Spine, Arthroplasty & Trauma Ortho MCQs - Part 161

About This Board Review Set

This is Part 161 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

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

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Topics Covered in Part 161

This module focuses heavily on: Arthroplasty, Elbow, Fracture, Hip, Spine.

Sample Questions from This Set

Sample Question 1: A 56-year-old woman sustained the fracture shown in Figures 30a and 30b in a motor vehicle accident. What mechanism is most likely responsible for the injury?...

Sample Question 2: Figure 199 is the clinical photograph of a 68-year-old man with a history of atrial fibrillation who was treated with warfarin. Nine days after undergoing elective total hip arthroplasty, he has a swollen left thigh. His wound remains dry a...

Sample Question 3: A 56-year-old man has a chief complaint of leg weakness and inability to walk. Examination reveals 5 out of 5 motor strength in all lower extremity muscle groups tested and normal sensation to light touch in both lower extremities. The pati...

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

Sample Question 5: For halo traction, what is the preferred site for anterior pin placement?...

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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

A 56-year-old woman sustained the fracture shown in Figures 30a and 30b in a motor vehicle accident. What mechanism is most likely responsible for the injury?

Explanation

DISCUSSION: The CT scans show a burst fracture that results from an axial load injury. The radiographic hallmark of a burst fracture is compression of the posterior cortex of the vertebral body with retropulsion of bone into the spinal canal. AP radiographs often show widening of the interpedicular distance with a fracture of the lamina.
REFERENCES: Theiss SM: Thoracolumbar and lumbar spine trauma, in Stannard JP, Schmidt AH, Kregor PJ (eds): Surgical Treatment of Orthopaedic Trauma. New York, NY, Thieme, 2007, pp 179-207.
Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 201-216.

Question 2

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

Explanation

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

Question 3

A 56-year-old man has a chief complaint of leg weakness and inability to walk. Examination reveals 5 out of 5 motor strength in all lower extremity muscle groups tested and normal sensation to light touch in both lower extremities. The patient is slow in getting up from a seated position and has an unsteady wide-based gait. An MRI scan of the lumbar spine is shown in Figure 1. What is the next most appropriate course of action? Review Topic

Explanation

Strict bedrest for six weeks then progressive weightbearing
Ambulation as tolerated with or without a TLSO
Surgical decompression and anterior stabilization
Surgical decompression and posterior stabilization
Surgical decompression and combined anterior/posterior stabilization
The patient has a L1 burst fracture with minimal retropulsion of bony fragments in the spinal canal. In the absence of neurological deficits and injury to the PLC, the most
appropriate treatment is ambulation as tolerated with or without a thoracolumbrosacral orthosis (TLSO).
Thoracolumbar burst fractures are typically caused by an axial load with flexion and commonly found in this location due to increased motion at these segments. With an intact posterior ligamentous complex (PLC) and no neural compromise, TLSO is the mainstay of treatment. If there is evidence of neurological deficit and/or PLC injury, decompression and fusion are indicated. The degree of acceptable kyphosis is controversial. The choice of anterior versus posterior approach is based on ease of decompression.
Vaccaro et al. introduced a new classification system for thoracolumbar injuries, TLICS, based on morphological appearance, integrity of the posterior ligamentous complex, and neurological status. They advocate use of the system for nonoperative versus operative decision making and communication between surgeons.
Bailey et al. completed a randomized, nonblinded controlled trial to determine the efficacy of bracing for AO type A0-A3 thoracolumbar burst fractures. Both groups were encouraged to ambulate as tolerated and the no brace group had bending restrictions for 8 weeks. They found no difference in the Roland Morris Disability Questionnaire (RMDQ) score at 3 months after injury.
Figure A is sagittal CT scan of the lumbar spine showing a burst fracture of L1 with minimal retropulsion. Illustration A is the TLICS classification with score of 4 being the branch point for nonoperative versus operative management.
Incorrect Answers:

Question 4

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

Explanation

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

Question 5

For halo traction, what is the preferred site for anterior pin placement?

Explanation

DISCUSSION: The safe zone for anterior halo pin insertion is marked laterally by the anterior border of the temporalis muscle (to avoid penetration of this muscle and relative thin cortex of the skull). Medially, the pin should be placed 4.5 cm lateral to the midline to avoid injury to the supraorbital nerve or the frontal sinus. The safe area is marked superiorly by the head equator to avoid cephalad migration of the pin and inferiorly by the supraorbital ridge to prevent displacement or penetration into the orbit.
REFERENCE: Ebraheim NA, Lu J, Biyani A, Brown JA: Anatomic considerations of halo pin placement. Am J Orthop 1996;25:754-756.

Question 6

maximize physical capacity and 4) obtain local control of the disease. Other trivia from the references include: After the lung and liver the skeletal system is the third most common site of metastasis. The spine is the most common site of skeletal metastasis. 60% of all skeletal lesions and 36% are asymptomatic. Breast, prostate, lung and renal carcinoma comprise 80% of the carcinomatous skeletal metastasis. 70% metastasis occur in the thoracic and thoracolumbar regions. 21% had involvement of the lumbar and sacral regions. 8% involved the cervical and cervicothoracic regions together. As many as 90% of patients who die of cancer may have Spinal metastasis at autopsy, and only half of patients who die from cancer will have symptoms from spinal mets. Fewer than 10% with spinal mets are treated surgically. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont IL., American academy of orthopaedic surgeons, 2002, pp 723-736. back to this question next question 03 What is the most frequently encountered complication following juvenile hallux valgus correction?

Explanation

Postoperative complications have been frequently reported following juvenile hallux valgus corrections. Recurrence following surgery is probably the most frequently reported complication and is likely due to the high rate of congruency associated with a juvenile hallux valgus deformity.

