Orthopedic Board Review MCQs: OITE & AAOS Part 219

About This Board Review Set

This is Part 219 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

This set has been strictly audited and contains 100 100% verified, high-yield multiple-choice questions (MCQs) modelled on the exact format of the Orthopaedic In-Training Examination (OITE) and the American Academy of Orthopaedic Surgeons (AAOS) board examinations.

How to Use the Interactive Quiz

Two distinct learning modes are available:

Study Mode — After selecting an answer, you immediately see whether you are correct or incorrect, together with a full clinical explanation and literature references.
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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 219

This module focuses heavily on: Foot, Fracture, Hip, Ligament.

Sample Questions from This Set

Sample Question 1: What complication is more likely following excessive medial retraction of the anterior covering structures during the anterolateral (Watson-Jones) approach to the hip?...

Sample Question 2: In the treatment of intra-articular calcaneal fractures, surgical reduction and fixation has been shown to have improved outcomes over nonoperative treatment in all of the following patient groups EXCEPT:...

Sample Question 3: 04 Which of the following laboratory studies is predictive of wound healing prior to performing a lower extremity amputation?...

Sample Question 4: Figure 16 shows the lateral radiograph of a patient who is scheduled to undergo an anterior cruciate ligament (ACL) reconstruction. If the graft is tensioned at 20° of flexion and the femoral tunnel is created by passing a reamer over the g...

Sample Question 5: Which of the following imaging modalities is most accurate in locating a toothpick in the plantar arch of the foot?...

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

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

Explanation

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

Question 2

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

Explanation

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

Question 3

04 Which of the following laboratory studies is predictive of wound healing prior to performing a lower extremity amputation?

Explanation

A serum albumin level of below 3.5 g/dl indicates malnourished patient. An absolute lymphocyte count below 1500/mm3 is a sign of immune deficiency. If possible, amputation surgery should be delayed in such patients. An absolute Doppler pressure of 70 mm Hg is the minimum inflow level. The ischemic index is the ratio of the Doppler pressure at the level being tested to the brachial systolic pressure. Genreally accepted to require an ischemic index of 0.5 or greater. Transcutaneous partial pressure of oxygen (TcpO2) is the present gold standard of vascular inflow. TcpO2 values of 40 mm Hg correlate with acceptable wound healing
(eliminates false positive predictions with using area under the Doppler waveform). Pressures less than 20 mm Hg are predictive of poor healing. Miller 505-6
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Question 4

Figure 16 shows the lateral radiograph of a patient who is scheduled to undergo an anterior cruciate ligament (ACL) reconstruction. If the graft is tensioned at 20° of flexion and the femoral tunnel is created by passing a reamer over the guide wire marked “A,” the resulting ligament reconstruction will excessively

Explanation

DISCUSSION: If the femoral tunnel is created using guide wire A, it will be too far anterior in the intercondylar notch. The distance between a central tibial insertion for the ACL and an anterior femoral tunnel will progressively increase as the knee is flexed. Therefore, if the graft is tensioned near extension, the ligament will excessively tighten as the knee flexes past 90°. This will result in restricted knee flexion or failure of the graft as full flexion is gained. There will be little effect on the ligament as it extends from 20° to 0° of flexion. If the graft is tensioned in significant flexion (greater than 60°), it will be excessively loose as the knee fully extends.
REFERENCES: Daniel DM, Fritschy D: Anterior cruciate ligament injuries, in DeLee JC, Drez D Jr (eds): Orthopaedic Sports Medicine: Principles and Practice. Philadelphia, PA, WB Saunders, 1994, pp 1313-1360.
Larson RL, Tailon M: Anterior cruciate ligament insufficiency: Principles of treatment. J Am Acad Orthop Surg 1994;2:26-35.

Question 5

Which of the following imaging modalities is most accurate in locating a toothpick in the plantar arch of the foot?

Explanation

DISCUSSION: Ultrasound is best at imaging abrupt changes in the density of adjacent tissue and therefore is best at imaging wood in the soft tissues of the foot.
REFERENCES: Mizel MS, Steinmetz ND, Trepman E: Detection of wooden foreign bodies in muscle tissue: Experimental comparison of computed tomography, magnetic resonance imaging, and ultrasonography. Foot Ankle Int 1994;15:437-443.
Jacobson JA, Powell A, Craig JG, et al: Wooden foreign bodies in soft tissue: Detection at US. Radiology 1998;206:45-48.

Question 6

A 33-year old man sustains a posterior elbow dislocation after a fall. Attempts at closed reduction result in recurrent instability. What is the most common ligamentous injury found at the time of surgical stabilization?

Explanation

Classic posterior elbow dislocations result from a posterolateral rotatory mechanism, whereby the hand is fixed (typically on the ground) while the weight of the body creates a valgus and external rotation moment on the elbow. This results first in tearing of the lateral collateral ligament that proceeds medially through the anterior and posterior joint capsules, ending with potential involvement of the ulnar collateral ligament (but this is not universal). McKee and associates assessed the lateral soft-tissue injury pattern of elbow dislocations
with and without associated fractures at the time of surgery. Injury to the lateral collateral ligament complex was seen in every case, with avulsion from the distal humerus as the most common finding. Midsubstance
tears, proximal avulsions, and distal bony avulsions of the ulnar collateral ligament are less common.

Question 7

Compared to metal-on-polyethylene total hip bearing surfaces, the debris particles generated by metal-on-metal articulations are

Explanation

DISCUSSION: Retrieval studies have shown that the debris particles produced by

metal-on-metal articulations in total hip arthroplasty are several orders of magnitude smaller

and may be up to 100 times more numerous than those found with metal-on-polyethylene articulations.
REFERENCES: Davies AP, Willert HG, Campbell PA, et al: An unusual lymphocytic perivascular infiltration in tissues around contemporary metal-on-metal joint replacements.

J Bone Joint Surg Am 2005;87:18-27.
Firkins PJ, Tipper JL, Saadatzadeh MR, et al: Quantitative analysis of wear and wear debris from metal-on-metal hip prostheses tested in a physiological hip joint simulator. Biomed Mater Eng 2001;11:143-157.

Question 8

A 45-year-old man has severe pain in both feet after his boots become wet while hunting. Examination 3 hours after the onset of symptoms reveals that his feet are cold to touch and the skin appears blanched. Management should consist of

Explanation

DISCUSSION: The patient has frostbite involving both feet. Rapid rewarming in a protected environment is the initial treatment. A footbath with water at 104.0 degrees F to 107.6 degrees F (40 degrees C to 42 degrees C) is ideal. This facilitates a uniform rewarming of the involved tissue. The other choices are less than ideal. Appliances such as heating pads provide uneven heating and may actually burn the skin.
REFERENCES: Pinzur MS: Frostbite: Prevention and treatment. Biomechanics 1997;4:14-21.
Fritz RL, Perrin DH: Cold exposure injuries: Prevention and treatment. Clin Sports Med 1989;8:111-128.

Question 9

A 23-year-old man who was the restrained driver in a car involved in a high-speed motor vehicle accident sustained the closed injury shown in Figures 32a through 32c. Which of the following factors has the greatest impact on the risk of osteonecrosis?

Explanation

DISCUSSION: The incidence of osteonecrosis following displaced talar neck fractures is most related to the extent of initial fracture displacement. With increasing fracture displacement, the tenuous vascular supply to the talar body is more at risk for damage, thereby increasing the risk of osteonecrosis. Although displaced talar neck fractures have historically been considered a surgical emergency, recent studies have shown that the timing of surgical intervention bears no impact on the development of osteonecrosis. While nicotine use has an influence on fracture healing, it has never been shown to be a factor in osteonecrosis, nor has posterior-to-anterior screw fixation or the quality of fracture reduction.
REFERENCES: Lindvall E, Haidukewych G, Dipasquale T, et al: Open reduction and stable fixation of isolated, displaced talar neck and body fractures. J Bone Joint Surg Am 2004;86:2229-2234.
Vallier HA, Nork SE, Barei DP, et al: Talar neck fractures: Results and outcomes. J Bone Joint Surg Am 2004;86:1616-1624.

Question 10

Which of the following factors is associated with improved outcomes following surgery for hip fractures?

Explanation

Many studies have looked at patient outcomes following hip fracture surgery. While early surgery in these patients is recommended, medical optimization prior to surgical intervention is warranted in all cases. Anesthetic type and discharge status have not been proven to alter patient outcomes. Total hip arthroplasty has improved function at 1 year compared with hemiarthroplasty; no changes in mortality have been reported.

Question 11

The patient is given a blood transfusion. After starting the transfusion, nurses note that her temperature is 38.8°C and she has shaking and chills. What is the most likely cause of this problem?

Explanation

DISCUSSION
Blood management and venous thromboembolism prevention are important considerations in the perioperative management of THA. Recommendations now focus on presurgical optimization of hemoglobin, use of antifibrinolytics intrasurgically, and minimized use of transfusions. Current recommendations do not favor autologous blood donation for patients with hemoglobin levels higher than 13 g/dL. There is a move toward increased use of aspirin for venous thromboembolism prophylaxis, but this modality can cause GI bleeding that may necessitate blood transfusion. Transfusion reactions are rare, and the most common cause is administration of an incompatible unit because of clerical error.

Question 12

Which of the following aids in correction of patellar tracking after total knee arthroplasty (TKA)?

Explanation

DISCUSSION: Correct patellofemoral tracking has proven to be a crucial aspect in TKA because a large percent of problems after TKA are related to the patellofemoral articulation. External rotation of the femoral and tibial components has been shown to aid in tracking. Likewise, medialization of the patellar button aids in patellar tracking and prevention of lateral subluxations and dislocations. Attention to the distal femoral cut is critical in maintaining the joint line and preventing patella baja or alta. Tibial sizing, however, is not directly related to patellar tracking after TKA.
REFERENCES: Callaghan JJ, Rosenberg AG, Rubash HE, et al (eds): The Adult Knee. Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 1245-1258.
Merkow RL, Soudry M, Insall JN: Patellar dislocation following total knee replacement. J Bone Joint Surg Am 1985;67:1321-1327.

Question 13

A 20-year-old collegiate pitcher sustains a medial collateral ligament (MCL) rupture of his throwing elbow for which surgical reconstruction is necessary. The goal of surgery is anatomic restoration of the MCL. Which statement best describes the kinematics of the native MCL?

Explanation

The anterior bundle is the most important portion of the complex when treating valgus instability of the elbow. The ligament originates from the anteroinferior surface of the medial epicondyle. The anterior bundle inserts on the medial border of the coronoid at the sublime tubercle. The anterior bundle of the medial collateral ligament (MCL) is the primary restraint to valgus stress, and the radial head is a secondary restraint. With anterior bundle sectioning, the resultant instability is most substantial between 60° and 70° and is lowest at
full extension and full flexion. True lateral radiographs reveal that the flexion-extension axis, or center of rotation, of the elbow lies in the center of the trochlea and capitellum. The origin of the anterior bundle of the MCL lies slightly posterior to the rotational center of the elbow. The anterior bundle is further divided into an anterior band and a posterior band. The eccentric origin of these anterior bundle components in relation to the rotational center through the trochlea creates a CAM effect during flexion and extension. The anterior band tightens during extension, and the posterior band tightens during flexion. This reciprocal tightening of the two functional components of the anterior bundle allows the ligament to remain taut throughout the full range of flexion. Cadaver dissection studies have identified the origin and insertion of both the medial and lateral stabilizing elbow ligaments. The anterior bundle of the MCL is isometric throughout the flexion/extension arc of motion, making Response C incorrect. The posterior bundle of the MCL elongates with elbow flexion, so Responses B and D are incorrect. The posterior bundle of the MCL also demonstrates the most change in
length from extension to flexion of all the elbow ligaments.

Question 14

A 26-year-old man is brought to the emergency department unresponsive and intubated after being found lying on the side of the road. He has a Glasgow Coma Scale score of 6. A chest tube has been inserted on the right side of the chest for a pneumothorax. An abdominal CT scan reveals a small liver laceration and minimal intraperitoneal hematoma. A pneumatic antishock garment (PASG) is on but not inflated. He has bilateral tibia fractures. A pelvic CT scan shows an anterior minimally displaced left sacral ala fracture and left superior and inferior rami fractures. He has received 2 L of saline solution and 4 units of blood but remains hemodynamically unstable. What is the next most appropriate step in management?

Explanation

DISCUSSION: There is no identifiable thoracic, abdominal, or long bone source of ongoing bleeding. The patient has a lateral compression Burgess-Young type I pelvic ring injury. This injury does not increase the pelvic volume because it is not unstable in external rotation. Application of a PASG, a pelvic clamp, or an external fixator may be helpful if the patient has a pelvic injury that is unstable in external rotation or translation but would be of little use in this injury pattern. Persistent hemodynamic instability after administration of 4 units of blood is the decision point where most authors would recommend angiography and embolization. If the pelvis is unstable in external rotation or translation, inflation of the PASG trousers or application of an external fixator is recommended before angiography. Attributing the hemodynamic instability to the head injury before ruling out the pelvis as a source is not indicated.
REFERENCES: Burgess AR, Eastridge BJ, Young JW, et al: Pelvic ring disruptions: Effective classification system and treatment protocols. J Trauma 1990;30:848-856.
Evers BM, Cryer HM, Miller FB: Pelvic fracture hemorrhage: Priorities in management. Arch Surg 1989;124:422-424.
Flint L, Babikian G, Anders M, Rodriguez J, Steinberg S: Definitive control of mortality from severe pelvic fracture. Ann Surg 1990;211:703-707.

Question 15

A 3-year-old child sustains a T2/T3 fracture-dislocation with complete paraplegia secondary to a car accident in which the child was an unrestrained passenger. What is the likelihood that this child will develop subsequent spinal deformity in the future?

Explanation

DISCUSSION: More than than 90% of preadolescent children who sustain a significant spinal cord injury subsequently develop scoliosis. Conversely, progressive paralytic spinal deformity is uncommon in the postadolescent patient. Bracing has not been shown to be effective in the prevention of scoliosis in the preadolescent patient with spinal cord injury.
REFERENCES: Mayfield JK, Erkkila JC, Winter RB: Spine deformity subsequent to acquired childhood spinal cord injury. J Bone Joint Surg Am 1981;63:1401-1411.
Dearolf WW III, Betz RR. Vogl LC, et al: Scoliosis in pediatric spinal cord-injured patients. J Pediatr Orthop 1990;10:214-218.
Mehta S, Betz RR. Mulcahey MJ, et al: Effect of bracing on paralytic scoliosis secondary to spinal cord injury. J Spinal Cord Med 2004;27:S88-S92.

Question 16

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease that is characterized by

Explanation

CTE is a neurodegenerative disease that occurs years or decades after recovery from acute or postacute effects of head trauma. The exact relationship between concussion and CTE is not entirely clear; however, early behavioral manifestations of CTE have been described by family and providers to include apathy, irritability, and suicidal ideation. For some patients, cognitive difficulty such as poor episodic memory and executive function may be the first signs of CTE. Onset most often occurs in midlife after athletes have completed their sports careers, with mean age of onset at 42 years. The effects on the brain are degenerative, leading to a permanent state of derangement. Autopsy findings demonstrate multiple gross pathological findings. The condition is more common among contact athletes.

Question 17

A 30-year-old man reports pain and weakness in his right arm. Examination reveals grade 4 strength in wrist flexion and elbow extension, decreased sensation over the middle finger, and decreased triceps reflex. These symptoms are most compatible with impingement on what spinal nerve root?

Explanation

DISCUSSION: Motor impulses to the triceps, wrist flexion and elbow extension, and sensation to the middle finger are associated most commonly with the C7 root.
REFERENCES: Hoppenfeld S: Physical Examination of the Spine and Extremities. Upper Saddle River, NJ, Prentice Hall, 1976, p 125.
Lauerman WC, Goldsmith ME: Spine, in Miller MD (ed): Review of Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 353-378.

Question 18

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

Explanation

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

Question 19

A 20-year-old college pitcher reports medial elbow pain after 3 innings of hard throwing. He recalls no injury and reports no pain with light throwing. The examination shown in the clinical photograph in Figure 48 reproduces the elbow pain. What is the most likely diagnosis?

Explanation

DISCUSSION: The milking test, as seen in the photograph, elicits pain when a tear is present in the medial collateral ligament. Complete rupture is possible but unlikely when there is no history of trauma and the patient is able to throw pain-free for several innings. Subluxation of the ulnar nerve and triceps tendon subluxation present as a painful snapping over the medial aspect of the elbow.
REFERENCES: Williams RJ III, Urquhart ER, Altchek DW: Medial collateral ligament tears in the throwing athlete. Instr Course Lect 2004;53:579-586.
Cain EL Jr, Dugas JR, Wolf RS, et al: Elbow injuries in throwing athletes: A current concepts review. Am J Sports Med 2003;31:621-635.

Question 20

The patient does well initially but returns for the 4-month postsurgical evaluation with ongoing stiffness and pain despite going to physical therapy twice weekly and working on motion at home. She is unable to bear weight comfortably. What is the best next step?

