)
Injuries/fractures inconsistent with or disproportional to the history; (5) Multiple injuries treated in different hospital emergency departments or by different providers.
Incorrect Answers:
OrthoCash 2020
A 45-year-old man undergoes open reduction and internal fixation for a comminuted intra-articular humerus fracture . An olecranon osteotomy is performed and subsequently fixed with an intramedullary cancellous screw. Which of the following options in the table shown in Figure A best describes the characteristics of this osteotomy?

Question 48:

The findings in Brown-Sequard syndrome include loss of which of the following? Review Topic

Options:

Greater loss of upper extremity motor function than lower extremity function
Ipsilateral motor function and ipsilateral pain and temperature sensation
Ipsilateral motor function and contralateral pain and temperature sensation
Contralateral motor function and ipsilateral pain and temperature sensation
Lower of extremity proprioception and balance

Correct Answer: Ipsilateral motor function and contralateral pain and temperature sensation

Explanation:

Question 49:

Which of the following is a function of siRNA (small interfering RNA)?

Options:

Identifies proteins
Blocks transcription of DNA
Separates DNA based on size
Blocks translation of mRNA
Identifies DNA sequences

Correct Answer: Blocks transcription of DNA

Explanation:

Question 50:

Options:

Observation and close follow-up
Dynamization of the intramedullary nail
Revision surgery, internally rotate distal fragment by 19 degrees
Revision surgery, externally rotate distal fragment by 8 degrees
Revision surgery, internally rotate proximal fragment by 11 degrees

Correct Answer: Dynamization of the intramedullary nail

Explanation:

Question 51:

Options:

irrigation and debridement.
single-stage exchange.
stage exchange.
observation.

Correct Answer: observation.

Explanation:

Question 52:

Options:

figure-of-8 splinting to maintain the clavicle in a reduced position.
an exercise program to stabilize the joint in a reduced position.
elective reconstruction of the sternoclavicular joint ligaments.
reassurance and local symptomatic treatment.
closed reduction and temporary pin fixation to stabilize the joint.

Correct Answer: reassurance and local symptomatic treatment.

Explanation:

Question 53:

During the approach to the lumbar spine for an L4-L5 anterior lumbar interbody fusion, which structure generally is found overlying the anterior surface of the L4 vertebra?

Options:

Aorta
Right common iliac artery
Left common iliac vein
Right ureter

Correct Answer: Aorta

Explanation:

Question 54:

- The Injury Severity Score (ISS), using point scores from five different body systems, is a method that aids in predicting the chances of mortality in a patient with multiple injuries by

Options:

adding the scores, in all five body systems
adding the squares of the scores in the three most severely injured systems
doubling the cumulative score for head and chest injuries
combining the scores from the most and least injured systems
correcting the score in the most severely injured system for age

Correct Answer: adding the squares of the scores in the three most severely injured systems

Explanation:

Question 55:

Options:

Decreased extent of cord edema only
Decreased extent of cord hemorrhage only
Decreased extent of both cord edema and hemorrhage
Increased extent of cord hemorrhage but decreased edema
No difference in extent of hemorrhage and edema

Correct Answer: Decreased extent of cord hemorrhage only

Explanation:

Question 56:

Figure 12 shows the lumbar CT scan of a 24-year-old man who was injured in a snowmobile accident. What is the mechanism of injury?

Options:

Flexion extension
Flexion distraction
Vertical compression
Extension compression
Extension distraction

Correct Answer: Vertical compression

Explanation:

Question 57:

A 28-year-old woman has left shoulder pain and a tender soft-tissue mass. Based on the MRI scan and biopsy specimens shown in Figures 74a through 74c, what is the most likely diagnosis?

