Orthopedic MCQs: Shoulder, Elbow, Knee, Ligament - Part 45

About This Board Review Set

This is Part 45 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 45

This module focuses heavily on: Elbow, Knee, Ligament, Shoulder.

Sample Questions from This Set

Sample Question 1: During the cocking and acceleration phases of the overhand throw (pitch), there are several static and dynamic restraints to provide medial elbow support and prevent valgus instability. The dynamic structures found to be most important duri...

Sample Question 2: What is the effect on knee kinematics following placement of an anterior cruciate ligament (ACL) graft at the 12 o’clock position?...

Sample Question 3: Figures 10a and 10b show the radiographs of a 47-year-old man who reports pain in both shoulders. He has a history of leukemia that was treated with chemotherapy and high-dose cortisone. What is the most reliable treatment option for pain r...

Sample Question 4: Second impact syndrome (SIS) after head injury is characterized by which of the following? Review Topic...

Sample Question 5: What muscle attaches to the site shown by the arrow in Figure 2?...

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

During the cocking and acceleration phases of the overhand throw (pitch), there are several static and dynamic restraints to provide medial elbow support and prevent valgus instability. The dynamic structures found to be most important during these phases of the overhand throw are the flexor digitorum Review Topic

Explanation

Biomechanical analysis has demonstrated that local dynamic stability of the elbow is provided by the flexor digitorum superficialis and the flexor carpi ulnaris, especially during the cocking and acceleration phases of the overhand throw. This provides dynamic joint compression across the elbow joint and may be protective to the static restraints such as the ulnar collateral ligament. It also emphasizes the need to strengthen distant muscles in the forearm to assist with elbow biomechanics and potentially prevent injury.

Question 2

What is the effect on knee kinematics following placement of an anterior cruciate ligament (ACL) graft at the 12 o’clock position?

Explanation

DISCUSSION: Endoscopic ACL reconstructive techniques may result in a vertical graft placement. The reconstructed ligament will resist anterior translation of the tibia but the graft will not restore rotatory stability. Decreased flexion and extension are caused by placement of the femoral tunnel too anterior and posterior, respectively. Impingement of the graft on the femoral notch is caused by anterior placement of the tibial tunnel or inadequate notchplasty.
REFERENCES: Scopp JM, Jasper LE, Belkoff SM, et al: The effect of oblique femoral tunnel placement on rotational constraint of the knee reconstructed using patellar tendon autografts. Arthroscopy 2004;20:294-299.
Carson EW, Simonian PT, Wickiewicz TL, et al: Revision anterior cruciate ligament reconstruction. Instr Course Lect 1998;47:361-368.

Question 3

Figures 10a and 10b show the radiographs of a 47-year-old man who reports pain in both shoulders. He has a history of leukemia that was treated with chemotherapy and high-dose cortisone. What is the most reliable treatment option for pain relief in this patient? Review Topic

Explanation

The radiographs reveal osteonecrosis with collapse. The most reliable and durable treatment for osteonecrosis of the humeral head remains prosthetic shoulder arthroplasty. Osteonecrosis of the humeral head may be seen after the use of steroids, and there is an increasing demand for shoulder arthroplasty in young people because of the use of high-dose steroids in chemotherapy regimes for the treatment of malignant tumors. The indications for most shoulder arthrodeses today include posttraumatic brachial plexus injury, paralytic disorders in infancy, insufficiency of the deltoid muscle and rotator cuff, chronic infection, failed revision arthroplasty, severe refractory instability, and bone deficiency following resection of a tumor in the proximal aspect of the humerus. Clearly, the role of arthroscopy and related minimally invasive techniques in the treatment of humeral head osteonecrosis remains unknown.

Question 4

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 5

What muscle attaches to the site shown by the arrow in Figure 2?

Explanation

DISCUSSION: The latissimus dorsi inserts on the humerus metaphysis between the pectoralis major (posterior) and teres major (anterior). Teres minor inserts on the base of the greater tuberosity. Pectoralis minor does not insert on the humerus.
REFERENCES: Williams PL, Warwick R, Dyson M, Bannister LH: Neurology, in Gray’s Anatomy, ed 37. Edinburgh, Scotland, Churchill Livingstone, 1989, pp 1131-1132.
Last RJ: Anatomy: Regional and Applied, ed 6. London, England, Churchill Livingstone, 1978, pp 131-132.

Question 6

The safest surgical approach to the insertion of the tibial posterior cruciate ligament uses the interval between which of the following muscles?

Explanation

DISCUSSION: Burks and Schaffer described an approach to the tibial insertion of the posterior cruciate ligament that uses the interval between the semimembranosus and the medial gastrocnemius. The medial gastrocnemius muscle is retracted laterally and protects the neurovascular bundle. This approach is used to repair an avulsion of the posterior cruciate ligament tibial attachment or for performing a posterior cruciate ligament tibial

inlay reconstruction.
REFERENCES: Berg EE: Posterior cruciate ligament tibial inlay reconstruction. Arthroscopy 1995;8:95-99.
Burks RT, Schaffer JJ: A simplified approach to the tibial attachment of the posterior cruciate ligament. Clin Orthop 1990;254:216-219.

Question 7

-If a physician elects to shorten a femur by 4 cm for traumatic bone loss treatment and places an intramedullary nail for fixation, which deformity will be created in the lower extremity?

Explanation

Question 8

Figures 36a and 36b show the MRI scans of a patient who has shoulder weakness. What is the most likely diagnosis?

Explanation

DISCUSSION: The sagittal image reveals increased signal and decreased size of the supraspinatus and infraspinatus muscles, indicating muscle atrophy. The rotator cuff tendon signal is normal. The subscapularis and teres minor muscles are unaffected. Muscular dystrophy and thoracic outlet syndrome would be expected to have a more global effect. Although muscular atrophy can occur in the setting of a rotator cuff tear, the coronal image shows an intact supraspinatus. The suprascapular nerve supplies the supraspinatus and infraspinatus muscles. Therefore, suprascapular nerve entrapment would result in atrophy of these muscles with sparing of the surrounding musculature. Any lesion within the suprascapular notch, including neoplastic disease, a venous varix, or neuroma, can place pressure on the suprascapular nerve. Suprascapular nerve entrapment most commonly results from extension of a paralabral cyst or ganglion, often with associated labral pathology. Spinal accessory nerve disruption would show trapezius muscle atrophy.
REFERENCES: Resnick D, Kang HS (eds): Internal Derangement of Joints: Emphasis on MR Imaging. Philadelphia, PA, WB Saunders, 1997, pp 308-317.
El-Khoury G: MRI of the Musculoskeletal System. Philadelphia, PA, JB Lippincott, 1998, p 123.

Question 9

What location is the primary source of vascular ingrowth for tendon-bone healing with rotator cuff repair?

Explanation

Question 10

A 220-lb 20-year-old man was involved in a motor vehicle accident. His work-up reveals that he has multiple long bone fractures as well as a splenic injury that is currently being managed nonsurgically. His initial blood pressure in the trauma bay was 70/30 mm Hg. After receiving 4 liters of fluid and 3 units of packed red blood cells, his blood pressure is currently 110/70, his heart rate is 100, his urine output is 90 mL/h (normal 0.5 to 1 mL/kg/h), and his core temperature is 97.9 degrees F (36.5 degrees C). At this point, the patient’s resuscitation can be described as which of the following?

Explanation

DISCUSSION: Although the end points of resuscitation are still unclear, what is known is that normalization of the standard hemodynamic parameters (blood pressure, heart rate, and urine output) is not adequate. Up to 85% of patients with normal hemodynamic parameters can still have inadequate tissue oxygenation or uncompensated shock. The initial base deficit, lactate level, or gastric pHi can be used to stratify patients for resuscitation needs, risks of death, and multiple organ failure (level 1 evidence). The time it takes to normalize the base deficit, the lactate level, or gastric pHi, can predict survival (level 2 evidence). Patients who have been in uncompensated shock (abnormal vital signs) should have their resuscitation monitored using data other than vital signs.
REFERENCES: Tisherman SA, Barie P, Bokhari F, et al: Clinical practice guideline: Endpoints of resuscitation. J Trauma 2004;57:898-912.
Moore FA, McKinley BA, Moore EE, et al: Inflammation and the Host Response to Injury,

a large-scale collaborative project: Patient-oriented research core--standard operating procedures for clinical care. III. Guidelines for shock resuscitation. J Trauma 2006;61:82-89.
Englehart MS, Schreiber MA: Measurement of acid-base resuscitation endpoints: Lactate, base deficit, bicarbonate or what? Curr Opin Crit Care 2006;12:569-574.

Question 11

A 32-year-old man has a closed oblique displaced fracture at the junction of the lower and middle third of the humeral shaft and a complete radial nerve palsy. Closed reduction is performed and is felt to be acceptable. Management of the radial nerve palsy should consist of

Explanation

DISCUSSION: In patients who have radial nerve dysfunction associated with a closed humeral fracture, nerve function usually will return to normal without surgical exploration. If clinical findings or electromyographic studies show no improvement at 3 months, surgical exploration and repair can be performed. Tendon transfers are performed if nerve repair is deemed unsuccessful.
REFERENCES: Pollock FH, Drake D, Bovill EG, et al: Treatment of radial neuropathy associated with fractures of the humerus. J Bone Joint Surg Am 1981;63:239-243.
Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 237-247.

Question 12

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

Explanation

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

Question 13

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

Explanation

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

Question 14

Six weeks after open reduction internal fixation of a closed tibial pilon fracture, a patient has a draining wound with surrounding erythema and swelling. Radiographs show lucency around screws. What is the most appropriate treatment sequence?

Explanation

Discussion: Management of acutely infected wounds is primarily surgical. Osteomyelitis frequently involves Orthopaedic hardware, which would ideally be removed or replaced given biofilm involvement. Multiple operative cultures of fluid collections, soft tissues and bone should routinely be obtained. Culture yield is highest if cultures are obtained before empiric antibiotic treatment is started. Tissue samples are greatly preferred to swabs, which are notoriously inaccurate.

Question 15

Smoking has been associated with lower fusion rates in both cervical and lumbar fusion. Which of the following statements best describes an explanation for these findings?

Explanation

Tobacco smoking is now the leading avoidable cause of morbidity and mortality in the United States. The musculoskeletal effects of smoking have been implicated in osteoporosis, low back pain, degenerative disk disease, poor wound healing, and delayed fusion and fracture healing. A number of studies have demonstrated the relationship between smoking and development of pseudarthrosis. Numerous studies
have been performed to offer an explanation of the mechanism mediating this effect. Whereas all of the above have been postulated as explanations, more recent studies have demonstrated that nicotine delivered via a transdermal patch significantly enhanced posterior spinal fusion in rabbits. Thus it appears that the effects of smoking on fracture healing are multifactorial and not yet fully understood.

Question 16

A patient has a large T11-T12 disk herniation that is causing substantial compression of the spinal cord. The patient reports walking imbalance over the past few weeks. Examination of the patient's reflexes is likely to show Review Topic

Explanation

The patient has a large thoracic disk herniation that is causing spinal cord compression. The history of gait imbalance suggests that the patient has thoracic level myelopathy. Assuming that the patient does not have lumbar stenosis, compression of the spinal cord at the T11-T12 level will cause upper motor neuron findings distal to it. Hyperreflexia of the upper extremities would suggest that the patient has cervical spinal cord compression. In this patient, the upper extremity reflexes should be normal. Most likely, the patient will exhibit hyperreflexia in the lower extremities, which is an upper motor tract sign.

Question 17

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

Explanation

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

Question 18

A 14-year-old patient has sustained a complete ACL tear of his right knee. Which of the following options has shown to be the most limiting factor for access to pediatric orthopaedic management in the United States?

Explanation

The type of health insurance in the pediatric population has shown to be a significant factor for access to specialized healthcare in the United States.
Access to pediatric orthopaedic management has been well investigated. Numerous Level 4 studies have shown that orthopaedic offices in urban and rural areas prefer treating patients with private insurance over patients with Medicaid.
Iobst et al. telephoned 100 urban and rural orthopaedic outpatient offices to schedule an appointment for a 10-year-old patient with a forearm fracture. They showed that 8/100 offices would schedule an appointment within 1 week to the child with Medicaid insurance, as compared to 36/100 that gave an appointment to a child with private insurance.
Pierce et al. contacted 42 orthopaedic practices to schedule an appointment for a 14-year-old patient with an ACL injury. They showed that 38/42 offices scheduled an appointment for the child within 2 weeks with private insurance. This compared to 6/42 that scheduled an appointment for a similar child with Medicaid.
Incorrect Answers:

Question 19

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

Explanation

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

Question 20

Which of the following tumors have characteristic chromosomal translocations?

Explanation

DISCUSSION: Ewing’s sarcoma has an 11;22 translocation that creates the EWS/FLI1 fusion gene, and synovial sarcoma has an X;18 translocation that creates the STT/SSX fusion gene. The other tumors do not have consistent translocations.
REFERENCES: Sandberg AA: Cytogenetics and molecular genetics of bone and soft-tissue tumors. Am J Med Genet 2002;115:189-193.
Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 11-20.

Question 21

Which of the following factors is associated with failure of arthroscopic excision of the distal clavicle?

Explanation

DISCUSSION: Uneven resection of bone, typically leaving a retained posterolateral corner of the distal clavicle, can lead to failure of arthroscopic distal clavicle excision. The amount of bone resected, the gender of the patient, or the diagnosis (osteoarthritis versus osteolysis) does not appear to affect the results.
REFERENCE: Flatow EL, Duralde XA, Nicholson GP, Pollock RG, Bigliani LU: Arthroscopic resection of the distal clavicle with a superior approach. J Shoulder Elbow Surg 1995;4:41-50.

Question 22

A 75-year-old woman who has groin pain states that she had total hip arthroplasty 15 years ago. The radiograph shown in Figure 40 reveals that the left acetabular component is grossly loose. Revision of the acetabular component should include use of a

Explanation

The patient has an all-poly acetabular component, which is grossly loose and has migrated. Intermediate and long-term results of revision THA’s using a cemented acetabular component have had high failure and re-revision rates. One of the reasons includes sclerotic bone lacking in the trabeculae needed for cement. Threaded cups and bipolar implants have also had unacceptably high failure rates. Published results using non-cemented components have shown they performed much better in the intermediate-term, especially those supplemented with fins, screws or spikes. The cited authors (Petrera and Rubash) preferred a titanium-mesh cup and place two supplemental screws if the cup is unstable (assessed by manipulation intraoperatively).

Question 23

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

Explanation

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

Question 24

A 61-year-old man reports right shoulder pain and loss of external rotation since having a seizure 5 months ago. MRI scans are shown in Figures 82a and 82b. What is the most appropriate treatment? Review Topic

Explanation

The patient has a chronic posterior shoulder dislocation with loss of approximately half of the humeral head. Hemiarthroplasty or osteochondral allograft to fill the defect would be required. Given the time since injury, the remaining native head and articular surface may have lost structural integrity, making hemiarthroplasty the preferred choice. The implant should be placed close to the patient's natural version, which normally is in the range of 20 to 30 degrees of retroversion. Excessive anteversion is not recommended to avoid repeat posterior dislocation. Closed reduction is highly unlikely to achieve a reduction and may cause displacement of an unrecognized humeral surgical neck fracture. Open reduction and lesser tuberosity transfer is best suited for smaller head defects and a less chronic dislocation. Glenoid integrity is not affected, thus a glenoid implant is unnecessary.

Question 25

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 26

A 35-year-old woman reports an 8-week history of neck pain radiating to her right upper extremity. She denies any history of trauma or provocative event. Examination reveals decreased pinprick sensation in her right middle finger, otherwise sensation is intact bilaterally. Finger flexors and interossei demonstrate 5/5 motor strength bilaterally. Finger extensors are 4/5 on the right and 5/5 on the left. The triceps reflex is 1+ on the right and 2+ on the left. The most likely diagnosis is a herniated nucleus pulposus at what level?

Explanation

DISCUSSION: The patient’s neurologic examination is consistent with a C7 radiculopathy on the right side. In a patient with this symptom complex in the absence of trauma, a cervical disk herniation is the most common etiology for a C7 radiculopathy. There are eight cervical nerve roots and the C7 nerve exits at the C6-7 disk space and is most frequently impinged by a disk herniation at this level.
REFERENCES: Houten JK, Errico TJ: Cervical spondylotic myelopathy and radiculopathy: Natural history and clinical presentation, in Clark CR (ed): The Cervical Spine, ed 4. Philadelphia, PA, Lippincott Williams & Wilkins, 2005, pp 985-990.
Hoppenfeld S: Orthopaedic Neurology: A Diagnostic Guide to Neurologic Levels. Philadelphia, PA, JB Lippincott, 1977, pp 7-43.

Question 27

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 28

In the management of an open tibia fracture, what factor is considered most important in preventing deep infection?

Explanation

DISCUSSION: The most important aspect of management of any open fracture, and in particular the tibia, is the degree and the completeness of the debridement of the soft tissue and most importantly, the muscle. The ultimate function is determined by the amount of muscle left, as well as the ability to heal. The amount of necrotic muscle left in the wound also determines the predisposition to infection. The method of fixation, the size of the wound, and the amount of contamination are controlled by the surgeon or the injury and have little to do with the long-term outcome. Initial wound cultures have little predictive value.
REFERENCES: Clifford P: Open fractures, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 617-638.
Lee J: Efficacy of cultures in the management of open fractures. Clin Orthop 1997;339:71-75.
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Question 29

An 18-year-old man sustained a knife injury to his midback, with the entry wound 2 cm to the left of the midline. He has been diagnosed with a hemicord transection. Neurologic examination will most likely reveal left-sided loss of

Explanation

DISCUSSION: Brown-Sequard syndrome results from an injury to one half of the spinal cord and is characteristically seen in penetrating injuries. The spinothalamic fibers cross the midline below the level of the lesion, resulting in contralateral loss of pain and temperature sensation. The posterior columns and corticospinal tracts carry vibratory, position, and light touch sensation, as well as motor function from the ipsilateral side of the body. This results in the characteristic neurologic findings seen with Brown-Sequard syndrome.
REFERENCES: Northrup BE, 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, pp 541-549.
Collins RD: Illustrated Manual of Neurologic Diagnosis. Philadelphia, PA, JB Lippincott, 1962, p 71.