Explanation

DISCUSSION
In a skeletally immature patient with OCD and minor symptoms, the lesion can be observed and healing obtained with activity limitations if the cartilage is stable (but this cannot be determined radiographically or clinically). Activity restriction and serial follow-up are appropriate if an MRI reveals a stable lesion. MRI is indicated when there is concern that a lesion may be unstable. Surgical treatment depends on MRI findings.
Observation is recommended for OCD lesions in growing patients for 6 months because healing has been observed. Early surgical procedures, although they may be needed in the future, are not appropriate for patients with well-controlled symptoms.
If symptoms continue for longer than 6 months, arthroscopic drilling is not indicated for unstable OCD. The appropriate treatment is OCD fixation. Debridement is not appropriate with a stable lesion.
Evaluation of the fixation and stability of the lesion with advanced imaging after weight bearing and therapy initiation is the most appropriate option. Manipulating the knee without determining whether the stiffness is attributable to subsidence of the fixation or mechanical block is not appropriate. After 4 months, aspiration of a hematoma (if still present) would not yield much benefit. More therapy is not likely to be useful when a patient is attending therapy regularly and working on a home program.

Question 21

A 68-year-old man reports a 4-week history of progressive left-sided lower back and hip pain. The pain is in the posterior buttock region with radiation to the groin and to the left anterior knee region. The pain is aggravated with walking and improves with rest. There is no history of previous trauma. Radiographs are seen in Figures 14a and 14b, and MRI scans are seen in Figures 14c through 14e. What is the most appropriate treatment option at this time?

Explanation

DISCUSSION: Although the imaging reveals generalized lumbar spondylosis and stenosis, in particular at L4-5, the MRI scan of the left hip clearly reveals a stress fracture of the femoral neck. Therefore, the treatment of choice is non-weight-bearing of the left lower extremity. During the evaluation of acute back pain, clinicians must include other possibilities within the differential diagnosis that may mimic mechanical axial back pain; thus, potential complications from a missed diagnosis can be avoided.
REFERENCES: Wong DA, Transfeldt E: Macnab’s Backache, ed 4. Philadelphia, PA, Lippincott Williams and Wilkins, 2007, pp 339-361.
Spivak JM, Connolly PJ (ed): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 43-56.

Question 22

A 13-year-old gymnast has had recurrent right elbow pain for the past year. She denies any history of trauma. Rest and anti-inflammatory drugs have failed to provide relief. Examination reveals no localized tenderness and only slight loss of both flexion and extension (10 degrees). What is the most likely diagnosis?

Explanation

DISCUSSION: Osteochondritis of the capitellum is characterized by pain, swelling, and limited motion. Catching, clicking, and giving way also can occur. It commonly affects athletes who participate in competitive sports with high stresses, such as pitching or gymnastics.
REFERENCES: Krijnen MR, Lim L, Willems WJ: Arthoscopic treatment of osteochondritis dissecans of the capitellum: Report of 5 female athletes. Arthroscopy 2003;19:210-214.
Schenck RC, Goodnight JM: Osteochondritis dissecans. J Bone Joint Surg Am 1996;3:439-456.

Question 23

A 22-year-old man sustained a cervical fracture-dislocation of the C5-6 level in a motor vehicle accident along with an associated spinal cord injury. Six months after his injury, he has 4 out of 5 biceps on the left, with 5 out of 5 biceps on the right. Deltoid is graded at 5 out of 5 bilaterally. There is 0 strength in the triceps, wrist flexors, wrist extensors, and digital extensors. He has neurogenic bowel and bladder with absent perianal sensation and no voluntary motor in the lower extremities. The patient's neurologic deficit is best categorized as which of the following? Review Topic

Explanation

The patient has a complete spinal cord injury. The level of a spinal cord injury is determined by the most distal intact (5/5) function. The lowest motor intact level in this patient is C5 based on the described examination. Central spinal cord injury and Brown-STquard injuries are both incomplete patterns of spinal cord injury.

Question 24

A 70-year-old man reports symptomatic medial knee pain that has become progressively worse during the past year. MRI reveals a complex, posterior horn medial meniscus tear with associated medial lateral and patellofemoral cartilage defects. Radiographs reveal medial joint space narrowing and osteophytes in the other compartments. What treatment is most likely to provide long-term, durable relief of symptoms?

Explanation

DISCUSSION:
Total knee replacement is a well-established surgery for diffuse, symptomatic osteoarthritis of the knee joint, and its efficacy has been shown in many studies. According to the 2008 AAOS Clinical Practice Guideline, Treatment of Osteoarthritis of the Knee, arthroscopy in the setting of existing osteoarthritis is efficacious for relieving the signs and symptoms of a torn meniscus but not for osteoarthritis. Likewise, in young and active patients, clinical outcomes show improvement after realignment osteotomy for single-compartment osteoarthritis. Unicondylar knee replacement is not indicated for tricompartmental disease of the knee.

Question 25

Figure 1 shows a radiograph obtained from an active 30-year-old man who sustained an injury to his ring finger 1 week earlier. The most appropriate treatment is

Explanation

EXPLANATION:

Figure 1 reveals evidence of an intra-articular distal phalanx fracture with a distal interphalangeal (DIP) joint dorsal subluxation. This injury is unstable and requires surgical management for an active individual. Volar distal phalanx fractures are often associated with flexor digitorum profundus avulsion injuries, which are addressed concomitantly. This injury was treated with ORIF of the intra-articular fracture, pinning of the DIP joint, and repair of an avulsed flexor digitorum profundus tendon with a button on the dorsal nail plate, as shown in Figure 2. Splint immobilization would not maintain a reduction of this unstable injury. The terminal tendon is not injured in this patient but is often injured in a dorsal distal phalanx fracture with a volar dislocation. Arthrodesis of the DIP is a salvage procedure and would not be considered acutely.

Question 26

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

Explanation

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

Question 27

Figure 46 shows the radiograph of an obese 12-year-old boy who has had left hip pain for the past 3 months. What is the best course of action?

Explanation

DISCUSSION: The patient has an obvious slipped capital femoral epiphysis of the left hip for which the recommended treatment is percutaneus pinning in situ. Development of a contralateral slip is less likely at this age; therefore, observation of the right hip is indicated because there is no general agreement regarding prophylactic fixation. Typically, there is no role for spica casting. Physical therapy is not indicated as a primary treatment, and reduction is contraindicated, as it has been associated with osteonecrosis.
REFERENCES: Loder RT, Aronsson DD, Greenfield ML: The epidemiology of bilateral slipped capital femoral epiphysis: A study of children in Michigan. J Bone Joint Surg Am 1993;75:1141-1147.
Aronsson DD, Karol LA: Stable slipped capital femoral epiphysis: Evaluation and management. J Am Acad Orthop Surg 1996;4:173-181.
Hurley JM, Betz RR, Loder RT, Davidson RS, Alburger PD, Steel HH: Slipped capital femoral epiphysis: The prevalence of late contralateral slip. J Bone Joint Surg Am 1996;78:226-230.
Loder RT, Aronson DD, Dobbs MB, Weinstein SL: Slipped capital femoral epiphysis. J Bone Joint Surg Am 2000;82:1170-1188.

Question 28

Figures 82a through 82c show the radiograph and 3-dimensional (3-D) CT scans of a 2-year-old boy whose scoliosis has progressed 15 degrees during the past year. The child is clinically healthy. He has been walking since 11 months of age. An MRI scan of the entire spine revealed no other anomalies. What additional study is indicated? Review Topic

Explanation

Renal anomalies are found in as many as one-third of patients with congenital scoliosis, so a renal ultrasound should be obtained. There may be other anomalies, including cardiac. There are no other anomalies on MRI, so flexion-extension cervical spine radiographs are not indicated. There is no associated marrow or platelet problem with hemivertebra. There is no indication for blood cultures because this is a noninfection disorder. The radiographs and 3-D CT scans show a hemivertebra scoliosis already beyond 45 degrees. Resection of the hemivertebra with stabilization is the indicated treatment. The scoliosis will get worse with observation and bracing. Fusion posteriorly can only minimally correct and not stop progression of the scoliosis.

Question 29

A 47-year-old obese man with a body mass index of 42 comes into the office with left knee pain 1 year after undergoing an uncomplicated left medial unicompartmental knee arthroplasty (UKA). Radiographs show a loose tibial component in varus. What is the most appropriate next step to treat this failed construct?

Explanation

DISCUSSION:
This patient likely is experiencing failure of the UKA secondary to poor patient selection. In this young, heavy man, the component likely loosened due to the ongoing varus alignment of the knee and his elevated
weight. Despite this likely scenario, the next step is determining whether an infection is the cause of his pain. Prior to obtaining an aspiration, the surgeon can order ESR and CRP studies to determine whether aspiration is warranted. If the laboratory studies are unremarkable, the surgeon likely can forgo the
aspiration and proceed to a revision TKA with possible augments on standby.

Question 30

Bacterial resistance to antibiotics in biofilm is an example of Review Topic

Explanation

Three basic mechanisms of antibiotic resistance have been identified: avoidance, decreased susceptibility, and inactivation. Biofilm formation is a classic example of avoidance, whereby the biofilm creates a physical barrier to the antibiotic. Bacteria can decrease their susceptibility to antibiotics by mutating the antibiotic target or generating a mechanism to inactivate the antibiotic. Biofilm formation develops when a sufficient mass of bacteria forms on a surface. The cell-to-cell signaling becomes sufficient to activate transcription of genes needed for biofilm formation in a process
known as quorum sensing. Once the bacteria produce a mature biofilm, they enter a greatly reduced or stationary phase of growth. Lastly, high-shear environments seem to stimulate biofilm production.

Question 31

A right-handed 35-year old man who underwent a Putti-Platt repair for recurrent anterior instability 20 years ago now has increasing shoulder pain and stiffness. Examination of the shoulder reveals internal rotation to the posterior superior iliac spine and external rotation to 10 degrees with the shoulder adducted. The supraspinatus and infraspinatus are moderately atrophied. What is the most likely diagnosis?

Explanation

Osteoarthrosis of the glenohumeral joint is a potential late complication of the anterior Putti-Platt capsulorrhaphy. Disabling pain in the shoulder began an average of 13.2 after a Putti-Platt repair that had been done for recurrent anterior unidirectional instability. Osteoarthrosis of the glenohumeral joint resulted in substantial limitation of motion. Complications of the Putti-Platt surgery include persistent pain, recurrent subluxation or dislocation, or residual weakness of the shoulder; paresthesias of the musculocutaneous nerve, and infection. This late complication develops when the repair is excessively tight, a 20-25 degree limitation of full external rotation is desired and expected after rehabilitation. The most direct correlation with the severity of osteoarthrosis was the degree of limitation of external rotation.

Question 32

A 40-year-old man with a history of Legg-Calve-Perthes disease underwent a right hip resurfacing 3 years ago with no perioperative complications. Hip pain has developed gradually during the last 4 months. Radiographs show no evidence of fixation loosening or any adverse changes at the femoral neck. No periarticular osteolysis is evident. What is the most appropriate management of this condition?

Explanation

DISCUSSION:
Controversy persists over what exactly is the best approach to managing patients with metal-on-metal (MOM) hip arthroplasties. All patients with painful MOM hip arthroplasties should be examined for fixation loosening, wear/osteolysis, and infection—no differently than patients without MOM hip arthroplasties. It is recommended to obtain serum trace element levels. If the levels are high, cross-sectional imaging should be obtained to determine whether any pseudotumor or tissue necrosis is present around the hip arthroplasty. Hip aspiration should be considered if concern for infection exists. Adverse tissue reaction has been identified to occur around MOM hip arthroplasties. The predominant histologic feature is tissue necrosis with infiltration of lymphocytes and plasma cells.

Question 33

Figures below show the radiographs obtained from a 75-year-old woman who underwent right total hip arthroplasty in 2009. She did well until last month, when a right posterior hip dislocation occurred after she fell from her bed to the floor. Successful closed reduction was performed. She sustained two more posterior dislocations requiring closed reduction under anesthesia. The surgical report from the index arthroplasty notes a 54-mm monoblock acetabular component with a 28-mm inner diameter compression molded polyethylene and a high offset neck cementless stem with a +8-mm length, 28-mm head. What is the best next step?

Explanation

DISCUSSION:
This patient has demonstrated recurrent instability, and her current implants lack the modularity to upsize and improve the head-neck ratio and range to impingement. Given the monoblock acetabular component and a +7-mm neck length, the best option is revision to a large-diameter femoral head or dual-mobility component. Placement of a hip spica cast and resection arthroplasty are unreasonable. Revision to a longer ball length likely would not solve this recurrent instability pattern.

Question 34

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

Explanation

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

Question 35

Figures 1 through 5 are the MR images of a 12-year-old boy with left lateral-sided knee pain following a football injury. He has a several-year history of recurrent knee pain that improves with rest. An examination reveals a moderate effusion. Range of motion is 0° to 90° and is limited by pain in deep flexion. He has tenderness to palpation along the lateral joint line, and no instability is noted. Treatment should include

Explanation

The MR images show a tear through a discoid lateral meniscus. A discoid meniscus is caused by a failure of apoptosis during development in utero and is considered a congenital abnormality. Discoid menisci are prone to tearing and can be caused by minimal trauma. There is no known genetic cause for this condition. Radiographic findings that may be present in the setting of a discoid meniscus include lateral joint space widening, squaring of the lateral femoral condyle, and cupping of the lateral tibial plateau. Contralateral discoid menisci are noted in 20% of patients. There are no other known associated conditions. Treatment of a symptomatic discoid meniscus should include partial meniscectomy and saucerization or repair.

Question 36

below show the radiographs obtained from a year old man with progressively worsening right side hip pain over the last 8 months. He is 6 feet tall, with a BMI of 51 kg/m 2 and reports that his index total hip arthroplasty was performed 8 years ago. The preoperative work-up includes negative infectious laboratory results. What is the most appropriate surgical plan for revision of the femoral component in this patient?

Explanation

DISCUSSION:
Submit Answer
The patient’s radiographs demonstrate varus femoral remodeling around a broken cylindrical, distally fixed femoral stem. Proximal femoral remodeling around loose or fractured stems occurs in 21% to 42% of femoral revisions, based on the definitions outlined by Foran and associates. In definition 1, varus femoral remodeling occurs when the template falls within 2 mm of the endosteal cortex of the metaphysis on templating with a diaphyseal engaging stem. In definition 2, varus femoral remodeling = when the template crosses the lateral femoral cortex proximally. Based on the templating or drawing a line from the isthmus proximally along the lateral cortex, implantation of a straight stem would perforate the cortex proximally, indicating varus femoral remodeling. An extended trochanteric osteotomy would aid in the removal of the well-fixed distal segment and enable the safe insertion of the new femoral component. The approach is not the concern in this case, because extended trochanteric osteotomies have been described from the posterior and direct lateral approaches with excellent outcomes and union rates. The key is that the extended osteotomy is necessary and not a trochanteric slide or standard (shorter or incomplete trochanteric) osteotomy. These types would not provide access to the well-fixed distal stem, nor would they afford a straight tube in which to insert a new femoral component.

Question 37

Which of the following is considered a physiologic effect of anemia?

Explanation

DISCUSSION: The expected physiologic effects of anemia include an increased heart rate and increased cardiac output. The coronary blood flow requirement increases. There is a decrease in peripheral resistance and blood viscosity.
REFERENCE: Carson JL, Duff A, Poses RM, et al: Effect of anemia and cardiovascular disease on surgical mortality and morbidity. Lancet 1996;348:1055-1060.

Question 38

Figure 1 is the MR image of a high school soccer player who sustained a right knee injury during a game while making a cut toward the ball. He felt a pop and his leg gave way. During physical examination, as the knee is moved from full extension into flexion with an internal rotation and valgus force, you notice a "clunk" within the knee. What is the most likely biomechanical basis for the "clunk"?

Explanation

This patient sustained an isolated anterior cruciate ligament (ACL) injury based upon the mechanism described and examination findings. The finding that produces the “clunk” is the pivot-shift maneuver, which is positive in a knee with an incompetent ACL. With an ACL-deficient knee in full extension and internal rotation, the lateral tibial plateau subluxates anteriorly. As the knee is flexed, the lateral tibial plateau slides posteriorly into a reduced position, causing an audible clunk. Response D correctly describes the pathomechanics that result in the audible clunk heard during the pivot-shift maneuver. Responses A and B are incorrect because they describe the medial tibial plateau, which is not part of the pathomechanics of the pivot shift. Response C is incorrect because in extension, the lateral tibial plateau is subluxated, not reduced.