Options:

Malignant fibrous histiocytoma
Lymphoma
Synovial sarcoma
Schwannoma
Neurofibroma

Correct Answer: Schwannoma

Explanation:

DISCUSSION: Schwannomas (neurilemomas) occur at all ages but are most frequently seen in persons between the ages of 20 and 50 years. MRI features of schwannomas are fairly nonspecific, but when they are associated with a large named nerve, the identification of a mass in continuity with that nerve is highly suggestive of a schwannoma. Most have a fairly homogeneous appearance with a high water content and often fusiform shape. Classically, the histology shows alternating Antoni A (dense spindle cell region) areas and Antoni B (loose myxoid tissue) areas. They also demonstrate uniform intense immunostaining with S-100 protein.
REFERENCES: Damron TA, Sim FH: Soft-tissue tumors about the knee. J Am Acad Orthop Surg 1997;5:141-152.
Weiss SW, Goldblum JR, Enzinger FM: Enzinger and Weiss’s Soft Tissue Tumors, ed 4. Philadelphia, PA, Elsevier, 2001, pp 1146-1167.

Question 58:

Which of the following findings helps to distinguish between stress fractures of the tibia and shin splints? Review Topic

Options:

With shin splints, a bone scan shows the posterior tibial cortex in a diffuse, longitudinal orientation.
With tibial shin splints, the bone scan is more intense.
A more diffuse area of tenderness is seen in tibial stress fractures.
A three-phase bone scan is positive in all phases with shin splints, but only positive in delayed images with tibial stress fractures.
After activity, pain persists longer with tibial stress fractures.

Correct Answer: With shin splints, a bone scan shows the posterior tibial cortex in a diffuse, longitudinal orientation.

Explanation:

Question 59:

Options:

closed reduction and cast immobilization.
closed reduction, carpal tunnel release, and cast immobilization.
open reduction and ligament repair via a dorsal approach.
open reduction and ligament repair via a volar approach.
open reduction and ligament repair via dorsal and volar approaches and an extended carpal tunnel release.

Correct Answer: open reduction and ligament repair via dorsal and volar approaches and an extended carpal tunnel release.

Explanation:

DISCUSSION: A spectrum of perilunate injury patterns exists, with the dorsal trans-scaphoid perilunate fracture-dislocation being the most common. Perilunate injuries are highly unstable complex carpal disruptions that are not amenable to closed treatment. Open reduction and internal fixation is necessary to accurately restore carpal alignment via fracture reduction and fixation and intercarpal ligament repair. Controversy exists regarding the need for dorsal or combined dorsal and volar approaches. Based on the radiographic findings of a volar dislocation of the lunate and the associated median nerve injury, the patient requires open reduction and internal fixation via combined dorsal and volar approaches with a concomitant carpal tunnel release.
REFERENCES: Herzberg G, Forissier D: Acute dorsal trans-scaphoid perilunate fracture-dislocations: Medium-term results. J Hand Surg Br 2002;27:498-502.
Melone CP Jr, Murphy MS, Raskin KB: Perilunate injuries: Repair by dual dorsal and volar approaches. Hand Clin 2000;16:439-448.
Herzberg G, Comtet JJ, Linscheid RL, et al: Perilunate dislocations and fracture-dislocations:
A multicenter study. J Hand Surg Am 1993;18:768-779.

Question 60:

A 47-year-old man has acute right shoulder pain after falling off a ladder. The MRI scan shown in Figure 9 reveals

Options:

aseptic necrosis of the humeral head.
a nondisplaced anatomic neck fracture.
a partial-thickness rotator cuff tear.
a full-thickness rotator cuff tear.
a bony Bankart defect.

Correct Answer: a full-thickness rotator cuff tear.

Explanation:

Question 61:

Options:

open reduction and internal fixation with a plate and screws.
open treatment with calcaneal bone graft.
percutaneous screw fixation with a 4.5-mm screw.
weight-bearing cast for 8 weeks.
spanning external fixation.

Correct Answer: percutaneous screw fixation with a 4.5-mm screw.

Explanation:

Question 62:

Figure 40 shows the radiographs of a 2-year-old boy who has a deformed leg. The patient is ambulatory and has no pain. What is the most appropriate management?