OKU Foot and Ankle 2 Rosemont IL., American academy of orthopaedic surgeons, pp135-150.
back to this question next question

Question 7

A concern when choosing irradiated (10 Mrad) and subsequently melted highly cross-linked polyethylene rather than lower dose–irradiated (4 Mrad) polyethylene is related to its inferior resistance to

Explanation

DISCUSSION
The higher the dose of radiation to the polyethylene, the higher the amount of cross-linking. Adhesive and abrasive wear resistance increases with an increase in cross-linking. However, fatigue properties of the material are decreased when polyethylene is melted (to remove free radicals) during the cross-linking process. Creep (deformation without wear) is also slightly increased with cross-linking of polyethylene.

Question 8

Radiographs of a 15-year-old girl with knee pain reveal a radiopaque lesion of the distal femoral metaphysis and epiphysis with a small associated soft-tissue mass. A biopsy specimen shows osteoid and pleomorphic cells with multiple mitotic figures. Staging studies show no other sites of disease. Treatment should consist of

Explanation

DISCUSSION: Based on the location and extent of the tumor, most patients are candidates for limb salvage surgery. The patient has an osteosarcoma; therefore, the treatment of choice is preoperative chemotherapy, wide resection, and reconstruction. There is no difference in survival rates between patients who undergo limb salvage surgery and those who undergo amputation. Curettage and placement of methylmethacrylate is used to treat benign lesions of bone and would not be appropriate in this patient.
REFERENCE: Simon MA, Springfield DS, et al: Common Malignant Bone Tumors: Osteosarcoma. Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 265-274.

Question 9

Which of the following enzymes is used to resorb bone by mature osteoclasts?

Explanation

Osteoclasts resorb bone. Osteoclasts are derived from monocytes and macrophages that fuse to form multinucleated cells in response to receptor activator of nuclear factor kappa b (RANKL) and macrophage colony stimulating factor (MCSF). Osteoclasts attach to bone surfaces through a specific cell attachment receptor called an integrin (av¯3 or vitronectin receptor). The ruffled border refers to multiple invaginations of plasma membrane against the bone matrix surface. Lysosomes move to the ruffled border of osteoclasts and discharge lysosomal enzymes into the resorption region. These enzymes include cathepsin K, matrix metalloproteinase, and carbonic anhydrase (CA II).

Question 10

Figures 48a and 48b are the initial radiograph and clinical photograph of a 21-year-old woman who sustained a severe mangling injury to her left foot in a rollover ATV crash. After multiple dTbridements, she underwent definitive transmetatarsal amputation with split-thickness skin graft. She did have intact plantar sensation. Figure 48c shows the clinical photograph 10 days after amputation. Her wounds healed without infection and she did not require further surgery. At 2 years after injury, which of these factors is most likely to be associated with improved level of satisfaction? Review Topic

Explanation

Anterior pelvic external fixation with pins placed in the AIIS and a posterior sacroiliac screw
Open reduction and internal fixation of the pubic symphysis with a two hole plate and posterior fixation with a iliosacral screw
Open reduction and internal fixation of the pubic symphysis with a non-locking multi-hole plate and posterior fixation with a iliosacral screw
Anterior pelvic external fixation and posterior triangular osteosynthesis
Open reduction and internal fixation of the pubic symphysis with a locked multi-hole plate and posterior sacral plate fixation
The radiographs and CT scan show a fracture pattern consistent with an APC-III injury. This is most appropriately treated with pubic symphysis ORIF with a multi-hole plate and posterior iliosacral screw fixation.
APC-III pelvic ring injuries are associated with with disruption of the anterior and posterior SI ligaments (SI dislocation) as well as disruption of sacrospinous and sacrotuberous ligaments. They are commonly associated with vascular injury and retroperitoneal bleeding.
Sagi et al studied the radiographic and clinical outcome of symphyseal plating techniques, specifically comparing two hole (THP) vs multi-hole plating (MHP). Retrospective review of charts and radiographs immediately after the index procedure to latest follow-up was performed. When comparing the 2 different methods of anterior fixation, they found that the rate of fixation failure was greater in group THP (33%) than group MHP (12%). When evaluating the presence of a malunion as a result of these 2 treatment methods, there were more present in the THP group (57%) than in the MHP group (15%). On the basis of these findings, the authors recommended multi-hole plating of unstable pubic symphyseal disruptions.
Grimshaw et al performed a biomechanical study to determine the failure risk and potential benefit to use of locked fixation constructs in simulated pelvic ring injuries. The authors used a six-hole 3.5-mm plate specifically designed for the symphysis pubis with the capability of fixation in locked or unlocked mode, six pelves were fixed with locked screws and six pelves were fixed standard unlocked bicortical screws. Biomechanical testing was performed, and no abrupt failures were noted. However, locked plating of the pubic symphysis did not appear to offer any advantage over the standard unlocked technique
Illustrations A, B, and C show the AP, outlet, and inlet postoperative radiographs. Incorrect Answers:
1,4-Anterior pelvic fixation is typically not used as definitive treatment of these
injuries unless performed in a damage-control setting. The patient in this case is stable.
2-Multi-hole plate fixation of the pubic symphysis is preferred over 2-hole plate fixation.
5-Posterior sacral plating is not indicated in this fracture pattern, as there is no significant sacral comminution of vertical shear component. Furthermore, no distinct advantage has been found with locked symphyseal plating.

Question 11

A 38-year-old woman who tripped and fell on her outstretched arm reports pain with movement. Examination reveals swelling. AP and lateral radiographs are shown in Figures 43a and 43b. Management should consist of

Explanation

DISCUSSION: The patient has a type I (Hahn-Steinthal) capitellar fracture that is best seen on the lateral radiograph. If a fracture fragment is seen proximal to the radial head, a capitellar fracture is the most likely injury because radial head fractures do not migrate proximally. The fragment is large enough for fixation. Excision is the preferred treatment for small shear osteochondral type II (Kocher-Lorenz) capitellar fractures. Closed reduction usually is not successful because of rotation of the displaced fragment.
REFERENCES: Mehdian H, McKee M: Management of proximal and distal humerus fractures. Orthop Clin North Am 2000;31:115-127.
Ring D, Jupiter J, Gulotta L: Articular fractures of the distal part of the humerus. J Bone Joint Surg Am 2003;85:232-238.