Question 39

A 48-year-old man undergoes arthroscopy to repair a rotator cuff tear. During the arthroscopy, the tear is characterized and found to involve the entire supraspinatus and a majority of the infraspinatus tendons. After mobilization, the posterior rotator cuff can reach the greater tuberosity. However, the supraspinatus tendon cannot reach its insertion point at the greater tuberosity. What is the most appropriate treatment? Review Topic

Explanation

If a complete rotator cuff repair is not possible, a partial rotator cuff repair should still be considered and is the appropriate treatment for this patient. In patients with an irreparable massive rotator cuff tear, acromioplasty with coracoacromial ligament
release, reverse acromioplasty, and tenotomy of the biceps tendon may improve shoulder pain. If these procedures fail, then a muscle transfer procedure can also be considered in select patients. If, however, a portion of the rotator cuff can be repaired, even partial repair can balance the coronal and axial forces about the shoulder to restore the kinematics of the joint. Reverse total shoulder arthroplasty is not appropriate for this relatively young patient.

Question 40

When standing, dorsiflexion of the great toe will accentuate

Explanation

DISCUSSION: Dorsiflexion of the great toe will accentuate rigidity of the transverse tarsal articulation. Through the windlass mechanism, dorsiflexion of the great toe tightens the plantar fascia, stabilizing the longitudinal arch and placing the foot in supination. Supination makes the talonavicular and calcaneocuboid joints nonparallel, accentuating the rigidity of the transverse tarsal articulation. The heel also tends to go into varus, resulting in obligatory external tibial rotation.
REFERENCES: Mann RA: Biomechanics of the foot and ankle, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, Mosby, 1993, pp 1-44.
Hicks JH: The mechanics of the foot: II. The plantar aponeurosis and the arch. J Anat 1954;88:25.

Question 41

A 35-year-old man who has had a 6-month history of low back pain and tenderness now reports worsening pain and stiffness in the hips and entire back. An AP radiograph of the pelvis demonstrates fusion of the sacroiliac joints bilaterally. What is the next most appropriate step in management? Review Topic

Explanation

The patient has a classic presentation of early ankylosing spondylitis. Sacroiliac joint fusion is the earliest radiographic finding and is typically followed by cephalad spinal progression. Early treatment of ankylosing spondylitis consists of nonsteroidal anti-inflammatory drugs and physical therapy to preserve spinal motion. HLA-B27 testing is positive in most (about 95%) patients; however, it is not pathognomonic because it can be positive with other conditions. Considering the progressive nature of this
disease, further work-up in a patient with potential ankylosing spondylitis is not warranted. Sacroiliac joint anesthetic injections and sacroiliac fusion are not recommended treatments for early ankylosing spondylitis. Aspiration of the sacroiliac joints can be done if sacroiliac joint infection is suspected; however, in the absence of fever or other constitutional symptoms, infection is unlikely.

Question 42

A 68-year-old man with no significant medical history underwent a total knee arthroplasty 4 years ago. A radiograph is shown in Figure 55. He reports that he had no problems with the knee until 6 weeks ago when he noted the gradual onset of pain following a colonoscopy. Examination reveals a painful, swollen knee. Knee aspiration reveals a WBC count of 40,000/mm 3 . Management should consist of

Explanation

DISCUSSION: The treatment of choice for a late hematogenous infection is two-stage resection arthroplasty and reimplantation, with parenteral antibiotics prior to reimplantation. This is particularly true when septic loosening has occurred as in this patient. Open irrigation and debridement with polyethylene exchange has been used successfully when the duration of symptoms is 3 weeks or less. Long-term suppressive antibiotics are most commonly used when the patient’s medical condition precludes further surgery. Delayed reimplantation has been shown to be superior to immediate reimplantation in multiple studies. Little data support the use of arthroscopic irrigation and debridement.
REFERENCES: Swanson KC, Windsor RE: Diagnosis of infection after total knee arthroplasty, in Callaghan JJ, Rosenberg AG, Rubash HE, et al (eds): The Adult Knee. Philadelphia, PA, JB Lippincott, 2003, vol 2, pp 1485-1491.
Hanssen AD, Rand JA, Osmon DR: Management of the infected total knee arthroplasty, in Morrey BF (ed): Joint Replacement Arthroplasty, ed 3. Philadelphia, PA, Churchill-Livingstone, 2003, pp 1070-1089.

Question 43

The force generated by a muscle is most highly dependent on its

Explanation

The cross-sectional area of a muscle determines to a great extent the force generated by the muscle. The force of a muscle contraction is controlled by the amount of myofibrils that contract; the greater the amount of contracting myofibrils, the greater the force of contraction. Fiber types have less to do with the force of contraction and more to do with the duration and speed of contraction. Muscle length affects contraction force through the Blix curve. The morphology of a muscle can affect the cross-sectional area by varying the angle of the fibers in relation to the force vector. Conditioning mostly affects duration and fatigability.

Question 44

An otherwise healthy 54-year-old man who underwent a successful multilevel lumbar decompression and fusion 4 years ago now reports increasingly severe bilateral thigh claudication with paresthesia and severe back pain for the past 12 months. Physical therapy, bracing, and epidural steroids have failed to provide relief. A radiograph and MRI scans are shown in Figures 15a through 15c. He is afebrile, and laboratory studies show an erythrocyte sedimentation rate of 5 mm/h and a normal WBC count. What is the best course of action?

Explanation

DISCUSSION: The patient has degeneration of an adjacent segment with resultant

kyphosis and stenosis. Because he is healthy, has responded well to previous surgery,

|and has a potentially correctable lesion, he is not a good candidate for an end-stage failed

back procedure such as a morphine pump. The stenosis is exacerbated by the deformity; therefore, a simple decompression will contribute to instability. Because of the kyphosis and the patient’s relatively young age, the treatment of choice is restoration of sagittal alignment and posterior decompression.
REFERENCE: Eck JC, Humphreys SC, Hodges SD: Adjacent-segment degeneration after lumbar fusion: A review of clinical, biomechanical, and radiographic studies. Am J Orthop 1999;28:336-340.

Question 45

An 18-year-old collegiate football player injures his right shoulder during a tackle. He reports pain and numbness in the shoulder and numbness radiating to his fingers. His symptoms improve within 15 minutes and he has no residual symptoms. This condition is best known as Review Topic

Explanation

The condition described in this case is known as a stinger or burner. It is caused by stretching the upper trunk of the brachial plexus in the C5 and C6 nerve roots. The symptoms are temporary and last 15 to 20 minutes. There are no residual deficits, unless the patient has had multiple repetitive injuries. Once motor and sensory examination findings and reflexes have normalized, the athlete can return to play. Acute spinal cord injury may cause temporary complete paralysis in the upper and lower extremities with resolution of symptoms within 24 hours. Central cord syndrome affects the upper more than lower extermities and affects mostly elderly patients. Nerve root avulsions lead to permanent deficits and have a poor prognosis for return of function. Guillain-Barre syndrome is an autoimmune disease that presents as an ascending paralysis with weakness in the legs that spreads to the upper limbs and the face along with complete loss of deep tendon reflexes.

Question 46

What is the most common non-anesthetic-related reversible cause of sustained changes in intraoperative neurophysiologic monitoring signals during spinal surgery? Review Topic

Explanation

Patient positioning that results in local nerve compression, plexus traction, or improper neck alignment is the most common non-anesthetic-related cause of changes in intraoperative neurophysiologic monitoring data during spinal surgery. Pedicle screw malpositioning, spinal cord ischemia, and retractor placement are all less common causes. Hypotension, not hypertension, can be a cause of intraoperative neurophysiologic changes.

Question 47

The natural history of cervical spondylolytic myelopathy is best described as

Explanation

DISCUSSION: The natural history of cervical myelopathy has been described by Lees and Turner as exacerbations of symptoms followed by often long periods of static or deteriorating function (or very rarely improvement). This stepwise pattern of decreasing function has been corroborated by Clarke and Robinson. These authors described long periods of stable neurologic function, sometimes lasting for years, in about 75% of their patients. In the majority of the patients, however, the condition deteriorated between quiescent streaks. About 20% of their patients showed a slow, steady progression of symptoms and signs without a stable period, and 5% had rapid deterioration of neurologic function.
REFERENCES: Emery SF: Cervical spondylotic myelopathy: Diagnosis and treatment. J Am Acad Orthop Surg 2001;9:376-388.
Lees F, Turner JA: The natural history and prognosis of cervical spondylosis. Brit Med J 1963;2:1607-1610.
Clarke E, Robinson PK: Cervical myelopathy: A complication of cervical spondylosis. Brain 1956;79:486-510.

Question 48

Figures 12a and 12b show the radiographs of a 56-year-old man with diabetes mellitus who has had left foot swelling with no pain for the past several weeks. He denies any history of trauma. Examination reveals warmth, moderate swelling, no tenderness, and mild pes planus with standing. Pulses are palpable, and his sensory examination is grossly intact to light touch. Standing radiographs are shown in Figures 12c and 12d. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographs show tarsometatarsal joint subluxation without fragmentation. The clinical history and delay in presentation with the radiographic findings suggest a neuropathic or Charcot arthropathy involving the midfoot area. Intact sensory examination to light touch is not diagnostic for an intact peripheral neurologic system; monofilament testing is a more accurate office baseline examination for the presence of sensory peripheral neuropathy. With an acute traumatic Lisfranc fracture-dislocation, a history of a traumatic event is necessary, and radiographic abnormalities are expected, although nonstanding radiographs still may be misleading. Acquired pes planus due to posterior tibial tendon rupture may have negative nonstanding radiographs. Standing radiographs may reveal pes planus. However, intermetatarsal disruption is not expected as seen in a Lisfranc abnormality. Localized osteomyelitis of the foot without a penetrating injury or cutaneous ulceration is extremely unlikely and does not fit with the clinical picture described. An isolated metatarsal stress fracture would show osseous irregularity without the instability pattern pictured.
REFERENCES: Brodsky JW: The diabetic foot, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 895-969.
Myerson MS: Diabetic neuroarthropathy, in Myerson MS (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, pp 439-465.

Question 49

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

Explanation

The athlete has symptoms referable to the axillary, musculocutaneous, and suprascapular nerves resulting from an injury to the upper trunk of the brachial plexus. This portion of the plexus is formed by contributions of the fourth through sixth cervical nerve roots. This area is often contused or stretched following a tackling maneuver that results in either depression of the shoulder from contact at Erb’s point or traction of the upper plexus from forced stretching of the neck to the contralateral side.

Question 50

Which of the following factors is associated with decreases in active periprosthetic osteolysis in total hip arthroplasty?

Explanation

DISCUSSION: A 32-mm head design results in less linear wear but more volumetric wear particles. Modular components that allow motion between the polyethylene insert and the shell can result in backside wear. The oxidative degradation of gamma-irradiated polyethylene stored in air leads to increased wear. All of these factors lead to a greater particulate load and more osteolysis. Circumferential porous coating blocks ingrowth of particle-laden fluid and decreases osteolysis.
REFERENCES: Bartel DL, Bicknell VL, Wright TM: The effect of conformity, thickness, and material on stresses in ultra-high molecular weight components for total joint replacement. J Bone Joint Surg Am 1986;68:1041-1051.
Fisher J, Hailey JL, Chan KL, et al: The effect of aging following irradiation on the wear of UHMWPE. Trans Orthop Res Soc 1995;20:12.
Archibeck MJ: The basic science of periprosthetic osteolysis. Instr Course Lect

2001;50:185-195.

Question 51

Denosumab, a monoclonal antibody used to treat osteoporosis, works through inhibition of

Explanation

Denosumab is a monoclonal antibody that targets and inhibits RANKL binding to the RANK receptor, which is found on osteoclasts. As a result, it inhibits activation of osteoclast cells and slows the process of bone resorption and bone turnover via osteoclast inhibition. The end result is similar to bisphosphonates in terms of effector cell, but the mechanism of action is very different. RANKL binds to RANK, but OPG inhibits RANK binding to RANKL. TNF is an inflammatory cytokine, and monoclonal antibodies to TNF are used to treat systemic inflammatory disease such as rheumatoid arthritis.

Question 52

A 16-year-old girl has had pain in the left groin for the past 4 months. She notes that the pain is worse at night; however, she denies any history of trauma and has no constitutional symptoms. There is no history of steroid or alcohol use. Examination reveals pain in the left groin with rotation of the hip. There is no associated soft-tissue mass. A radiograph and MRI scan are shown in Figures 32a and 32b, and biopsy specimens are shown in Figures 32c and 32d. What is the most likely diagnosis?

Explanation

DISCUSSION: Based on the epiphyseal location and sharp, well-defined borders, the radiograph suggests chondroblastoma. Histologically, multinucleated giant cells are scattered among mononuclear cells. The nuclei are homogenous and contain a characteristic longitudinal groove. Although not seen here, “chicken-wire calcification” with a bland giant cell-rich matrix is also typical for chondroblastoma. Clear cell chondrosarcoma occurs in epiphyseal locations but has a more aggressive histologic pattern and occurs in an older age group. Giant cell tumors occur in the epiphysis but have a more uniform giant cell population histologically. Aneurysmal bone cyst often results in bone remodeling and has a different pathologic appearance. Osteonecrosis has a typical histologic pattern of empty lacunae and necrotic bone.
REFERENCES: Springfield DS, Capanna R, Gherlinzoni F, et al: Chondroblastoma: A review of seventy cases. J Bone Joint Surg Am 1985;67:748-755.
Simon M, Springfield D, et al: Chrondroblastoma: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, p 190.
Wold LA, et al: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990,
pp 62-67.

Question 53

A 55-year-old woman is referred for evaluation of a painful knee replacement. She underwent total knee arthroplasty (TKA) more than 1 year ago without perioperative complications but has had consistent pain since the surgery. The patient’s preoperative radiographs and postoperative radiographs are shown in Figures below. Examination reveals medial laxity during valgus stress testing and range of motion of 0° to 70°. Her erythrocyte sedimentation rate and C-reactive protein level are normal. What is the best next step?

Explanation

DISCUSSION:
The radiographs show substantial valgus malalignment of the femoral component, with lateral mechanical axis deviation. Clinically, by examination she displays instability and stiffness as a result. Revision knee replacement is appropriate and should consist of total revision to stemmed femoral and tibial components with a varus-valgus constrained insert, given the likely attenuation of the medial collateral ligament. Open debridement with ligament balancing and polyethylene exchange do not address the underlying cause and are inappropriate. Distal femoral osteotomy is not useful in the setting of previous total knee replacement.
Nonsurgical treatment with an unloader brace would be ineffective in correcting the alignment.

Question 54

A child presents with the radiograph shown in Figure A. Which of the following conditions is LEAST likely to be associated with this disorder? Review Topic

Explanation

Sever's disease (calcaneal apophysitis) is not associated with congenital scoliosis.
Congenital scoliosis is associated with other anomalies 60% of the time. These anomalies can appear independently, or as part of the VACTERL syndrome (vertebral anomalies, anorectal atresia, tracheoesophageal fistula, and renal and vascular anomalies). Other associated orthopedic conditions include clubfoot, developmental dysplasia of the hip, limb hypoplasia, Sprengel’s deformity, Klippel-Feil syndrome, foot asymmetry, vertical tali, leg atrophy and pes cavus.
Hedequist et al. (2004) reviewed congenital scoliosis. They recommend surgery in young children, severe deformities, or deformities that tend to progress rapidly, truncal imbalance, and anomalies at the cervicothoracic and lumbosacral junction (because of imbalance in the shoulders/neck and lumbar region respectively). Surgical options include in situ fusion, convex hemiepiphysiodesis, hemivertebra excision, correction and instrumented fusion, osteotomies with fusion, growing rods and expandable ribs.
Hedequist et al. (2007) reviewed congenital scoliosis. They state that fully segmented hemivertebra with definable disks above and below are more likely to cause curvature compared with an unsegmented hemivertebra fused to the vertebra above and below. Also, anomalies at the cervicothoracic and lumbosacral junctions produce more visible deformities than that at other areas.
Figure A shows a spine with multiple hemivertebrae, examples of failure of formation in congenital scoliosis.
Incorrect Answers:

Question 55

Limited weight bearing usually is recommended following open reduction and internal fixation of intra-articular lower extremity fractures. A bone graft, or bone graft substitute is often placed in the metaphyseal void beneath the reduced articular fragments. Which of the following bone grafts or bone graft substitutes will most likely permit earlier weight bearing without subsidence of the articular reduction?

Explanation

Most bone graft substitutes have a low compressive strength, similar to cancellous bone. Calcium phosphate cements, when hardened, have a much higher compressive strength compared to any of the other bone grafts or bone graft substitutes. In a study of 26 patients undergoing open reduction and internal fixation of displaced tibial plateau fractures, calcium phosphate was found to produce good outcomes. Because of the high mechanical strength of the cement, the authors allowed early weight bearing after a mean postoperative period of 4.5 weeks, with a range from 1 to 6 weeks. Despite early weight bearing, only two patients in this series had a partial loss of reduction. In biomechanical studies of displaced tibial plateau fractures, calcium phosphate compared favorably to cancellous bone graft. In one clinical series of patients undergoing open reduction and internal fixation for a calcaneus fracture, those patients whose reductions were supported with calcium phosphate were allowed to begin full weight bearing at 3 weeks and displayed no radiographic evidence of reduction loss. The effectiveness of calcium phosphate to resist deformation with cyclical loading in simulated calcaneal fractures has been confirmed in a biomechanical study.