Options:

Observation
Patellar tendon bearing (PTB) orthosis
Osteotomy to correct the deformity and fixation with an intramedullary rod
Vascularized fibular graft from the contralateral leg
Amputation

Correct Answer: Patellar tendon bearing (PTB) orthosis

Explanation:

DISCUSSION: The patient has a prefractured stage of congenital pseudarthrosis of the tibia and is at risk for fracture. The PTB orthosis may prevent or delay the fracture. Osteotomy is frequently complicated by nonunion. When established nonunion does not respond to intramedullary nailing and bone grafting, vascularized grafting may succeed. Amputation is a salvage procedure.
REFERENCES: Murray HH, Lovell WW: Congenital pseudarthrosis of the tibia: A long-term follow-up study. Clin Orthop 1982;166:14-20.
Crossett LS, Beaty JH, Betz RR, et al: Congenital pseudarthrosis of the tibia: Long-term
follow-up study. Clin Orthop 1989;245:16-18.

Question 63:

Which of the following anatomic structures is labeled 6 in Figure 27?

Options:

A2 pulley
Grayson’s ligament
Cleland’s ligament
Triangular ligament
Sagittal band

Correct Answer: A2 pulley

Explanation:

Question 64:

Figure 13 is the photograph of 18-month-old triplets with a lower-limb condition. What is the best initial treatment? Review Topic

Options:

Vitamin D supplementation and serum level monitoring
Mechanical axis alignment measurements on serial standing knee radiographs
Genetic testing and counseling for short-stature syndrome
Observation and clinical follow-up.

Correct Answer: Mechanical axis alignment measurements on serial standing knee radiographs

Explanation:

These triplets exhibit genu varum and internal tibial torsion that can be part of normal development. Fetal packing is the likely major contributing cause for these triplets, however. Observation and follow-up will be sufficient. Bowing and torsion can be clinical features of vitamin D deficiency, Blount disease, and short-stature syndromes, but these are not the most likely diagnoses. Radiographic diagnosis of Blount disease may not be accurate at this age.
(SBQ13PE.56) A 22-month-old female is hospitalized with a fever and malaise. She is found to be bacteremic, and blood cultures grow methicillin-sensitive Staphylococcus aureus (MSSA). During her hospitalization, the pediatrician notices her arm is slightly swollen and appears painful to use. MRI is obtained and demonstrated in figure A. Which feature of the MRI suggests the need for surgical management?
Review Topic
Brodie's Abscess
Osteomyelitis of the humeral metaphysis
Subperiosteal abscess of the humerus
Presence of subcutaneous air
High risk of proximal humeral growth arrest
This patient has osteomyelitis of the humerus with a large subperiosteal abscess. The presence of subperiosteal abscess necessitates surgical intervention for irrigation and debridement (I&D).
The diagnosis of acute osteomyelitis in children is made based upon a constellation of findings including pain, systemic signs of infection, elevated serum inflammatory markers, and imaging studies demonstrative of osseous infection. It is most commonly hematogenously spread to the metaphysis of immature bone, which is highly vascular prior to skeletal maturity. Treatment involves obtaining specimen for culture, empiric antibiotic treatment, and surgical irrigation and debridement of known abscesses. The end-point of treatment is return of pain-free functionality and the resolution of local/systemic signs of infection.
Conrad reviewed the management of acute hematogenous osteomyelitis and emphasized that surgical intervention in the presence of abscess can be both therapeutic and diagnostic: I&D can obtain culture and narrow the antibiotic plan.
Jones et. al. reviewed chronic pediatric osteomyelitis and report that surgery is the mainstay of treatment because removal of dead bone is essential for resolution of infection. This may be performed with sequestrectomy and curettage, with an emphasis on prevention of pathologic fracture, growth disturbances, bone loss, joint involvement, and permanent loss of function.
Figure A is a coronal STIR MRI image of the humerus demonstrating osteomyelitis
with extensive subperiosteal abscess.
Incorrect Answers:
Brodie's abscess is a type of subacute osteomyelitis which remains indolent and creates a focal intra-osseous abscess. This is not demonstrated in the clinical image.
The patient does have osteomyelitis of the humeral metaphysis, but this alone is not the indication for surgery. Uncomplicated osteomyelitis may be treated effectively with antibiotics alone.
Presence of subcutaneous air is suggestive of necrotizing fasciitis, which is a surgical emergency. The MRI however does not demonstrate this finding.
The infection and its surgical management both increase risk of injury to the proximal humeral physis and has the potential for growth arrest or angular deformity.
(SBQ13PE.3) Figure A demonstrates a physical examination maneuver in a 1 month old infant. What is this maneuver?
Review Topic
Ortolani Test
Barlow Test
Galeazzi Sign
Patrick test
Teratologic Sign
Figure A shows a schematic image of the Ortalani test.
The Ortolani test, or Ortolani maneuver, is part of the physical examination for developmental dysplasia of the hip. It is used alongside the Barlow test to detect subluxated hips that are either reducible or irreducible. A positive sign is a distinctive 'clunk' which can be heard and felt as the femoral head relocates anteriorly into the acetabulum.
Guille et al. showed that the use of Pavlik harness has become the mainstay of initial treatment for the infant who has not yet begun to stand. If concentric reduction of the hip cannot be obtained, surgical reduction of the dislocated hip is the next step before they are able to stand.
Video V is a lecture discussing the hip examination of the infant. Incorrect Answers:
pressure on the knee, directing the force the femoral head posteriorly. A positive Barlow test would result in posterior subluxation/dislocation of the hip. Answer 3: Galeazzi test is performed by flexing an infant's knees in the supine position so that the ankles touch the buttocks. If the knees are not level then the test is positive, which indicates a potential congenital hip issue (e.g. DDH). Answer 4: Patrick or Faber test (flexion, abduction, external rotation) has been described both for stressing the SI joint and for isolating symptoms to the hip Answer 5: Teratologic dislocation of the hip is a term used to imply that the hip joint did not develop normally in utero, thus the hip is in a fixed dislocated position at birth.