Question 12

Which of the following is considered a specific advantage of using COX-2 inhibitors over COX-1 inhibitors?

Explanation

DISCUSSION: Inflammation is mediated through two isoforms of cyclooxygenase that convert arachidonic acid to prostaglandins. Selectivity, but not specificity, is one of the unique characteristics of this process that has been able to provide more protection from the effects of gastric mucosal alterations using the COX-2 selective inhibitors. The use of COX-1 selective inhibitors is associated with side effects such as ulcerative conditions and platelet interference, both of which have been difficult to control in the past until the advent of the COX-2 inhibitors. PGE₂ inhibition by COX-1 in the intestinal track can then be bypassed, thereby reducing ulceration complications associated with use of nonsteroidal anti-inflammatory drugs.
REFERENCES: Lane JM: Anti-inflammatory medications: Selective COX-2 inhibitors. J Am Acad Orthop Surg 2002;10:75-78.
Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002.
Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000.

Question 13

A 20-year-old man is brought to the emergency department after a high-speed motor vehicle accident. His initial blood pressure is 70/40 mm Hg. He is currently receiving intravenous fluids as well as blood. His Focused Assessment with Sonography for Trauma examination did not show any free fluid in his abdomen and his chest radiograph is unremarkable. An AP pelvis radiograph is shown in Figure 15. What is the next most appropriate step in the management of his pelvic injury?

Explanation

DISCUSSION: This hypotensive patient has an obvious open book injury of the pelvic ring on the AP pelvis radiograph and further radiographs are not needed prior to the initiation of treatment. Although angiography may be indicated if he does not respond to stabilization of his pelvis and fluid/blood administration, temporary stabilization of the pelvis with a sheet or binder should be performed first because it is simple, quick, and has been shown to be effective. This patient does not need a laparotomy at this point since the FAST examination did not show any free intra-abdominal fluid and his chest radiograph was unremarkable, leaving the most likely source of bleeding the pelvic fracture. Open reduction with internal fixation of a pelvic injury is not indicated in an acutely ill patient.
REFERENCES: Kreig JC, Mohr M, Ellis TJ, et al: Emergent stabilization of pelvic ring injuries by controlled circumferential compression: A clinical trial. J Trauma 2005;59:659-664.
Croce MA, Magnotti LJ, Savage SA, et al: Emergent pelvic fixation in patients with exsanguinating pelvic fractures. J Am Coll Surg 2007;204:935-942.
Routt ML Jr, Falicov A, Woodhouse E, et al: Circumferential pelvic antishock sheeting:

A temporary resuscitation aid. J Orthop Trauma 2002;16:45-48.

Question 14

A 25-year-old student sustains the injury shown in Figures 13a through 13c after falling off a curb. Initial management should consist of

Explanation

DISCUSSION: The radiographs reveal a fracture entering the 4-5 intermetatarsal articulation, consistent with a zone 2 injury. This classically is also referred to as a Jones fracture. The history and radiographic findings indicate this is an acute fracture, which guides management. A zone 1 fracture enters the fifth tarsometatarsal joint, and a zone 3 fracture is a proximal diaphyseal fracture distal to the 4-5 articulation. Initial management is usually nonsurgical and consists of non-weight-bearing in a short leg cast. This method has been shown to result in a better healing rate compared to weight bearing as tolerated.
REFERENCES: Rosenberg GA, Sterra JJ: Treatment strategies for acute fractures and nonunions of the proximal fifth metatarsal. J Am Acad Orthop Surg 2000;8:332-338.
Lawrence SJ, Botte MJ: Jones’ fracture and related fractures of the proximal fifth metatarsal. Foot Ankle 1993;14:358-365.

Question 15

Figures 1 through 4 show the radiographs and MRI obtained from a 40-year-old man who has a 6-week history of ring finger pain, redness, and swelling after puncturing the finger with a toothpick. Purulent drainage from the puncture wound site grew Eikenella corrodens . The patient was initially treated with oral antibiotics for 10 days and then intravenous (IV) antibiotics for 3 weeks. What is the best next step in treatment?

Explanation

EXPLANATION:
This patient has a septic distal interphalangeal joint, which was treated with antibiotics alone. As a result, the patient developed osteomyelitis with bone destruction and abscess. The best way to treat this problem is to perform surgical débridement of bone and soft tissue, along with abscess drainage and an appropriate antibiotic regimen. Antibiotic treatment without surgery would not be successful in eliminating this particular infection. Bone scan with biopsy is not the correct option, because this problem is an infection and not a tumor, and MRI already has provided enough diagnostic information.

Question 16

The use of multiagent adjuvant chemotherapy is associated with a clear survival benefit in which of the following diseases?

Explanation

DISCUSSION: The use of multiagent chemotherapy has been shown to be associated with a survival benefit in patients with osteosarcoma. The use of chemotherapy in adults with soft-tissue sarcoma remains somewhat controversial. It has not been associated with improved survival rates in patients with renal carcinoma, dedifferentiated chondrosarcoma, or melanoma.
REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 53.
Link M, Goorin A, Miser A, et al: The effect of adjuvant chemotherapy and relapse free survival in patients with osteosarcoma of the extremity. N Engl J Med 1986;314:1600-1606.

Question 17

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

Explanation

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

Question 18

Which of the following findings is seen in the chest radiograph shown in Figure 13?

Explanation

DISCUSSION: Orthopaedic surgeons are often responsible for interpreting radiographs of general examinations such as the chest radiograph shown. For accurate interpretation, it is important to systematically review all of the information available on the radiograph. Using this approach, the fracture of the left proximal humerus is readily recognized. Linear air soft-tissue density at the lung periphery would suggest a pneumothorax, but this finding is not shown on the radiograph. The upper thoracic spine is well aligned. The sternoclavicular and distal clavicles are normal.
REFERENCE: Bone LB: Emergency treatment of the injured patient, in Browner BD, Jupiter JB, Levine AM, Trafton PG (eds): Skeletal Trauma. Philadelphia, PA, WB Saunders, 1992, pp 133-138.