Question 56

Figures below show the radiographs obtained from an 86-year-old-woman who has had chronic left hip pain for several years. She now uses a walker and a wheelchair for ambulation. She is medically healthy. What is the most appropriate surgical intervention?

Explanation

DISCUSSION:
This 86-year-old woman has poor bone quality and osteoarthritis of the left hip. Her lateral radiograph confirms Dorr type C bone quality. A hybrid left THA with a cemented femoral stem would be the treatment of choice.

Question 57

A 21-year-old man has mild but persistent aching pain in his left proximal thigh during impact loading activities. He denies pain at rest and has no other symptoms. Figures 34a through 34e show the radiographs and T1-weighted, T2-weighted, and gadolinium MRI scans of the left hip. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographs show a centrally located radiolucent lesion with cortical thinning and mild osseous expansion; these findings are the hallmarks of a simple bone cyst. Whereas this particular lesion does not demonstrate sclerosis, the distinct margin of this lesion with sharp transition to normal bone is common. The MRI scans reveal a purely cystic lesion with bright T2 signal, and the gadolinium image shows the classic rim enhancement of cystic lesions. Fibrous dysplasia with cystic degeneration might have a very similar appearance and should be considered in the differential diagnosis.
REFERENCES: Parsons TW: Benign bone tumors, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 1027-1035.
May DA, Good RB, Smith DK, et al: MR imaging of musculoskeletal tumors and tumor mimickers with intravenous gadolinium: Experience with 242 patients. Skeletal Radiol 1997;26:2-15.
Resnick D, Kyriakos M, Greenway GD: Tumors and tumor-like lesions of bone: Imaging and pathology of specific lesions, in Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4. Philadelphia, PA, WB Saunders, 2002, vol 4, pp 4023-4034.

Question 58

A 27-year-old man has had pain in the right index finger for the past 9 months. The pain is completely relieved with ibuprofen. An AP radiograph and CT scan are shown in Figures 80a and 80b. What is the most likely diagnosis?

Explanation

DISCUSSION: Osteoid osteoma is a round or oval, well-circumscribed lesion with a

radiolucent nidus. A small area of calcification may be present within the center of the nidus. The radiolucent nidus is surrounded by a thick rim of sclerotic bone. These diagnostic

features are frequently better seen on CT. An increase in cyclooxygenase activity has been demonstrated within osteoid osteomas, which may explain why aspirin and other nonsteroidal anti-inflammatory drugs classically relieve the pain associated with these lesions.
REFERENCES: Kneisl JS, Simon MA: Medical management compared with operative treatment for osteoid-osteoma. J Bone Joint Surg Am 1992;74:179-185.
Unni KK: Dahlin’s Bone Tumors: General Aspects and Data on 11,087 Cases, ed 5. Philadelphia, PA, Lippincott-Raven, 1996, pp 121-130.

Question 59

A 45-year-old woman has had intense pain in her foot for the last 3 days. She also reports a mild fever and difficulty with shoe wear. Examination reveals a swollen, slightly erythematous warm foot with tenderness at the great toe metatarsophalangeal joint and pain with passive motion of the joint. An AP radiograph is shown in Figure 13. Which of the following will best aid in determining a definitive diagnosis?

Explanation

DISCUSSION: The patient has gouty arthropathy of the first metatarsophalangeal joint. This definitive diagnosis is achieved with aspiration of the joint and polarized light microscopy that shows needle-shaped negatively birefringent monosodium urate crystals. Differential diagnoses of infectious arthritis and pseudogout are also definitively made through joint aspiration. Although rheumatoid arthritis is a possibility, a serum rheumatoid factor is not always diagnostic and a patient with rheumatoid arthritis may have concomitant gouty arthritis. The radiographic findings are not typical of diabetes mellitus or of a patient with Charcot arthropathy.
REFERENCES: Wise CM, Agudelo CA: Diagnosis and management of complicated gout. Bull Rheum Dis 1998;47:2-5.
Harris MD, Siegel LB, Alloway JA: Gout and hyperuricemia. Am Fam Physician 1999;59:925-934.

Question 60

Figure 35 shows the radiograph of a 35-year-old weightlifter who has had pain with overhead lifts for the past 7 months. Cortisone injections in the acromioclavicular joint provided only temporary relief. A bone scan reveals increased activity of the acromioclavicular joint. Treatment should now consist of

Explanation

DISCUSSION: Osteolysis of the distal clavicle is common in weightlifters; therefore, distal clavicle excision is the treatment of choice. A subacromial decompression alone would not alleviate the acromioclavicular joint symptoms. Interval closure, biceps degeneration, and superior labrum anterior and posterior repair would limit superior migration but would not explain the abnormal bone scan. Thermal capsular shrinkage does not have a role here.
REFERENCES: Flatow EL, Cordasco FA, McCluskey GM, Bigliani LU: Arthroscopic resection of the distal clavicle via a superior portal: A critical quantitative radiographic assessment of bone removal. Arthroscopy 1990;6:153-154.
Lyons FR, Rockwood CA: Osteolysis of the clavicle, in DeLee JC, Drez D (eds): Orthopaedic Sports Medicine. Philadelphia, PA, WB Saunders, 1994, pp 541-546.

Question 61

A 17-year-old girl has multidirectional instability of the shoulder. What is the most appropriate initial management?

Explanation

DISCUSSION: Multidirectional instability of the shoulder is defined as symptomatic instability in two or more directions (anterior, posterior) but must include a component of inferior instability. Initial treatment should always include physical therapy and instruction in a home exercise program that emphasizes periscapular and rotator cuff strengthening to improve the dynamic stability of the glenohumeral joint. Immobilization has not been shown to be effective. Open capsular shift and arthroscopic capsular plication remain the surgical options when appropriate nonsurgical management fails (typically a minimum of 6 months of dedicated therapy and home program). Thermal capsulorrhaphy remains controversial but is not recommended by many clinicians because of reported complications including recurrent instability, axillary nerve injury, chondrolysis, and capsular injury.
REFERENCES: Neer CS II, Foster CR: Inferior capsular shift for involuntary inferior and multidirectional instability of the shoulder: A preliminary report. J Bone Joint Surg Am 1980;62:897-908.
D’Alessandro DF, Bradley JP, Fleischli JE, et al: Prospective evaluation of thermal capsulorrhaphy for shoulder instability: Indications and results, two- to five-year follow-up.

Am J Sports Med 2004;32:21-33.
Levine WN, Clark AM Jr, D’Alessandro DF, et al: Chondrolysis following arthroscopic thermal capsulorrhaphy to treat shoulder instability: A report of two cases. J Bone Joint Surg Am 2005;87:616-621.
Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 278-279.

Question 62

A homebound 75-year-old woman with diabetes mellitus has had progressive left knee pain and swelling for the past 6 weeks. She is febrile with a temperature of 103 degrees F (39.5 degrees C). History reveals that she underwent arthroplasty 5 years ago. Examination shows passive range of motion of 0 to 100 degrees with no active extension. Knee aspiration reveals purulent fluid with a Gram stain showing gram-negative rods. A radiograph is shown in Figure 27. In addition to IV antibiotics, which of the following management options offers the best chance of a successful outcome?

Explanation

DISCUSSION: The patient has an infected total knee arthroplasty and an interrupted extensor mechanism. A late infection of a total knee arthroplasty in a patient with diabetes mellitus and a virulent organism requires removal of the components, debridement, antibiotic spacers, and surveillance to ensure eradication of the infection. Reconstruction of an incompetent extensor mechanism in an infected knee is extremely unlikely to be successful. Arthrodesis is the procedure of choice if a revision total knee arthroplasty is not likely to succeed. Resection arthroplasty is recommended only as a long-term solution if the patient is medically unable to undergo further surgery.
REFERENCES: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgery, 2002, pp 513-536.
Hanssen AD, Rand JA: Evaluation and treatment of infection at the site of a total hip or knee arthroplasty. Instr Course Lect 1999;48:111-122.

Question 63

A cartilage water content increase is the hallmark of which osteoarthritis stage?

Explanation

The first stage of osteoarthritis is marked by an increase in water content secondary to disruption of the matrix framework. This is followed by an increase in chondrocyte anabolic and catabolic activity in response to tissue damage. Wnt-induced signal protein 1 increases chondrocyte protease expression. Failure to restore tissue balance ultimately leads to continued destruction and osteoarthritis. One hallmark of osteoarthritic cartilage is a reduced repair mechanism attributable to decreased chondrocyte response to growth factor stimulation (transforming growth factor-alpha and insulin-like growth factor-1). Mitochondrial dysfunction and increased production of reactive oxygen species may promote cell senescence, a progressive slowing of cellular activity. Microscopic evidence of cartilage degeneration begins with fibrillation of the superficial and transition zones, followed by disruption of the tidemark by subchondral blood vessels and eventual subchondral bone remodeling. This process ultimately leads to cartilage degradation with decreased water content in the late and terminal phases of osteoarthritis.

Question 64

Nutritional rickets is associated with which of the following changes in chemical blood level?

Explanation

DISCUSSION: Nutritional rickets is associated with decreased dietary intake of Vitamin D, resulting in low levels of Vitamin D that result in decreased intestinal absorption of calcium

and low to normal serologic levels of calcium. To boost serum calcium levels, there is a compensatory increase in PTH and bone resorption, leading to increased alkaline

phosphatase levels.
REFERENCES: Brinker MR: Cellular and molecular biology, immunology, and genetics in orthopaedics, in Miller MD (ed): Review of Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2001, pp 81-94.
Pettifor J: Nutritional and drug-induced rickets and osteomalacia, in Farrus MJ (ed): Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2003, pp 399-466.
Einhorn TA: Metabolic bone disease, 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 65

Patients who sustain bilateral femoral shaft fractures when compared to unilateral femur fractures have higher rates of the following EXCEPT:

Explanation

DISCUSSION: Copeland et al performed a retrospective analysis using their trauma registry data on consecutive blunt trauma patients with unilateral (800 patients) or bilateral (85 patients) femoral shaft fractures. Patients with bilateral femoral fractures had a significantly higher Injury Severity Score (30.2 versus 24.5, p < 0.05) and higher mortality rate (25.9 vs 11.7%, p < 0.014) than patients with unilateral femoral fractures. Bilateral fracture patients also had significantly more closed head injuries,open skull fractures, intraabdominal injuries requiring surgical intervention, and pelvic fractures. The rates of thoracic injury were similar (answer 3). Regression analysis of variables evident on admission revealed a significant correlation between bilateral femoral fractures and death; however, other factors (shock, closed head injury, and thoracic injury) had much stronger correlations with mortality

Question 66

Figures below show the radiographs, MRI, and MR arthrogram obtained from a 25-year-old collegiate soccer player who has new-onset left groin pain. He played competitive soccer from a young age and has competed or practiced 5 to 6 times per week since the age of 10. He denies any specific hip injury that necessitated treatment, but his trainer contends that he had a groin pull. He reports groin pain with passive flexion and internal rotation of the left hip, and his hip has less internal rotation than his asymptomatic right hip. He is otherwise healthy.When counseling patients who have a cam deformity, the orthopaedic surgeon should note that

Explanation

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

Question 67

Figures below show the radiographs, and the CT obtained from a 58-year-old woman who underwent cementless left total hip arthroplasty. Nine months after surgery, she continued to have groin pain when actively flexing her hip. She has trouble walking up stairs and getting out of her car. What is the most likely diagnosis?

Explanation

DISCUSSION:
Groin pain after total hip replacement has a number of possible causes, and an exact diagnosis may remain elusive in some patients. Infection should be ruled out with laboratory studies and, if indicated, diagnostic aspiration of the hip joint. Implant loosening should be evaluated by plain radiograph and bone scan, if indicated. Synovitis resulting from wear debris should be considered in patients with polyethylene liners who experience late-onset symptoms or in any patient with a metal-on-metal bearing. This patient's symptoms are classic for iliopsoas tendonitis. Physical examination usually reveals pain and weakness with resisted hip flexion. A cross-table lateral radiograph and CT show that the anterior edge of the acetabulum protrudes beyond the anterior wall, thereby acting as a source of iliopsoas tendon irritation. In such cases, acetabular component revision and repositioning are indicated. Fluoroscope-guided iliopsoas cortisone injection can help to establish the diagnosis and relieve groin pain. If the acetabular component is well positioned, then iliopsoas tenotomy should be considered.

Question 68

A healthy 65-year-old woman undergoes anatomic total shoulder arthroplasty to address osteoarthritis (OA). The surgery is uncomplicated. What is the most common indication for future revision?

Explanation

The most common reason for revision surgery following unconstrained shoulder arthroplasty for glenohumeral OA is loosening of an implant. In most studies that distinguish glenoid from humeral loosening, it appears the glenoid is the problem. Comprehensive systematic reviews have found that radiographic glenoid loosening can comprise nearly 30% to 40% of all complications following shoulder arthroplasty for non-
inflammatory arthritis. Infections, periprosthetic fractures, and rotator cuff tears are uncommon. In the population-based study by Matsen and associates, 10% of the revisions were performed for loosening versus
7% for infection and 7% for rotator cuff tearing.

Question 69

A previously healthy 65-year-old woman has a closed fracture of the right clavicle after falling down the basement stairs. Examination reveals good capillary refill in the digits of her right hand. Radial and ulnar pulses are 1+ at the right wrist compared with 2+ on the opposite side. In the arteriogram shown in Figure 36, the arrow is pointing at which of the following arteries?

Explanation

DISCUSSION: The axillary artery commences at the first rib as a direct continuation of the subclavian artery and becomes the brachial artery at the lower border of the teres major. The arteriogram reveals a nonfilling defect in the third portion of the artery just distal to the subscapular artery. The complex arterial collateral circulation in this region often permits distal perfusion of the extremity despite injury.
REFERENCE: Radke HM: Arterial circulation of the upper extremity, in Strandness DE Jr (ed): Collateral Circulation in Clinical Surgery. Philadelphia, PA, WB Saunders, 1969, pp 294-307.

Question 70

A comparison of dural tears repaired with suture alone and those treated by suture with fibrin glue supplementation will reveal which of the following findings?

Explanation

DISCUSSION: Animal studies assessing the influence of fibrin glue supplementation have detected a markedly greater inflammatory response at the site of application. An increased incidence of infection and delays in healing were not noted.
REFERENCES: Cain JE Jr, Rosenthal HG, Broom MJ, Jauch EC, Borek DA, Jacobs RR: Quantification of leakage pressures after durotomy repairs in the canine. Spine 1990;15:969-970.
Cain JE Jr, Dryer RF, Barton BR: Evaluation of dural closure techniques: Suture methods, fibrin adhesive sealant, and cyanoacrylate polymer. Spine 1988;13:720-725.

Question 71

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

Explanation

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

Question 72

-Figures 52c and 52d show the proton density fat-saturated MRI scans. Treatment at this stage includes arthroscopy and

Explanation

DISCUSSION FOR QUESTIONS 52 THROUGH 54
This patient’s examination indicates a patellar or peripatellar knee injury. Initial evaluation with radiographs will assess for fracture, subluxation, or osteochondral injury. Examination findings did not demonstrate a need for emergent surgery, an MRI scan, or an ultrasound, so radiographs are the initial diagnostic imaging choice. Radiographs show an osseous or osteochondral loose fragment.
There is no evidence of obvious nondisplaced fracture or physeal changes. In suspected patella dislocation or subluxation with loose fragment seen on radiographs, an MRI scan is indicated. Lateral release alone is seldom indicated in a knee that was normal before injury. Acute proximal realignment has not been shown to alter long-term outcomes for first-time dislocators. The examination and MRI scan did not indicate a need for MCL repair. Closed reduction of the osteochondral fragment would not be indicated or appropriate for this injury. Treatment should consist of arthroscopy or arthrotomy and attempted internal fixation of this fragment. If fixation is not possible, the loose body can be removed.

Question 73

Etanercept is a recombinant genetically engineered fusion protein used to treat rheumatoid arthritis. What is its mode of action?

Explanation

DISCUSSION: Etanercept is a molecule consisting of the Fc portion of IgG fused to the extracellular domain of the p76 human THF-α receptor. It is soluble and binds TNF-α. Infliximab is the monoclonal antibody that binds TNF-α. IL-1 receptor antagonists are still in development. Leflunomide is a drug that inhibits pyrimidine synthesis and is similar to methotrexate as an antimetabolite.
REFERENCE: Koval KJ (ed): Orthopaedic Knowlegde Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 193-199.

Question 74

A year-old obese man with a body mass index of 42 comes into the office with left knee pain 1 year after undergoing an uncomplicated left medial unicompartmental knee arthroplasty (UKA). Radiographs show a loose tibial component in varus. What is the most appropriate next step to treat this failed construct?

Explanation

Question 75

A 62-year-old active man returns for routine follow-up 16 years after hip replacement. He has no hip pain. Radiographs reveal a well-circumscribed osteolytic lesion around a single acetabular screw. All hip components are perfectly positioned. Comparison radiographs obtained 6 months later show an increase in the size of the osteolytic lesion. CT depicts a well-described lesion that is 3 cm at its largest diameter and is localized around one screw hole with an eccentric femoral head. What treatment is appropriate, assuming that well-fixed cementless total hip components are in place?