Question 65:

Options:

Arthrotomy, debridement, and polyethylene exchange
One-stage exchange arthroplasty
Two-stage exchange arthroplasty
Parenteral antibiotics
Nonsurgical management without antibiotics

Correct Answer: Nonsurgical management without antibiotics

Explanation:

DISCUSSION: Synovial fluid analysis is a very sensitive tool for detecting infection in total knee arthroplasties. Several studies have demonstrated that an absolute leukocyte count in the synovial fluid of less than 1,700 to 2,500/mm
3
is an accurate predictor of absence of infection. Similarly, a differential cell count of the WBCs demonstrating less than 50% to 60% neutrophils is an accurate predictor of absence of infection. If both parameters are normal, it is unlikely that the patient has an infection. The three surgical options are contraindicated based on the normal examination findings and laboratory parameters. Similarly, antibiotics should be avoided. The work-up should include tests to evaluate noninfectious sources of knee pain and sources of referred knee pain.
REFERENCES: Trampuz A, Hanssen AD, Osmon DR, et al: Synovial fluid leukocyte count and differential for the diagnosis of prosthetic knee infection. Am J Med 2004;117:556-562.
Mason JB, Fehring TK, Odum SM, et al: The value of white blood cell counts before revision total knee arthroplasty. J Arthroplasty 2003;18:1038-1043.
Kersey R, Benjamin J, Mason B: White blood cell counts and differential in synovial fluid of aseptically failed total knee arthroplasty. J Arthroplasty 2000;15:301-304.

Question 66:

Which of the following tissues used for anterior cruciate ligament (ACL) reconstruction has the highest maximum load to failure?

Options:

Allograft ACL
Bone-patellar tendon-bone with a width of 10 mm
Fascia lata with a width of 15 mm
Central quadriceps tendon with a width of 15 mm
Quadruple semitendinosus and gracilis tendons

Correct Answer: Quadruple semitendinosus and gracilis tendons

Explanation:

Question 67:

A diskectomy is performed in which the disk space is not aggressively debrided. When compared to techniques that involve aggressive debridement of the disk space, this results in

Options:

less intraoperative blood loss.
an increased rate of recurrent disk herniation.
a shorter length of hospital stay.
a higher rate of surgical complications.