Question 19

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

Explanation

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

Question 20

In a patient with rheumatoid arthritis of the wrist, which of the following extensor tendons is most at risk of rupture?

Explanation

DISCUSSION: The tendon most prone to rupture in a patient with rheumatoid arthritis of the wrist is the extensor digiti quinti. It can be a silent injury since the extensor digitorum communis can provide extension to the fifth finger. The extensor digiti quinti is at high risk since it is overlying the ulnar head where it is prone to attritional rupture (Vaughan-Jackson syndrome).
REFERENCES: Vaughan-Jackson OJ: Rupture of extensor tendons by attrition at the inferior radioulnar joint: A report of two cases. J Bone Joint Surg Br 1948;30:528-530.
Papp SR, Athwal GS, Pichora DR: The rheumatoid wrist. J Am Acad Orthop Surg

2006;14:65-77.

Question 21

What is the most common malignant bone tumor seen in patients with multiple hereditary exostosis?

Explanation

DISCUSSION: Secondary chondrosarcomas are most common in patients with multiple hereditary exostosis. Dedifferentiated chondrosarcoma is less common and refers to bone lesions in which a high-grade spindle cell sarcoma component is located immediately adjacent to a low-grade cartilage neoplasm. Mesenchymal chondrosarcoma, clear cell chondrosarcoma, and periosteal osteosarcoma are no more common in patients with multiple hereditary exostosis than in the general population.
REFERENCES: Mirra JM: Bone Tumors: Clinical, Radiologic, and Pathologic Correlations. Philadelphia, PA, Lea and Febiger, 1989, pp 1660-1669.
Simon MA, Springfield DS, et al: Common Malignant Bone Tumors: Chondrosarcoma. Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 275-286.

Question 22

During a dual incision fasciotomy of the leg, the soleus is elevated from the tibia to allow access to which of the following compartments?

Explanation

DISCUSSION: The soleus is elevated/released from the posterior tibia during the medial approach to allow access to the deep posterior compartment. Release of this compartment cannot be done without proper elevation of the soleus. The superficial posterior compartment mass is primarily located in the proximal half of the leg, while the deep posterior musculature is located in the distal 2/3 of the leg.

Question 23

A 65-year-old man with ankylosing spondylitis has neck pain after falling back over his lawnmower, striking his thoracic spine, and forcing his neck into extension. Examination reveals subtle weakness of the intrinsics and finger flexors at approximately 4+/5. Initial management consists of immobilization in a rigid collar, and placing his head in the anatomic position. Radiographs reveal a subtle extension fracture of the lower cervical spine. Approximately 6 hours after the injury, he reports increasing paresthesias in his upper and lower extremities, and examination now shows his intrinsics are 2/5, finger flexors are 3/5, and his triceps are now weak at 4/5 on manual motor testing. In addition, his lower extremities now show weakness in both dorsal and plantar flexion of the ankle in the range of 4/5. Repeat radiographs appear unchanged. An MRI scan is shown in Figure 2. Management should now consist of

Explanation

DISCUSSION: It is not uncommon for patients with ankylosing spondylitis to sustain extension-type fractures, most typically of the cervicothoracic junction. These fractures can appear nondisplaced or minimally displaced initially, making them difficult to diagnose. Because there is no mobility between vertebrae, fractures tend to occur more like those of a transverse fracture of a long bone. In addition, the vertebral bodies are vascular and their canals are relatively enclosed, making them vulnerable to epidural bleeding. The MRI scan reveals an epidural hematoma located posteriorly on the cord; therefore, the treatment of choice is surgical evacuation and a posterior laminectomy. Because of the intrinsic instability of such fractures at the time of the laminectomy, internal fixation and stabilization with a posterior fusion is warranted. A simple laminectomy will only increase instability, and control is unlikely with halo vest immobilization. An anterior procedure will not effectively treat the problem given the location of the hematoma. Consideration can be given to methylprednisolone and observation; however, this will not eradicate the problem.
REFERENCES: Bohlman HH: Acute fractures and dislocations of the cervical spine. J Bone Joint Surg Am 1979;61:1119-1142.
Weinstein PR, Karpman RR, Gall EP, et al: Spinal cord injury, spine fracture and spinal stenosis in ankylosing spondylitis. J Neurosurg 1982;57:609-616.

Question 24

A 64-year-old female sustains a nondisplaced distal radius fracture and undergoes closed treatment using a cast. Three months after the fracture she reports an acute loss of her ability to extend her thumb. What is the most likely etiology of her new loss of function?

Explanation

DISCUSSION: According to the referenced article by Jupiter and Fernandez, the most common scenario of extensor pollicis longus rupture after a distal radius fracture is when the fracture is non or minimally displaced. The hypothesis is that the rupture happens at an area of relative hypovascularity and healing callus can aggravate this area, leading to a degenerative tear. Hove et al reported an incidence of delayed tendon rupture after distal radius fracture of 0.3 percent. In their series of 18 extensor pollicis longus tendon ruptures, 15 were treated with tendon transfers. They reported good results: nearly 100% patient satisfaction, all patients were able to elevate the thumb to the level of the palm, and full independent index finger movements.

Question 25

A 62-year-old patient with rheumatoid arthritis has had pain and instability of the elbow following total elbow replacement 2 years ago. A complete work-up, including aspiration and cultures, is negative. Figures 9a and 9b show the AP and lateral radiographs. Treatment should consist of

Explanation

DISCUSSION: The patient has aseptic loosening of the original semiconstrained prosthesis and significant proximal ulnar bone destruction; therefore, the treatment of choice is revision arthroplasty using a semiconstrained design. Although orthotic stabilization could be used, it will not provide long-term pain relief. Resection arthroplasty after removal of the components may lead to painful instability. Elbow arthrodesis would be difficult with the bone stock loss and is not considered the best option. Two main contraindications to the use of an unconstrained prosthesis are significant bone loss and previous use of a hinged or semiconstrained prosthesis. An ulnar allograft could be combined with the use of a semiconstrained long-stemmed ulnar prosthesis as a treatment modification.
REFERENCES: Ewald FC, Simmons ED Jr, Sullivan JA, et al: Capitellocondylar total elbow replacement in rheumatoid arthritis: Long-term results. J Bone Joint Surg Am 1993;75:498-507.
Morrey BF, King GJ: Revision of failed total elbow arthroplasty, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 602-610.