Explanation

DISCUSSION:
Given a well-fixed acetabular metal shell and a localized osteolytic lesion, good outcomes can be expected from liner revision in this clinical scenario with retention of the metal socket, assuming no damage to the components or other unexpected findings arise during revision surgery. Here, complete cup revision is not warranted, considering the appropriate implant position. Beaulé and associates reviewed 83 consecutive patients (90 hips) in whom a well-fixed acetabular component was retained in a clinical scenario such as the one described. No hip showed recurrence or expansion of periacetabular osteolytic lesions. If the metal cup is unstable, acetabular component revision may be indicated.

Question 76

Which structure is shown in Video 27? 27

Explanation

DISCUSSION
Video 27 shows the medial patellofemoral ligament running from the medial epicondyle of the femur to the medial portion of the patella. The posterior oblique ligament and the superficial medial collateral ligament run from medial epicondyle to the tibia.
RECOMMENDED READINGS
Babb JR, Detterline AJ, Noyes FR. AAOS Orthopaedic Video Theater. The Key to the Knee: A Layer-by-Layer Video Demonstration of Medial and Anterior Aatomy. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009.
Hoppenfeld S, deBoer P. Surgical Exposures in Orthopedics. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2003:493-568.

Question 77

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

Explanation

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

Question 78

Based on the Young and Burgess classification of pelvic ring injuries, an anterior-posterior compression type II injury does not result in disruption of which of the following?

Explanation

DISCUSSION: An APC type 1 involves slight widening of pubic symphysis and/or anterior sacroiliac (SI) joint. An APC II is a continuation of this force, and additionally involves a disrupted anterior SI joint, as
well as sacrotuberous and sacrospinous ligaments. An APC III also involves disrupted posterior SI ligaments, causing complete SI joint disruption with potential translational and rotational displacement.
The reference by Young et al is a classic article that describes the Young and Burgess classification of pelvic ring injuries. They retrospectively analyzed pelvic ring radiographs and discussed four patterns of injury: anteroposterior compression, lateral compression, vertical shear, and a complex/combined pattern.
The reference by Burgess et al is a validation of the aforementioned classification and study, as they reviewed 210 consecutive patients who sustained a pelvic ring injury. They validated the classification scheme and found that overall blood replacement averaged: lateral compression, 3.6 units; anteroposterior compression, 14.8 units; vertical shear, 9.2 units; combined mechanical, 8.5 units. Overall mortality was: lateral compression, 7.0%; anteroposterior, 20.0%, vertical shear, 0%; combined mechanical, 18.0%.
Incorrect answers:
1,2,4,5: An APC - 2 pelvic ring injury involves injury to all of these structures.

Question 79

An active 66-year-old man who underwent total shoulder arthroplasty 3 years ago now reports pain. Laboratory studies reveal an elevated erythrocyte sedimentation rate and C-reactive protein. Intraoperative frozen section reveals greater than 10 white blood cells per high power field on two slides and the Gram stain reveals gram-positive cocci in clusters. What is the most appropriate surgical treatment to eradicate the infection and maintain function? Review Topic

Explanation

The prosthesis is grossly infected. Removal of the components and placement of an antibiotic spacer is necessary to eradicate the infection and allow for a second stage reimplantation. Resection arthroplasty is an option to treat the infection but the functional outcome would be limited. Bone grafting with concurrent infection is not likely to heal and should be delayed until the second stage. Humeral head exchange and debridement or arthroscopic debridement alone is unlikely to eradicate the infection.

Question 80

Which of the following methods is effective in correcting recurrent dislocation following total hip arthroplasty?

Explanation

DISCUSSION: Recurrent dislocation following total hip arthroplasty is a difficult problem to correct. Studies conducted by the Mayo Clinic show a failure rate of close to 40% with surgical treatment. A variety of methods have been successful, but no specific approach has been reported to be the most predictably successful. To select and institute the proper treatment option, the cause of the dislocation must be identified. Surgical options fall into several broad categories that include increasing soft-tissue tension (trochanteric advancement or longer neck lengths) or more stable articulation (larger diameter head component, bipolar prosthesis, or a constrained component). In a series of total hip arthroplasties done with a constrained cup, the loosening rates of the cup and the stem were reported to be 6% each, comparable to a reported series of complex revision total hip arthroplasties at a similar follow-up interval.
REFERENCES: Woo RY, Morrey BF: Dislocations after total hip arthroplasty. J Bone Joint Surg Am 1982;64:1295-1306.
Goetz DD, Capello WN, Callaghan JJ, Brown TD, Johnston RC: Salvage of a recurrently dislocating total hip prosthesis with use of a constrained acetabular component: A retrospective analysis of fifty-six cases. J Bone Joint Surg Am 1998;80:502-509.

Question 81

What is the most common physical examination finding in a patient with chronic painful spondylolysis? Review Topic

Explanation

Patients with spondylolysis typically demonstrate increased pain with lumbar extension, not with forward flexion. In the absence of a disk herniation, a straight leg raise test result should be negative. Pain with forward flexion is not common in spondylolysis, and without nerve root impingement there should be no loss of the tendo-Achilles reflex.

Question 82

Figures 22a and 22b show the radiographs of a patient who reports stiffness of the hip and associated pain. Management should consist of

Explanation

DISCUSSION: The patient has grade IV heterotopic ossification with the limb in an abnormal nonfunctional position. Treatment should consist of excision of the bone to restore hip motion and prophylaxis to prevent recurrent formation. The best time to excise the bone is controversial, with no conclusive evidence supporting early or late excision.
REFERENCES: Pellegrini VD Jr, Koniski AA, Gastel JA, Rubin P, Evarts CM: Prevention of heterotopic ossification with irradiation after total hip arthroplasty: Radiation therapy with a single dose of eight hundred centigray administered to a limited field. J Bone Joint Surg Am 1992;74:186-200.
Warren SB, Brooker AF Jr: Excision of heterotopic bone followed by irradiation after total hip arthroplasty. J Bone Joint Surg Am 1992;74:201-210.

Question 83

A 14-year-old boy sustains a right leg injury after being thrown from his motorcycle while racing. He reports diffuse right leg pain starting at his knee and proceeding distally to include his foot. After the injury the patient’s mother reports the tibia moving posteriorly then anteriorly while she was supporting the leg. In the emergency department 4 hours after injury, examination reveals a large knee effusion, firm compartments of the leg, a palpable posterior tibialis pulse with a warm, pink foot, and capillary refill of 2 seconds at the toes. His blood pressure is 100/50 mm Hg. Motor examination is intact, but there is decreased sensation in the dorsal first interspace and plantar aspect of the foot. Compartment pressure measurement reveals all four compartments with pressures of 33, 36, 33, and 38 mm Hg respectively. Radiographs are shown in Figure 59a and 59b. The remainder of the skeletal examination is normal. What is the optimal management for this injury?

Explanation

DISCUSSION: The patient has a compartment syndrome based on the firm compartments of the leg and the elevated compartment pressures measured at the diastolic pressure reading. Muscle ischemia occurs quickly when compartment pressures are elevated, and within 6 hours irreversible damage can occur. Emergent fasciotomies permit decompression of all four compartments and reestablishment of vascular supply to the muscles. Stabilization of the fracture prevents further soft-tissue injury.
REFERENCE: Beaty JH, Kasser JR (eds): Fractures in Children, ed 6. Philadelphia, PA, Lippincott, 2006, pp 1057-1061.

Question 84

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

Explanation

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

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

Question 85

Figure 44 shows the radiograph of an 11-year-old girl who has hip pain. Further diagnostic workup should include

Explanation

DISCUSSION: The patient has severe acetabular protrusio, a condition that is frequently associated with Marfan syndrome. An echocardiogram is necessary to rule out the most serious consequence of this syndrome, aortic root widening, which can lead to aortic valve dysfunction or fatal aortic rupture. An electromyogram may be indicated for Charcot-Marie-Tooth disease, which is associated with acetabular dysplasia, but not protrusio. The renal ultrasound, the MRI scan, and the biopsy would be of no value in this patient. Protrusio can also be seen in patients with osteogenesis imperfecta and juvenile rheumatoid arthritis.
REFERENCES: Steel HH: Protrusio acetabuli: Its occurrence in the completely expressed Marfan syndrome and its musculoskeletal component and a procedure to arrest the course of protrusion in the growing pelvis. J Pediatr Orthop 1996;16:704-718.
Wenger DR, Ditkoff TJ, Herring JA, Mauldin DM: Protrusio acetabuli in Marfan’s syndrome. Clin Orthop 1980;147:134-138.

Question 86

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 87

During total knee arthroplasty, the patella is noted to subluxate laterally despite a lateral retinacular release. Which of the following methods is most likely to improve patellar stability?

Explanation

DISCUSSION: Slight external rotation of the tibial component will cause a net medialization of the tibial tubercle when the knee is articulated. This will help centralize the extensor mechanism over the trochlear groove and minimize the tendency for lateral subluxation. Internal rotation of the femoral component increases the risk of patellar instability. Anterior translation of the tibial component moves the patellar tendon insertion posteriorly, and may increase force on the patella but should not substantially alter patellar tracking. Clinical studies have shown no patellofemoral benefits to the use of fixed- or mobile-bearing designs. Thicker patellar components will not improve tracking, and may compound the problem.
REFERENCES: Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 207, 323-337
Pagnano MW, Trousdale RT, Stuart MJ, et al: Rotating platform knees did not improve patellar tracking: A prospective, randomized study of 240 primary total knee arthroplasties. Clin Orthop 2004;428:221-227.
Lotke PA, Garino JP (eds): Revision Total Knee Arthroplasty. Philadelphia PA, Lippincott-Raven, 1999, pp 427-435.

Question 88

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

Explanation

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

Question 89

Which of the following acetabular/femoral head components would be expected to show an optimal combination of linear and volumetric wear?

Explanation

The size of the femoral head and the calculated mean annual rate of volumetric wear has a significant relationship. Rate of volumetric wear was highest in assoc with 32 mm femoral lowest in assoc with 22 mm heads. The predominant mechanisms of wear of the polyethylene were abrasion and adhesions rather than fatigue-cracking or delamination on the subsurface. Decreased thickness of the polyethylene has an adverse effect on the rate of wear of the metal-backed components. Rate of linear wear is highest in assoc. with 22-mm heads and lowest in relation to 32-mm heads, so the optimal size of a femoral head should be 28 mm where there is minimal linear and volumetric wear.

Question 90

-The patient experienced little improvement with activity modification and physical therapy. An intraarticular corticosteroid injection provides excellent but short-lived pain control. She requests surgical treatment for her hip and she is counseled regarding arthroscopy and consent is obtained. Intraoperatively,a capsulolabral separation is observed with an underlying pincer lesion. No articular cartilage injury is seen. What treatment is most appropriate considering these findings?

Explanation

DISCUSSION FOR QUESTIONS 26 THROUGH 29
The clinical scenario, examination, and MRI scans are consistent with a pincer-type FAI. The decreased range of motion is secondary to the pain produced by the continued abutment of the femoral head against the anterosuperior acetabulum. Flexing the hip while internally rotating and adducting the leg recreates this contact and is typically painful. No clinical signs suggest sacroiliac joint arthritis, an intra-articular loose body, or trochanteric bursitis, although these are all diagnoses that should be considered in a patient with a painful hip. The most sensitive and specific study to detect an acetabular labral tear is an MRI arthrogram of the hip. This study should be obtained in this patient to evaluate the labrum as well as the status of the articular cartilage. An MRI scan without intra-articular contrast is not as sensitive as an arthrogram. An ultrasound can provide a dynamic assessment of the hip and help in the setting of a snapping hip; however, this study is not reliable to determine the presence of a labral tear. In the setting of pincer FAI, the forced leverage of the anterosuperior femoral head upon the anterior acetabulum results in abnormal forces against the posteroinferior acetabulum. This continued force can lead to a chondral lesion in this location know as a “counter-coup” injury. Chondral lesions of the femoral head are rare in the setting of pincer FAI. The posterosuperior quadrant does not experience increased force and rarely sustains chondral injuries. The patient is a young, active individual with no pre-existing degenerative changes, so repair of the tear with bony resection of the pincer lesion is the most appropriate treatment.A capsulolabral detachment should be repaired because these tears can heal and the labrum functions as a seal, preventing egress of synovial fluid from the joint space. If the pincer lesion is not resected, the patient will continue to experience abnormal contact and the repair will likely fail. There is no evidence that the patient has a cam impingement, and recontouring of the femoral head/neck junction is not appropriate. Simple debridement should be reserved for intrasubstance tears of the labrum, which would not be expected to heal with repair.
CLINICAL SITUATION FOR QUESTIONS 30 THROUGH 32
Figures 30a and 30b are the radiographs of a 20-year-old college multisport athlete who has had longstanding pain in his left hip. He denies any specific event that initiated his pain, but he notes that he had hip problems when he was an infant. He denies pain with activities of daily living, but he
believes his pain is increasingly limiting his ability to exercise. He localizes the pain to his groin. He denies low-back or buttock pain or pain that radiates down his leg.

Question 91

A 30-year-old man has had intermittent swelling of his right ankle for the past 6 months. He denies any history of trauma. Radiographs reveal osteolytic changes on both sides of the joint. An axial CT scan and a T 2 -weighted MRI scan are shown in Figures 40a and 40b. He undergoes surgical excision. An intraoperative photograph and a biopsy specimen are shown in Figures 40c and 40d. What is the most likely diagnosis?

Explanation

DISCUSSION: Pigmented villonodular synovitis often presents with intermittent swelling and minimal pain. It often occurs around joints but may be found around tendon sheaths and bursal linings. Periarticular erosions involving both sides of joints are typical, and multiple joint involvement has been described. Portions of low-signal intensity on T₁- and T₂-weighted images are characteristic of hemosiderin-laden processes. High-signal content is suggestive of high water content. The combination of low-signal intensity areas in intra-articular lesions with or without osseous destruction is diagnostic of pigmented villonodular synovitis. Aspiration reveals bloody or brownish fluid. The treatment of choice is synovectomy performed arthroscopically or open. Recurrence is common.
REFERENCES: Walling AK: Soft tissue and bone tumors, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 1007-1032.
Simon M, Springfield D: Surgery for the Bone and Soft-Tissue Tumors. Philadelphia, PA, Lippincott Williams & Wilkins, 1998, p 36.

Question 92

A 43-year-old bus driver sustains a hyperextension injury to her arm and shoulder 4 months after undergoing an open Bankart repair. Examination reveals increased external rotation, anterior shoulder pain, and internal rotation weakness. Her examination also reveals the findings shown in Figure 44. What is the most likely diagnosis?

Explanation

DISCUSSION: An isolated tear of the subscapularis tendon has been noted as early as 1835 by Smith. In Gerber and associates’ 1991 report of 16 men with an average age of 51 years, isolated subscapularis tendon rupture was often caused by a violent hyperextension injury. All patients reported pain anteriorly along with night pain. They also noted pain and weakness of the arm. The lift-off test is performed by having the patient lift the palm of the hand away from the small of the back. The patient must have sufficient internal rotation to allow this test to be performed. A subscapularis rupture is likely if the patient cannot perform the lift-off test.
REFERENCES: Hertel R, Ballmer FT, Lombert SM, Gerber C: Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996;5:307-313.
Gerber C, Krushell RJ: Isolated rupture of the tendon of the subscapularis muscle: Clinical features in 16 cases. J Bone Joint Surg Br 1991;73:389-394.
Greis PE, Kuhn JE, Schultheis J, Hintermeister R, Hawkins R: Validation of the lift-off test and analysis of subscapularis activity during maximal internal rotation. Am J Sports Med 1996;24:589-593.
Gerber C, Hersche O, Farron A: Isolated rupture of the subscapularis tendon. J Bone Joint Surg Am 1996;78:1015-1023.

Question 93

When do most symptomatic thromboembolic events occur after total joint arthroplasty?

Explanation

DISCUSSION:
Most clinical venous thromboembolism events occur between the second and sixth weeks after surgery. It is estimated that 10% of patients are readmitted to the hospital within the first 3 months after total hip or knee arthroplasties. Most pulmonary events on the day of surgery are related to fat embolism or cardiac events.

Question 94

Which of the following tumors is most likely to present with a pathologic fracture in a child?

Explanation

DISCUSSION: In nearly 50% of patients with a unicameral bone cyst, the lesion remains asymptomatic until a fracture occurs, usually as the result of relatively minor trauma. If the lesion expands, the bone is weakened and may cause pain. Fibrous cortical defects are usually an incidental finding and typically asymptomatic. Malignant bone tumors such as osteosarcoma and Ewing’s sarcoma most commonly cause pain, and pathologic fracture occurs in less than 10% of patients. Giant cell tumors are uncommon in children and usually are painful.
REFERENCES: Wilkins RM: Unicameral bone cysts. J Am Acad Orthop Surg 2000;8:217-224.
Dormans JP, Pill SG: Fractures through bone cysts: Unicameral bone cysts, aneurysmal bone cysts, fibrous cortical defects, and nonossifying fibromas. Instr Course Lect 2002;51:457-467.
Hecht AC, Gebhardt MC: Diagnosis and treatment of unicameral and aneurysmal bone cysts in children. Curr Opin Pediatr 1998;10:87-94.