Correct Answer: an increased rate of recurrent disk herniation.

Explanation:

DISCUSSION
This patient has disk herniation at the left L5-S1 level. This will generally affect the traversing S1 nerve. The S1 dermatome is on the lateral aspect and sole of the foot.
Surgical treatment generally involves a diskectomy with removal of the herniated fragment. This can be performed via a conventional open approach or minimally invasive endoscopic technique. Several recent meta-analyses have demonstrated equivalent outcomes with regard to leg pain and clinical outcomes. Although minimally invasive techniques have been associated with an increased rate of dural tear, the overall complication rate between the 2 techniques is not significantly different. Several studies have demonstrated a substantial learning curve associated with minimally invasive techniques, and the rate of complications decreases significantly with surgeon experience.
When performing a diskectomy, the herniated fragment alone can be removed (sequestrectomy) or some of the disk that remains in the disk space can be removed (complete diskectomy). Studies have shown no change in surgical time, blood loss, length of stay, or surgical complications when performing a sequestrectomy (compared to a more complete diskectomy). A sequestrectomy is associated with a higher rate of recurrent disk herniation at the surgical level.
RECOMMENDED READINGS
Kamper SJ, Ostelo RW, Rubinstein SM, Nellensteijn JM, Peul WC, Arts MP, van Tulder MW. Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis.
Eur Spine J. 2014 May;23(5):1021-43. doi: 10.1007/s00586-013-3161-2. Epub 2014 Jan 18.
PubMed PMID: 24442183.
View Abstract at PubMed
Dasenbrock HH, Juraschek SP, Schultz LR, Witham TF, Sciubba DM, Wolinsky JP, Gokaslan ZL, Bydon A. The efficacy of minimally invasive discectomy compared with open discectomy: a meta-analysis of prospective randomized controlled trials. J Neurosurg Spine. 2012 May;16(5):452-62. doi: 10.3171/2012.1.SPINE11404. Epub 2012 Mar 9. PubMed PMID:

Question 68:

A 17-year-old high school football player reports wrist pain after being tackled. Radiographs are shown in Figures 22a through 22c. What is the recommended intervention?

Options:

Pedicled vascularized bone graft
Long arm thumb spica cast
Percutaneous screw fixation
Corticocancellous bone grafting via a volar approach (Matti-Russe)
Open reduction and differential pitch screw placement via a dorsal approach

Correct Answer: Open reduction and differential pitch screw placement via a dorsal approach

Explanation:

DISCUSSION: The patient has an acute fracture of the proximal pole. A 100% healing rate has been reported for open reduction and internal fixation of proximal pole fractures via a dorsal approach. This allows for direct viewing of the fracture line, facilitates reduction, and bone grafting can be done through the same incision if necessary. A vascularized or corticocancellous graft is reserved for nonunions. Proximal fractures are very slow to heal with a cast, if they heal at all. As a small fragment, percutaneous fixation is very difficult and has been reported for waist fractures.
REFERENCES: Rettig ME, Raskin KB: Retrograde compression screw fixation of acute proximal pole scaphoid fractures. J Hand Surg Am 1999;24:1206-1210.
Raskin KB, Parisi D, Baker J, et al: Dorsal open repair of proximal pole scaphoid fractures. Hand Clin 2001;17:601-610.

Question 69:

Options:

Pulse oximeter measurement at the great toe
Angiography
Measurement of the ankle-brachial index (ABI)
Doppler ultrasound
Assessment of capillary refill in the nail beds

Correct Answer: Measurement of the ankle-brachial index (ABI)

Explanation:

Question 70:

What method of spinal fixation requires the largest force to disrupt the bone-implant interface?

Options:

Sublaminar cables
Laminar hooks
Pedicle hooks
Pedicle screws

Correct Answer: Pedicle screws

Explanation:

Question 71:

A 44-year-old man sustains the injury shown in Figures 1 through 3. What is the most appropriate treatment?