Question 30

During the application of halo skeletal fixation, the most appropriate position for the placement of the anterior halo pins is approximately 1 cm above the superior orbital rim and Review Topic

Explanation

Halo fixation is the most rigid form of cervical orthosis but complications can arise from improper placement of the fixation pins. A relatively safe zone for anterior pin placement is located 1 cm above and within the lateral third of the superior orbital rim. This position avoids the supraorbital and supratrochlear nerves over the medial one third of the orbit. The more lateral positions in the temporal fossa have very thin bone and can interfere with the muscles of mastication.

Question 31

A 28-year-old man has left knee pain after a snow skiing accident. The MRI scan shown in Figure 47 reveals which of the following? Review Topic

Explanation

Bone bruises are often noted on MRI after anterior cruciate and medial collateral ligament injuries. The significance of these injuries awaits long-term follow-up studies. The areas of increased signal on T2-weighted images represent areas of acute hemorrhage and are secondary to microfractures of the adjacent medullary trabeculae.

Question 32

Flow cytometry of tumors measures the

Explanation

Flow cytometry is a method of quantitating components or structural features of cells primarily by optical means. Ploidy and cell cycle analysis of cancers is the major diagnostic use. Cells are passed single file through a laser beam by continuous flow and several parameters are measured including Cell Diameter, proportional quantity of granular (DNA) within the cell, and using fluorescent probes the total DNA or a specific DNA/mRNA sequence can be counted. In examining tumors the amount of DNA in each cell is important for determining neoplasia.

Question 33

-What is the most likely mechanism of injury?

Explanation

DISCUSSION FOR QUESTIONS 56 THROUGH 58
The MRI scan shows a bone bruise of the lateral femoral condyle and lateral tibial plateau. This injury pattern is commonly associated with anterior cruciate ligament (ACL) rupture and an abnormal pivot shift test result. Treatment of an ACL tear in a high-demand athlete should consist of ligament reconstruction.In this patient, surgery should be delayed until she regains full range of motion to minimize risk for arthrofibrosis after surgery. Recent analysis has shown that the noncontact mechanism is more consistent with anterior translation, affecting both the medial and lateral compartments. The bone bruise in the lateral femoral condyle occurs more anterior than that of the medial femoral condyle, suggesting that internal rotation has occurred. The external rotation recurvatum test assesses for posterolateral corner injury, and a positive quadriceps active test is consistent with posterior cruciate ligament rupture. An abnormal patellar apprehension test result is suggestive of patellar instability. Nonsurgical treatment is unlikely to result in sufficient stability if this patient returns to sports at her preinjury level of activity.Primary ACL repair is associated with high failure rates. Although the precise mechanism of injury varies,injuries can be broadly classified into contact and noncontact injuries. Noncontact injuries occur with the knee in slight flexion, valgus, and internal rotation, and contact injuries typically involve a lateralside impact producing a valgus force to the knee. The valgus component of noncontact injuries has been thought to cause mainly lateral compartment bone bruising. Posterior translation is the most common mechanism of posterior cruciate ligament rupture, and hyperextension and varus is associated with posterolateral corner injury.

Question 34

Which of the following is the primary mechanism of polyethylene wear in the hip?

Explanation

DISCUSSION: Although previous theories on acetabular wear implicated fatigue cracking and delamination as primary wear mechanisms, these have actually manifested as major modes of polyethylene wear in knees. The primary mechanism of wear in polyethylene acetabular components appears to be adhesion and abrasion. In an analysis of 128 components retrieved at autopsy or revision surgery, wear appeared to occur mostly at the surface of the components and was the result of large strain plastic deformation and orientation of the surface layers into fibrils that subsequently ruptured during multidirectional motion. It was also shown conclusively that 32-mm heads displayed significantly more wear (volumetric wear) than either 22-mm or

26-/28-mm heads (1-mm increase in size increased volumetric wear by 10%). The wear at the articulating surface was characterized by highly worn polished areas superiorly and less worn areas inferiorly separated by a ridge. Abrasion was very common, occurring after adhesion and plastic deformation of polyethylene fibrils, and abrasion secondary to third-body wear. Wear rates decreased with longer survival of components, indicating a “bedding in” phenomenon, arguing against oxidative and fatigue wear. Crevice corrosion occurs in fatigue cracks with low oxygen tension (under screw heads, etc). Oscillatory fretting consists of cyclical abrading of the outer surface from small movements. Fatigue and delamination is predominant in total knee arthroplasty where stresses are maximum just below the surface of the polyethylene component, causing fatigue over time with subsequent delamination. In contrast, hip wear occurs primarily at the surface of the polyethylene component.
REFERENCES: Jasty M, Goetz DD, Bragdon CR, et al: Wear of polyethylene acetabular components in total hip arthroplasty: An analysis of one hundred and twenty-eight components retrieved at autopsy or revision operations. J Bone Joint Surg Am 1997;79:349-358.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 47-53.
Bell CJ, Walker PS, Abeysundera MR, et al: Effect of oxidation on delamination of
ultrahigh-molecular-weight polyethylene tibial components. J Arthroplasty 1998;13:280-290.
Sutula LC, Collier JP, Saum KA, et al: The Otto Aufranc Award: Impact of gamma sterilization on clinical performance of polyethylene in the hip. Clin Orthop 1995;319:28-40.

Question 35

Figure 25 shows the clinical photograph of a 48-year-old man who has had a forefoot ulcer for the past 4 months. History reveals that he has had type II diabetes mellitus for the past 10 years. Examination reveals sensory and motor neuropathy, with weak ankle dorsiflexion. The ankle cannot be passively dorsiflexed past a neutral position. Initial management should consist of

Explanation

DISCUSSION: Foot deformity and decreased joint motion have been associated with increased plantar pressures and an increased risk of ulceration. In a partial-thickness ulcer without exposed bone or tendon, total contact casting is highly effective. Concomitant Achilles tendon lengthening increases the likelihood that healing of the ulcer can be obtained and perhaps more importantly, maintained.
REFERENCES: Lin SS, Lee TH, Wapner KL: Plantar forefoot ulceration with equinus deformity of the ankle in diabetic patients: The effect of tendo-Achilles lengthening and total contact casting. Orthopedics 1996;19:465-475.
Armstrong DG, Stacpoole-Shea S, Nguyen H, Harkless LB: Lengthening of the Achilles tendon in diabetic patients who are at high risk for ulceration of the foot. J Bone Joint Surg Am 1999;81:535-538.

Question 36

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

Explanation

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

Question 37

Figure 41a shows the AP radiograph of a 15-year-old boy who reports lateral knee pain. Figures 41b and 41c show a radiograph of the distal femur that was obtained 5 years ago and a current CT scan. The indication for surgery in this patient would be

Explanation

DISCUSSION: In a young person with solitary osteochondroma, the best surgical indication is symptoms that limit activity. A growth deformity is unlikely to occur at this age. Malignant degeneration is exceptionally rare and noted most commonly in adults. Growth is expected until skeletal maturity.
REFERENCES: Mirra JM: Bone Tumors: Clinical, Radiologic, and Pathologic Correlations. Philadelphia, PA, Lea and Febiger, 1989, pp 1626-1659.
Simon MA, Springfield DS, et al: Common Benign Bone Tumors and Usual Treatment: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 181-205.

Question 38

An otherwise healthy 76-year-old woman has pain 2 years after total hip arthroplasty. The clinical photograph in Figures below demonstrates her skin envelope, and associated radiograph. Her C-reactive protein level is normal, and her erythrocyte sedimentation rate is mildly elevated. The white blood cell count is normal. Hip aspiration attempted under fluoroscopy generates no fluid. What is the best definitive treatment?

Explanation

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

Question 39

A 62-year-old woman has loss of function of her left shoulder and dull pain. She denies any history of trauma, and there were no previous surgical procedures. MRI scans are shown in Figures 42a and 42b. The etiology of this pathology is most likely confirmed by Review Topic

Explanation

Neuropathic arthropathy of the shoulder is an uncommon diagnosis that often presents on radiographs with advanced degenerative findings on both sides of the joint, with relatively minor pain complaints. Function is often significantly compromised due to the loss of conforming joint surfaces. MRI of the brain and cervical spine will often reveal a type 2 Arnold-Chiari malformation, a syrinx of the cervical spinal cord, or both. Recognition of this as a neuropathic problem is imperative to avoid inappropriate surgical management of the shoulder with rotator cuff repairs or primary arthroplasty.

Question 40

A 70-year-old man who underwent an uncomplicated large rotator cuff repair 6 months ago is now seeking a second opinion regarding persistent pain and weakness in his shoulder. Examination reveals that his incision is well healed and unreactive. The surgical report suggests that the tendons were secured back to bone with sutures through the greater tuberosity. Figure 28 shows a radiograph that was obtained 1 week ago. What is the most likely diagnosis?

Explanation

DISCUSSION: Symptoms can persist following a rotator cuff repair for a variety of reasons. In the early postoperative period, infection is the primary concern. Stiffness and loss of motion can occur because of postoperative scarring. Complex regional pain syndrome can occur but is rare, and the diagnosis is not made with a plain radiograph. This radiograph shows a superiorly migrated humeral head that articulates with the acromion, indicating that the repair has failed. While large to massive tears may fail more commonly than once thought, the clinical outcome may be satisfactory in many patients.
REFERENCES: Mansat P, Cofield RH, Kersten TE, Rowland CM: Complications of rotator cuff repair. Orthop Clin North Am 1997;28:205-213.
Jost B, Pfirrmann CW, Gerber C, Switzerland Z: Clinical outcome after structural failure of rotator cuff repairs. J Bone Joint Surg Am 2000;82:304-314.

Question 41

A 40-year-old patient who has a type II odontoid fracture is placed in a halo vest for 12 weeks; however, current radiographs show no evidence of healing. The next most appropriate step in management should consist of

Explanation

DISCUSSION: Because nonsurgical managment has failed and a significant number of type II odontoid fractures will go on to a nonunion, the salvage treatment of choice is posterior fusion at C1-2. Odontoid screws are contraindicated in patients with a chronic nonunion, which this patient has at the end of 3 months.
REFERENCES: Montesano PX: Anterior and posterior screw and plate techniques used in the cervical spine, in Bridwell KH, DeWald RL (eds): The Textbook of Spinal Surgery, ed 2. Philadelphia, PA, Lippincott-Raven, 1996, vol 2, pp 1743-1761.
Bohler J: Anterior stabilization for acute fractures and non-unions of the dens. J Bone Joint Surg Am 1982;64:18-27.
Anderson PA, Steinmann JC: Internal fixation of the cervical spine, in Frymoyer JW (ed): The Adult Spine, Principles and Practice, ed 2. Philadelphia, PA, Lippincott Raven, 1997, pp 1119-1147.

Question 42

A 9-month-old nonambulatory girl is seen in the emergency department with a fracture of her right forearm. The mother says she fell from the changing table yesterday and continues to cry and not use her right arm. Radiographs are shown in Figure 31. Treatment should consist of which of the following? Review Topic

Explanation

The occurrence of a forearm fracture in a 9-month-old child has a greater than 50% chance that the injury is due to child abuse. It is mandatory to report this to child protective services unless there is some compelling reason that it is definitely not child abuse. In addition, a skeletal survey should be requested to look for other injuries. A bone scan would show other injuries, but a skeletal survey is a more
efficient way to evaluate for other fractures. A MRI of the brain is not indicated unless fundoscopic examination reveals an abnormality.

Question 43

A 2-week-old infant has had diminished movement of the right upper extremity since birth. Examination reveals weakness of shoulder abduction and external rotation, elbow flexion, and forearm supination. Both pupils are equally round and responsive to light. The remainder of the examination is normal. Radiographs of the upper limb show a healing middle-third clavicle fracture. Management should consist of

Explanation

DISCUSSION: The patient has a classic Erb’s palsy with weakness of the muscles innervated by the fifth and sixth cervical roots. Horner syndrome, a poor prognostic indicator for recovery, is absent in this infant. All infants with brachial plexus birth palsies initially should be monitored for spontaneous recovery during the first 3 to 6 months of life. During this period of observation, glenohumeral motion, especially external rotation, should be maintained. Many infants will begin to show recovery within the first 6 to 8 weeks after birth and continue on to normal function. The timing of microsurgery is controversial. A recent study found that the outcome of microsurgical repair in patients who had no recovery of biceps function within 3 months after birth was similar compared to those who had recovery of biceps function between 3 and 6 months and no microsurgical repair. The author concluded that microsurgical repair was effective in improving function in those infants who had no evidence of recovery of biceps function within the first 6 months of life.
REFERENCES: Waters PM: Comparison of the natural history, the outcome of microsurgical repair, and the outcome of operative reconstruction in brachial plexus birth palsy. J Bone Joint Surg Am 1999;81:649-659.
Greenwald AG, Schute PC, Shiveley JL: Brachial plexus birth palsy: A 10-year report on the incidence and prognosis. J Pediatr Orthop 1984;4:689-692.

Question 44

A 15-year-old boy has a fracture of the proximal tibia extending from the apophysis of the tubercle up through the posterior part of the proximal tibial epiphysis and into the joint. What is the most likely mechanism of injury?

Explanation

Tibial Tuberosity Fractures Fractures of the tibial tuberosity are uncommon avulsion injuries. Most are sportsrelated and occur in older adolescents. Type I fractures represent an avulsion of a small fragment of the tuberosity. Type II fractures involve the entire anterior tuberosity with extension proximally to the level of the horizontal portion of the proximal tibial physis. Type III injuries involve the entire tuberosity with extension proximally into the articular surface, a SalterHarris type III fracture. Patients present with pain, swelling, and tenderness over the tuberosity. Patella alta may be present. Surgical treatment of type I fractures is needed if patella alta (compared to the normal uninjured side) and a significant bony prominence are present. Displaced types II and III fractures are treated with open reduction and internal fixation. A cancellous interfragmentary screw may be placed through the tuberosity into the metaphysis. Because this injury occurs in patients near skeletal maturity, growth arrest with secondary genu recurvatum is rare.

Question 45

A 20-year-old professional baseball pitcher has had a 3-year history of increased aching in his shoulder that is associated with pitching, and he is now seeking a second opinion. Nonsurgical management consisting of rest, anti-inflammatory drugs, ice, heat, and cortisone injections has failed to provide relief. A previous work-up that included radiographs and gadolinium-enhanced MRI arthrography was negative. Results of an arteriogram suggest quadrilateral space syndrome. Assuming that this is the correct diagnosis, what nerve needs to be decompressed?

Explanation

DISCUSSION: Quadrilateral space syndrome is a rare condition and is the result of compression of the contents of the quadrilateral space. The contents of the quadrilateral space include the posterior circumflex vessels and the axillary nerve.
REFERENCES: Cahill BR, Palmer RE: Quadrilateral space syndrome. J Hand Surg 1983;8:65-69.
Lester B, Jeong GK, Weiland AJ, Wickiewicz TL: Quadrilateral space syndrome: Diagnosis, pathology, and treatment. Am J Orthop 1999;28:718-722.

Question 46

A 20-year-old man has a symptomatic lesion of fibrous dysplasia in the femoral neck. Management should consist of

Explanation

DISCUSSION: Fibrous dysplasia in the femoral neck frequently warrants treatment because of the risk of pathologic fracture. Cortical strut grafts reduce the risk of local recurrence compared with cancellous bone grafting. Because of the consequences associated with fracture in this location, prophylactic fixation is recommended. Radiation therapy and chemotherapy are not used for this benign condition.
REFERENCES: Simon M, et al: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 197.
Enneking WF, Gearen PF: Fibrous dysplasia of the femoral neck: Treatment by cortical bone grafting. J Bone Joint Surg Am 1986;68:1415.

Question 47

Figures 9a and 9b show the radiographs of a 4-year-old child who sustained an elbow injury. What is the most likely complication resulting from this fracture if treated in a cast?

Explanation

DISCUSSION: The radiographs show a lateral condyle fracture with 2 mm of displacement. As opposed to other pediatric elbow fractures, lateral condyle fractures have a higher incidence of nonunion. This may be due to minimal metaphyseal bone on the distal fragment, the intra-articular nature of the fracture, or from further displacement when treated nonsurgically. These fractures with 2 mm and greater of displacement should be treated with reduction and stabilization. Osteonecrosis and fishtail deformity may be seen in very rare cases of lateral condyle fractures. The incidence is certainly less than the rates of nonunion seen in nonsurgically treated fractures with 2 mm and greater of displacement. Varus malunion from overgrowth and elbow stiffness are more likely seen in fractures treated surgically.
REFERENCES: Pirker ME, Weinberg AM, Hollwarth ME, et al: Subsequent displacement of initially nondisplaced and minimally displaced fractures of the lateral humeral condyle in children. J Trauma 2005;58:1202-1207.
Finnbogason T, Karlsson G, Lindberg L, et al: Nondisplaced and minimally displaced fractures of the lateral humeral condyle in children: A prospective radiographic investigation of fracture stability. J Pediatr Orthop 1995;15:422-425.
Flynn JC: Nonunion of slightly displaced fractures of the lateral humeral condyle in children: An update. J Pediatr Orthop 1989;9:691-696.

Question 48

A 48-year-old man has had pain and swelling of the hallux metatarsophalangeal joint for the past 9 months. A rocker bottom stiff-soled shoe has failed to provide relief; however, two cortisone injections have temporarily alleviated his symptoms. The radiographs shown in Figures 20a and 20b reveal diffuse arthritis of the entire hallux metatarsophalangeal joint. What is the most definitive surgical treatment?

Explanation

DISCUSSION: Because the radiographs demonstrate severe arthritis, hallux metatarsophalangeal arthrodesis is the treatment of choice. Cheilectomy alone will not relieve pain because the entire joint is degenerative. Joint replacement has not been shown to be a long-term solution. Keller resection arthroplasty is not indicated in younger active patients. Hallux valgus correction will not address arthritis of the joint and could stiffen the joint further.
REFERENCES: Smith RW, Joanis TL, Maxwell PD: Great toe metatarsophalangeal joint arthrodesis: A user-friendly technique. Foot Ankle 1992;13:367-377.
Mann RA: Hallux rigidus. Instr Course Lect 1990;39:15-21.

Question 49

Figure 1 is the clinical photograph of a 64-year-old man who crashed while riding his motorcycle. An examination reveals his long-finger metacarpophalangeal (MP) joint is stuck in extension. He cannot passively or actively flex at the MP joint. A hand radiograph is seen in Figure 2. Which interposed structure is preventing reduction?