Question 26

A 12½-year-old boy reports intermittent knee pain and limping that interferes with his ability to participate in sports. He actively participates in football, basketball, and baseball. He denies any history of injury. Examination shows full range of motion without effusion. Radiographs reveal an osteochondritis dissecans (OCD) lesion on the lateral aspect of the medial femoral condyle. MRI scans are shown in Figures 14a and 14b. Initial treatment should consist of

Explanation

DISCUSSION: This skeletally immature patient has a small OCD lesion that appears stable, and he has not undergone any treatment. Therefore, a trial of immobilization until pain resolves is the best initial choice. Thereafter, cessation of sport activities for 4 to 6 months may allow healing of the lesion. Surgical treatment of juvenile OCD lesions is reserved for unstable lesions, patients who have not shown radiographic evidence of healing and are still symptomatic after 6 months of nonsurgical management, or patients who are approaching skeletal maturity. Good results with stable in situ lesions that have failed to respond to nonsurgical management have been reported with both transarticular and retroarticular drilling. Results after excision alone are poor at 5-year follow-up, and it is unclear if microfracture will improve the long-term outcome. Mosaicplasty may be the next best option for patients who remain or become symptomatic after excision of the fragment and microfracture.
REFERENCES: Wall E, Von Stein D: Juvenile osteochondritis dissecans. Orthop Clin North Am 2003;34:341-353.
Kocher MS, Micheli LJ, Yaniv M, et al: Functional and radiographic outcome of juvenile osteochondritis dissecans of the knee treated with transarticular arthroscopic drilling.

Am J Sports Med 2001;29:562-566.

Question 27

A 35-year-old woman is involved in a head-on collision while driving. Initial radiographs are shown in Figures 8a and 8b. Injury to what vessel increases the risk for osteonecrosis of the injured bone?

Explanation

The patient has a Hawkins type III talar neck fracture-dislocation with a risk of osteonecrosis ranging from 69% to 100%. Anatomic studies have shown that the artery of the tarsal canal supplies the lateral two thirds of the talar body. The other vessels listed provide no significant contribution to the talus.

Question 28

When reconstructing the anterior cruciate ligament (ACL) with autograft, what is the most common source of surgical failure?

Explanation

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

Question 29

Treatment should include

Explanation

DISCUSSION
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 30

Figure 27 shows the radiograph of a 68-year-old woman with a history of rheumatoid arthritis who was injured in a fall. History reveals that she has been asymptomatic since undergoing a left total knee arthroplasty 9 years ago. Management should consist of

Explanation

DISCUSSION: A supracondylar fracture of the femur that occurs after total knee replacement can be treated effectively by a number of methods. For this fracture, the use of a retrograde supracondylar nail has been found to be effective in several series. The treatment of these complex injuries needs to be individualized based on the stability of the implant, the quality of the bone, and the extent of comminution of the fracture. Revision with the use of an unstemmed implant will not result in effective stabilization of the knee or the fracture.
REFERENCE: Ayers DC: Supracondylar fracture of the distal femur proximal to a total knee replacement, in Springfield DS (ed): Instructional Course Lectures 46. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-203.

Question 31

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

Explanation

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

Question 32

A 70-year-old man has worn through his metal-backed patellar component and sustained damage to the femoral component. Following removal of the components and debridement of the metal-stained synovium, the surgeon finds that the thickness of the remaining patella is 10 mm. Treatment should now include

Explanation

DISCUSSION: Revision of a failed patellar component can be difficult because of bone loss and damage to the extensor mechanism. Several authors have advised against reinsertion of a patellar component if the residual patellar thickness is 10 mm or less. Leaving an unresurfaced bony remnant in place at the time of revision or reimplantation surgery has been shown to be a reasonable option; however, the results are of a lower quality when compared with revision surgery where the patellar component can be retained or revised. The other treatment options have not been shown to be effective approaches to this problem.
REFERENCES: Rand JA: The patellofemoral joint in total knee arthroplasty. J Bone Joint Surg Am 1994;76:612-620.
Pagnano MW, Scuderi GR, Insall JN: Patellar component resection in revision and reimplantation total knee arthroplasty. Clin Orthop 1998;356:134-138.
Barrack RL, Matzkin E, Ingraham R, Engh G, Rorabeck C: Revision knee arthroplasty with patella replacement versus bony shell. Clin Orthop 1998;356:139-143.

Question 33

A 42-year-old woman underwent an instrumented posterior spinal fusion at L3-S1 with transforaminal lumbar interbody fusion. She had an excellent

Explanation

The MRI scans reveal a postoperative infection. Observation and antibiotics are not appropriate choices. There is a large fluid collection and this requires decompression because the patient has neurologic changes. There is considerable debate regarding the removal of hardware. Many contend that biofilm on the implants can harbor the infection. However, these complications usually can be treated with serial irrigations, debridements, and IV antibiotics. The incidence of infection has been widely studied with varying rates in fusions with instrumentation. Rates appear to be increased with instrumentation, yet these infections usually can be managed without hardware removal.

Question 34

A 45-year-old man has a draining sinus and recurrent infection of his right total knee arthroplasty. He has had two prior revision surgeries after the primary procedure and three other surgeries before his initial replacement, including a proximal tibial osteotomy and subsequent hardware removal. On clinical examination, he has a draining sinus in the mid portion of his surgical scar and a range of motion of 5° to 85°. AP and lateral radiographs of the right knee are shown in Figures below. During surgery, the femoral component is found to be grossly loose, but the tibial component is well fixed. What is the most appropriate extensile approach that would provide adequate exposure and aid in tibial component extraction?