Options:

Reduction and internal fixation
Closed reduction and splinting alone
Carpometacarpal arthrodesis
Carpometacarpal (CMC) joint suspension arthroplasty

Correct Answer: Reduction and internal fixation

Explanation:

Question 72:

Options:

Better functional outcome than that associated with infections from sensitive organisms
Same functional outcome as that associated with infections from sensitive organisms
Same prognosis for eradication of infection as that associated with infections from sensitive organisms
Poorer prognosis for eradication of infection than that associated with infection from sensitive organisms

Correct Answer: Poorer prognosis for eradication of infection than that associated with infection from sensitive organisms

Explanation:

DISCUSSION:
The patient has a late infection of at least 4 weeks symptomatic duration that most likely is hematogenous in etiology. This infection is not an acute hematogenous infection that can successfully be treated with irrigation and debridement. Retention of the implants with debridement and irrigation alone has been associated with a poor prognosis. In a recent study, the success rate was only 44% in a series of 104 patients at a mean 5.7-year follow-up. In one study of 50 infections attributable to MRSA or methicillin- resistant
Staphylococcus epidermidis
organisms treated with a two-stage protocol, the failure rate was
21%. Patients who experienced successful infection treatment had lower functional outcome measures using the Western Ontario and McMaster Universities Osteoarthritis Index, the University of California
Los Angeles Activity Score, and the 12-item Oxford Knee Score, however.

Question 73:

Options:

Type I acromion
Type III acromion
Meso os acromiale
Meta os acromiale
Pre os acromiale

Correct Answer: Meso os acromiale

Explanation:

DISCUSSION: The MRI scans reveal a meso os acromiale with edema at the site in a skeletally mature patient.
REFERENCES: Sher JS: Anatomy, biomechanics, and pathophysiology of rotator cuff disease, in Iannotti JP, Williams GR (eds): Disorders of the Shoulder: Diagnosis and Management. Philadelphia, PA, Lippincott Williams & Wilkins, 1999, p 23.
Sammarco VJ: Os acromiale: Frequency, anatomy, and clinical implications. J Bone Joint Surg Am 2000;82:394-400.

Question 74:

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 75:

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 76:

Figure 1 is the MRI scan of a 19-year-old man who has an acute anterior shoulder dislocation. The bony fragment occupies 10% of the glenoid articular surface. What is the most appropriate treatment?

Options:

Open structural iliac crest graft
Open reduction and internal fixation
Arthroscopic coracoid transfer
Arthroscopic repair incorporating the bone lesion

Correct Answer: Arthroscopic repair incorporating the bone lesion

Explanation:

Question 77:

Options:

Intramedullary screw fixation of the fibula
Plating of the fibula with a one third tubular plate
Subtalar arthrodesis with deformity correction
Varus producing distal tibial osteotomy
Ankle arthrodesis

Correct Answer: Subtalar arthrodesis with deformity correction

Explanation:

Question 78:

What is the most common diagnosis in a patient older than age 40 years with a destructive bony lesion?

Options:

Metastatic carcinoma
Osteosarcoma
Lymphoma
Multiple myeloma
Chondrosarcoma

Correct Answer: Metastatic carcinoma

Explanation:

Question 79:

A player on a professional football team sustains a knee injury and is diagnosed with an anterior cruciate ligament rupture. When employed as the team physician, your ethical obligation is to inform

Options:

the player but not the team.
the team but not the player.
neither the team nor the player.
both the team and the player.
the team, the player, and the media

Correct Answer: both the team and the player.

Explanation:

Question 80:

5 mm of change in the atlanto-dens interval (ADI) between flexion and extension views

Options:

Posterior atlanto-dens interval (PADI) <14 mm
Progressive myelopathy
ADI > 10 mm with no change on flexion/extension views

Correct Answer: Posterior atlanto-dens interval (PADI) <14 mm

Explanation:

Question 81:

Options:

arthroscopic loose body removal.
arthroscopic debridement and loose body removal for osteochondritis dissecans of the capitellum.
annular ligament reconstruction for posttraumatic posterior subluxation of the radial head.
radial head resection for congenital type II dislocation of the radial head.
lateral collateral ligament reconstruction for posterolateral rotatory instability.