Explanation

EXPLANATION:
This patient has a dorsally dislocated MP joint. In these cases, the volar plate can be displaced dorsal to the metacarpal head, preventing reduction. Although early publications described a “noose effect” of the lumbrical and flexor tendons, the primary block to reduction is the volar plate. Simple MP dislocations can be reduced closed by flexing the wrist and then gently sliding the base of the proximal phalanx over the end of the metacarpal. Longitudinal traction on the finger will only incarcerate the volar plate further and should be avoided. Patients with complex dislocations that fail closed reduction require open
reduction.

Question 50

The familial occurrence of Legg-Calve-Perthes disease may, in some cases, be attributed to

Explanation

One of the suggested causes of Perthes disease is a hypercoaguable state in a child. This would lead to thrombotic venous occlusion in the proximal femur resulting in venous hypertension and osteonecrosis of the femoral head. Therefore look for an answer that would result in a hypercoaguable state. There is no link between hypophosphatemia or high dietary cholesterol intake and a hypercoaguable state. Elevated levels of antithrombin III would result in bleeding, not coagulation. The referenced paper demonstrated a familial occurrence in protein S and protein C deficiency and elevated levels of lipoprotien A. Protein C and S are antithrombotic factors and lipoprotein A is a thrombogenic, atherogenic lipoprotein associated with osteonecrosis in adults.

Question 51

A well-healed bulk proximal tibia osteoarticular allograft is removed 10 years after implantation due to arthropathy. Histologic examination of the host allograft junction site will most likely reveal

Explanation

Retrieval studies of well-fixed bulk allografts reveal that the junction site heals with bridging external callus and there is persistence of callus perpendicular to the junction site. External callus is annealed to the surface of the allograft. There is very little penetration of the allograft and the bone graft is not remodeled. Direct osteonal penetration of the allograft with haversian remodeling defines primary bone healing seen in fractures, which does not occur with allografts. Fibrovascular tissue is seen early in the healing phase of the cancellous portion of the allografts.

Question 52

Figures 11a and 11b show the T 2 -weighted MRI scans of the lumbar spine of a 53-year-old woman who has low back and right lower extremity pain. What structure is the arrow pointing to in Figure 11a?

Explanation

DISCUSSION: The arrow is pointing to a cystic-appearing structure with high signal intensity on T₂-weighted image sequencing. It appears to be contiguous with the hypertrophied right facet joint, which appears to also have high signal intensity. The mass significantly narrows the right lateral recess. The high signal intensity suggests that this is a fluid-filled mass. In addition, the facet joints are degenerative and there is a very mild degree of anterolisthesis on the sagittal image. These findings make a lumbar synovial cyst the most likely diagnosis. Most lumbar juxtafacet cysts are observed at the L4-5 level, extradurally and adjacent to the degenerative facet joint. They may contain synovial fluid and/or extruded synovium. Presentation is indistinguishable from that of a herniated disk. The etiology of spinal cysts remains unclear, but there appears to be a strong association between their formation and worsening spinal instability. They occasionally regress spontaneously and may respond to aspiration and injection of corticosteroids, though there is a high recurrence rate with nonsurgical management. Synovial cysts resistant to nonsurgical management should be treated surgically. If the patient’s symptoms can be attributable to radicular findings, a microsurgical decompression that limits further destabilization should suffice. However, if there is significant low back pain attributable to spinal instability, decompression and fusion remains an appropriate option.
REFERENCES: Banning CS, Thorell WE, Leibrock LG: Patient outcome after resection of lumbar juxtafacet cysts. Spine 2001;26:969-972.
Deinsberger R, Kinn E, Ungersbock K: Microsurgical treatment of juxta facet cysts of the lumbar spine. J Spinal Disord Tech 2006;19:155-160.
Khan AM, Synnot K, Cammisa FP, et al: Lumbar synovial cysts of the spine: An evaluation of surgical outcome. J Spinal Disord Tech 2005;18:127-131.

Question 53

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 54

A 19-year-old female field hockey player sustains a right ankle injury last night during a game. The patient is on crutches and reports that she has not been able to put any weight on her right ankle since the injury. She was running alongside with another player when her right ankle “gave out” and she twisted it, falling to the ground. Physical examination reveals discoloration similar to a hematoma and significant swelling around the lateral ankle area. Pain is elicited during palpation of the anterior talofibular ligament. What test should be performed to aid in this diagnosis?

Explanation

The anterior drawer test is performed with the ankle in 10° of plantar flexion, which results in the greatest amount of translation. The test investigates the integrity of the anterior talofibular ligament with a key distance of translation being 8 to 10 mm. While the patient is sitting and has her knees flexed over the edge of a table or bench, the physician uses one hand to stabilize the distal leg and with the other hand applies an anterior force to the heel in an attempt to gap the talus anteriorly from under the tibia. The anterior talofibular ligament and calcaneofibular ligament are both compromised based on the examination findings. The anterior drawer test result reflects injury to the anterior talofibular ligament and a possible injury to the calcaneofibular ligament. A lateral talar tilt test angle measurement >15° degrees reflects a rupture of both anterior talofibular ligament and calcaneofibular ligaments. The diagnosis is a severe lateral ligament complex sprain. This is optimally managed with early mobilization and a guided rehabilitation program that emphasizes proprioceptive stability.

Question 55

A 46-year-old woman reports pain and a shortened appearance of her toe after undergoing a Keller resection arthroplasty 2 years ago for hallux rigidus. Examination reveals mild swelling and motion limited to 25 degrees at the metatarsophalangeal joint. Radiographs show large dorsal osteophytes on the first metatarsal head, 50% resection of the proximal phalanx, and complete loss of the metatarsophalangeal joint space. Which of the following is considered the most reliable procedure to improve her pain and the appearance of her toe?

Explanation

DISCUSSION: Because the patient has significant arthritis, arthrodesis is the treatment of choice. Adding a bone graft will prevent further shortening and add length to her toe, resulting in improved cosmesis. A cheilectomy will not alleviate her arthritis pain. The toe is too short for an effective Moberg phalangeal dorsiflexion osteotomy. A Waterman first metatarsal dorsal osteotomy will not address the degenerative joint disease or shortening. Silastic arthroplasty may help, but there is the risk of additional problems with foreign body reaction and a significant risk of failure known to occur with Silastic materials.
REFERENCES: Myerson MS, Schon LC, McGuigan FX, Oznur A:Result of arthrodesis of the hallux metatarsophalangeal joint using bone graft for restoration of length. Foot Ankle Int 2000;21:297-306.
Mann RA, Coughlin MJ: Adult hallux valgus, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 252-253.
Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 293-303.

Question 56

Figure 17 shows the radiograph of a 2-year-old girl who sustained a fracture of the femur in a fall while walking with her parents. History reveals that this is her third long bone fracture, having sustained a humerus fracture 1 year ago and a fracture of the opposite femur 9 months ago. There is no family history of any similar problem. Examination reveals distinctly blue sclerae, normal appearing teeth, and no skin lesions. What is the most likely cause of this patient’s disorder?

Explanation

DISCUSSION: Osteogenesis imperfecta (OI) is a genetically determined disorder of type I collagen synthesis that is characterized by bone fragility. This patient has had three fractures of the long bones by age 2 years, with the last one occurring after relatively minor trauma. The patient’s history and clinical features are consistent with a diagnosis of Sillence type IA OI. Type I OI is the mildest and most common form. Inheritance is autosomal-dominant; however, as in this patient, new mutations are frequent. Type I is subclassified into the A type (absence of dentinogenesis imperfecta) and B type (presence of dentinogenesis imperfecta). The sclerae are blue, and the first fractures usually occur in the preschool years after walking has begun. Cells from individuals with type I OI largely demonstrate a quantitative defect of type I collagen; they synthesize and secrete about half the normal amount of type I procollagen. Qualitative mutations that lead to an abnormal type I procollagen molecule result in more severe types of the disorder. There are no indications that this child has been abused. Radiographs of the femur show no evidence of rickets, pyknodysostosis, or osteopetrosis. Morquio syndrome, characterized by excess excretion of keratin sulfate in the urine, is not associated with bone fragility.
REFERENCES: Kocher MS, Shapiro F: Osteogenesis imperfecta. J Am Acad Orthop Surg 1998;6:225-236.
Sillence DO, Senn A, Danks DM: Osteogenesis imperfecta: An expanding panorama of variants. Clin Orthop 1981;159:11-25.
Cole WG: Etiology and pathogenesis of heritable connective tissue diseases. J Pediatr Orthop 1993;13:392-403.

Question 57

When examining a patient with marked hyperreflexia, which of the following findings best suggests that the condition is not caused by a cerivcal spine pathology?

Explanation

DISCUSSION: A positive jaw jerk reflex suggests that the problem is above the level of the pons. All of the other physical signs are exhibited in patients with cervical myelopathy. Although these signs also may be present in conditions affecting the brain, they do not help differentiate between a brain etiology and a cervical spine etiology. A jaw jerk reflex, however, is not present in patients with cervical myelopathy alone.
REFERENCES: Montgomery DM, Brower RS: Cervical spondylotic myelopathy: Clinical syndrome and natural history. Orthop Clin North Am 1992;23:487-493.
Ono K, Ebara S, Fuji T, Yonenobu K, Fujiwara K, Yamashita K: Myelopathy hand: New clinical signs of cervical cord damage. J Bone Joint Surg Br 1987;69:215-219.
An HS, Simpson JM: Surgery of the Cervical Spine. Baltimore, MD, Williams and

Wilkins, 1994.

Question 58

Why is tendon considered an anisotropic material?

Explanation

DISCUSSION: Anisotropic materials have mechanical properties that vary based on the direction of loading. The relative values of Young’s modulus for tendon, ligament, and bone are not relevant to isotropy. The mechanical properties of tendon do change with preconditioning, but this change is related to viscoelasticity. The intrinsic mechanical properties of tendon do vary with the rate of loading, but this variance is related to viscoelasticity.
REFERENCES: Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 134-180.
Lu L, Kaufman KR, Yaszemski MJ: Biomechanics, in Einhorn TA, O’Keefe RJ,

Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, in press.

Question 59

A 12-year-old boy who has had a 1-month history of right thigh pain and a limp reports worsening of the pain after a fall, and he can no longer walk or bear weight on the involved extremity. Radiographs of the pelvis reveal a slipped capital femoral epiphysis with moderate to severe displacement. While positioning the patient on the fracture table for screw fixation, partial reduction of the slip is achieved. No further reduction maneuvers are attempted, and the epiphysis is stabilized with a single cannulated screw. What complication is most likely to develop following this procedure?

Explanation

DISCUSSION: Traditional classification of slipped capital femoral epiphyses is based on the following temporal criteria: acute (symptoms that persist for less than 3 weeks); chronic (symptoms that persist for more than 3 weeks); or acute on chronic (acute exacerbation of long-standing symptoms). A newer classification differentiates between a stable slip where weight bearing is possible, and an unstable slip if it is not. Reduction of an unstable slip often occurs unintentionally with induction of anesthesia and positioning of the patient for surgery. The rate of satisfactory results is lower primarily because of a much higher incidence of osteonecrosis following internal fixation of an unstable slip.
REFERENCES: Loder RT, Richards BS, Shapiro PS, Reznick LR, Aronson DD: Acute slipped capital femoral epiphysis: The importance of physeal stability. J Bone Joint Surg Am 1993;75:1134-1140.
Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 151-159.

Question 60

A 70-year-old female presents with right thigh ache for 6 months. Except for a history of osteoporosis, she is otherwise healthy. She has been on antiresorptive therapy for 8 years. Her radiograph is shown in Figure A. Four months later, she trips over a rug and falls, sustaining the injury shown in Figures B and C. Which of these statements is TRUE regarding surgical fixation of this fracture compared with conventional fractures?

Explanation

This patient has a bisphosphonate-related (BP) fracture. There is increased risk of iatrogenic fracture with IM nailing of this fracture.
Subtrochanteric fractures are fractures extending from the lesser trochanter to 5cm distal to it. BP fractures are characterized by (1) focal lateral cortical thickening, (2) transverse fracture orientation, (3) medial spike and (4) lack of comminution. There is increased risk of iatrogenic fracture with IM nailing because BP fractures have thickened, brittle cortices and the mismatch between medullary diameter and increased proximal nail diameter results in iatrogenic fracture.
Weil et al. reviewed the outcome of surgically treated bisphosphonate fractures. IM nailing resulted in healing in 54% of bisphosphonate fractures with 98-99% of conventional fractures. In their study, 46% required revision procedures.
Prasarn et al. compared plate and nail treated bisphosphonate fractures with conventional fractures. They found that the bisphosphonate group had more major and minor complications (68%) than the conventional group (10%). The most common complications were intraoperative femoral shaft comminution (nail) and hardware failure (plate).
Figure A shows diffuse cortical thickening with an antero-lateral cortical ridge. Figure B shows a transverse subtrochanteric fracture extending through the middle of the cortical ridge seen previously. Note also healed fractures of the left superior and inferior rami. Figure C is a post-reduction radiograph showing the transverse fracture through the beak-shaped region of the previous insufficiency fracture. Illustration A shows a typical bisphosphonate-related fracture with transverse fracture orientation,
focal lateral cortical thickening (white arrows), medial beak (black arrow), and lack of comminution. Illustration B shows a conventional subtrochanteric fracture. Illustration C shows intraoperative iatrogenic fracture with anterolateral comminution during nailing. Illustration D shows fixation with a proximal femoral hook LCP Plate with late hardware failure at 3 months.
Incorrect Answers:

Question 61

Which of the following clinical disorders is the result of a mutation in fibroblast growth factor recepter 3 (FGFR3)?

Explanation

DISCUSSION: Camptomelic dysplasia is caused by a heterozygous loss of function of the Sox9 gene. The alternatives have genetic causes, but are not linked to Sox9. Cleidocranial dysplasia is related to a defect in Cbfa-1 (Osf-2, Runx2). Schmid metaphyseal chondrodysplasia is related to Type X collagen. Fibrous dysplasia is related to a defect in the alpha subunit of stimulatory guanine-nucleotide-binding protein (Gs). Achondroplasia is related to a defect in fibroblast growth factor receptor 3.
REFERENCES: Wagner T, Wirth J, Meyer J, et al: Autosomal sex reversal and camptomelic dysplasia are caused by mutations in and around the SRY-related gene SOX9. Cell 1994;79:1111-1120.
Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 111-131.
Dietz FR, Murray JC: Update on the genetic bases of disorders with orthopaedic manifestations, in Einhorn TA, O’Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006,

in press.

Question 62

A 35-year-old man reports the development of a painful 2-cm nodule on his dorsal wrist over the past 3 years. A surgeon excised the lesion with a presumptive diagnosis of a ganglion cyst. Histology sections from the excision are shown in Figures 11a and 11b. What is the most likely diagnosis?

Explanation

DISCUSSION: The histologic appearance of the soft-tissue lesion reveals compact nests of cells with a clear cytoplasm surrounded by a delicate border of fibrocollagenous tissue. There can be scattered multinucleated giant cells. This is consistent with a clear cell sarcoma, also called malignant melanoma of soft parts. This tumor is usually positive for S-100 and HMB45 (a melanoma-associated antigen). These tumors are frequently found around the foot and ankle. Similar to epithelioid sarcoma, it is usually intimately bound to tendons or tendon sheaths. Often the tumors are present for many years. The classic histologic appearance of this lesion differentiates it from the other choices.
REFERENCES: Enzinger FM, Weiss SW: Soft Tissue Tumors, ed 3. St Louis, MO, Mosby, 1995, p 913.
Lucas DR, Nascimento AG, Sim FH: Clear cell sarcoma of soft tissues: Mayo Clinic experience with 35 cases. Am J Surg Pathol 1992;16:1197-1204.

Question 63

A 23-year-old male is involved in a motor vehicle accident and sustains a left open femur fracture, right open humeral shaft fracture, and an LC-II pelvic ring injury. Which of the following best describes the radiographic findings associated with this pelvic injury pattern using the Young-Burgess Classification system?

Explanation

DISCUSSION: Lateral compression type II fractures (as described by the Young-Burgess Classification System) are associated with a crescent fracture of the iliac wing located on the side of impact. A representative CT scan image and illustration of this injury are shown in Illustration A and B respectively. A table describing each pelvic injury and their associated complications is shown in Illustration C. Illustration D shows each Young-Burgess pelvic injury type.
Burgess et al discuss the effectiveness of a treatment protocol as determined by their pelvic injury classification and hemodynamic status. The injury classification system was based on lateral compression, anteroposterior compression, vertical shear, and combined mechanical injury types. They found that their classification-based treatment protocols reduce the morbidity and mortality related to pelvic ring disruption.
Tile discusses acute pelvic trauma and his classification system for pelvic injuries (ie. Types A, B, and C). He states that any classification system must be seen only as a general guide to treatment, and that the management of each patient requires careful, individualized decision making.
Incorrect
2:
This
describes
an
APC-II
injury
3:
This
describes
an
APC-III
injury
4:
This
describes
and
LC-I
injury

Question 64

Figures 20a and 20b show the sagittal and coronal T1-weighted MRI scans of a patient’s left knee. Abnormal findings include

Explanation

DISCUSSION: The MRI scans show meniscal tissue extending across the entire lateral compartment, revealing a discoid lateral meniscus. The increased signal within the lateral meniscal tissue indicates a tear. Discoid lateral menisci are congenital variants that often present with mechanical symptoms in adolescents. The other structures in the knee are normal.
REFERENCES: Ahn JH, Shim JS, Hwang CH, et al: Discoid lateral meniscus in children: Clinical manifestations and morphology. J Pediatr Orthop 2001;21:812-816.
Andrish JT: Meniscal injuries in children and adolescents: Diagnosis and management.

J Am Acad Orthop Surg 1996;4:231-237.

Question 65

An olecranon fracture-dislocation of the elbow in which the fracture line exits distal to the coronoid process is best managed by open reduction and

Explanation

DISCUSSION: Fracture-dislocations of the elbow present difficult management problems. Standard olecranon fractures normally are not associated with a dislocation; however, the surgeon needs to recognize that some fractures that have a dislocation, in particular a posterior dislocation, represent a Monteggia equivalent. These injuries are not ulnar shaft fractures because they are fractured at or just distal to the coronoid; however, because of the unstable fracture-dislocation, the forces across this reduction are high. Two Kirschner wires and a tension band wire provide inadequate fixation. Therefore, the preferred method of fixation is plate osteosynthesis with a 3.5-mm low-contact dynamic compression plate or reconstruction plate.
REFERENCES: Jupiter JP, Kellam JF: Fractures of the forearm, in Browner BD, Jupiter JP, Levine AM, Trafton P (eds): Skeletal Trauma, ed 2. Philadelphia, PA, WB Saunders, 1998,

pp 421-454.
Quintero J: Fracture of the forearm, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 323-337.
Jupiter JB, Leibovic SJ, Ribbans W, Wilk RM: The posterior Monteggia lesion. J Orthop Trauma 1991;5:395-402.