Question 95

A skeletally mature 15-year-old girl who was thrown from the car in a rollover accident sustained the injuries shown in Figures 23a through 23d. Examination reveals no neurologic deficit, but the patient has moderate posterior spinal tenderness at the level of the injury. What is the most appropriate treatment?

Explanation

DISCUSSION: The majority of patients with thoracolumbar burst fractures without neurologic deficit can be effectively treated with a TLSO or a hyperextension body cast. Indications for surgery are neurologic deficit and/or significant deformity (greater than 50% loss of anterior vertebral body height or marked kyphosis).
REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.
Chow GH, Nelson BJ, Gebhard JS, Brugman JL, Brown CW, Donaldson DH: Functional outcome of thoracolumbar burst fractures managed with hyperextension casting or bracing and early mobilization. Spine 1996;21:2170-2175.

Question 96

Which of the following complications is more likely with an inside-out repair technique compared to an all-inside techniques for a medial meniscus tear? Review Topic

Explanation

All of the answers are possible complications of meniscal repair. There are large volumes of literature evaluating the results of meniscal repair, both for the all-inside technique, as well as the inside-out technique. Failure rates are similar. Intra-articular synovitis occurs with absorbable sutures and absorbable implants. Peroneal nerve injuries are more common with the lateral-sided repairs. Saphenous nerve injuries are more common with medial-sided tears. Because of the incision required and the technique of tying over soft tissue, the risk of a saphenous nerve injury is greater with an inside-out technique than with an all-inside technique.

Question 97

It has been shown that bisphosphonate-based supportive therapy (pamidronate or zoledronate) reduces skeletal events (onset or progression of osteolytic lesions) both in patients with multiple myeloma and in cancer patients with bone metastasis. The use of biphosphonate therapy has been associated with

Explanation

DISCUSSION: The use of bisphosphonates has been recently associated with the development of osteonecrosis of the jaw. Length of exposure seems to be the most important risk factor for this complication. The type of bisphosphonate may play a role and previous dental procedures may be a precipitating factor. Bisphosphonates are a class of therapeutic agents originally designed to treat loss of bone density (ie, alendronate). The primary mechanism of action of these drugs is inhibition of osteoclastic activity, and it has been shown that these drugs are useful in diseases with propensities toward osseous metastases. In particular, they are effective in diseases in which there is clear upregulation of osteoclastic or osteolytic activity, such as breast cancer and multiple myeloma, and have developed into a mainstay of treatment for individuals with these diseases. Although shown to reduce skeletal events, there has been no improvement in patient survival.
REFERENCES: Bamias A, Kastritis E, Bamia C, et al: Osteonecrosis of the jaw in cancer after treatment with bisphosphonates: Incidence and risk factors. J Clin Oncol 2005;23:8580-8587.
Thakkar SG, Isada C, Smith J, et al: Jaw complications associated with bisphosphonate use in patients with plasma cell dyscrasias. Med Oncol 2006;23:51-56.
Van Poznak C: The phenomenon of osteonecrosis of the jaw in patients with metastatic breast cancer. Cancer Invest 2006;24:110-112.

Question 98

Figure 7 shows the radiograph of a 64-year-old man who has neck pain and weakness of the upper and lower extremities following a motor vehicle accident. Examination reveals 3/5 quadriceps and 4/5 hip flexors but no ankle dorsiflexion or plantar flexion. His intrinsics are 1/5, with finger flexors of 3/5. He is awake, alert, and cooperative. Management should consist of

Explanation

DISCUSSION: In patients with facet dislocations and an incomplete neurologic deficit, early decompression of the canal via reduction of the dislocation generally is considered safe if the patient is alert and can cooperate. However, patients who cannot cooperate with serial neurologic examinations during the reduction are at risk for increased deficit secondary to herniated nucleus pulposus, and MRI should be performed prior to either closed or
open reduction.
REFERENCES: Star AM, Jones AA, Cotler JM, et al: Immediate closed reduction of cervical spine dislocations using traction. Spine 1990;15:1068-1072.
Cotler JM, Herbison GJ, Nasuti JF, et al: Closed reduction of traumatic cervical spine dislocations using traction weight up to 140 pounds. Spine 1993;18:386-390.

Question 99

-Figure 162 is the CT scan of a 74-year-old woman who struck her head during a ground-level fall and has severe neck pain. Examination reveals normal strength and sensation in her upper and lower extremities.What is the most appropriate treatment option?

Explanation

Question 100

An 18-year-old man sustained a traumatic laceration of the common peroneal nerve when glass fell on the outer part of his leg 1 year ago. He has used a molded foot and ankle orthosis for the past 10 months, but would now like surgical intervention. Electromyography shows no function in the anterior or lateral compartments. He has 5/5 muscle strength of the superficial and deep posterior compartments. What is the most appropriate treatment?

Explanation

In a patient with a drop foot and with 5/5 muscle strength of the posterior tibial tendon, a split posterior tibial tendon transfer would be the most appropriate treatment option based on the options presented. The deep peroneal nerve innervates the anterior tibial tendon. This muscle has been affected by the injury; therefore, the anterior tibial tendon cannot be transferred. A subtalar fusion would help correct inversion and eversion deformities, but is not effective for plantar flexion deformities. The foot drop is caused by a neurologic condition in this patient, not a contracture of the gastrocsoleus complex. Therefore, a recession would not be beneficial. A flexor
hallucis longus tendon transfer would not take the deforming force and make it a corrective force.

Full Question & Answer Text (for Search Engines)

Question 1:

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

Options:

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

Correct Answer: Quadriceps weakness

Explanation:

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

Question 2:

Options:

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

Correct Answer: Sedentary job

Explanation:

Question 3:

04 Which of the following laboratory studies is predictive of wound healing prior to performing a lower extremity amputation?

Options:

Total protein level
Calcium level
Serum albumin level
Platelet count
ESR back answer Question 11.04

Correct Answer: Serum albumin level

Explanation:

Question 4:

Options:

tighten as the knee extends past 10° of flexion.
tighten as the knee flexes past 90°.
loosen as the knee extends past 10° of flexion.
loosen as the knee flexes past 30°.
loosen as the knee flexes past 90°.

Correct Answer: tighten as the knee flexes past 90°.

Explanation:

Question 5:

Which of the following imaging modalities is most accurate in locating a toothpick in the plantar arch of the foot?

Options:

Radiograph
CT
MRI
Ultrasound
Bone scan

Correct Answer: Ultrasound

Explanation:

DISCUSSION: Ultrasound is best at imaging abrupt changes in the density of adjacent tissue and therefore is best at imaging wood in the soft tissues of the foot.
REFERENCES: Mizel MS, Steinmetz ND, Trepman E: Detection of wooden foreign bodies in muscle tissue: Experimental comparison of computed tomography, magnetic resonance imaging, and ultrasonography. Foot Ankle Int 1994;15:437-443.
Jacobson JA, Powell A, Craig JG, et al: Wooden foreign bodies in soft tissue: Detection at US. Radiology 1998;206:45-48.

Question 6:

Options:

Midsubstance tear of the lateral ulnar collateral ligament
Proximal avulsion of the ulnar collateral ligament
Proximal avulsion of the lateral ulnar collateral ligament
Distal bony avulsion of the ulnar collateral ligament from the sublime tubercle

Correct Answer: Proximal avulsion of the lateral ulnar collateral ligament

Explanation:

Question 7:

Compared to metal-on-polyethylene total hip bearing surfaces, the debris particles generated by metal-on-metal articulations are

Options:

larger and less numerous.
larger and more numerous.
smaller and less numerous.
smaller and more numerous.
not detectable.

Correct Answer: smaller and more numerous.

Explanation:

DISCUSSION: Retrieval studies have shown that the debris particles produced by
metal-on-metal articulations in total hip arthroplasty are several orders of magnitude smaller
and may be up to 100 times more numerous than those found with metal-on-polyethylene articulations.
REFERENCES: Davies AP, Willert HG, Campbell PA, et al: An unusual lymphocytic perivascular infiltration in tissues around contemporary metal-on-metal joint replacements.
J Bone Joint Surg Am 2005;87:18-27.
Firkins PJ, Tipper JL, Saadatzadeh MR, et al: Quantitative analysis of wear and wear debris from metal-on-metal hip prostheses tested in a physiological hip joint simulator. Biomed Mater Eng 2001;11:143-157.

Question 8:

Options:

slow rewarming in cool 77 degrees F (25 degrees C) water.
rapid rewarming in a footbath at 104.0 degrees F to 107.6 degrees F (40 degrees C to 42 degrees C).
rewarming in 98.6 degrees F (37 degrees C) water.
heated blankets at 100.4 degrees F (38 degrees C).
a heating pad at 104.0 degrees F (40 degrees C).

Correct Answer: rapid rewarming in a footbath at 104.0 degrees F to 107.6 degrees F (40 degrees C to 42 degrees C).

Explanation:

Question 9:

Options:

Surgical stabilization within 6 to 8 hours of injury
Extent of initial fracture displacement
Nicotine use
Posterior-to-anterior screw fixation
Anatomic fracture reduction

Correct Answer: Extent of initial fracture displacement

Explanation:

DISCUSSION: The incidence of osteonecrosis following displaced talar neck fractures is most related to the extent of initial fracture displacement. With increasing fracture displacement, the tenuous vascular supply to the talar body is more at risk for damage, thereby increasing the risk of osteonecrosis. Although displaced talar neck fractures have historically been considered a surgical emergency, recent studies have shown that the timing of surgical intervention bears no impact on the development of osteonecrosis. While nicotine use has an influence on fracture healing, it has never been shown to be a factor in osteonecrosis, nor has posterior-to-anterior screw fixation or the quality of fracture reduction.
REFERENCES: Lindvall E, Haidukewych G, Dipasquale T, et al: Open reduction and stable fixation of isolated, displaced talar neck and body fractures. J Bone Joint Surg Am 2004;86:2229-2234.
Vallier HA, Nork SE, Barei DP, et al: Talar neck fractures: Results and outcomes. J Bone Joint Surg Am 2004;86:1616-1624.

Question 10:

Which of the following factors is associated with improved outcomes following surgery for hip fractures?

Options:

Immediate surgical intervention
Early discharge to a skilled nursing facility
Choosing spinal versus general anesthesia for surgery
Choosing total hip arthroplasty instead of hemiarthroplasty for a displaced femoral neck fracture
Correction of metabolic abnormalities prior to surgical intervention

Correct Answer: Correction of metabolic abnormalities prior to surgical intervention

Explanation:

Question 11:

The patient is given a blood transfusion. After starting the transfusion, nurses note that her temperature is 38.8°C and she has shaking and chills. What is the most likely cause of this problem?

Options:

Bacterial contamination of intravenous tubing
Transmission of the hepatitis virus
Reaction to Kidd antigen in transfused blood
Blood transfusion incompatibility

Correct Answer: Blood transfusion incompatibility

Explanation:

Question 12:

Which of the following aids in correction of patellar tracking after total knee arthroplasty (TKA)?

Options:

Internal rotation of the femoral component
Internal rotation of the tibial component
Increasing size of the tibial component
Medialization of the patellar component
Joint line elevation

Correct Answer: Medialization of the patellar component

Explanation:

DISCUSSION: Correct patellofemoral tracking has proven to be a crucial aspect in TKA because a large percent of problems after TKA are related to the patellofemoral articulation. External rotation of the femoral and tibial components has been shown to aid in tracking. Likewise, medialization of the patellar button aids in patellar tracking and prevention of lateral subluxations and dislocations. Attention to the distal femoral cut is critical in maintaining the joint line and preventing patella baja or alta. Tibial sizing, however, is not directly related to patellar tracking after TKA.
REFERENCES: Callaghan JJ, Rosenberg AG, Rubash HE, et al (eds): The Adult Knee. Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 1245-1258.
Merkow RL, Soudry M, Insall JN: Patellar dislocation following total knee replacement. J Bone Joint Surg Am 1985;67:1321-1327.

Question 13:

Options:

The posterior bundle demonstrates the greatest change in tension from flexion to extension.
The posterior bundle is isometric.
The anterior bundle becomes tight in flexion and lax in extension.
The anterior and posterior bundles are isometric.

Correct Answer: The posterior bundle demonstrates the greatest change in tension from flexion to extension.

Explanation:

Question 14:

Options:

Inflation of the abdominal portion of the PASG
Application of a pelvic clamp
Application of a pelvic external fixator
Rapid infusion of 4 more units of blood
Angiography and embolization

Correct Answer: Angiography and embolization

Explanation:

Question 15:

Options:

0% if bracing is used
25%
50%
75%
90% or greater

Correct Answer: 90% or greater

Explanation:

Question 16:

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease that is characterized by

Options:

onset most often by age 30.
a temporary state of neuronal and axonal derangement.
manifestations of affect such as apathy, irritability, and suicidal ideation.
absence of gross pathological brain changes upon autopsy.

Correct Answer: manifestations of affect such as apathy, irritability, and suicidal ideation.

Explanation:

Question 17:

Options:

Correct Answer: C7

Explanation:

Question 18:

Options:

Ewing’s sarcoma
Osteosarcoma
Rhabdomyosarcoma
Osteomyelitis
Malignant fibrous histiocytoma

Correct Answer: Osteosarcoma

Explanation:

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

Question 19:

Options:

Flexor-pronator avulsion
Ulnar nerve subluxation
Medial collateral ligament injury
Lateral ulnar collateral ligament rupture
Triceps tendon subluxation

Correct Answer: Medial collateral ligament injury

Explanation:

DISCUSSION: The milking test, as seen in the photograph, elicits pain when a tear is present in the medial collateral ligament. Complete rupture is possible but unlikely when there is no history of trauma and the patient is able to throw pain-free for several innings. Subluxation of the ulnar nerve and triceps tendon subluxation present as a painful snapping over the medial aspect of the elbow.
REFERENCES: Williams RJ III, Urquhart ER, Altchek DW: Medial collateral ligament tears in the throwing athlete. Instr Course Lect 2004;53:579-586.
Cain EL Jr, Dugas JR, Wolf RS, et al: Elbow injuries in throwing athletes: A current concepts review. Am J Sports Med 2003;31:621-635.

Question 20:

Options:

Manipulate the knee under anesthesia
Aspirate the knee for persistent hematoma to improve motion
Obtain advanced imaging to evaluate the lesion and fixation
Prescribe more intensive physical therapy 3 to 5 times a week to achieve motion

Correct Answer: Obtain advanced imaging to evaluate the lesion and fixation

Explanation:

Question 21:

Options:

Epidural steroid injection at L4-5
Outpatient physical therapy for the lower back
Non-weight-bearing of the left lower extremity
Home exercise program, analgesics, and limited use of muscle relaxants
Cortisone injection of the left greater trochanter region

Correct Answer: Non-weight-bearing of the left lower extremity

Explanation:

DISCUSSION: Although the imaging reveals generalized lumbar spondylosis and stenosis, in particular at L4-5, the MRI scan of the left hip clearly reveals a stress fracture of the femoral neck. Therefore, the treatment of choice is non-weight-bearing of the left lower extremity. During the evaluation of acute back pain, clinicians must include other possibilities within the differential diagnosis that may mimic mechanical axial back pain; thus, potential complications from a missed diagnosis can be avoided.
REFERENCES: Wong DA, Transfeldt E: Macnab’s Backache, ed 4. Philadelphia, PA, Lippincott Williams and Wilkins, 2007, pp 339-361.
Spivak JM, Connolly PJ (ed): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 43-56.

Question 22:

Options:

Recurrent valgus overload (medial collateral ligament sprain)
Posterior lateral rotatory instability
Biceps tendinitis
Medial epicondylitis
Osteochondritis of the capitellum

Correct Answer: Osteochondritis of the capitellum

Explanation:

Question 23:

Options:

Incomplete C5 spinal cord injury
Complete C5 spinal cord injury
Complete C6 spinal cord injury
Central spinal cord injury
Brown-STquard syndrome

Correct Answer: Complete C5 spinal cord injury

Explanation:

Question 24:

Options:

High tibial osteotomy
Total knee replacement
Unicondylar knee replacement
Arthroscopic partial meniscectomy

Correct Answer: Total knee replacement

Explanation:

Question 25:

Figure 1 shows a radiograph obtained from an active 30-year-old man who sustained an injury to his ring finger 1 week earlier. The most appropriate treatment is

Options:

open reduction and internal fixation (ORIF).
a mallet splint.
repair of the terminal tendon.
arthrodesis.

Correct Answer: open reduction and internal fixation (ORIF).