Explanation

DISCUSSION:
Extended tibial tubercle osteotomy is an extensile approach to revision total knee arthroplasty that affords excellent exposure and can facilitate removal of tibial sleeves and cones. This patient has had multiple surgeries, including a proximal tibial osteotomy, as well as poor range of motion, patella baja, and a well-fixed metaphyseal sleeve component. Classically, an extended tibial tubercle osteotomy provides outstanding exposure for component removal in the setting of prior high tibial osteotomy and patella baja. For this patient, it is important to recognize the patella baja on the radiographs, as well as the tibial sleeve. In many of these cases the osteotomy provides access to the sleeve to help with extraction, because the stem will not pull through the sleeve or detach from the tray to allow visualization of the sleeve. The extended medial parapatellar approach is just a long medial approach that typically yields good exposure
but would not help with the patella baja or extraction of the tibial sleeve. The quadriceps snip would give good exposure to the knee but would not aid in tibial component removal. Lastly, the medial epicondyle osteotomy could help with exposure and tensioning of the medial complex of the knee but would not help with tibial component extraction.

Question 35

A previously healthy 13-year-old girl has had thigh pain for the past 3 weeks. The radiograph shown in Figure 47a reveals a lesion in the right femur. A bone scan and CT scan of the chest show no evidence of other lesions. A biopsy specimen is shown in Figure 47b. What is the most likely diagnosis?

Explanation

DISCUSSION: The patient has Langerhans cell histiocytosis that may be solitary (eosinophilic granuloma) or associated with systemic illness (Hand-Schuller-Christian disease and Letterer-Siwe disease). The solitary form of the disease, eosinophilic granuloma, typically affects patients in the first three decades of life. Radiographically, it is characterized as a well-defined, lytic, “punched out” intramedullary lesion. Histologically, two cell types, eosinophils and Langerhans cells, are seen. The Langerhans cells are seen as mononuclear histiocyte-like cells with oval nuclei with well-defined round or oval cytoplasm. A prominent nuclear groove can be seen in most of the nuclei (coffee bean nuclei). A mixture of inflammatory cells and lipid-laden foam cells with nuclear debris may be present as well. The lack of nuclear atypia and atypical mitoses excludes malignant conditions such as Ewing’s sarcoma, lymphoma of bone, and metastatic neuroblastoma. The lack of acute inflammatory cells excludes the diagnosis of osteomyelitis. The eosinophils have bi-lobed nuclei and granular eosinophilic cytoplasm.
REFERENCES: Dorfman H, Czerniak B: Bone Tumors. St Louis, MO, Mosby, 1988.
Mirra, JM: Bone Tumors: Clinical, Radiologic, and Pathologic Correlations. Philadelphia, PA, Lea & Febiger, 1989.

Question 36

Lateral malleolus fractures can be treated with a variety of techniques, including posterior antiglide plating or lateral neutralization plating. What is an advantage of using lateral neutralization plating instead of posterior antiglide plating?

Explanation

DISCUSSION: Posterior antiglide plating is a technique that involves placement of a plate on the posterior aspect of the distal fibula, using the plate as a reduction tool and direct buttress against distal fracture fragment displacement.
Schaffer et al showed from a biomechanical standpoint that posterior antiglide plating was superior to lateral neutralization plating for distal fibula fracture fixation.
Weber et al reported a (30/70) 43% rate of plate removal secondary to peroneal discomfort. In addition, peroneal tendon lesions were found in 9 of the 30 patients.

Question 37

Figure 1 is the T2 coronal MRI scan of a 52-year-old woman with a 6- month history of shoulder pain. She does not recall a history of trauma. Physical therapy is recommended. What is the most significant predictor of failure of nonoperative treatment?

Explanation

Figures 1 through 3 are the MRI scans of a 51-year-old active man who injured his right shoulder after a fall while sailing 4 days ago. Optimal surgical management of the patient’s pathology is expected to involve

Question 38

A 20-year-old male lacrosse player sustains an anterior dislocation of the shoulder. He is extremely concerned about recurrent dislocations. Which of the following treatments has been shown to reduce the risk of recurrent dislocation?

Explanation

DISCUSSION: Recent evidence has shown that the position of immobilization of the shoulder after a dislocation influences the reduction of the Bankart lesion. In an MRI study in patients who sustained an anterior dislocation, the Bankart lesion was reduced to the glenoid anatomically with the arm in 30 degrees of external rotation. Subsequently, a clinical follow-up study has shown a reduction in recurrence rates when the arm is immobilized in external rotation compared to internal rotation.
REFERENCES: Itoi E, Hatakeyama Y, Kido T, et al: A new method of immobilization after traumatic anterior dislocation of the shoulder: A preliminary study. J Shoulder Elbow Surg 2003;12:413-415.
Itoi E, Sashi R, Minagawa H, et al: Position of immobilization after dislocation of the glenohumeral joint: A study with use of magnetic resonance imaging. J Bone Joint Surg Am 2001;83:661-667.

Question 39

Figure 65 is the lumbar spine MR image of a 63-year-old woman who has a 3-year history of increasingly bothersome back pain and bilateral buttock and leg pain. She has performed 6 weeks of physical therapy, received epidural injections, and experienced some good short-term results, but her leg pain continues to worsen. What is the most appropriate course of treatment?