Question 66

The underlying cause of the neoplasm is

Explanation

DISCUSSION
The bone scan reveals multiple bone lesions, which does not rule out any of the responses. The radiographs reveal dysplastic bone with a “ground glass” appearance, suggesting fibrous dysplasia as the preferred response. Multiple myeloma typically demonstrates purely lytic, “punched out” lesions and would be highly unusual in a 23-year-old woman. Multiple hereditary exostosis would demonstrate more expansile lesions concentrated in the metaphysis. Metastatic carcinoma could have a lytic or blastic appearance but is less likely to occur in a 23-year-old woman.
McCune-Albright syndrome in polyostotic fibrous dysplasia is present in as many as 50% of patients and should be evaluated for during an endocrine consultation. Adrenal, pituitary, parathyroid, and thyroid endocrinopathies may be present. Untreated hyperthyroidism can be life threatening during a surgical procedure. There is no indication to repeat the nuclear bone scan. Although phosphate wasting and, rarely, oncogenic osteomalacia have been reported in polyostotic fibrous dysplasia, an endocrinology consultation always should be sought.
Café au lait macules are the most common extraskeletal manifestation of fibrous dysplasia, often referred to as “coast of Maine” in appearance because of their irregular borders (in comparison to the “Coast of California” with smooth borders as seen in neurofibromatosis). Multiple myeloma would not ordinarily appear with increased uptake on a bone scan unless a pathologic fracture of some duration were present. A long area of bone involvement would not appear in patients with metastatic lung adenocarcinoma.
An ALK rearrangement occurs in nonsmall-cell lung cancer. The translocation t(11;14)(q13;q32) should be recognized as a poor prognosticator in multiple myeloma. The germline alteration in EXT1 and EXT2 occurs in multiple hereditary exostosis.
All forms of fibrous dysplasia are caused by a nongerm-cell mutation that occurs during early embryogenesis. A missense mutation of the GNAS1 gene, which encodes the alpha subunit of the stimulatory G-protein-couple-receptor, Gs alpha, results in G-protein activation and the production of cyclic adenosine monophosphate affecting melanocytes, endocrine cells, and osteoprogenitor cells.
RECOMMENDED READINGS
DiCaprio MR, Enneking WF. Fibrous dysplasia. Pathophysiology, evaluation, and treatment. J Bone Joint Surg Am. 2005 Aug;87(8):1848-64. Review.View Abstract at PubMed
Parekh SG, Donthineni-Rao R, Ricchetti E, Lackman RD. Fibrous dysplasia. J Am Acad Orthop Surg. 2004 Sep-Oct;12(5):305-13. Review. PubMed PMID: 15469225. View Abstract at PubMed
Shin HJ, Kim K, Lee JJ, Song MK, Lee EY, Park SH, Kim SH, Jang MA, Kim SJ, Chung JS. The t(11;14)(q13;q32) translocation as a poor prognostic parameter for autologous stem cell transplantation in myeloma patients with extramedullary plasmacytoma. Clin Lymphoma Myeloma Leuk. 2015 Apr;15(4):227-35. doi: 10.1016/j.clml.2014.12.007. Epub 2014 Dec 12.View Abstract at PubMed
Esfahani K, Agulnik JS, Cohen V. A Systemic Review of Resistance Mechanisms and Ongoing Clinical Trials in ALK-Rearranged Non-Small Cell Lung Cancer. Front Oncol. 2014 Jul 21;4:174. doi: 10.3389/fonc.2014.00174. eCollection 2014. Review. PubMed PMID: 25101240. View Abstract at PubMed

Question 67

What do the T2-weighted, fat-saturated MRI scans shown in Figures 1 through 4 reveal?

Explanation

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 68

A 47-year-old man sustained a degloving injury over the pretibial surface and anterior ankle region in a motor vehicle accident. After debridement and irrigation, there is inadequate tissue for closure of the exposed anterior tibial tendon and tibia. Prior to definitive soft-tissue coverage, management should consist of

Explanation

DISCUSSION: With soft-tissue loss, local or free flap coverage may be necessary to treat exposed tendon and bone. However, a vacuum-assisted closure device is a good temporizing dressing. It prevents external contamination, reduces edema around the wound, increases oxygen tension in the wound, and promotes the formation of granulation tissue. The use of this negative pressure device has been described in both acute traumatic and in chronic wound scenarios. If sufficient granulation tissue forms, closure may be by split graft, avoiding a more complex coverage procedure. Immediate skin grafting over the exposed anterior tibial tendon and tibia would have a low likelihood of success. Dressing changes with sulfasalazine may be beneficial in a burn wound to assist with removal of skin slough; however, in a granulating wound, the material may be toxic to early epithelialization. Xenograft is a foreign body and should not be applied to an acute contaminated open wound. Historically, a cross-leg flap was a treatment alternative for lower extremity soft-tissue loss; however, its current applications are extremely limited.
REFERENCES: Webb LX: New techniques in wound management: Vacuum assisted wound closure. J Am Acad Orthop Surg 2002;10:303-311.
Clare MP, Fitzgibbons TC, McMullen ST, et al: Experience with the vacuum assisted closure negative pressure technique in the treatment of non-healing diabetic and dysvascular wounds. Foot Ankle Int 2002;23:896-901.

Question 69

Wear particles of ultra-high molecular weight polyethylene that are generated by total hip implants are predominantly of what diameter?

Explanation

DISCUSSION: Multiple studies have shown that the size of an ultra-high molecular weight polyethylene particle generated by total hip implants is typically less than 1 micron. This finding is significant in that particles of that size are readily phagocytized by macrophages.
REFERENCES: Campbell P, Ma S, Yeom B, McKellop H, Schmalzried TP, Amstutz HC: Isolation of predominantly submicron-sized UHMWPE wear particles from periprosthetic tissues. J Biomed Mater Res 1995;29:127-131.
Shanbhag AS, Jacobs JJ, Glant TT, Gilbert JL, Black J, Galante JO: Composition and morphology of wear debris in failed uncemented total hip replacement. J Bone Joint Surg Br 1994;76:60-67.
Maloney WJ, Smith RL, Schmalzried TP, Chiba J, Huene D, Rubash H: Isolation and characterization of wear particles generated in patients who have had failure of a hip arthroplasty without cement. J Bone Joint Surg Am 1995;77:1301-1310.

Question 70

Figures 78a and 78b show the CT scans of a 22-year-old man with back pain after falling out of a tree. Examination reveals no palpable spinal step-offs, posterior spinal pain, and normal neurologic function in the lower extremities. Normal perineal sensation and normal rectal tone are present. What is the best management? Review Topic

Explanation

The patient has a stable L2 burst fracture. There is no evidence of neurologic injury or disruption of the posterior ligamentous complex. According to the Thoracolumbar Injury Classification System (TLICS), the severity score for this injury is 2 and therefore nonsurgical management is recommended. The TLICS was developed to define injury based on three clinical characteristics: injury morphology, integrity of the posterior ligamentous complex, and neurologic status of the patient. Point values are assigned to each major category based on injury severity. The sum of these points represents the TLICS severity score, which may be used to guide treatment. The injury scores are totaled to produce a management grade that is, in turn, used to guide treatment. A score of >4 suggests the need for surgical treatment because of significant instability, whereas a score of <4 suggests nonsurgical management. The severity score offers prognostic information and is helpful in medical decision making. An external orthosis provides enough support to obviate the need for bed rest and avoid associated complications (deep venous thrombosis, pulmonary embolism, pneumonia, skin ulceration). Surgical treatment, either through an anterior or posterior approach, has been shown by Wood and associates to result in increased pain and disability and is therefore not indicated in this setting. Additionally, there is no need for decompression in the setting of a neurologically intact patient.

Question 71

The best definitive treatment for this patient’s left knee is

Explanation

DISCUSSION
This patient now has a major fixed flexion contracture and severe varus alignment and instability. Infection of the knee joint has to be ruled out. The radiograph shows all the hallmarks of Charcot arthropathy, including disintegration and fragmentation of the joint with major deformity. Infection of the knee joint and contiguous osteomyelitis still have to be ruled out. The clinical and radiographic findings are highly suggestive of a Charcot neurogenic arthropathy associated with uncontrolled diabetes. This patient is an unsuitable candidate for total knee arthroplasty (TKA) because he is noncompliant regarding his diabetes and has had a previously infected native joint that now is associated with Charcot arthropathy. He is nonambulatory. The failure rate of TKA or knee arthrodesis is extremely high in this setting. He will best be served with observation or amputation depending upon his symptom severity.

Question 72

Closed-chain exercise differs from open-chain exercise in which of the following ways?

Explanation

DISCUSSION: Closed-chain exercise requires the distal portion of the extremity to be fixed. It is more commonly used in lower extremity exercise, and movement is produced by co-contraction of muscles. Joint compression is increased, and multiple joints are involved with closed-chain exercise. In open-chain exercise, the distal portion of the extremity is free.
REFERENCES: Braddom RL (ed): Physical Medicine and Rehabilitation, ed 2. Philadelphia, PA, Saunders, 2000, pp 975-976.
Childs DC, Irrang JJ: The language of exercise and rehabilitation, in Delee JC, Drez D (eds): Orthopaedic Sports Medicine, ed 2. Philadelphia, PA, WB Saunders, 2003, vol 1, p 329.

Question 73

Which of the following benign bone lesions can develop lung metastases?

Explanation

DISCUSSION: Although considered benign bone lesions, lung metastases can develop in giant cell tumors and chondroblastomas. These often can be treated with multiple thoracotomies, resulting in long-term survival.
REFERENCES: Roberts PF, Taylor JG: Multifocal benign chondroblastomas: Report of a case. Hum Pathol 1980;11:296-298.
Bloem JL, Mulder JD: Chondroblastoma: A clinical and radiological study of 104 cases. Skeletal Radiol 1985;14:1-9.

Question 74

Figure 62 is an arthroscopic view of the intercondylar notch of a right knee from an anterolateral portal. What is the main function of the structure delineated by the black asterisks? Review Topic

Explanation

The structure shown is the posterolateral bundle of the anterior cruciate ligament (ACL). This bundle is optimally positioned in the knee to resist rotatory forces during terminal knee extension. "Resist anterior translation during knee flexion" best describes the anteromedial bundle. "Resist rotatory loads during knee flexion" is unlikely because the posterolateral bundle is tightest during knee extension. The posterior cruciate ligament, not the ACL, functions to resist posterior translation.

Question 75

The mother of an otherwise healthy 1-month-old infant reports that he is not moving his left leg after falling from his high chair 2 days ago. He has a temperature of 99.5°F (37.5°C). Examination reveals that the left thigh is moderately tender to palpation. Because the infant is apprehensive, range of motion is difficult to quantify, but appears to be normal at the hips and ankles. Range of motion of the left knee is approximately 25° to 90°. A radiograph of the leg is shown in Figure 27. Management should consist of

Explanation

DISCUSSION: The patient has a bucket-handle fracture of the distal femur with bilateral corner fractures of the distal femur and a transverse fracture of the proximal tibia. These fractures are virtually pathognomonic of child abuse. The infant should be admitted to the hospital, and child protection services should be notified for investigation of possible abuse. A skeletal survey should be obtained, along with laboratory studies that include a CBC, a platelet count, a prothrombin time, a partial thromboplastin time, and a bleeding time.
REFERENCES: Akbarnia BA: The role of the orthopaedic surgeon in child abuse, in Morrissy RT, Weinstein SL (eds): Lovell & Winter’s Pediatric Orthopaedics, ed 4. Philadelphia, Pa, Lippincott-Raven, 1996, pp 1315-1334.
Black GB: Child abuse fractures, in Letts RM (ed): Management of Pediatric Fractures. New York, NY, Churchill Livingstone, 1994, pp 931-944.

Question 76

Which of the following alternatives to autogenous bone grafting functions through osteoinduction?

Explanation

Allograft bone is one of the most common bone graft substitutes, and is frequently used as a bone graft extender. The sterilization process kills all cells but their three-dimensional structure is retained, offering an osteoconductive scaffold. Tricalcium phosphate, calcium phosphate, and calcium sulfate are also osteoconductive materials with a three-dimensional scaffold similar to native cancellous bone. Bone morphogenetic protein is an inductive protein, which stimulates osteoprogenitor cells to differentiate along a bone-forming lineage.

Question 77

Which of the following is not a reported mode of failure for a constrained acetabular component?

Explanation

DISCUSSION: There is no evidence of increased polyethylene wear in constrained acetabular components. The rates of wear appear to be the same using standard or constrained liners.
REFERENCES: Lachiewicz PF, Kelley SS: Constrained components in total hip arthroplasty. J Am Acad Orthop Surg 2002;10:233-238.
Anderson MJ, Murray WR, Skinner HB: Constrained acetabular components. J Arthroplasty 1994;9:17-23.
Fisher DA, Kiley K: Constrained acetabular cup disassembly. J Arthroplasty 1994;9:325-329.

Question 78

A 17-year-old basketball player and pole vaulter who has had anterior knee pain for the past 18 months now reports a recent inability to jump. Based on the MRI scan shown in Figure 11, management should consist of

Explanation

DISCUSSION: The MRI scan reveals a partial patellar tendon rupture in conjunction with chronic patellar tendinitis. Mild and moderate patellar tendinitis may be treated nonsurgically with rest, stretching, strengthening, and anti-inflammatory drugs. Severe tendinopathy or extensor mechanism disruption is best treated surgically with tendon debridement and repair.
REFERENCES: Al-Duri ZA, Aichroth PM: Surgical aspects of patella tendonitis: Techniques and results. Am J Knee Surg 2001;14:43-50.
Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 218-219.

Question 79

A 47-year-old landscaper presents with worsening left shoulder pain and weakness. Three years ago, he injured the left shoulder in a fall and elected for nonoperative management to minimize time off from work. Physical therapy was effective until 6 months ago when his shoulder function worsened to the point that he is now unable to work. Examination of his active range of motion reveals forward elevation 120° with pain, abduction 100°, IR at neutral to T8 and ER at neutral 5°. He has a positive ER lag sign and Hornblower's sign. Belly press and lift-off tests are normal. A recent radiograph is shown in Figures A. MRI images are shown in Figures B and C. Which of the following is the best treatment option? Review Topic

Explanation

This patient has a chronic massive posterosuperior rotator cuff tear with marked atrophy, tendon retraction and loss of external rotation strength that is impacting his daily life. The best treatment option for this middle-aged laborer with an irreparable posterosuperior rotator cuff tear is a latissimus dorsi transfer to restore external rotation strength and motion.
Irreparable rotator cuff tears are marked by: (1) Superior displacement of the humeral head (AHI < 5-7mm), (2) Fatty infiltration of the rotator cuff muscles (Goutallier stage 3-4), (3) Increased duration of the tendon tear and (4) Profound external rotation weakness. These findings are predictive of poor-quality tissue and stiffness of the muscle-tendon unit, not amenable to primary repair. In this setting, a latissimus dorsi
transfer can be utilized to restore shoulder strength, function and improve pain. Relative contraindications include subscapularis deficiency, deltoid deficiency, pseudoparalysis of the shoulder and advanced glenohumeral arthritis.
Gerber et al. performed a case series analysis of 67 patients with irreparable rotator cuff tears managed with latissimus dorsi transfer. Patients with an intact subscapularis demonstrated improvement in pain, range of motion and strength postoperatively, while no improvement was noted in patients with subscapularis deficiency. The authors conclude that latissimus dorsi transfer should not be performed in the setting of poor subscapularis function.
Iannotti et al. found that better clinical results following latissimus dorsi transfer were associated with: preserved active shoulder range of motion and strength (specifically forward elevation > 90° and external rotation > 20°), synchronous firing of the transferred latissimus dorsi muscle and male gender.
Figure A is an AP radiograph of the left shoulder with superior migration of the humeral head (AHI < 5mm) and no evidence of glenohumeral arthritis. Figures B and C show a retracted posterosuperior rotator cuff tear and Goutallier stage 4 atrophy (more fat than muscle) of the supraspinatus, infraspinatus and teres minor, rendering this tear irreparable. Illustration A shows a latissimus dorsi transfer. The latissimus dorsi tendon is positioned over the top of the humeral head, covering most of the rotator cuff defect. The tendon is then secured to the subscapularis tendon edge and lesser tuberosity anteriorly, the remnant supraspinatus and infraspinatus tendons medially, and the greater tuberosity laterally.
Incorrect Answers:

Question 80

One advantage of using onlay strut allograft in femoral revision surgery is that it can

Explanation

DISCUSSION: Onlay grafts can provide more structural support than morcellized grafts. They are more easily incorporated into the host femur than bulk segmental total femur allografts; however, the incorporation is never complete. The use of onlay grafts is principally directed at addressing segmental defects of the femur; their use can be applied with either cementless or cement fixation of the femoral stem.
REFERENCES: Emerson RH Jr, Malinin TI, Cuellar AD, Head WC, Peters PC: Cortical strut allografts in the reconstruction of the femur in revision total hip arthroplasty: A basic science and clinical study. Clin Orthop 1992;285:35-44.
Pak JH, Paprosky WG, Jablonsky WS, Lawrence JM: Femoral strut allografts in cementless revision total hip arthroplasty. Clin Orthop 1993;295:172-178.
Head WC, Emerson RH Jr, Malinin TI: Structural bone grafting for femoral reconstruction. Clin Orthop 1999;369:223-229.

Question 81

An 80-year-old woman notes a painless mass posterior to her left knee. MRI scans are shown in Figures 31a and 31b. What is the best course of action?

Explanation

DISCUSSION: The MRI scans show a popliteal cyst (Baker’s cyst) in its most common location. The cyst emerges from the knee joint between the medial head of the gastrocnemius muscle and the tendon of the semimembranosus muscle. These images are diagnostic; therefore, no further work-up is indicated. Since the patient is asymptomatic, no treatment is necessary.
REFERENCES: Dlabach JA: Nontraumatic soft tissue disorders, in Canale ST (ed): Campbell’s Operative Orthopaedics, ed 10. Philidelphia, PA, Mosby, 2003, vol 1, pp 885-969.
Fritschy D, Fasel J, Imbert JC, et al: The popliteal cyst. Knee Surg Sports Traumatol Arthrosc 2006;14:623-628.