Explanation:

EXPLANATION:
Figure 1 reveals evidence of an intra-articular distal phalanx fracture with a distal interphalangeal (DIP) joint dorsal subluxation. This injury is unstable and requires surgical management for an active individual. Volar distal phalanx fractures are often associated with flexor digitorum profundus avulsion injuries, which are addressed concomitantly. This injury was treated with ORIF of the intra-articular fracture, pinning of the DIP joint, and repair of an avulsed flexor digitorum profundus tendon with a button on the dorsal nail plate, as shown in Figure 2. Splint immobilization would not maintain a reduction of this unstable injury. The terminal tendon is not injured in this patient but is often injured in a dorsal distal phalanx fracture with a volar dislocation. Arthrodesis of the DIP is a salvage procedure and would not be considered acutely.

Question 26:

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

Options:

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

Correct Answer: Blocks transcription of DNA

Explanation:

Question 27:

Figure 46 shows the radiograph of an obese 12-year-old boy who has had left hip pain for the past 3 months. What is the best course of action?

Options:

Decreased activities and physical therapy
Left hip reduction and internal fixation
Left hip pinning in situ
Bilateral hip pinning in situ
Spica cast immobilization

Correct Answer: Left hip pinning in situ

Explanation:

Question 28:

Options:

Renal ultrasound
Blood cultures
Flexion-extension cervical spine radiographs
Platelet count

Correct Answer: Renal ultrasound

Explanation:

Question 29:

Options:

Aspiration of joint fluid to obtain a cell count
Revision of the UKA using primary total knee arthroplasty (TKA) components
Revision of the UKA using a revision TKA with augments
Procurement of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level

Correct Answer: Procurement of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level

Explanation:

Question 30:

Bacterial resistance to antibiotics in biofilm is an example of Review Topic

Options:

avoidance.
decreased susceptibility.
inactivation.
mutation.

Correct Answer: avoidance.

Explanation:

Question 31:

- A right-handed 35-year old man who underwent a Putti-Platt repair for recurrent anterior instability 20 years ago now has increasing shoulder pain and stiffness. Examination of the shoulder reveals internal rotation to the posterior superior iliac spine and external rotation to 10 degrees with the shoulder adducted. The supraspinatus and infraspinatus are moderately atrophied. What is the most likely diagnosis?

Options:

C5 radiculopathy
Subscapularis rupture
Glenohumeral arthrosis
Rotator cuff arthropathy
Suprascapular nerve compression at the spinoglenoid notch

Correct Answer: Glenohumeral arthrosis

Explanation:

Question 32:

Options:

Continue to observe with repeat radiographs in 6 months
Fluoroscopic-guided iliopsoas tendon cortisone injection
Hip aspiration
Serum cobalt and chromium levels and metal-reduction MRI scan

Correct Answer: Serum cobalt and chromium levels and metal-reduction MRI scan

Explanation:

Question 33:

Options:

Hip spica cast placement
Acetabular revision arthroplasty
Resection arthroplasty
Femoral head revision to a 28-mm diameter, +10-mm length head

Correct Answer: Acetabular revision arthroplasty

Explanation:

Question 34:

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

Options:

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

Correct Answer: Persistent unilateral ptosis, myosis, and anhydrosis

Explanation:

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

Question 35:

Options:

anterior cruciate ligament reconstruction with lateral meniscus repair.
partial lateral meniscectomy with saucerization.
lateral meniscus transplant.
protected weight bearing with referral for genetic testing.

Correct Answer: partial lateral meniscectomy with saucerization.

Explanation:

The MR images show a tear through a discoid lateral meniscus. A discoid meniscus is caused by a failure of apoptosis during development in utero and is considered a congenital abnormality. Discoid menisci are prone to tearing and can be caused by minimal trauma. There is no known genetic cause for this condition. Radiographic findings that may be present in the setting of a discoid meniscus include lateral joint space widening, squaring of the lateral femoral condyle, and cupping of the lateral tibial plateau. Contralateral discoid menisci are noted in 20% of patients. There are no other known associated conditions. Treatment
of a symptomatic discoid meniscus should include partial meniscectomy and saucerization or repair.

Question 36:

Options:

Superior approach with trochanteric slide
Direct anterior approach with a chevron modification of the standard greater trochanteric osteotomy
Lateral approach with a partial greater trochanter osteotomy
Posterolateral approach with an extended trochanteric osteotomy

Correct Answer: Posterolateral approach with an extended trochanteric osteotomy

Explanation:

Question 37:

Which of the following is considered a physiologic effect of anemia?

Options:

Decreased heart rate
Decreased coronary artery flow requirement
Increased cardiac output
Increased peripheral resistance
Increased blood viscosity

Correct Answer: Increased cardiac output

Explanation:

Question 38:

Options:

In extension with internal rotation/valgus force, the medial tibial plateau is subluxated; with flexion, the medial tibial plateau reduces.
In extension with internal rotation/valgus force, the medial tibial plateau is reduced; with flexion, the medial tibial plateau subluxates.
In extension with internal rotation/valgus force, the lateral tibial plateau is reduced; with flexion, the lateral plateau subluxates.
In extension with internal rotation/valgus force, the lateral tibial plateau is subluxated; with flexion, the lateral plateau reduces.

Correct Answer: In extension with internal rotation/valgus force, the lateral tibial plateau is subluxated; with flexion, the lateral plateau reduces.

Explanation:

Question 39:

Options:

Conversion to a latissimus dorsi muscle tendon transfer
Acromioplasty and coracoacromial ligament release
Reverse acromioplasty (tuberoplasty)
Reverse total shoulder arthroplasty
Partial repair of the rotator cuff

Correct Answer: Partial repair of the rotator cuff

Explanation:

Question 40:

When standing, dorsiflexion of the great toe will accentuate

Options:

midfoot pronation.
heel valgus.
internal tibial rotation.
rigidity of the transverse tarsal articulation.
parallel alignment of the talonavicular and calcaneocuboid joints.

Correct Answer: rigidity of the transverse tarsal articulation.

Explanation:

Question 41:

Options:

Anesthetic injections in both sacroiliac joints
Sacroiliac fusion with plate fixation
Anti-inflammatory medications, physical therapy, and HLA-B27 testing
Patient reassurance and follow-up as needed
Immediate bilateral sacroiliac joint aspiration and culture

Correct Answer: Anti-inflammatory medications, physical therapy, and HLA-B27 testing

Explanation:

Question 42:

Options:

suppressive antibiotics.
open irrigation and debridement with polyethylene exchange.
one-stage resection arthroplasty and reimplantation.
two-stage resection arthroplasty and reimplantation.
arthroscopic irrigation and debridement.

Correct Answer: two-stage resection arthroplasty and reimplantation.

Explanation:

Question 43:

The force generated by a muscle is most highly dependent on its

Options:

cross-sectional area.
fiber type.
length.
morphology.
level of conditioning.

Correct Answer: cross-sectional area.

Explanation:

Question 44:

Options:

Referral to the pain clinic to consider insertion of a morphine pump
L1-2 laminectomy
L1-2 anterior lumbar interbody fusion via a minimally invasive technique
Posterior laminectomy and uninstrumented fusion
Posterior decompression and instrumented fusion

Correct Answer: Posterior decompression and instrumented fusion

Explanation:

DISCUSSION: The patient has degeneration of an adjacent segment with resultant
kyphosis and stenosis. Because he is healthy, has responded well to previous surgery,
|and has a potentially correctable lesion, he is not a good candidate for an end-stage failed
back procedure such as a morphine pump. The stenosis is exacerbated by the deformity; therefore, a simple decompression will contribute to instability. Because of the kyphosis and the patient’s relatively young age, the treatment of choice is restoration of sagittal alignment and posterior decompression.
REFERENCE: Eck JC, Humphreys SC, Hodges SD: Adjacent-segment degeneration after lumbar fusion: A review of clinical, biomechanical, and radiographic studies. Am J Orthop 1999;28:336-340.

Question 45:

Options:

acute and transient spinal cord injury.
central cord syndrome.
nerve root avulsion.
Guillain-Barre syndrome.
stinger/burner.

Correct Answer: stinger/burner.

Explanation:

Question 46:

What is the most common non-anesthetic-related reversible cause of sustained changes in intraoperative neurophysiologic monitoring signals during spinal surgery? Review Topic

Options:

Pedicle screw misplacement
Patient positioning
Spinal cord ischemia
Retractor placement
Hypertension

Correct Answer: Patient positioning

Explanation:

Question 47:

The natural history of cervical spondylolytic myelopathy is best described as

Options:

slow, steady deterioration.
rapid deterioration.
stable over time.
stable for long periods with stepwise deterioration.
significant improvement after an initial episode of severe symptoms.

Correct Answer: stable for long periods with stepwise deterioration.

Explanation:

Question 48:

Options:

Acute traumatic Lisfranc fracture-dislocation
Acquired pes planus due to rupture of the posterior tibial tendon
Neuropathic arthropathy
Osteomyelitis
Metatarsal stress fracture

Correct Answer: Neuropathic arthropathy

Explanation:

Question 49:

Options:

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

Correct Answer: Upper trunk of the brachial plexus

Explanation:

Question 50:

Which of the following factors is associated with decreases in active periprosthetic osteolysis in total hip arthroplasty?

Options:

Large heads in metal-on-polyethylene articulations
Modular acetabular components
Circumferential porous coating
Sterilization of polyethylene by gamma irradiation with storage in air
Supplemental screw fixation

Correct Answer: Circumferential porous coating

Explanation:

Question 51:

Denosumab, a monoclonal antibody used to treat osteoporosis, works through inhibition of

Options:

receptor activator of nuclear factor kappa beta (RANK).
RANK ligand (RANKL).
osteoprotegrin (OPG).
tumor necrosis factor (TNF).

Correct Answer: RANK ligand (RANKL).

Explanation:

Question 52:

Options:

Clear cell chondrosarcoma
Chondroblastoma
Giant cell tumor
Aneurysmal bone cyst
Osteonecrosis of the femoral head

Correct Answer: Chondroblastoma

Explanation:

Question 53:

Options:

Unloader brace
Distal femoral osteotomy
Open arthrofibrosis debridement with lateral ligament balancing and polyethylene exchange
Revision TKA of both the femoral and tibial components

Correct Answer: Revision TKA of both the femoral and tibial components

Explanation:

Question 54:

A child presents with the radiograph shown in Figure A. Which of the following conditions is LEAST likely to be associated with this disorder? Review Topic

Options:

Unilateral absent kidney
Sever's disease
Ventricular septal defect
Tethered cord
Thumb hypoplasia

Correct Answer: Unilateral absent kidney

Explanation:

Question 55:

Options:

Autogenous iliac crest bone graft
Calcium phosphate
Calcium sulfate
Tricalcium phosphate
Coralline hydroxyapatite blocks

Correct Answer: Calcium phosphate

Explanation:

Question 56:

Options:

Cemented left total hip arthroplasty (THA)
Cementless left THA with a proximally porous coated femoral stem
Hybrid left THA
Cementless left THA with a diaphyseal engaging conical femoral stem

Correct Answer: Hybrid left THA

Explanation:

Question 57:

Options:

Enchondroma
Giant cell tumor
Osteosarcoma
Simple bone cyst
Histiocytosis

Correct Answer: Simple bone cyst

Explanation:

Question 58:

Options:

Brodie’s abscess
Hyperparathyroidism
Stress fracture
Enchondroma
Osteoid osteoma

Correct Answer: Osteoid osteoma

Explanation:

DISCUSSION: Osteoid osteoma is a round or oval, well-circumscribed lesion with a
radiolucent nidus. A small area of calcification may be present within the center of the nidus. The radiolucent nidus is surrounded by a thick rim of sclerotic bone. These diagnostic
features are frequently better seen on CT. An increase in cyclooxygenase activity has been demonstrated within osteoid osteomas, which may explain why aspirin and other nonsteroidal anti-inflammatory drugs classically relieve the pain associated with these lesions.
REFERENCES: Kneisl JS, Simon MA: Medical management compared with operative treatment for osteoid-osteoma. J Bone Joint Surg Am 1992;74:179-185.
Unni KK: Dahlin’s Bone Tumors: General Aspects and Data on 11,087 Cases, ed 5. Philadelphia, PA, Lippincott-Raven, 1996, pp 121-130.

Question 59:

Options:

Gadolinium-enhanced MRI of the great toe
Serum uric acid level, C-reactive protein, and erythrocyte sedimentation rate
Serum rheumatoid factor
Aspiration of the first metatarsophalangeal joint
Fasting serum glucose level

Correct Answer: Aspiration of the first metatarsophalangeal joint

Explanation:

DISCUSSION: The patient has gouty arthropathy of the first metatarsophalangeal joint. This definitive diagnosis is achieved with aspiration of the joint and polarized light microscopy that shows needle-shaped negatively birefringent monosodium urate crystals. Differential diagnoses of infectious arthritis and pseudogout are also definitively made through joint aspiration. Although rheumatoid arthritis is a possibility, a serum rheumatoid factor is not always diagnostic and a patient with rheumatoid arthritis may have concomitant gouty arthritis. The radiographic findings are not typical of diabetes mellitus or of a patient with Charcot arthropathy.
REFERENCES: Wise CM, Agudelo CA: Diagnosis and management of complicated gout. Bull Rheum Dis 1998;47:2-5.
Harris MD, Siegel LB, Alloway JA: Gout and hyperuricemia. Am Fam Physician 1999;59:925-934.

Question 60:

Options:

rotator cuff interval closure.
distal clavicle excision.
superior labrum anterior and posterior repair.
biceps tenodesis.
thermal capsulorrhaphy.

Correct Answer: distal clavicle excision.

Explanation:

Question 61:

A 17-year-old girl has multidirectional instability of the shoulder. What is the most appropriate initial management?

Options:

Immobilization in a sling and swathe
Open capsular shift
Arthroscopic capsular plication
Thermal capsulorrhaphy
Physical therapy and home exercises

Correct Answer: Physical therapy and home exercises

Explanation:

DISCUSSION: Multidirectional instability of the shoulder is defined as symptomatic instability in two or more directions (anterior, posterior) but must include a component of inferior instability. Initial treatment should always include physical therapy and instruction in a home exercise program that emphasizes periscapular and rotator cuff strengthening to improve the dynamic stability of the glenohumeral joint. Immobilization has not been shown to be effective. Open capsular shift and arthroscopic capsular plication remain the surgical options when appropriate nonsurgical management fails (typically a minimum of 6 months of dedicated therapy and home program). Thermal capsulorrhaphy remains controversial but is not recommended by many clinicians because of reported complications including recurrent instability, axillary nerve injury, chondrolysis, and capsular injury.
REFERENCES: Neer CS II, Foster CR: Inferior capsular shift for involuntary inferior and multidirectional instability of the shoulder: A preliminary report. J Bone Joint Surg Am 1980;62:897-908.
D’Alessandro DF, Bradley JP, Fleischli JE, et al: Prospective evaluation of thermal capsulorrhaphy for shoulder instability: Indications and results, two- to five-year follow-up.
Am J Sports Med 2004;32:21-33.
Levine WN, Clark AM Jr, D’Alessandro DF, et al: Chondrolysis following arthroscopic thermal capsulorrhaphy to treat shoulder instability: A report of two cases. J Bone Joint Surg Am 2005;87:616-621.
Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 278-279.

Question 62:

Options:

Incision and drainage with repair of the extensor mechanism
Removal of components and delayed revision knee arthroplasty with an allograft extensor mechanism
Removal of components and immediate exchange revision total knee arthroplasty
Removal of components and delayed knee arthrodesis
Removal of components and delayed revision knee arthroplasty with extensor mechanism repair

Correct Answer: Removal of components and delayed knee arthrodesis

Explanation:

Question 63:

A cartilage water content increase is the hallmark of which osteoarthritis stage?

Options:

Prearthritis
Early
Late
Terminal

Correct Answer: Early

Explanation:

Question 64:

Nutritional rickets is associated with which of the following changes in chemical blood level?

Options:

Low Vitamin D levels
High to normal calcium levels
High phosphate levels
Decreased PTH
Decreased alkaline phosphatase levels

Correct Answer: Low Vitamin D levels

Explanation:

DISCUSSION: Nutritional rickets is associated with decreased dietary intake of Vitamin D, resulting in low levels of Vitamin D that result in decreased intestinal absorption of calcium
and low to normal serologic levels of calcium. To boost serum calcium levels, there is a compensatory increase in PTH and bone resorption, leading to increased alkaline
phosphatase levels.
REFERENCES: Brinker MR: Cellular and molecular biology, immunology, and genetics in orthopaedics, in Miller MD (ed): Review of Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2001, pp 81-94.
Pettifor J: Nutritional and drug-induced rickets and osteomalacia, in Farrus MJ (ed): Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2003, pp 399-466.
Einhorn TA: Metabolic bone disease, 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 65:

Patients who sustain bilateral femoral shaft fractures when compared to unilateral femur fractures have higher rates of the following EXCEPT:

Options:

closed head injury
mortality
thoracic injury
open skull fractures
pelvic fractures

Correct Answer: closed head injury

Explanation:

Question 66:

Options:

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

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

Explanation:

Question 67:

Options:

Trochanteric bursitis
Femoral component loosening
Iliopsoas tendonitis
Acetabular component loosening

Correct Answer: Iliopsoas tendonitis

Explanation:

Question 68:

A healthy 65-year-old woman undergoes anatomic total shoulder arthroplasty to address osteoarthritis (OA). The surgery is uncomplicated. What is the most common indication for future revision?