Correct Answer: lateral collateral ligament reconstruction for posterolateral rotatory instability.

Explanation:

Question 82:

Options:

Equal at 10 years
Lower at 10 years
Higher at 10 years
Not known when using a mobile-bearing UKA

Correct Answer: Lower at 10 years

Explanation:

Question 83:

When elevating the arm, the ratio of scapulothoracic to glenohumeral motion over the total range of motion is best described as

Options:

1:2, and in the first 30 degrees the ratio is 1:5.
1:2, and in the first 30 degrees the ratio is variable.
2:1, and in the first 30 degrees the ratio is variable.
2:1, and in the first 30 degrees the ratio is 3:1.
highly variable and no definitive statement can be made about the ratios.

Correct Answer: 1:2, and in the first 30 degrees the ratio is variable.

Explanation:

Question 84:

Options:

Decreased risk of posttraumatic arthritis
Avoid growth arrest
Minimize risk of osteonecrosis
Prevent clinical internal rotation deformity
Prevent development of a late tarsal tunnel syndrome

Correct Answer: Decreased risk of posttraumatic arthritis

Explanation:

DISCUSSION: Triplane fractures generally occur in children who are near skeletal maturity. The injury is generally caused by a supination external rotation mechanism. The number of fracture fragments present (two or three) depends on what part of the physes is closed at the time of injury. Articular congruity is the major concern in the management of these injuries since the patient has almost reached skeletal maturity. The goal is to restore articular congruity to minimize the development of posttraumatic arthritis.
REFERENCES: Vaccaro A (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 757-765.
Kling TF Jr, Bright RW, Hensinger RN: Distal tibial physeal fractures in children that may require open reduction. J Bone Joint Surg Am 1984;66:647-657.
Spiegel PG, Mast JW, Cooperman DR, et al: Triplane fractures of the distal tibial epiphysis.
Clin Orthop Relat Res 1984;188:74-89.

Question 85:

Options:

a brief (2 to 3 days) period of bed rest and nonsteroidal anti-inflammatory drugs.
bed rest for 2 weeks and nonsteroidal anti-inflamatory drugs, followed by physical therapy.
epidural steroid injections.
lumbar radiographs and MRI of the lumbar spine.
electromyography.

Correct Answer: a brief (2 to 3 days) period of bed rest and nonsteroidal anti-inflammatory drugs.

Explanation:

Question 86:

Options:

Left L4
Right L4
Left L5
Right L5
Left S1

Correct Answer: Left L5

Explanation:

Question 87:

Options:

radiocapitellar joint dislocation.
fat pad sign.
proximal radioulnar joint dislocation.
double arc sign.

Correct Answer: double arc sign.

Explanation:

Question 88:

Options:

Annual monitoring of serum metal ion levels
Repeated MRI with MARS in 6 months
Conversion of the THA to a cobalt alloy femoral head and polyethylene bearing
Conversion of the THA to a ceramic femoral head with an inner titanium sleeve and polyethylene bearing

Correct Answer: Conversion of the THA to a ceramic femoral head with an inner titanium sleeve and polyethylene bearing

Explanation:

Question 89:

A patient with a transverse femur fracture undergoes statically locked antegrade intramedullary nailing. Postoperatively, the patient appears to have a

Options:

Settle the case because the surgeon made an error that resulted in unnecessary surgery, and thus the case is indefensible.
Settle the case because they are likely to lose the case, and it would be cheaper to settle than to defend.
Defend the case alleging that there was no error, and no damages, and that the patient is malingering.
Defend the case because despite there being an error, the error was corrected and there were little or no damages compared with expected outcomes.
Contact the patient directly to discuss why he is suing and attempt an amicable resolution.

Correct Answer: Defend the case because despite there being an error, the error was corrected and there were little or no damages compared with expected outcomes.