Question 82

A 28-year-old man reports an episode of buckling and giving-way of his right knee. Figure 54a and 54b show a radiograph and sagittal MRI scan. What is the most likely diagnosis? Review Topic

Explanation

The radiograph shows patella alta consistent with a rupture of the patellar tendon. The MRI scan confirms disruption of the patellar tendon from the inferior pole of the patella. The cruciate ligaments are not visualized in this image, and would not result in patella alta. Quadriceps tendon rupture would result in patella baja. There is no evidence of meniscal tearing on these images.

Question 83

Because of the ongoing pain and instability and the demonstration of radiographic instability when the ankle is stressed, what surgical procedure should be performed to restore stability to the ankle joint based on the CT findings?

Explanation

DISCUSSION FOR QUESTIONS 107 AND 108:
The fracture at the insertion of the AITFL into the fibula represents a syndesmosis injury. In some cases, a direct repair of the fracture will stabilize the syndesmosis, but in most cases this injury should most likely be reinforced by placing a screw or suture tensioning device across the syndesmosis for additional support.A Brostrom or allograft reconstruction is indicated for an ankle sprain involving the ATFL or CFL.Simply excising the fragment will leave the patient with an incompetent syndesmosis. Repairing the SPR with or without a groove deepening procedure is indicated if there is evidence of subluxated or dislocated peroneal tendons, which is not demonstrated on the CT scans. The bone has been avulsed off the fibula by the portion of the AITFL that attaches to the fibula, therefore indicating that there is a syndesmosis injury. Allograft lateral ligament reconstruction and excision of loose body/fracture fragment are incorrect procedures based on location. The deltoid is a medial structure and this fracture is lateral. The ATFL and CFL attach at the inferior margin of the fibula near the lateral process of the talus and calcaneus. A SPR avulsion would present as an avulsion off the lateral wall of the fibula, not superior and not into the syndesmotic space as shown on the CT scans.

Question 84

It is important to avoid which of the following exercises in the immediate postoperative period after humeral head replacement for an acute four-part fracture?

Explanation

DISCUSSION: It is critical to withhold active range of motion of the shoulder within the first 6 weeks after arthroplasty for acute fracture to prevent tuberosity avulsion. When radiographic and clinical findings show that the tuberosities are healed, active motion may be instituted, usually at 6 to 8 weeks. Immediate passive range-of-motion exercises, including external rotation with a stick, pendulum, and passive elevation, should begin within the limits of the repair on the day of surgery to prevent stiffness.
REFERENCES: Hartstock LA, Estes WJ, Murray CA, et al: Shoulder hemiarthroplasty for proximal humerus fractures. Orthop Clin North Am 1998;29:467-475.
Hughes M, Neer CS: Glenohumeral joint replacment and postoperative rehabilitation. Phys Ther 1975;55:850-858.

Question 85

A 35-year-old man who is an avid weight lifter competing in local tournaments reports new onset pain and loss of motion in his dominant right shoulder. Examination reveals joint line tenderness, active elevation to 100 degrees, and external rotation to 10 degrees. His contralateral shoulder reveals 170 degrees forward elevation and 50 degrees external rotation. Radiographs are shown in Figures 46a and 46b. What is the next most appropriate step in management? Review Topic

Explanation

New onset pain and stiffness in the young arthritic shoulder is a difficult problem to treat. Initial management should be aimed at reducing pain and improving motion in all planes. This patient’s activities and age preclude a shoulder arthroplasty at this time. If nonsurgical management fails to provide relief, then arthroscopic debridement and capsular release may be beneficial.

Question 86

A 25-year-old professional baseball pitcher reports a 4-month history of gradually increasing medial elbow pain that occurs during the late cocking and acceleration phases of throwing. The pain occasionally refers distally along the ulnar aspect of the forearm. He denies any weakness; however, he notes occasional paresthesias. A nerve conduction velocity study demonstrates increased latency across the cubital tunnel. Management consisting of 6 weeks of rest and rehabilitation fails to provide relief as the symptoms returned when he resumed throwing. What is the best course of action?

Explanation

DISCUSSION: In the thrower’s elbow, ulnar neuritis is felt to result from both chronic compression and traction on the nerve that occurs during the throwing motion. Occasionally, subluxation of the nerve also can lead to symptoms. If nonsurgical management fails to provide relief, transposition of the nerve to an anterior subcutaneous location is the surgical procedure of choice. The nerve is held in its new position by one or two fascial slings created from the fascia of the common flexor origin.
REFERENCES: Schickendantz MS: Diagnosis and treatment of elbow disorders in the overhead athlete. Hand Clin 2002;18:65-75.
Eaton RG, Crowe JF, Parkes JC III: Anterior transposition of the ulnar nerve using a non-compressing fasciodermal sling. J Bone Joint Surg Am 1980;62:820-825.

Question 87

The peroneus tertius is a commonly used landmark for arthroscopic portal placement. What is the function of this tendon?

Explanation

DISCUSSION: The peroneus tertius, although absent in 10% of the population, originates on the distal third of the extensor surface of the fibula and inserts onto the base of the fifth metatarsal, possibly extending to the fascia over the fourth interosseous space. The muscle is located in the anterior compartment of the leg and is innervated by the deep peroneal nerve. The tendon produces dorsiflexion and eversion when walking and can be used as an insertion point during tendon transfers to assist dorsiflexion. This tendon is peculiar to humans and is a proximally migrated deep extensor of the fifth toe.
REFERENCES: Joshi SD, Joshi SS, Athavale SA: Morphology of the peroneus tertius muscle.

Clin Anat 2006;19:611-614.
Williams PL, Bannister LH, Berry MM, et al (eds): Gray’s Anatomy, ed 38. London, Churchill Livingston, 1995, p 883.
Hansen ST Jr: Functional Reconstruction of the Foot and Ankle. Philadelphia, PA, Lippincott Williams & Wilkins, 2000, p 21.

Question 88

A 42-year-old woman has a history of nontraumatic ankle swelling with tenderness over the Achilles tendon and plantar fascia. She reports that while vacationing in Connecticut 2 months ago she noted the presence of a “red bull’s eye” rash. Management should consist of

Explanation

DISCUSSION: The most likely diagnosis is Lyme disease because of the patient’s recent vacation in an area with a high risk of exposure. The most effective treatment is doxycycline.
REFERENCES: Neu HC: A perspective on therapy of Lyme infection. Ann NY Acad Sci 1988;539:314-316.
Faller J, Thompson F, Hamilton W: Foot and ankle disorders resulting from Lyme disease. Foot Ankle 1991;11:236-238.

Question 89

A 74-year-old man with ankylosing spondylitis falls off a step stool and now has a minimally displaced T10-T11 extension-type fracture. He is initially treated with percutaneous pedicle screw fixation from T8-L1 and has good pain relief. The next day, however, he experiences increased back pain and loss of strength in his lower extremities.

Explanation

DISCUSSION
Cauda equina syndrome, typically the result of severe central canal stenosis in the lower lumbar region, often is caused by a large central disk herniation. Symptoms include severe back or leg pain, perineal numbness, possible motor weakness, and initial urinary retention followed by an overflow incontinence. When bowel or bladder deficits are present, this is considered a surgical emergency because successful recovery is most likely if decompression occurs within the first 48 hours.
Ankylosing spondylitis can lead to progressive autofusion of the vertebrae and significant limitation in motion. Any sudden improvement in motion should be considered a fracture until proven otherwise. These fractures are commonly missed when using plain radiographs or even CT scan because minimal or no displacement often is noted. MR imaging can be useful to identify edema at
the fracture site. These fractures are typically very unstable and necessitate surgery to avoid displacement and potential neurologic injury.
Some fractures associated with ankylosing spondylitis can be effectively treated with percutaneous pedicle screw fixation. However, because of the highly vascular nature of some of these fractures, they pose risk for an epidural hematoma, potential neurologic deficit, and emergent decompression.
RECOMMENDED READINGS
Patel AR, Alton TB, Bransford RJ, Lee MJ, Bellabarba CB, Chapman JR. Spinal epidural abscesses: risk factors, medical versus surgical management, a retrospective review of 128 cases. Spine J. 2014 Feb 1;14(2):326-30. doi: 10.1016/j.spinee.2013.10.046. Epub 2013 Nov 12. PubMed PMID: 24231778. View Abstract at PubMed
Mathews M, Bolesta MJ. Treatment of spinal fractures in ankylosing spondylitis. Orthopedics. 2013 Sep;36(9):e1203-8. doi: 10.3928/01477447-20130821-25. PubMed PMID: 24025014.
View Abstract at PubMed
McCarthy MJ, Aylott CE, Grevitt MP, Hegarty J. Cauda equina syndrome: factors affecting long-term functional and sphincteric outcome. Spine (Phila Pa 1976). 2007 Jan 15;32(2):207-

Question 90

A 68-year-old woman who sustained a closed distal tibia fracture 2 years ago was initially treated with an external fixator across the ankle for 12 weeks, followed by intramedullary nailing of the fibula and lag screw fixation of the tibia. She continued to report persistent pain so she was treated with a brace and a bone stimulator. She now reports pain in her ankle. Examination reveals ankle range of motion of 8 degrees of dorsiflexion to 25 degrees of plantar flexion. She is neurovascularly intact. Current radiographs are shown in Figures 9a through 9c. What is the next most appropriate step in management?

Explanation

DISCUSSION: The patient has a nonunion of the distal fifth of the tibia. The nonunion appears to be oligotrophic, somewhere between atrophic and hypertrophic. Management requires stabilization and stimulation of the local biology, which can be accomplished with open reduction and internal fixation with bone grafting. Bracing or casting does not provide enough stability. Ultrasound bone stimulation has been shown to speed fresh fracture repair but is not indicated in nonunions. The distal segment is too short for intramedullary nailing. A fibular osteotomy alone would increase instability and, even with prolonged casting, would be unlikely to lead to successful repair.
REFERENCES: Carpenter CA, Jupiter JB: Blade plate reconstruction of metaphyseal nonunion of the tibia. Clin Orthop 1996;332:23-28.
Lonner JH, Siliski JM, Jupiter JB, Lhowe DW: Posttraumatic nonunion of the proximal tibial metaphysis. Am J Orthop 1999;28:523-528.
Stevenson S: Enhancement of fracture healing with autogenous and allogeneic bone grafts. Clin Orthop 1998;355:S239-S246.
Wiss DA, Johnson DL, Miao M: Compression plating for non-union after failed external fixation of open tibial fractures. J Bone Joint Surg Am 1992;74:1279-1285.

Question 91

Figures 1 through 3 are the weight-bearing radiograph and MRI scans of a 27-year-old man who twisted his knee coming down awkwardly from a lay-up during a basketball game. He felt a sharp stabbing pain in the posterior aspect of his knee at the time of the injury. Physical examination reveals a trace effusion, full range of motion but pain with hyperflexion >90° degrees and tenderness over the affected joint line. What is the most appropriate treatment at this time?

Explanation

The MRI scan shows a posterior horn medial meniscus root avulsion with bony edema at the tibial root insertion. The radiograph shows no significant degenerative changes. If left untreated, posterior meniscal
root tears lead to progressive degenerative changes as a result of the altered tibiofemoral contact pressures and areas. Nonsurgical treatment including injections, physical therapy, and unloader braces are more appropriate in the older patient with pre-existing advanced degenerative changes.

Question 92

What is the preferred treatment of a symptomatic curly toe deformity in a 6-year-old child?

Explanation

DISCUSSION: While some curly toe deformities spontaneously improve in younger children, the deformity is likely to persist in a 6-year-old child. Taping techniques result in no change or only a temporary decrease in deformity. Studies have shown that simple flexor tenotomy is as effective as flexor tendon transfer. Arthrodesis is rarely indicated.
REFERENCES: Hamer A, Stanley D, Smith TW: Surgery for curly toe deformity: A

double-blind, randomized, prospective trial. J Bone Joint Surg Br 1993;75:662-663.
Ross ER, Menelaus MB: Open flexor tenotomy for hammer toes and curly toes in childhood.

J Bone Joint Surg Br 1984;66:770-771.

Question 93

A 68-year-old man embarks on a 24-week strength training program. He trains at 80% of his single repetition maximum for both the upper and lower extremities. Which of the following changes can be anticipated?

Explanation

DISCUSSION: Consistent, long-term exercise training in older athletes has proven very beneficial in reversing both endurance and strength losses that traditionally have been seen with aging. This patient’s program will lead to a significant increase in the strength, cross-sectional area, and capillary density of the trained muscles. No major changes in aerobic capacity are anticipated. Strength improvements of up to 5% per day, similar to those for younger athletes, have been identified in this population in one study.
REFERENCES: Kirkendall DT, Garrett WE Jr: The effects of aging and training on skeletal muscle. Am J Sports Med 1998;26:598-602.
Frontera WR, Meredith CN, O’Reilly KP, Knuttgen HG, Evans WJ: Strength conditioning in older men: Skeletal muscle hypertrophy and improved function. J Appl Physiol 1988;64:1038-1044.

Question 94

Figure 11 shows the radiograph of an otherwise healthy 22-year-old man who sustained a midfoot injury in a motor vehicle accident 9 days ago. Treatment should consist of

Explanation

DISCUSSION: The dislocation is between the medial and middle cuneiform. Although the first and second tarsometatarsal joints are aligned, there is a gap between the cuneiforms. The radiograph shows a Lisfranc dislocation variant. In a healthy active individual, open reduction and internal fixation yields the best results. The reestablishment of the normal arch and medial column support with anatomic reduction is critical to obtaining the best possible outcome from these injuries.
REFERENCES: Teng AL, Pinzur MS, Lomasney L, et al: Functional outcome following anatomic restoration of the tarsal-metatarsal fracture dislocation. Foot Ankle Int

2002;23:922-926.
Kuo RS, Tejwani NC, DiGiovanni CW, et al: Outcome after open reduction and internal fixation of Lisfranc joint injuries. J Bone Joint Surg Am 2000;82:1609-1618.

Question 95

Item Deleted by AAOS Question 40 - Figure 8 shows the AP radiograph of a 38-yea-old woman who has constant pain in her shoulder as the results of a motor vehicle accident. Examination reveals marked restriction in external rotation. Which of the following studies should be ordered to aid in making a diagnosis?

Explanation

Figure eight demonstrates a posterior dislocation. Therefore the simplest, and best test would be the Axillary lateral. Rockwood and Green (fourth edition) discusses several radiographic signs that indicate that a posterior dislocations exists. Absence of the normal elliptical overlap shadow; the vacant glenoid sign; presence of the Trough line; Loss of profile of the neck of the humerus; and void in the inferior or superior glenoid fossa. Furthermore the clinical picture of loss of external rotation should also make one suspect of a posterior dislocation.

Question 96

A 47-year-old woman who reports mild, aching pain in her knee has no history of trauma. Examination of the knee is normal. Figure 23a shows the AP radiograph. A bone scan shows increased uptake at this site only. Figure 23b shows the CT scan, and Figure 23c shows the histology from the CT scan-guided needle biopsy. Treatment should include

Explanation

Patients with giant cell tumors typically present with local pain, swelling and tenderness. Radiographs usually reveal a lesion destructive of both medullary and cortical bone. The lesion is characterized by an expanding zone of radiolucency that is located eccentrically in the end of a long bone in an adult.
The modern technique for the removal of a giant cell tumor involves wide decortication of all the bone overlying the area of the tumor. The cavity is filled with methylmethacrylate bone cement and covered with demineralized bone matrix to stimulate the restoration of strong cortical
boundaries. The other procedures are much more invasive and not necessary to treat a low-grade neo-plastic lesion such as a giant cell tumor. Fewer complications and better functional results have been found after intralesional excision and insertion of methylmethacrylate than other techniques.

Question 97

What percent of patients initially diagnosed with classic, high-grade osteosarcoma of the extremity have visible evidence of pulmonary metastasis on CT of the chest?

Explanation

DISCUSSION: CT studies show that approximately 10% to 20% of patients with high-grade osteosarcoma have pulmonary metastases at diagnosis. Although not visible on current staging studies, it is believed that up to 80% of patients have micrometastatic disease that requires systemic chemotherapy. Because it is not possible to identify those patients who do not have disseminated micrometastatic disease, most patients are treated presumptively with chemotherapy.
REFERENCES: Kaste SC, Pratt CB, Cain AM, et al: Metastases detected at the time of diagnosis of primary pediatric extremity osteosarcoma at diagnosis: Imaging features. Cancer 1999;86:1602-1608.
Link MP, Goorin AM, Miser AW, et al: The effect of adjuvant chemotherapy on relapse-free survival in patients with osteosarcoma of the extremity. N Engl J Med 1986;314:1600-1606.

Question 98

A 69-year-old man has nonpainful weakness in the upper and lower extremities. He also notes progressive instability in his gait and increasing difficulty ambulating, as well as manipulating small objects with his hands. MRI scans of his cervical spine are shown in Figures 85a and 85b. When would be the most appropriate time to proceed with surgical treatment? Review Topic

Explanation

The natural history of cervical myelopathy is one of slow deterioration over time, typically in a stepwise fashion with a variable period of stable neurologic function. More recent studies suggest that surgery should be performed as soon as possible when cervical spondylotic myelopathy has been diagnosed. Both anterior and posterior are effective and there is no statistical difference between their outcomes. Surgical outcome is related to the patient's age, disease course, the presence of osseous spinal stenosis, preoperative comorbidities, the preoperative spinal cord functional score, and the presence of high-signal abnormalities on T2-weighted images. To improve the operative result, all the influencing factors should be considered. Patients with focal high-intensity intramedullary signal changes on T2-weighted images have better clinical outcomes following surgery than do patients with demonstrable multisegmental high-intensity intramedullary signal changes on T2-weighted sequences. The transverse area and shape of the spinal cord at the involved segment may also be predictive of surgical outcome. With progressive compression, the cross section of the spinal cord changes from a boomerang shape to a teardrop shape to a triangular shape. In patients with a Nurick grade of I, there are signs of cord involvement, but gait remains normal. With a Nurick grade of II, there are mild gait abnormalities, not affecting the patient's employment status. With a Nurick grade of III, gait abnormalities prevent employment, but the patient remains able to ambulate without assistance. In Nurick grade IV, the patient is only able to ambulate with assistance. In Nurick grade V, the patient is chair-bound or bedridden. Clearly, it is desirable to operate when the patient is functioning with a Nurick grade of I or II. Whereas many patients presenting with cervical spondylotic myelopathy also report axial neck pain and radicular symptoms in the upper extremities, this is not always the case. Surgical intervention will generally be effective in eliminating this pain; however, the pain is not the determining factor for performing surgery. Surgery is performed to preserve and restore function. Changes in bowel and bladder function can occur in extremely severe cases of myelopathy, but this is quite rare.