Options:

Deep infection
Periprosthetic fracture
Glenoid component loosening
Rotator cuff tear

Correct Answer: Glenoid component loosening

Explanation:

Question 69:

Options:

Brachiocephalic
Innominate
Subclavian
Axillary
Circumflex scapular

Correct Answer: Axillary

Explanation:

DISCUSSION: The axillary artery commences at the first rib as a direct continuation of the subclavian artery and becomes the brachial artery at the lower border of the teres major. The arteriogram reveals a nonfilling defect in the third portion of the artery just distal to the subscapular artery. The complex arterial collateral circulation in this region often permits distal perfusion of the extremity despite injury.
REFERENCE: Radke HM: Arterial circulation of the upper extremity, in Strandness DE Jr (ed): Collateral Circulation in Clinical Surgery. Philadelphia, PA, WB Saunders, 1969, pp 294-307.

Question 70:

A comparison of dural tears repaired with suture alone and those treated by suture with fibrin glue supplementation will reveal which of the following findings?

Options:

Delayed arachnoid interposition with fibrin glue supplementation
Delayed primary dural healing with fibrin glue supplementation
A more marked inflammatory response with fibrin glue supplementation
Higher infection rates with fibrin glue supplementation
No significant differences

Correct Answer: A more marked inflammatory response with fibrin glue supplementation

Explanation:

Question 71:

Options:

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

Correct Answer: Heuter-Volkmann principle

Explanation:

Question 72:

-Figures 52c and 52d show the proton density fat-saturated MRI scans. Treatment at this stage includes arthroscopy and

Options:

early functional rehabilitation.
proximal realignment alone.
attempted internal fixation.
medial collateral ligament (MCL) repair.

Correct Answer: attempted internal fixation.

Explanation:

DISCUSSION FOR QUESTIONS 52 THROUGH 54
This patient’s examination indicates a patellar or peripatellar knee injury. Initial evaluation with radiographs will assess for fracture, subluxation, or osteochondral injury. Examination findings did not demonstrate a need for emergent surgery, an MRI scan, or an ultrasound, so radiographs are the initial diagnostic imaging choice. Radiographs show an osseous or osteochondral loose fragment.
There is no evidence of obvious nondisplaced fracture or physeal changes. In suspected patella dislocation or subluxation with loose fragment seen on radiographs, an MRI scan is indicated. Lateral release alone is seldom indicated in a knee that was normal before injury. Acute proximal realignment has not been shown to alter long-term outcomes for first-time dislocators. The examination and MRI scan did not indicate a need for MCL repair. Closed reduction of the osteochondral fragment would not be indicated or appropriate for this injury. Treatment should consist of arthroscopy or arthrotomy and attempted internal fixation of this fragment. If fixation is not possible, the loose body can be removed.

Question 73:

Etanercept is a recombinant genetically engineered fusion protein used to treat rheumatoid arthritis. What is its mode of action?

Options:

Monoclonal antibody that binds TNF-α
Blocks the binding of IL-1 to receptors
Soluble receptor that binds TNF-α
Soluble factor that binds rheumatoid factor
Directly inhibits pyrimidine synthesis

Correct Answer: Soluble receptor that binds TNF-α

Explanation:

Question 74:

Options:

Aspiration of joint fluid to obtain a cell count
Revision of the UKA using primary total knee arthroplasty (TKA) components
Revision of the UKA using a revision TKA with augments
Procurement of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level

Correct Answer: Procurement of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level

Explanation:

Question 75:

Options:

Revision of the polyethylene liner, removal of the screw, and debridement of the osteolytic lesion with or without bone grafting
Revision of the acetabular component to a newer design without screws
Removal of the screw, revision of the polyethylene liner, and stem cell injection into the lytic lesion
Removal of the offending screw from the metal socket and placement of a new polyethylene liner in the existing socket

Correct Answer: Revision of the polyethylene liner, removal of the screw, and debridement of the osteolytic lesion with or without bone grafting

Explanation:

Question 76:

Which structure is shown in Video 27? 27

Options:

Superficial medial collateral ligament
Semimembranosus tendon
Posterior oblique ligament
Medial patellofemoral ligament

Correct Answer: Medial patellofemoral ligament

Explanation:

Question 77:

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

Options:

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

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

Explanation:

Question 78:

Based on the Young and Burgess classification of pelvic ring injuries, an anterior-posterior compression type II injury does not result in disruption of which of the following?

Options:

pubic symphysis
anterior sacroiliac ligaments
posterior sacroiliac ligaments
sacrospinous ligament
sacrotuberous ligament

Correct Answer: pubic symphysis

Explanation:

Question 79:

Options:

Removal of the components and placement of an antibiotic spacer
Removal of the components, placement of an antibiotic spacer, and bone grafting of the glenoid defect
Resection arthroplasty
Exchange of the humeral head and debridement
Arthroscopic debridement

Correct Answer: Removal of the components and placement of an antibiotic spacer

Explanation:

Question 80:

Which of the following methods is effective in correcting recurrent dislocation following total hip arthroplasty?

Options:

Lateralization of the greater trochanter without advancement
Use of a shorter neck length
Use of a constrained acetabular component
Use of a small diameter head
High cup abduction angle

Correct Answer: Use of a constrained acetabular component

Explanation:

Question 81:

What is the most common physical examination finding in a patient with chronic painful spondylolysis? Review Topic

Options:

Positive straight leg raise
Pain with forward flexion
Pain with lumbar extension
Absent tendo-Achilles reflex

Correct Answer: Pain with lumbar extension

Explanation:

Question 82:

Figures 22a and 22b show the radiographs of a patient who reports stiffness of the hip and associated pain. Management should consist of

Options:

use of a cane for ambulation.
diphosphonate therapy.
physical therapy and indomethacin.
surgical excision and radiation therapy.
revision arthroplasty.

Correct Answer: surgical excision and radiation therapy.

Explanation:

Question 83:

Options:

Emergent four compartment fasciotomies
Emergent four compartment fasciotomies and open reduction and internal fixation of the fracture
Elevation of the limb overnight and four compartment fasciotomies in the morning
Elevation of the limb overnight and a recheck of compartment pressures in the morning
Emergent MRI of the knee and leg

Correct Answer: Emergent four compartment fasciotomies and open reduction and internal fixation of the fracture

Explanation:

DISCUSSION: The patient has a compartment syndrome based on the firm compartments of the leg and the elevated compartment pressures measured at the diastolic pressure reading. Muscle ischemia occurs quickly when compartment pressures are elevated, and within 6 hours irreversible damage can occur. Emergent fasciotomies permit decompression of all four compartments and reestablishment of vascular supply to the muscles. Stabilization of the fracture prevents further soft-tissue injury.
REFERENCE: Beaty JH, Kasser JR (eds): Fractures in Children, ed 6. Philadelphia, PA, Lippincott, 2006, pp 1057-1061.

Question 84:

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

Options:

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

Correct Answer: Normal findings

Explanation:

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

Question 85:

Figure 44 shows the radiograph of an 11-year-old girl who has hip pain. Further diagnostic workup should include

Options:

a renal ultrasound.
an echocardiogram.
an electromyogram.
an MRI scan of the spine.
an iliac crest biopsy.

Correct Answer: an echocardiogram.

Explanation:

Question 86:

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 87:

During total knee arthroplasty, the patella is noted to subluxate laterally despite a lateral retinacular release. Which of the following methods is most likely to improve patellar stability?

Options:

Slight external rotation of the tibial component
Slight internal rotation of the femoral component
Slight anterior translation of the tibial component
Use of a fixed-bearing knee as opposed to a mobile-bearing knee
Use of a thicker patellar component

Correct Answer: Slight external rotation of the tibial component

Explanation:

DISCUSSION: Slight external rotation of the tibial component will cause a net medialization of the tibial tubercle when the knee is articulated. This will help centralize the extensor mechanism over the trochlear groove and minimize the tendency for lateral subluxation. Internal rotation of the femoral component increases the risk of patellar instability. Anterior translation of the tibial component moves the patellar tendon insertion posteriorly, and may increase force on the patella but should not substantially alter patellar tracking. Clinical studies have shown no patellofemoral benefits to the use of fixed- or mobile-bearing designs. Thicker patellar components will not improve tracking, and may compound the problem.
REFERENCES: Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 207, 323-337
Pagnano MW, Trousdale RT, Stuart MJ, et al: Rotating platform knees did not improve patellar tracking: A prospective, randomized study of 240 primary total knee arthroplasties. Clin Orthop 2004;428:221-227.
Lotke PA, Garino JP (eds): Revision Total Knee Arthroplasty. Philadelphia PA, Lippincott-Raven, 1999, pp 427-435.

Question 88:

Options:

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

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

Explanation:

Question 89:

- Which of the following acetabular/femoral head components would be expected to show an optimal combination of linear and volumetric wear?

Options:

mm femoral head in combination with a metal-backed polyethylene component
mm femoral head in combination with an all-polyethylene acetabular component
mm femoral head in combination with a metal-backed polyethylene component
mm femoral head in combination with an all-polyethylene component
mm femoral head in combination with a metal-backed polyethylene component

Correct Answer: mm femoral head in combination with a metal-backed polyethylene component

Explanation:

Question 90:

Options:

Suture anchor repair of the labral tear and no bony resection
Suture anchor repair of the labral tear and bony resection of the pincer lesion
Debridement of the labral tear and bony resection of the pincer lesion
Debridement of the labral tear with no bony resection of the pincer lesion

Correct Answer: Suture anchor repair of the labral tear and bony resection of the pincer lesion

Explanation:

DISCUSSION FOR QUESTIONS 26 THROUGH 29
The clinical scenario, examination, and MRI scans are consistent with a pincer-type FAI. The decreased range of motion is secondary to the pain produced by the continued abutment of the femoral head against the anterosuperior acetabulum. Flexing the hip while internally rotating and adducting the leg recreates this contact and is typically painful. No clinical signs suggest sacroiliac joint arthritis, an intra-articular loose body, or trochanteric bursitis, although these are all diagnoses that should be considered in a patient with a painful hip. The most sensitive and specific study to detect an acetabular labral tear is an MRI arthrogram of the hip. This study should be obtained in this patient to evaluate the labrum as well as the status of the articular cartilage. An MRI scan without intra-articular contrast is not as sensitive as an arthrogram. An ultrasound can provide a dynamic assessment of the hip and help in the setting of a snapping hip; however, this study is not reliable to determine the presence of a labral tear. In the setting of pincer FAI, the forced leverage of the anterosuperior femoral head upon the anterior acetabulum results in abnormal forces against the posteroinferior acetabulum. This continued force can lead to a chondral lesion in this location know as a “counter-coup” injury. Chondral lesions of the femoral head are rare in the setting of pincer FAI. The posterosuperior quadrant does not experience increased force and rarely sustains chondral injuries. The patient is a young, active individual with no pre-existing degenerative changes, so repair of the tear with bony resection of the pincer lesion is the most appropriate treatment.A capsulolabral detachment should be repaired because these tears can heal and the labrum functions as a seal, preventing egress of synovial fluid from the joint space. If the pincer lesion is not resected, the patient will continue to experience abnormal contact and the repair will likely fail. There is no evidence that the patient has a cam impingement, and recontouring of the femoral head/neck junction is not appropriate. Simple debridement should be reserved for intrasubstance tears of the labrum, which would not be expected to heal with repair.
CLINICAL SITUATION FOR QUESTIONS 30 THROUGH 32
Figures 30a and 30b are the radiographs of a 20-year-old college multisport athlete who has had longstanding pain in his left hip. He denies any specific event that initiated his pain, but he notes that he had hip problems when he was an infant. He denies pain with activities of daily living, but he
believes his pain is increasingly limiting his ability to exercise. He localizes the pain to his groin. He denies low-back or buttock pain or pain that radiates down his leg.

Question 91:

Options:

Synovial sarcoma
Infection
Pigmented villonodular synovitis
Malignant fibrous histiocytoma
Synovial chondromatosis

Correct Answer: Pigmented villonodular synovitis

Explanation:

DISCUSSION: Pigmented villonodular synovitis often presents with intermittent swelling and minimal pain. It often occurs around joints but may be found around tendon sheaths and bursal linings. Periarticular erosions involving both sides of joints are typical, and multiple joint involvement has been described. Portions of low-signal intensity on T
1
- and T
2
-weighted images are characteristic of hemosiderin-laden processes. High-signal content is suggestive of high water content. The combination of low-signal intensity areas in intra-articular lesions with or without osseous destruction is diagnostic of pigmented villonodular synovitis. Aspiration reveals bloody or brownish fluid. The treatment of choice is synovectomy performed arthroscopically or open. Recurrence is common.
REFERENCES: Walling AK: Soft tissue and bone tumors, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 1007-1032.
Simon M, Springfield D: Surgery for the Bone and Soft-Tissue Tumors. Philadelphia, PA, Lippincott Williams & Wilkins, 1998, p 36.

Question 92:

Options:

Superior labrum anterior and posterior lesion, type III
Isolated traumatic dislocation
Axillary nerve disruption
Subscapularis rupture
Internal impingement

Correct Answer: Subscapularis rupture

Explanation:

Question 93:

When do most symptomatic thromboembolic events occur after total joint arthroplasty?

Options:

More than 3 months after surgery
On the day of surgery
Within the first week after surgery
Between 1 week and 6 weeks after surgery

Correct Answer: Within the first week after surgery

Explanation:

Question 94:

Which of the following tumors is most likely to present with a pathologic fracture in a child?

Options:

Unicameral bone cyst
Fibrous cortical defect
Osteosarcoma
Ewing’s sarcoma
Giant cell tumor

Correct Answer: Unicameral bone cyst

Explanation:

Question 95:

Options:

Chairback brace
Thoracolumbosacral orthosis (TLSO) molded in extension
Posterior stabilization of the fracture with segmental fixation and iliac crest bone grafting
Anterior corpectomy, strut grafting, and plating
Combined anterior corpectomy, structural grafting and plating, and posterior stabilization and fusion

Correct Answer: Thoracolumbosacral orthosis (TLSO) molded in extension

Explanation:

Question 96:

Which of the following complications is more likely with an inside-out repair technique compared to an all-inside techniques for a medial meniscus tear? Review Topic

Options:

Failure
Intra-articular synovitis
Peroneal nerve injury
Saphenous nerve injury
Arthrofibrosis

Correct Answer: Saphenous nerve injury

Explanation:

Question 97:

Options:

increased medical complications of treatment.
osteonecrosis of the jaw.
improved long-term survival rates.
anorexia.
decreased quality of life measures.

Correct Answer: osteonecrosis of the jaw.

Explanation:

DISCUSSION: The use of bisphosphonates has been recently associated with the development of osteonecrosis of the jaw. Length of exposure seems to be the most important risk factor for this complication. The type of bisphosphonate may play a role and previous dental procedures may be a precipitating factor. Bisphosphonates are a class of therapeutic agents originally designed to treat loss of bone density (ie, alendronate). The primary mechanism of action of these drugs is inhibition of osteoclastic activity, and it has been shown that these drugs are useful in diseases with propensities toward osseous metastases. In particular, they are effective in diseases in which there is clear upregulation of osteoclastic or osteolytic activity, such as breast cancer and multiple myeloma, and have developed into a mainstay of treatment for individuals with these diseases. Although shown to reduce skeletal events, there has been no improvement in patient survival.
REFERENCES: Bamias A, Kastritis E, Bamia C, et al: Osteonecrosis of the jaw in cancer after treatment with bisphosphonates: Incidence and risk factors. J Clin Oncol 2005;23:8580-8587.
Thakkar SG, Isada C, Smith J, et al: Jaw complications associated with bisphosphonate use in patients with plasma cell dyscrasias. Med Oncol 2006;23:51-56.
Van Poznak C: The phenomenon of osteonecrosis of the jaw in patients with metastatic breast cancer. Cancer Invest 2006;24:110-112.

Question 98:

Options:

halo vest immobilization.
MRI.
Gardner-Wells tongs and closed reduction.
posterior open reduction and fusion.
observation until the patient’s general medical status improves, followed by closed reduction via Gardner-Wells tongs.

Correct Answer: Gardner-Wells tongs and closed reduction.

Explanation:

Question 99:

Options:

Cervical traction
Halo-vest orthosis
Anterior single-level fusion
Posterior single-level fusion
Posterior multilevel fusion

Correct Answer: Posterior multilevel fusion

Question 100:

Options:

Gastrocsoleus recession
Subtalar fusion
Split anterior tibial tendon transfer
Split posterior tibial tendon transfer
Flexor hallucis longus tendon transfer

Correct Answer: Split posterior tibial tendon transfer

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

Orthopedic Board Review MCQs: Foot & Ankle, Hip, Trauma & Sports Medicine | Part 219

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 219

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index