Explanation

DISCUSSION
This patient has symptoms consistent with neurogenic claudication secondary to lumbar spinal stenosis and degenerative spondylolisthesis. Her symptoms are chronic and she has undergone an appropriate course of nonsurgical care. Nevertheless, her symptoms are worsening and surgical intervention is a
reasonable consideration. Studies have shown that patients with lumbar spinal stenosis with associated degenerative spondylolisthesis benefit most from decompression of the neural elements that are stenotic and subsequent fusion across the degenerative slip. Anterior lumbar interbody fusion likely will not address stenosis at the level of the slip and may not result in adequate neurologic decompression. Partial laminotomy and diskectomy likely will not provide adequate neural decompression because these procedures would only address unilateral compression and this patient has bilateral issues. Lumbar laminectomy without fusion could be performed but has been associated with results inferior to lumbar laminectomy with fusion when addressing stenosis with spondylolisthesis.
RECOMMENDED READINGS
Weinstein JN, Lurie JD, Tosteson TD, Zhao W, Blood EA, Tosteson AN, Birkmeyer N, Herkowitz H, Longley M, Lenke L, Emery S, Hu SS. Surgical compared with nonoperative treatment for lumbar degenerative spondylolisthesis. four-year results in the Spine Patient Outcomes Research Trial (SPORT) randomized and observational cohorts. J Bone Joint Surg Am. 2009 Jun;91(6):1295-304. PubMed PMID: 19487505. View Abstract at PubMed
Herkowitz HN, Kurz LT. Degenerative lumbar spondylolisthesis with spinal stenosis. A prospective study comparing decompression with decompression and intertransverse process arthrodesis. J Bone Joint Surg Am. 1991 Jul;73(6):802-8. PubMed PMID: 2071615. View Abstract at PubMed
Lombardi JS, Wiltse LL, Reynolds J, Widell EH, Spencer C 3rd. Treatment of degenerative spondylolisthesis. Spine (Phila Pa 1976). 1985 Nov;10(9):821-7. PubMed PMID: 4089657. View Abstract at PubMed
RESPONSES FOR QUESTIONS 66 THROUGH 69
Deep surgical-site infection
Adjacent segment degeneration
Pressure ulcers
Iatrogenic neurologic injury
Incidental durotomy
Hardware failure
Match the frequently encountered complication listed above with the appropriate clinical scenario below.

Question 40

Compared with cobalt-chromium, the biomechanical properties of titanium on polyethylene articulation in total hip replacement result in

Explanation

DISCUSSION: The surface hardness of titanium is low compared with that of cobalt-chromium alloys. Titanium articulations are easily scratched, resulting in a significantly increased rate of wear and debris production. The wear and resulting lysis can also result in an increased rate of loosening.
REFERENCES: Simon SR (ed): Orthopaedic Basic Science. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 449-486.
Agins HJ, Alcock NW, Bansal M, et al: Metallic wear in failed titanium-alloy total hip replacements: A histological and quantitative analysis. J Bone Joint Surg Am 1988;70:347-356.
Robinson RP, Lovell TP, Green TM, Bailey GA: Early femoral component loosening in DF-80 total hip arthroplasty. J Arthroplasty 1989;4:55-64.

Question 41

A 22-year-old college football player reports shortness of breath and dyspnea after a tackle. Examination reveals tachypnea, tachycardia, the trachea is shifted to the right, and there are decreased breath sounds on the left lung fields. The first line of treatment on the field should be

Explanation

DISCUSSION: The patient has a tension pneumothorax. This is a life-threatening emergency where air is trapped between the pleura and the lung, which prevents expansion of the lung. This causes hypoxia and cardiopulmonary compromise. The first line of treatment is to place a needle into the second intercostal space in the midclavicular line. The athlete should then be transported to the emergency department for chest tube placement. The athlete cannot return to play, and resuscitation is not necessary because he has not gone into cardiopulmonary arrest.
REFERENCES: Amaral JF: Thoracoabdominal injuries in the athlete. Clin Sports Med 1997;16:739-753.
Perron AD: Chest pain in athletes. Clin Sports Med 2003;22:37-50.

Question 42

A 32-year-old man sustains multiple injuries in a motorcycle accident including ipsilateral open right femur and comminuted tibia fractures. He has acute abdominal distention and tenderness to palpation. The pelvis is stable to examination. He has a blood pressure of 70/40 mm Hg despite appropriate fluid resuscitation and a pulse rate of 120/min; the pulse is thready. Which of the following procedures is considered the highest priority in the management of this patient?

Explanation

DISCUSSION: The patient is in hemorrhagic shock, and timely hemostasis in the operating room should be the highest priority. Further imaging and insertion of central lines carry the risk of further delays in arresting the source of the patient’s bleeding. Albumin (colloid) solutions have questionable indications, are expensive, and have been associated with increased mortality. Crystalloid solutions such as normal saline or lactated Ringer’s solution are the initial resuscitative fluid of choice until blood becomes available. Pneumatic antishock garments have been associated with higher mortality rates, particularly in patients with cardiac and thoracic vascular injuries.
REFERENCES: Krettek C, Simon RG, Tscherne H: Management priorities in patients with polytrauma. Langenbecks Arch Surg 1998;383:220-227.
Weigelt JA: Resuscitation and initial management. Crit Care Clin 1993;9:657-671.

Question 43

Radiographs of a 12-year-old boy who has knee pain show a 2-cm osteochondral lesion of the lateral aspect of the medial femoral condyle. The fragments are not detached from the femur. Initial management should consist of

Explanation

DISCUSSION: For a pediatric patient without mechanical symptoms, initial management of an osteochondral defect lesion that is not detached should consist of casting in flexion. Failure to respond to several weeks or months of nonsurgical management may warrant surgical treatment.
REFERENCE: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 505-520.

Question 44

An otherwise healthy 50-year-old man who is a smoker undergoes a posterior spine fusion with instrumentation for spondylolisthesis. What can the patient do to minimize his risk for pseudarthrosis?

Explanation

Smoking is the biggest risk factor for nonunion and should be strictly avoided. NSAIDs interfere with bone healing, but not as strongly as smoking. Early mobilization would potentially stress the construct, inducing movement that leads to nonunion. Without history of calcium and vitamin D deficiency, increasing intake would not decrease the risk of nonunion.