Question 99

A 63-year-old woman with a history of poliomyelitis has a fixed 30-degree equinus contracture of the ankle, rigid hindfoot valgus, and normal knee strength and stability. She reports persistent pain and has had several medial forefoot ulcerations despite a program of stretching, bracing, and custom footwear. What is the next most appropriate step in management?

Explanation

DISCUSSION: The patient has a fixed deformity of the hindfoot and an Achilles tendon contracture; therefore, the treatment of choice is triple arthrodesis with Achilles tendon lengthening. Further bracing will not be helpful. Amputation is not indicated, and ankle arthrodesis will not address the hindfoot deformity. Palliative management would be more appropriate if the knee was unstable or the quadriceps were weak, because the equinus balances the ground reaction force across the knee.
REFERENCES: Perry J, Fontaine JD, Mulroy S: Findings in post-poliomyelitis syndrome: Weakness of muscles of the calf as a source of late pain and fatigue of muscles of the thigh after poliomyelitis. J Bone Joint Surg Am 1995;77:1148-1153.
Dehne R: Congenital and acquired neurologic disorders, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, vol 1, pp 552-553.

Question 100

A 17-year old boy who sustained a closed clavicle fracture after he was ejected from an all-terrain vehicle was treated with a figure-of-8 brace 1 year ago. He now reports continuous pain at the site of the fracture and is unable to actively raise his arm above his head. A radiograph is shown in Figure 1. Management should now include

Explanation

The radiograph illustrates a middle third clavicular fracture with bone loss. According to Jupiter and associates, the biomechanics of the clavicle predisposes the middle third to be prone for fracture secondary to both moments of tension and bending and also torsional forces. In their study, fixation was best accomplish with plate fixation and a bone graft.[JBJS 1987, 69-A pg. 753-759]
Selection (1) would not provide adequate fixation to promote healing. (2) Electrical stimulation would not be sufficient for the above reasons. (3) Resection of the distal clavicle would not be indicate for this case because it promote further instability of the clavicle and increasing the affected forces to the clavicle.
(5) Kirschner wire fixation with bone graft, the author stated would provide fixation, but they achieved better results with plate fixation and bone graft Question 6 -
A 75-year-old woman sustains a fracture below the level of a total hip prosthesis. Radiographs demonstrate loosening of the prosthetic component. Treatment should consist of
a cast brace
a spica cast
plate fixation
allograft strut fixation
long stem revision
The key to this question lies in the radiographic evidence of loosening of the prosthetic component. The long stem revision is clearly indicated in this case because of various factors, one decreases impingement of the loose stem against the lateral femoral cortex. A non-surgical approach in the elderly patient will only increase the many risk factors such as atelectasis, pneumonia, and thromboembolic disease.[Instructional Course 44 pg. 293-303]

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

profundus and extensor carpi radialis longus.
profundus and extensor carpi radialis brevis.
superficialis and extensor carpi radialis longus.
superficialis and flexor carpi ulnaris.
superficialis and flexor carpi radialis.

Correct Answer: superficialis and flexor carpi ulnaris.

Explanation:

Question 2:

What is the effect on knee kinematics following placement of an anterior cruciate ligament (ACL) graft at the 12 o’clock position?

Options:

Decreased rotational stability
Decreased anterior-posterior stability
Decreased flexion
Decreased extension
Graft failure secondary to impingement

Correct Answer: Decreased rotational stability

Explanation:

Question 3:

Options:

Arthroscopic debridement
Arthrodesis
Resection arthroplasty
Hemiarthroplasty
Cortisone injection

Correct Answer: Hemiarthroplasty

Explanation:

Question 4:

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 5:

What muscle attaches to the site shown by the arrow in Figure 2?

Options:

Teres minor
Teres major
Latissimus dorsi
Pectoralis major
Pectoralis minor

Correct Answer: Latissimus dorsi

Explanation:

Question 6:

The safest surgical approach to the insertion of the tibial posterior cruciate ligament uses the interval between which of the following muscles?

Options:

Semimembranosus and medial gastrocnemius
Semimembranosus and semitendinosus
Medial and lateral gastrocnemius
Lateral gastrocnemius and biceps femoris tendon
Popliteus and lateral gastrocnemius

Correct Answer: Semimembranosus and medial gastrocnemius

Explanation:

DISCUSSION: Burks and Schaffer described an approach to the tibial insertion of the posterior cruciate ligament that uses the interval between the semimembranosus and the medial gastrocnemius. The medial gastrocnemius muscle is retracted laterally and protects the neurovascular bundle. This approach is used to repair an avulsion of the posterior cruciate ligament tibial attachment or for performing a posterior cruciate ligament tibial
inlay reconstruction.
REFERENCES: Berg EE: Posterior cruciate ligament tibial inlay reconstruction. Arthroscopy 1995;8:95-99.
Burks RT, Schaffer JJ: A simplified approach to the tibial attachment of the posterior cruciate ligament. Clin Orthop 1990;254:216-219.

Question 7:

-If a physician elects to shorten a femur by 4 cm for traumatic bone loss treatment and places an intramedullary nail for fixation, which deformity will be created in the lower extremity?

Options:

Patella alta
Medial mechanical axis deviation
Lateral mechanical axis deviation
Increased anatomic tibiofemoral angle
Translation of the anatomical axis of the femur

Correct Answer: Medial mechanical axis deviation

Question 8:

Figures 36a and 36b show the MRI scans of a patient who has shoulder weakness. What is the most likely diagnosis?

Options:

Suprascapular nerve entrapment
Supraspinatus and infraspinatus tendon tear
Muscular dystrophy
Thoracic outlet syndrome
Spinal accessory nerve disruption

Correct Answer: Suprascapular nerve entrapment

Explanation:

Question 9:

- What location is the primary source of vascular ingrowth for tendon-bone healing with rotator cuff repair?

Options:

Intra-articular bleeding
Intratendinous layer of the rotator cuff
Articular surface of the rotator cuff
Holes in the greater tuberosity
Bleeding from the decompressed acromion

Correct Answer: Holes in the greater tuberosity

Question 10:

Options:

Complete based on the normalization of his blood pressure, urine output, and heart rate
Cannot be determined based on the data presented
Incomplete based on his fluid requirements calculated using his initial blood pressure as a measure of blood volume loss
Incomplete since he will need surgery on the long bone fractures and should be “tanked up” prior to losing blood in the operating room
Incomplete based on his heart rate

Correct Answer: Cannot be determined based on the data presented

Explanation:

DISCUSSION: Although the end points of resuscitation are still unclear, what is known is that normalization of the standard hemodynamic parameters (blood pressure, heart rate, and urine output) is not adequate. Up to 85% of patients with normal hemodynamic parameters can still have inadequate tissue oxygenation or uncompensated shock. The initial base deficit, lactate level, or gastric pHi can be used to stratify patients for resuscitation needs, risks of death, and multiple organ failure (level 1 evidence). The time it takes to normalize the base deficit, the lactate level, or gastric pHi, can predict survival (level 2 evidence). Patients who have been in uncompensated shock (abnormal vital signs) should have their resuscitation monitored using data other than vital signs.
REFERENCES: Tisherman SA, Barie P, Bokhari F, et al: Clinical practice guideline: Endpoints of resuscitation. J Trauma 2004;57:898-912.
Moore FA, McKinley BA, Moore EE, et al: Inflammation and the Host Response to Injury,
a large-scale collaborative project: Patient-oriented research core--standard operating procedures for clinical care. III. Guidelines for shock resuscitation. J Trauma 2006;61:82-89.
Englehart MS, Schreiber MA: Measurement of acid-base resuscitation endpoints: Lactate, base deficit, bicarbonate or what? Curr Opin Crit Care 2006;12:569-574.

Question 11:

Options:

exploration and repair of the radial nerve if clinical findings or electromyographic studies show no improvement at 2 to 3 weeks.
exploration and repair of the radial nerve if clinical findings or electromyographic studies show no improvement at 14 weeks.
transfer of the pronator teres to the extensor carpi radialis brevis if clinical findings or electromyographic studies show no improvement at 14 weeks.
immediate exploration and repair of the radial nerve, along with internal fixation with a plate and screws.
immediate exploration and repair of the radial nerve, along with internal fixation with an intramedullary nail.

Correct Answer: exploration and repair of the radial nerve if clinical findings or electromyographic studies show no improvement at 14 weeks.

Explanation:

Question 12:

Options:

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

Correct Answer: DEXA scan

Explanation:

Question 13:

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

Options:

Osteoid osteoma
Bone island
Spondylolysis
Osteoblastic metastases
Aneurysmal bone cyst

Correct Answer: Osteoid osteoma

Explanation:

Question 14:

Options:

Start IV antibiotics, obtain wound swab for culture, perform irrigation and debridement and retain hardware
Start IV antibiotics, obtain deep soft tissue and bone cultures in OR, perform irrigation and debridement and remove hardware
Obtain wound swab for culture, start IV antibiotics, perform irrigation and debridement and remove hardware
Obtain deep bone and soft tissue cultures in OR, start IV antibiotics, perform irrigation and debridement and remove hardware

Correct Answer: Obtain deep bone and soft tissue cultures in OR, start IV antibiotics, perform irrigation and debridement and remove hardware

Explanation:

Question 15:

Smoking has been associated with lower fusion rates in both cervical and lumbar fusion. Which of the following statements best describes an explanation for these findings?

Options:

Nicotine impairs osteoblast activity, thus interfering with bone remodeling.
The effects of smoking on bone healing are multifactorial and not yet fully understood.
The vasoconstrictive and platelet-activating properties of nicotine inhibit fracture healing.
Nicotine inhibits the function of fibroblasts, red blood cells, and macrophages.
Hydrogen cyanide inhibits oxidative metabolism at the cellular level.

Correct Answer: The effects of smoking on bone healing are multifactorial and not yet fully understood.

Explanation:

Question 16:

Options:

normal reflexes in the upper extremities and hyperreflexia in the lower extremities.
hyperreflexia in the upper extremities and normal reflexes in the lower extremities.
hyperreflexia in the upper extremities and hyporeflexia in the lower extremities.
hyperreflexia in the upper and lower extremities.
hyporeflexia in the upper and lower extremities.

Correct Answer: normal reflexes in the upper extremities and hyperreflexia in the lower extremities.

Explanation:

Question 17:

Options:

Gender
Age
Race
Environment

Correct Answer: Race

Explanation:

Question 18:

Options:

Sex of the patient
Type of health insurance
Child greater than 10 years of age
Acute knee injuries requiring operative treatment
Timing of the referral

Correct Answer: Sex of the patient

Explanation:

Question 19:

Options:

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

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

Explanation:

Question 20:

Which of the following tumors have characteristic chromosomal translocations?

Options:

Ewing’s sarcoma and osteosarcoma
Ewing’s sarcoma and conventional chondrosarcoma
Ewing’s sarcoma and synovial sarcoma
Osteosarcoma and conventional chondrosarcoma
Myeloma and malignant fibrous histiocytoma

Correct Answer: Ewing’s sarcoma and synovial sarcoma

Explanation:

Question 21:

Which of the following factors is associated with failure of arthroscopic excision of the distal clavicle?

Options:

Removal of less than 2 cm of bone
Male gender
Female gender
Diagnosis of osteolysis
Uneven resection of bone

Correct Answer: Uneven resection of bone

Explanation:

Question 22:

- A 75-year-old woman who has groin pain states that she had total hip arthroplasty 15 years ago. The radiograph shown in Figure 40 reveals that the left acetabular component is grossly loose. Revision of the acetabular component should include use of a

Options:

constrained acetabular component
protrusion ring with morselized graft
cemented metal backed acetabular component
cemented all-polyethylene acetabular component
cementless hemispherical component with screw fixation

Correct Answer: cementless hemispherical component with screw fixation

Explanation:

Question 23:

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

Options:

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

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

Explanation:

Question 24:

Options:

Closed reduction and application of a shoulder immobilizer
Open reduction and lesser tuberosity transfer
Hemiarthroplasty placed in anatomic version
Hemiarthroplasty placed in anteversion
Total shoulder arthroplasty

Correct Answer: Hemiarthroplasty placed in anatomic version

Explanation:

Question 25:

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 26:

Options:

C3-4
C4-5
C5-6
C6-7
C7-T 1

Correct Answer: C6-7

Explanation:

DISCUSSION: The patient’s neurologic examination is consistent with a C7 radiculopathy on the right side. In a patient with this symptom complex in the absence of trauma, a cervical disk herniation is the most common etiology for a C7 radiculopathy. There are eight cervical nerve roots and the C7 nerve exits at the C6-7 disk space and is most frequently impinged by a disk herniation at this level.
REFERENCES: Houten JK, Errico TJ: Cervical spondylotic myelopathy and radiculopathy: Natural history and clinical presentation, in Clark CR (ed): The Cervical Spine, ed 4. Philadelphia, PA, Lippincott Williams & Wilkins, 2005, pp 985-990.
Hoppenfeld S: Orthopaedic Neurology: A Diagnostic Guide to Neurologic Levels. Philadelphia, PA, JB Lippincott, 1977, pp 7-43.

Question 27:

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 28:

In the management of an open tibia fracture, what factor is considered most important in preventing deep infection?

Options:

Size of the skin lesion
Degree and the completeness of the debridement
Amount of contamination
Method of fixation
Cultures of the wound

Correct Answer: Degree and the completeness of the debridement

Explanation:

Question 29:

Options:

vibratory and light touch sensation and motor function, and right-sided loss of pain and temperature sensation.
pain and temperature sensation and motor function, and right-sided loss of vibratory and light touch sensation.
pain, temperature, vibratory, and light touch sensation and motor function.
motor function, and right-sided loss of pain, temperature, vibratory, and light touch sensation.
light touch and pain sensation and motor function, and right-sided loss of vibratory and temperature sensation.

Correct Answer: vibratory and light touch sensation and motor function, and right-sided loss of pain and temperature sensation.

Explanation:

DISCUSSION: Brown-Sequard syndrome results from an injury to one half of the spinal cord and is characteristically seen in penetrating injuries. The spinothalamic fibers cross the midline below the level of the lesion, resulting in contralateral loss of pain and temperature sensation. The posterior columns and corticospinal tracts carry vibratory, position, and light touch sensation, as well as motor function from the ipsilateral side of the body. This results in the characteristic neurologic findings seen with Brown-Sequard syndrome.
REFERENCES: Northrup BE, 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, pp 541-549.
Collins RD
: Illustrated Manual of Neurologic Diagnosis. Philadelphia, PA, JB Lippincott, 1962, p 71.

Question 30:

During the application of halo skeletal fixation, the most appropriate position for the placement of the anterior halo pins is approximately 1 cm above the superior orbital rim and Review Topic

Options:

lateral placement, directly within the temporalis muscle.
within the lateral third of the superior orbital rim.
lateral to the superior orbital rim.
medial third of the superior orbital rim.
lateral between the temporalis muscle and zygomatic temporal nerve.

Correct Answer: within the lateral third of the superior orbital rim.

Explanation:

Question 31:

A 28-year-old man has left knee pain after a snow skiing accident. The MRI scan shown in Figure 47 reveals which of the following? Review Topic

Options:

Osteosarcoma
Bucket-handle medial meniscal tear
Lateral collateral ligament tear
Bone bruise
Tibial spine avulsion

Correct Answer: Bone bruise

Explanation:

Question 32:

Flow cytometry of tumors measures the

Options:

Size of cells
Amount of DNA in cells
Nucleus-cytoplasm ratio
Specific DNA sequences
Specific messenger RNA sequences

Correct Answer: Amount of DNA in cells

Explanation:

Question 33:

-What is the most likely mechanism of injury?

Options:

External rotation
Posterior translation
Hyperextension and varus
Anterior translation and internal rotation

Correct Answer: Anterior translation and internal rotation

Explanation:

DISCUSSION FOR QUESTIONS 56 THROUGH 58
The MRI scan shows a bone bruise of the lateral femoral condyle and lateral tibial plateau. This injury pattern is commonly associated with anterior cruciate ligament (ACL) rupture and an abnormal pivot shift test result. Treatment of an ACL tear in a high-demand athlete should consist of ligament reconstruction.In this patient, surgery should be delayed until she regains full range of motion to minimize risk for arthrofibrosis after surgery. Recent analysis has shown that the noncontact mechanism is more consistent with anterior translation, affecting both the medial and lateral compartments. The bone bruise in the lateral femoral condyle occurs more anterior than that of the medial femoral condyle, suggesting that internal rotation has occurred. The external rotation recurvatum test assesses for posterolateral corner injury, and a positive quadriceps active test is consistent with posterior cruciate ligament rupture. An abnormal patellar apprehension test result is suggestive of patellar instability. Nonsurgical treatment is unlikely to result in sufficient stability if this patient returns to sports at her preinjury level of activity.Primary ACL repair is associated with high failure rates. Although the precise mechanism of injury varies,injuries can be broadly classified into contact and noncontact injuries. Noncontact injuries occur with the knee in slight flexion, valgus, and internal rotation, and contact injuries typically involve a lateralside impact producing a valgus force to the knee. The valgus component of noncontact injuries has been thought to cause mainly lateral compartment bone bruising. Posterior translation is the most common mechanism of posterior cruciate ligament rupture, and hyperextension and varus is associated with posterolateral corner injury.

Question 34:

Which of the following is the primary mechanism of polyethylene wear in the hip?