Explanation:

Question 90:

Options:

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

Correct Answer: Reduction and fixation of the fracture

Explanation:

Question 91:

Spondyloepiphyseal dysplasia congenita and tarda, precocious osteoarthropathy, and Stickler syndrome are caused by a mutation in the gene coding for

Options:

type-I collagen
type-II collagen
cartilage oligomeric protein (COMP)
fibroblast growth factor 2 (FGFR2)
fibroblast growth factor 3 (FGFR3)

Correct Answer: type-II collagen

Explanation:

Question 92:

Figure 9 shows a cross-sectional view of the spinal cord at the lower cervical level. Injury to the structure indicated by the black arrow will lead to what neurologic deficit?

Options:

Complete paraplegia
Contralateral weakness below the level of the injury
Ipsilateral weakness below the level of the injury
Unilateral loss of position sense, proprioception, and vibratory sense below the level of the injury
Loss of pain and temperature sensation below the level of the injury

Correct Answer: Unilateral loss of position sense, proprioception, and vibratory sense below the level of the injury

Explanation:

Question 93:

The fracture seen in Figure 1 is most likely associated with injury to what ligamentous structure?

Options:

Inferior glenohumeral ligament
Acromioclavicular (AC) ligaments
Coracoclavicular ligaments
Coracoacromial ligament The radiograph shows an extra-articular distal clavicle fracture lateral to the clavicular attachment point of the coracoclavicular ligaments (conoid and trapezoid). However, unlike a scenario featuring a typical Neer type I fracture, the interval between coracoid and clavicle is clearly widened, and there is marked fracture displacement. This signifies disruption to the coracoclavicular ligaments. The inferior glenohumeral ligament is important to glenohumeral joint stability, but has no effect on the relationship between clavicle and scapula. The AC ligaments are thickenings of the AC joint capsule. They have been shown to be responsible for 90% of anteroposterior stability of the AC joint. The coracoclavicular ligaments are responsible for 77% of stability for superior translation (as in this case). The coracoacromial ligament connects two parts of the scapula (coracoid and acromion) and is part of the arch that supports the rotator cuff.

Correct Answer: Acromioclavicular (AC) ligaments

Explanation:

Question 94:

Options:

Incorrect graft choice
Improper tunnel position
Tibial graft-tunnel mismatch
Poor femoral fixation

Correct Answer: Improper tunnel position

Explanation:

Question 95:

Options:

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

Correct Answer: Cobalt and chromium serum metal ion level testing

Explanation:

Question 96:

What is the primary mechanism of injury for the fracture shown in Figures 33a and 33b?

Options:

Hyperdorsiflexion
External rotation of the foot
Internal rotation of the foot
Adduction of the foot and ankle
Excessive eversion of the foot and ankle

Correct Answer: External rotation of the foot

Explanation:

Question 97:

Options:

Halo-vest orthosis
C1-C2 posterior cervical fusion
Occiput to C2 posterior cervical fusion
Cervical traction and closed reduction
Open reduction and internal fixation of C1

Correct Answer: C1-C2 posterior cervical fusion

Question 98:

-What do the T2-weighted, fat-saturated MRI scans shown in Figures 76a through 76d reveal?

Options:

Posterior cruciate ligament (PCL) tear, isolated
PCL tear and medial meniscus tear
Anterior cruciate ligament (ACL) tear, isolated
ACL tear and medial meniscus tear

Correct Answer: ACL tear and medial meniscus tear

Explanation:

Question 99:

Options:

Hamstring autograft
Revision ACL reconstruction and posterior cruciate ligament (PCL) reconstruction
Revision ACL reconstruction and posteromedial corner reconstruction
Revision ACL reconstruction and posterolateral corner reconstruction

Correct Answer: Revision ACL reconstruction and posterolateral corner reconstruction

Explanation:

Question 100:

Options:

Bankart repair
Humeral head bone augmentation
Remplissage
Coracoid autograft
Connolly procedure

Correct Answer: Humeral head bone augmentation

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

Orthopedic Surgery Board Review MCQs: Hip, Shoulder & Arthroplasty | Part 179

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 179

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index