Options:

Fatigue cracking and delamination
Oscillatory fretting
Crevice corrosion
Oxidative degradation
Adhesion and abrasion

Correct Answer: Adhesion and abrasion

Explanation:

DISCUSSION: Although previous theories on acetabular wear implicated fatigue cracking and delamination as primary wear mechanisms, these have actually manifested as major modes of polyethylene wear in knees. The primary mechanism of wear in polyethylene acetabular components appears to be adhesion and abrasion. In an analysis of 128 components retrieved at autopsy or revision surgery, wear appeared to occur mostly at the surface of the components and was the result of large strain plastic deformation and orientation of the surface layers into fibrils that subsequently ruptured during multidirectional motion. It was also shown conclusively that 32-mm heads displayed significantly more wear (volumetric wear) than either 22-mm or
26-/28-mm heads (1-mm increase in size increased volumetric wear by 10%). The wear at the articulating surface was characterized by highly worn polished areas superiorly and less worn areas inferiorly separated by a ridge. Abrasion was very common, occurring after adhesion and plastic deformation of polyethylene fibrils, and abrasion secondary to third-body wear. Wear rates decreased with longer survival of components, indicating a “bedding in” phenomenon, arguing against oxidative and fatigue wear. Crevice corrosion occurs in fatigue cracks with low oxygen tension (under screw heads, etc). Oscillatory fretting consists of cyclical abrading of the outer surface from small movements. Fatigue and delamination is predominant in total knee arthroplasty where stresses are maximum just below the surface of the polyethylene component, causing fatigue over time with subsequent delamination. In contrast, hip wear occurs primarily at the surface of the polyethylene component.
REFERENCES: Jasty M, Goetz DD, Bragdon CR, et al: Wear of polyethylene acetabular components in total hip arthroplasty: An analysis of one hundred and twenty-eight components retrieved at autopsy or revision operations. J Bone Joint Surg Am 1997;79:349-358.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 47-53.
Bell CJ, Walker PS, Abeysundera MR, et al: Effect of oxidation on delamination of
ultrahigh-molecular-weight polyethylene tibial components. J Arthroplasty 1998;13:280-290.
Sutula LC, Collier JP, Saum KA, et al: The Otto Aufranc Award: Impact of gamma sterilization on clinical performance of polyethylene in the hip. Clin Orthop 1995;319:28-40.

Question 35:

Options:

an extra-depth shoe with an accommodative orthosis.
surgical debridement and metatarsal head resection.
posterior tibial tendon transfer through the interosseous membrane.
Achilles tendon lengthening and total contact casting.
hyperbaric oxygen therapy.

Correct Answer: Achilles tendon lengthening and total contact casting.

Explanation:

Question 36:

Options:

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

Correct Answer: Remove fixation and repeat vascular exam

Explanation:

Question 37:

Options:

activity limitations because of localized pain.
the likelihood of development of malignant degeneration in adulthood.
the likelihood of development of a growth deformity.
ambiguity regarding the diagnosis based on the imaging studies.
obvious progression over the past 5 years, raising suspicion of malignant degeneration.

Correct Answer: activity limitations because of localized pain.

Explanation:

Question 38:

Options:

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

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

Explanation:

Question 39:

Options:

genetic screening.
routine serum electrolytes and CBC count.
whole body bone scan.
MRI of the brain and cervical spine.
CT scan of the abdomen and pelvis.

Correct Answer: MRI of the brain and cervical spine.

Explanation:

Question 40:

Options:

Infection
Complex regional pain syndrome with associated osteopenia
Frozen shoulder
Failed rotator cuff repair
Acromioclavicular joint arthritis

Correct Answer: Failed rotator cuff repair

Explanation:

Question 41:

Options:

removal of the halo vest, followed by observation if the patient remains asymptomatic.
use of the halo vest for an additional 4 weeks, followed by repeat radiographs.
placement of one odontoid screw and the addition of bone graft.
placement of two odontoid screws.
posterior fusion at C1-2.

Correct Answer: posterior fusion at C1-2.

Explanation:

Question 42:

Options:

Closed reduction and a long arm cast
Closed reduction, a long arm cast, and a skeletal survey
Closed reduction, a long arm cast, a skeletal survey, and a referral to child protective services
Closed reduction and a long arm cast, a bone scan, and referral to child protective services
Closed reduction and a long arm cast, MRI of the brain, and a referral to child protective services

Correct Answer: Closed reduction, a long arm cast, a skeletal survey, and a referral to child protective services

Explanation:

Question 43:

Options:

cervical spine radiographs.
MRI of the shoulder.
decompressive osteotomy of the clavicle.
microsurgical repair of the brachial plexus.
observation and range-of-motion exercises.

Correct Answer: observation and range-of-motion exercises.

Explanation:

Question 44:

Options:

Varus stress
Valgus stress
Torsional loading
Hyperextension of the knee
Contraction of the quadriceps while axially loaded

Correct Answer: Contraction of the quadriceps while axially loaded

Explanation:

Question 45:

Options:

Suprascapular
Infraspinatus branch of the suprascapular
Long thoracic
Axillary
Lateral cord of the brachial plexus

Correct Answer: Axillary

Explanation:

Question 46:

A 20-year-old man has a symptomatic lesion of fibrous dysplasia in the femoral neck. Management should consist of

Options:

curettage, cortical strutting, and internal fixation.
curettage only.
observation.
neoadjuvant chemotherapy.
radiation therapy.

Correct Answer: curettage, cortical strutting, and internal fixation.

Explanation:

Question 47:

Figures 9a and 9b show the radiographs of a 4-year-old child who sustained an elbow injury. What is the most likely complication resulting from this fracture if treated in a cast?

Options:

Elbow stiffness
Nonunion
Osteonecrosis
Varus malunion from overgrowth
Fishtail deformity

Correct Answer: Nonunion

Explanation:

DISCUSSION: The radiographs show a lateral condyle fracture with 2 mm of displacement. As opposed to other pediatric elbow fractures, lateral condyle fractures have a higher incidence of nonunion. This may be due to minimal metaphyseal bone on the distal fragment, the intra-articular nature of the fracture, or from further displacement when treated nonsurgically. These fractures with 2 mm and greater of displacement should be treated with reduction and stabilization. Osteonecrosis and fishtail deformity may be seen in very rare cases of lateral condyle fractures. The incidence is certainly less than the rates of nonunion seen in nonsurgically treated fractures with 2 mm and greater of displacement. Varus malunion from overgrowth and elbow stiffness are more likely seen in fractures treated surgically.
REFERENCES: Pirker ME, Weinberg AM, Hollwarth ME, et al: Subsequent displacement of initially nondisplaced and minimally displaced fractures of the lateral humeral condyle in children. J Trauma 2005;58:1202-1207.
Finnbogason T, Karlsson G, Lindberg L, et al: Nondisplaced and minimally displaced fractures of the lateral humeral condyle in children: A prospective radiographic investigation of fracture stability. J Pediatr Orthop 1995;15:422-425.
Flynn JC: Nonunion of slightly displaced fractures of the lateral humeral condyle in children: An update. J Pediatr Orthop 1989;9:691-696.

Question 48:

Options:

Dorsal cheilectomy
Keller resection arthroplasty
Silastic joint replacement
Hallux metatarsophalangeal arthrodesis
Hallux valgus correction

Correct Answer: Hallux metatarsophalangeal arthrodesis

Explanation:

Question 49:

Options:

Flexor tendons
Lateral band
Lumbrical
Volar plate

Correct Answer: Volar plate

Explanation:

Question 50:

- The familial occurrence of Legg-Calve-Perthes disease may, in some cases, be attributed to

Options:

hypophosphatemia
high dietary cholesterol intake
deficiency of lipoprotein A
deficiency of protein S and protein C
elevated levels of antithrombin III

Correct Answer: deficiency of protein S and protein C

Explanation:

Question 51:

Options:

bridging external callus along the allograft and perpendicular callus at the junction site.
direct osteonal penetration of the allograft with haversian remodeling.
complete incorporation of the allograft with obliteration of the host allograft junction site.
fibrovascular invasion with absence of callus formation.
gap formation with resorption of the allograft surface.

Correct Answer: bridging external callus along the allograft and perpendicular callus at the junction site.

Explanation:

Question 52:

Figures 11a and 11b show the T 2 -weighted MRI scans of the lumbar spine of a 53-year-old woman who has low back and right lower extremity pain. What structure is the arrow pointing to in Figure 11a?

Options:

Ligamentum flavum
Lumbar synovial cyst
Tarlov cyst
Pseudomeningocele
Herniated nucleus pulposus

Correct Answer: Lumbar synovial cyst

Explanation:

DISCUSSION: The arrow is pointing to a cystic-appearing structure with high signal intensity on T
2
-weighted image sequencing. It appears to be contiguous with the hypertrophied right facet joint, which appears to also have high signal intensity. The mass significantly narrows the right lateral recess. The high signal intensity suggests that this is a fluid-filled mass. In addition, the facet joints are degenerative and there is a very mild degree of anterolisthesis on the sagittal image. These findings make a lumbar synovial cyst the most likely diagnosis. Most lumbar juxtafacet cysts are observed at the L4-5 level, extradurally and adjacent to the degenerative facet joint. They may contain synovial fluid and/or extruded synovium. Presentation is indistinguishable from that of a herniated disk. The etiology of spinal cysts remains unclear, but there appears to be a strong association between their formation and worsening spinal instability. They occasionally regress spontaneously and may respond to aspiration and injection of corticosteroids, though there is a high recurrence rate with nonsurgical management. Synovial cysts resistant to nonsurgical management should be treated surgically. If the patient’s symptoms can be attributable to radicular findings, a microsurgical decompression that limits further destabilization should suffice. However, if there is significant low back pain attributable to spinal instability, decompression and fusion remains an appropriate option.
REFERENCES: Banning CS, Thorell WE, Leibrock LG: Patient outcome after resection of lumbar juxtafacet cysts. Spine 2001;26:969-972.
Deinsberger R, Kinn E, Ungersbock K: Microsurgical treatment of juxta facet cysts of the lumbar spine. J Spinal Disord Tech 2006;19:155-160.
Khan AM, Synnot K, Cammisa FP, et al: Lumbar synovial cysts of the spine: An evaluation of surgical outcome. J Spinal Disord Tech 2005;18:127-131.

Question 53:

Options:

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

Correct Answer: Not known when using a mobile-bearing UKA

Explanation:

Question 54:

Options:

Thompson test
External rotation stress test
Anterior drawer test
Squeeze test

Correct Answer: Anterior drawer test

Explanation:

Question 55:

Options:

Silastic arthroplasty
Cheilectomy and soft-tissue interposition arthroplasty
Moberg phalangeal dorsiflexion osteotomy
Bone graft interposition arthrodesis
Waterman first metatarsal dorsal osteotomy

Correct Answer: Bone graft interposition arthrodesis

Explanation:

Question 56:

Options:

A quantitative defect of type I collagen synthesis
A deficiency of vitamin D
Parental abuse
Abnormal osteoclast function
Excess excretion of keratin sulfate in the urine

Correct Answer: A quantitative defect of type I collagen synthesis

Explanation:

Question 57:

When examining a patient with marked hyperreflexia, which of the following findings best suggests that the condition is not caused by a cerivcal spine pathology?

Options:

Positive finger adduction test and finger escape sign
Positive grip and release test and rapid opening and closing of the hand
Positive jaw jerk reflex
Extensor Babinski response
Loss of proprioception in the great toes

Correct Answer: Positive jaw jerk reflex

Explanation:

Question 58:

Why is tendon considered an anisotropic material?

Options:

Young’s modulus is greater than that of bone.
Young’s modulus is greater than that of ligament.
Mechanical properties change with preconditioning.
Intrinsic mechanical properties vary depending on the direction of loading.
Intrinsic mechanical properties vary depending on the rate of loading.

Correct Answer: Intrinsic mechanical properties vary depending on the direction of loading.

Explanation:

DISCUSSION: Anisotropic materials have mechanical properties that vary based on the direction of loading. The relative values of Young’s modulus for tendon, ligament, and bone are not relevant to isotropy. The mechanical properties of tendon do change with preconditioning, but this change is related to viscoelasticity. The intrinsic mechanical properties of tendon do vary with the rate of loading, but this variance is related to viscoelasticity.
REFERENCES: Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 134-180.
Lu L, Kaufman KR, Yaszemski MJ: Biomechanics, in Einhorn TA, O’Keefe RJ,
Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, in press.

Question 59:

Options:

Infection
Chondrolysis
Nonunion
Osteonecrosis
Epiphyseal arrest

Correct Answer: Osteonecrosis

Explanation:

Question 60:

Options:

There is an increased risk of revision surgery with plate fixation.
There is an increased risk of iatrogenic fracture with plate fixation.
There is an increased risk of non-union with plate fixation.
There is an increased risk of iatrogenic fracture with intramedullary nail fixation.
There is an increased risk of hardware failure with nail fixation.

Correct Answer: There is an increased risk of revision surgery with plate fixation.

Explanation:

Question 61:

Which of the following clinical disorders is the result of a mutation in fibroblast growth factor recepter 3 (FGFR3)?

Options:

Cleidocranial dysplasia
Schmid metaphyseal chondrodysplasia
Achondroplasia
Fibrous dysplasia
Camptomelic dysplasia

Correct Answer: Achondroplasia

Explanation:

Question 62:

Options:

Ganglion cyst
Clear cell sarcoma
Epithelioid sarcoma
Epidermal inclusion cyst
Synovial sarcoma

Correct Answer: Clear cell sarcoma

Explanation:

DISCUSSION: The histologic appearance of the soft-tissue lesion reveals compact nests of cells with a clear cytoplasm surrounded by a delicate border of fibrocollagenous tissue. There can be scattered multinucleated giant cells. This is consistent with a clear cell sarcoma, also called malignant melanoma of soft parts. This tumor is usually positive for S-100 and HMB45 (a melanoma-associated antigen). These tumors are frequently found around the foot and ankle. Similar to epithelioid sarcoma, it is usually intimately bound to tendons or tendon sheaths. Often the tumors are present for many years. The classic histologic appearance of this lesion differentiates it from the other choices.
REFERENCES: Enzinger FM, Weiss SW: Soft Tissue Tumors, ed 3. St Louis, MO, Mosby, 1995, p 913.
Lucas DR, Nascimento AG, Sim FH: Clear cell sarcoma of soft tissues: Mayo Clinic experience with 35 cases. Am J Surg Pathol 1992;16:1197-1204.

Question 63:

Options:

Crescent fracture located on the side of impact
Widened anterior SI joint, disrupted sacrotuberous and sacrospinous ligaments with intact posterior SI ligaments
Complete SI disruption with lateral displacement
Sacral compression fracture on side of impact with transverse pubic rami fractures
Open-book injury with contralateral sacral compression fracture

Correct Answer: Open-book injury with contralateral sacral compression fracture

Explanation:

Question 64:

Figures 20a and 20b show the sagittal and coronal T1-weighted MRI scans of a patient’s left knee. Abnormal findings include

Options:

enchondroma of the proximal tibia.
a bone bruise of the lateral femoral condyle.
a tear of the lateral collateral ligament.
a tear of the discoid lateral meniscus.
a physeal fracture of the proximal femur.

Correct Answer: a tear of the discoid lateral meniscus.

Explanation:

Question 65:

An olecranon fracture-dislocation of the elbow in which the fracture line exits distal to the coronoid process is best managed by open reduction and

Options:

tension band wire fixation of the olecranon.
plate fixation of the olecranon.
elbow bridging external fixation
transarticular Kirschner wire fixation.
cast immobilization.

Correct Answer: plate fixation of the olecranon.

Explanation:

DISCUSSION: Fracture-dislocations of the elbow present difficult management problems. Standard olecranon fractures normally are not associated with a dislocation; however, the surgeon needs to recognize that some fractures that have a dislocation, in particular a posterior dislocation, represent a Monteggia equivalent. These injuries are not ulnar shaft fractures because they are fractured at or just distal to the coronoid; however, because of the unstable fracture-dislocation, the forces across this reduction are high. Two Kirschner wires and a tension band wire provide inadequate fixation. Therefore, the preferred method of fixation is plate osteosynthesis with a 3.5-mm low-contact dynamic compression plate or reconstruction plate.
REFERENCES: Jupiter JP, Kellam JF: Fractures of the forearm, in Browner BD, Jupiter JP, Levine AM, Trafton P (eds): Skeletal Trauma, ed 2. Philadelphia, PA, WB Saunders, 1998,
pp 421-454.
Quintero J: Fracture of the forearm, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 323-337.
Jupiter JB, Leibovic SJ, Ribbans W, Wilk RM: The posterior Monteggia lesion. J Orthop Trauma 1991;5:395-402.

Question 66:

The underlying cause of the neoplasm is

Options:

ALK gene rearrangement.
a nongerm-cell mutation of the GNAS1 gene.
a germline alteration in EXT1 and EXT2.
an abnormality arising from the translocation t(11;14)(q13;q32).

Correct Answer: a nongerm-cell mutation of the GNAS1 gene.

Explanation:

DISCUSSION
The bone scan reveals multiple bone lesions, which does not rule out any of the responses. The radiographs reveal dysplastic bone with a “ground glass” appearance, suggesting fibrous dysplasia as the preferred response. Multiple myeloma typically demonstrates purely lytic, “punched out” lesions and would be highly unusual in a 23-year-old woman. Multiple hereditary exostosis would demonstrate more expansile lesions concentrated in the metaphysis. Metastatic carcinoma could have a lytic or blastic appearance but is less likely to occur in a 23-year-old woman.
McCune-Albright syndrome in polyostotic fibrous dysplasia is present in as many as 50% of patients and should be evaluated for during an endocrine consultation. Adrenal, pituitary, parathyroid, and thyroid endocrinopathies may be present. Untreated hyperthyroidism can be life threatening during a surgical procedure. There is no indication to repeat the nuclear bone scan. Although phosphate wasting and, rarely, oncogenic osteomalacia have been reported in polyostotic fibrous dysplasia, an endocrinology consultation always should be sought.
Café au lait macules are the most common extraskeletal manifestation of fibrous dysplasia, often referred to as “coast of Maine” in appearance because of their irregular borders (in comparison to the “Coast of California” with smooth borders as seen in neurofibromatosis). Multiple myeloma would not ordinarily appear with increased uptake on a bone scan unless a pathologic fracture of some duration were present. A long area of bone involvement would not appear in patients with metastatic lung adenocarcinoma.
An ALK rearrangement occurs in nonsmall-cell lung cancer. The translocation t(11;14)(q13;q32) should be recognized as a poor prognosticator in multiple myeloma. The germline alteration in EXT1 and EXT2 occurs in multiple hereditary exostosis.
All forms of fibrous dysplasia are caused by a nongerm-cell mutation that occurs during early embryogenesis. A missense mutation of the GNAS1 gene, which encodes the alpha subunit of the stimulatory G-protein-couple-receptor, Gs alpha, results in G-protein activation and the production of cyclic adenosine monophosphate affecting melanocytes, endocrine cells, and osteoprogenitor cells.
RECOMMENDED READINGS
DiCaprio MR, Enneking WF. Fibrous dysplasia. Pathophysiology, evaluation, and treatment. J Bone Joint Surg Am. 2005 Aug;87(8):1848-64. Review.
View Abstract at PubMed
Parekh SG, Donthineni-Rao R, Ricchetti E, Lackman RD. Fibrous dysplasia. J Am Acad Orthop Surg. 2004 Sep-Oct;12(5):305-13. Review. PubMed PMID: 15469225.
View Abstract at PubMed
Shin HJ, Kim K, Lee JJ, Song MK, Lee EY, Park SH, Kim SH, Jang MA, Kim SJ, Chung JS. The t(11;14)(q13;q32) translocation as a poor prognostic parameter for autologous stem cell transplantation in myeloma patients with extramedullary plasmacytoma. Clin Lymphoma Myeloma Leuk. 2015 Apr;15(4):227-35. doi: 10.1016/j.clml.2014.12.007. Epub 2014 Dec 12.
View Abstract at PubMed
Esfahani K, Agulnik JS, Cohen V. A Systemic Review of Resistance Mechanisms and Ongoing Clinical Trials in ALK-Rearranged Non-Small Cell Lung Cancer. Front Oncol. 2014 Jul 21;4:174. doi: 10.3389/fonc.2014.00174. eCollection 2014. Review. PubMed PMID: 25101240.
View Abstract at
PubMed

Question 67:

What do the T2-weighted, fat-saturated MRI scans shown in Figures 1 through 4 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:

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 68:

Options:

immediate split-thickness skin grafting.
immediate Xenograft application.
a vacuum-assisted closure device.
dressing changes with sulfasalazine cream.
a cross-leg flap.

Correct Answer: a vacuum-assisted closure device.

Explanation:

Question 69:

Wear particles of ultra-high molecular weight polyethylene that are generated by total hip implants are predominantly of what diameter?

Options:

Less than 1 micron
10 to 50 microns
100 to 200 microns
500 to 750 microns
Greater than 1,000 microns

Correct Answer: Less than 1 micron

Explanation:

Question 70:

Options:

Bed rest
External orthosis
Anterior corpectomy and arthrodesis
Posterior instrumented arthrodesis
Posterior decompression and instrumented arthrodesis

Correct Answer: External orthosis

Explanation:

Question 71:

The best definitive treatment for this patient’s left knee is

Options:

total knee replacement.
knee arthrodesis using an anterior plate and screws.
knee arthrodesis using an external fixator.
observation.

Correct Answer: observation.

Explanation:

Question 72:

Closed-chain exercise differs from open-chain exercise in which of the following ways?

Options:

Distal portion of the extremity is free during exercise
More commonly used in upper extremity exercise
Predictable movement is produced by co-contraction of muscles
Joint compression is decreased
Usually involves a single joint

Correct Answer: Predictable movement is produced by co-contraction of muscles

Explanation:

Question 73:

Which of the following benign bone lesions can develop lung metastases?

Options:

Chondroblastoma
Chondromyxoid fibroma
Fibrous dysplasia
Aneurysmal bone cyst
Desmoplastic fibroma

Correct Answer: Chondroblastoma

Explanation:

Question 74:

Figure 62 is an arthroscopic view of the intercondylar notch of a right knee from an anterolateral portal. What is the main function of the structure delineated by the black asterisks? Review Topic

Options:

Resist anterior translation during knee flexion
Resist posterior translation during knee flexion
Resist rotatory loads during knee flexion
Resist rotatory loads during knee extension

Correct Answer: Resist rotatory loads during knee extension

Explanation:

Question 75:

Options:

application of a long leg splint and admission to the hospital for further evaluation and consultation.
application of a long leg cast, with follow-up radiographs in 3 days.
immediate application of a spica cast under general anesthesia.
a CBC, an erythrocyte sedimentation rate, blood cultures, aspiration of the distal femur for culture, and hospital admission with administration of IV antibiotics if required.
a CBC, an erythrocyte sedimentation rate, a technetium bone scan, and consultation for bone marrow aspiration.

Correct Answer: application of a long leg splint and admission to the hospital for further evaluation and consultation.

Explanation:

Question 76:

Which of the following alternatives to autogenous bone grafting functions through osteoinduction?

Options:

Allograft
Tricalcium phosphate
Calcium phosphate
Calcium sulfate
Bone morphogenetic protein

Correct Answer: Bone morphogenetic protein

Explanation:

Question 77:

Which of the following is not a reported mode of failure for a constrained acetabular component?

Options:

Loosening of the acetabular component
Disengagement of the constraining ring (with or without redislocation)
Increased abrasive (polyethylene) wear
Dissociation of the femoral head from the neck
Dissociation of the polyethylene liner from the acetabular shell

Correct Answer: Increased abrasive (polyethylene) wear

Explanation:

Question 78:

Options:

debridement and repair.
cast immobilization.
aggressive overload eccentric strengthening.
ice massage and continued athletic participation.
steroid injection.

Correct Answer: debridement and repair.

Explanation:

Question 79:

Options:

Continue physical therapy
Latissimus dorsi transfer
Arthroscopic rotator cuff repair
Pectoralis major transfer
Reverse total shoulder arthroplasty

Correct Answer: Pectoralis major transfer

Explanation:

Question 80:

One advantage of using onlay strut allograft in femoral revision surgery is that it can

Options:

provide some structural support to host bone.
provide better osteoconductive properties than cancellous graft.
completely incorporate into the host femur to restore bone stock.
be used for cavitary defects of the femur.
be used as a primary structural support for the femoral component.

Correct Answer: provide some structural support to host bone.

Explanation:

Question 81:

An 80-year-old woman notes a painless mass posterior to her left knee. MRI scans are shown in Figures 31a and 31b. What is the best course of action?

Options:

Observation
Medical management
Needle biopsy
Incisional biopsy
Resection

Correct Answer: Observation

Explanation:

DISCUSSION: The MRI scans show a popliteal cyst (Baker’s cyst) in its most common location. The cyst emerges from the knee joint between the medial head of the gastrocnemius muscle and the tendon of the semimembranosus muscle. These images are diagnostic; therefore, no further work-up is indicated. Since the patient is asymptomatic, no treatment is necessary.
REFERENCES: Dlabach JA: Nontraumatic soft tissue disorders, in Canale ST (ed): Campbell’s Operative Orthopaedics, ed 10. Philidelphia, PA, Mosby, 2003, vol 1, pp 885-969.
Fritschy D, Fasel J, Imbert JC, et al: The popliteal cyst. Knee Surg Sports Traumatol Arthrosc 2006;14:623-628.

Question 82:

A 28-year-old man reports an episode of buckling and giving-way of his right knee. Figure 54a and 54b show a radiograph and sagittal MRI scan. What is the most likely diagnosis? Review Topic

Options:

Anterior cruciate ligament rupture
Posterior cruciate ligament rupture
Quadriceps tendon rupture
Patellar tendon rupture
Displaced bucket-handle meniscus tear

Correct Answer: Patellar tendon rupture

Explanation:

Question 83:

Options:

Brostrom procedure
Syndesmosis repair or stabilization
Allograft lateral ligament reconstruction
Excision of loose body/fracture fragment
Repair of the SPR with possible fibular groove deepening

Correct Answer: Syndesmosis repair or stabilization

Explanation:

DISCUSSION FOR QUESTIONS 107 AND 108:
The fracture at the insertion of the AITFL into the fibula represents a syndesmosis injury. In some cases, a direct repair of the fracture will stabilize the syndesmosis, but in most cases this injury should most likely be reinforced by placing a screw or suture tensioning device across the syndesmosis for additional support.A Brostrom or allograft reconstruction is indicated for an ankle sprain involving the ATFL or CFL.Simply excising the fragment will leave the patient with an incompetent syndesmosis. Repairing the SPR with or without a groove deepening procedure is indicated if there is evidence of subluxated or dislocated peroneal tendons, which is not demonstrated on the CT scans. The bone has been avulsed off the fibula by the portion of the AITFL that attaches to the fibula, therefore indicating that there is a syndesmosis injury. Allograft lateral ligament reconstruction and excision of loose body/fracture fragment are incorrect procedures based on location. The deltoid is a medial structure and this fracture is lateral. The ATFL and CFL attach at the inferior margin of the fibula near the lateral process of the talus and calcaneus. A SPR avulsion would present as an avulsion off the lateral wall of the fibula, not superior and not into the syndesmotic space as shown on the CT scans.

Question 84:

It is important to avoid which of the following exercises in the immediate postoperative period after humeral head replacement for an acute four-part fracture?

Options:

Pendulum exercises
External rotation with a stick
Passive forward elevation
Active forward elevation
Active range of motion of the elbow, wrist, and hand

Correct Answer: Active forward elevation

Explanation:

Question 85:

Options:

Total shoulder arthroplasty
Hemiarthroplasty with glenoid interposition
Surface replacement hemiarthroplasty
Arthroscopic debridement
Anti-inflammatory drugs and a range-of-motion stretching program

Correct Answer: Anti-inflammatory drugs and a range-of-motion stretching program

Explanation:

Question 86:

Options:

Further rehabilitation
Corticosteroid injection
Reconstruction of the medial collateral ligament
Subcutaneous transposition of the ulnar nerve
Arthroscopic debridement of medial osteophytes

Correct Answer: Subcutaneous transposition of the ulnar nerve

Explanation:

Question 87:

The peroneus tertius is a commonly used landmark for arthroscopic portal placement. What is the function of this tendon?

Options:

Dorsiflexion
Eversion
Dorsiflexion and eversion
Fifth toe extension
Lesser toe extension

Correct Answer: Dorsiflexion and eversion

Explanation:

DISCUSSION: The peroneus tertius, although absent in 10% of the population, originates on the distal third of the extensor surface of the fibula and inserts onto the base of the fifth metatarsal, possibly extending to the fascia over the fourth interosseous space. The muscle is located in the anterior compartment of the leg and is innervated by the deep peroneal nerve. The tendon produces dorsiflexion and eversion when walking and can be used as an insertion point during tendon transfers to assist dorsiflexion. This tendon is peculiar to humans and is a proximally migrated deep extensor of the fifth toe.
REFERENCES: Joshi SD, Joshi SS, Athavale SA: Morphology of the peroneus tertius muscle.
Clin Anat 2006;19:611-614.
Williams PL, Bannister LH, Berry MM, et al (eds): Gray’s Anatomy, ed 38. London, Churchill Livingston, 1995, p 883.
Hansen ST Jr: Functional Reconstruction of the Foot and Ankle. Philadelphia, PA, Lippincott Williams & Wilkins, 2000, p 21.

Question 88:

Options:

physical therapy.
doxycycline.
ciprofloxacin.
nonsteroidal anti-inflammatory drugs.
gentamicin.

Correct Answer: doxycycline.

Explanation:

Question 89:

Options:

Fracture displacement or subluxation leading to neurologic injury
Symptomatic epidural hematoma
Sepsis and death
Permanent nerve root injury and neurologic deficit
Loss of bowel or bladder control
Spinal cord injury

Correct Answer: Symptomatic epidural hematoma

Explanation:

DISCUSSION
Cauda equina syndrome, typically the result of severe central canal stenosis in the lower lumbar region, often is caused by a large central disk herniation. Symptoms include severe back or leg pain, perineal numbness, possible motor weakness, and initial urinary retention followed by an overflow incontinence. When bowel or bladder deficits are present, this is considered a surgical emergency because successful recovery is most likely if decompression occurs within the first 48 hours.
Ankylosing spondylitis can lead to progressive autofusion of the vertebrae and significant limitation in motion. Any sudden improvement in motion should be considered a fracture until proven otherwise. These fractures are commonly missed when using plain radiographs or even CT scan because minimal or no displacement often is noted. MR imaging can be useful to identify edema at
the fracture site. These fractures are typically very unstable and necessitate surgery to avoid displacement and potential neurologic injury.
Some fractures associated with ankylosing spondylitis can be effectively treated with percutaneous pedicle screw fixation. However, because of the highly vascular nature of some of these fractures, they pose risk for an epidural hematoma, potential neurologic deficit, and emergent decompression.
RECOMMENDED READINGS
Patel AR, Alton TB, Bransford RJ, Lee MJ, Bellabarba CB, Chapman JR. Spinal epidural abscesses: risk factors, medical versus surgical management, a retrospective review of 128 cases. Spine J. 2014 Feb 1;14(2):326-30. doi: 10.1016/j.spinee.2013.10.046. Epub 2013 Nov 12. PubMed PMID: 24231778.
View
Abstract at PubMed
Mathews M, Bolesta MJ. Treatment of spinal fractures in ankylosing spondylitis. Orthopedics. 2013 Sep;36(9):e1203-8. doi: 10.3928/01477447-20130821-25. PubMed PMID: 24025014.
View Abstract at PubMed
McCarthy MJ, Aylott CE, Grevitt MP, Hegarty J. Cauda equina syndrome: factors affecting long-term functional and sphincteric outcome. Spine (Phila Pa 1976). 2007 Jan 15;32(2):207-

Question 90:

Options:

A cast and weight bearing as tolerated
A brace and an ultrasound bone stimulator
Intramedullary nailing
Open reduction and plate fixation with bone grafting
Fibular osteotomy

Correct Answer: Open reduction and plate fixation with bone grafting

Explanation:

Question 91:

Options:

Lateral meniscus repair
Corticosteroid injection and physical therapy
Medial meniscus repair
Unloader brace

Correct Answer: Medial meniscus repair

Explanation:

The MRI scan shows a posterior horn medial meniscus root avulsion with bony edema at the tibial root insertion. The radiograph shows no significant degenerative changes. If left untreated, posterior meniscal
root tears lead to progressive degenerative changes as a result of the altered tibiofemoral contact pressures and areas. Nonsurgical treatment including injections, physical therapy, and unloader braces are more
appropriate in the older patient with pre-existing advanced degenerative changes.

Question 92:

What is the preferred treatment of a symptomatic curly toe deformity in a 6-year-old child?

Options:

Observation
Tape the toe to the adjacent toes for 8 weeks
Tenotomy of the flexor tendons
Transfer of the flexor tendons to the extensor mechanism
Arthrodesis of the proximal interphalangeal joint

Correct Answer: Tenotomy of the flexor tendons

Explanation:

DISCUSSION: While some curly toe deformities spontaneously improve in younger children, the deformity is likely to persist in a 6-year-old child. Taping techniques result in no change or only a temporary decrease in deformity. Studies have shown that simple flexor tenotomy is as effective as flexor tendon transfer. Arthrodesis is rarely indicated.
REFERENCES: Hamer A, Stanley D, Smith TW: Surgery for curly toe deformity: A
double-blind, randomized, prospective trial. J Bone Joint Surg Br 1993;75:662-663.
Ross ER, Menelaus MB: Open flexor tenotomy for hammer toes and curly toes in childhood.
J Bone Joint Surg Br 1984;66:770-771.

Question 93:

Options:

An absolute decrease in aerobic capacity
A decrease in capillary density in the trained muscles
A significant increase in strength
A significant improvement in Vo 2max
No change in the cross-sectional area of the trained muscles

Correct Answer: A significant increase in strength

Explanation:

Question 94:

Figure 11 shows the radiograph of an otherwise healthy 22-year-old man who sustained a midfoot injury in a motor vehicle accident 9 days ago. Treatment should consist of

Options:

open reduction and internal fixation.
a short leg weight-bearing cast.
a short leg non-weight-bearing cast.
first tarsometatarsal fusion.
functional brace application and early range of motion.

Correct Answer: open reduction and internal fixation.

Explanation:

DISCUSSION: The dislocation is between the medial and middle cuneiform. Although the first and second tarsometatarsal joints are aligned, there is a gap between the cuneiforms. The radiograph shows a Lisfranc dislocation variant. In a healthy active individual, open reduction and internal fixation yields the best results. The reestablishment of the normal arch and medial column support with anatomic reduction is critical to obtaining the best possible outcome from these injuries.
REFERENCES: Teng AL, Pinzur MS, Lomasney L, et al: Functional outcome following anatomic restoration of the tarsal-metatarsal fracture dislocation. Foot Ankle Int
2002;23:922-926.
Kuo RS, Tejwani NC, DiGiovanni CW, et al: Outcome after open reduction and internal fixation of Lisfranc joint injuries. J Bone Joint Surg Am 2000;82:1609-1618.

Question 95:

Options:

MRI scan
Bone scan
Arthrogram
Axillary lateral radiograph
CT arthrogram

Correct Answer: Axillary lateral radiograph

Explanation:

Question 96:

- A 47-year-old woman who reports mild, aching pain in her knee has no history of trauma. Examination of the knee is normal. Figure 23a shows the AP radiograph. A bone scan shows increased uptake at this site only. Figure 23b shows the CT scan, and Figure 23c shows the histology from the CT scan-guided needle biopsy. Treatment should include

Options:

extended curettage and polymethylmethacrylate cementation
extra-articular resection of the knee and an allograft arthrodesis
wide resection of the proximal tibia and custom prosthetic replacement
prophylactic internal fixation and postoperative irradiation
excision of the lateral condyle and reconstruction with a hemicondylar allograft

Correct Answer: extended curettage and polymethylmethacrylate cementation

Explanation:

Question 97:

What percent of patients initially diagnosed with classic, high-grade osteosarcoma of the extremity have visible evidence of pulmonary metastasis on CT of the chest?

Options:

5% to 10%
10% to 20%
40% to 50%
60% to 80%
80% to 90%

Correct Answer: 10% to 20%

Explanation:

Question 98:

Options:

When the patient is medically stable for surgery
When the MRI scans show multisegmental high-intensity intramedullary signal changes on T2-weighted sequences
When he reaches a Nurick grade of IV for his preoperative neurologic function
When he reports neck and/or extremity pain that becomes intolerable or not controlled by medication
When he develops bowel or bladder incontinence

Correct Answer: When the patient is medically stable for surgery

Explanation:

Question 99:

Options:

CROW walker
Hyperbaric oxygen treatment
Triple arthrodesis with Achilles tendon lengthening
Transtibial amputation
Ankle arthrodesis

Correct Answer: Triple arthrodesis with Achilles tendon lengthening

Explanation:

Question 100:

- A 17-year old boy who sustained a closed clavicle fracture after he was ejected from an all-terrain vehicle was treated with a figure-of-8 brace 1 year ago. He now reports continuous pain at the site of the fracture and is unable to actively raise his arm above his head. A radiograph is shown in Figure 1. Management should now include

Options:

an onlay bone graft
electrical stimulation
resection of the distal clavicle
plate fixation and a bone graft
smooth Kirschner wire fixation and a bone graft

Correct Answer: smooth Kirschner wire fixation and a bone graft

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

Orthopedic Surgery Board Review MCQs: Shoulder, Elbow, Knee, & Ligament | Part 45

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 45

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index