Question 45

A 34-year-old man sustains an extra-articular fracture of the proximal phalanx of his right index finger in a fall. Examination reveals that the fracture is closed and oblique in orientation. Closed reduction and splinting fail to maintain the reduction. Management should now consist of

Explanation

DISCUSSION: The patient has an unstable oblique fracture of the proximal phalanx that is easily reducible but unstable; therefore, the treatment of choice is closed reduction and percutaneous pin fixation, followed by casting. Closed reduction and percutaneous pin fixation offers a better functional result than open reduction and plate fixation. Repeat closed reduction and buddy taping is inadequate because of the inherently unstable fracture pattern. Buddy taping will allow the dislocation to recur. The other options represent more aggressive surgical techniques than are necessary to treat this fracture.
REFERENCES: Stern PJ: Fractures of the metacarpals and phalanges, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, 1999,

pp 711-771.
Green DP, Anderson JR: Closed reduction and percutaneous pin fixation of fractured phalanges. J Bone Joint Surg Am 1973;55:1651-1653.

Question 46

A 12-year-old boy who pitches on two “select” baseball teams has had pain in his dominant right shoulder for the past 6 weeks. The pain is present only with throwing and is associated with decreased throwing velocity and control. He has no radiation of pain or paraesthesias of the upper extremity. An AP radiograph and MRI scan are shown in Figures 19a and 19b, respectively. Management should consist of Review Topic

Explanation

The imaging study demonstrates characteristics of Little Leaguer’s shoulder, including physeal widening. This condition is secondary to overuse (typically throwing) and responds well to rest from the inciting activity. There is no evidence from the patient’s history or examination that he has an impingement syndrome, nor is there any indication of labral pathology on the MRI scan. The changes in the proximal humerus are classic for this condition and are not suggestive of a neoplastic process requiring biopsy for definitive diagnosis.

Question 47

Figures 51a and 51b show the radiographs of a 12-year-old boy obtained after an attempted closed reduction of an elbow injury in the emergency department. His motor examination is intact but he reports decreased sensation along the palmar aspect of his ring and little finger. What is the best treatment plan? Review Topic

Explanation

Angle A, ilium and cartilaginous acetabulum
Angle A, ilium and bony acetabulum
Angle B, ilium and cartilaginous acetabulum
Angle B, ilium and bony acetabulum
Angle B, bony acetabulum and acetabular labrum
The alpha angle is subtended by (1) a line drawn down the ilium to a point where it intersects with the bony and cartilaginous confluence of the acetabulum and (2) a line drawn along the roof of the bony acetabulum.
The coronal flexion view (as depicted in figure A) of the infant hip is perhaps more familiar if rotated 90 degrees to view as one would view an anterior posterior radiograph of the pelvis. Acetabular development is evaluated primarily by the alpha angle, indicating the morphology of the developing acetabulum, and the percentage of the femoral head that is covered by the bony acetabulum. These are each readily apparent on ultrasound. Normal hips should have an alpha angle of at least 60 degrees by 6-8 weeks of age.
Harcke et al. provide a current concepts review on the state of ultrasound in the diagnosis and management of developmental dysplasia of the hip (as of 1991). They report, since that time, ultrasound has become the mainstay for diagnostic confirmation and management of DDH.
LeBa et al. performed a study to look at whether ultrasound screening would increase in effectiveness if targeted toward infants with established risk factors for developmental dysplasia of the hip and normal findings on physical examination. They found dynamic ultrasound evaluation showed developmental dysplasia in 7.8% of patients who had normal physical exams and led to a change in treatment in 8%. They conclude selective ultrasound screening in infants with risk factors and normal
findings on physical examination is effective and leads to more effective treatment.
Figure A shows an ultrasound exam of a 2 week old infant. The alpha angle is labeled 'B'. The beta angle is lableled 'A'. Illustration A is a diagram from Tachdjian's illustrating diagrammatically the elements of these angles.
Incorrect answers.

Question 48

A 5-year-old girl sustains an isolated injury to the right shoulder area after falling off the monkey bars. Examination reveals intact neurovascular function in the extremity distally, but she is quite uncomfortable. An AP radiograph of the proximal humerus is shown in Figure 24. Her parents state that she is a very talented gymnast. Considering her age and potential athletic career, management should consist of

Explanation

DISCUSSION: In this age group, bayonet apposition can produce very good results. Healing occurs rapidly, and remodeling usually is complete in less than 1 year. All of the other methods have significant risks of complications and are unnecessary for this fracture.
REFERENCES: Martin RF: Fractures of the proximal humerus and humeral shaft, in Letts RM (ed): Management of Pediatric Fractures. New York, NY, Churchill Livingstone, 1994,

pp 144-148.
Sanders JO, Rockwood CA Jr, Curtis RJ: Fractures and dislocation of the humeral shaft and shoulder, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 937-939.

Question 49

What is the most common bacteria cultured from dog and cat bites to the upper extremity?

Explanation

DISCUSSION: To define bacteria responsible for dog and cat bite infections, a prospective study yielded a median of five bacterial isolates per culture. Pasteurella is most common from both dog bites (50%) and cat bites (75%). Pasteurella canis was the most frequent pathogen of dog bites, and Pasteurella multocida was the most common isolate of cat bites. Other common aerobes included streptococci, staphylococci, moraxella, and neisseria.
REFERENCE: Talan DA, Citron DM, Abrahamian FM, et al: Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group. N Engl J Med 1999;340:85-92.

Question 50

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

Explanation

images with tibial stress fractures.
After activity, pain persists longer with tibial stress fractures.
DISCUSSION: Anterior tibial pain can often be difficult to diagnose. A bone scan showing the tibial cortex in a diffuse, longitudinal orientation is consistent with shin splints compared to a more discreet, localized uptake more commonly seen with a stress fracture. Bone stress injuries are due to cyclical overuse of the bone. They are relatively common in athletes and military recruits but are also seem in otherwise healthy people who have recently started new or intensive physical activity. Diagnosis of bone stress injuries is based on the patient’s history of increased physical activity and on imaging findings.
The general symptom of a bone stress injury is stress-related pain. Bone stress injuries are difficult to diagnose based only on a clinical examination because the clinical symptoms may vary depending on the phase of the pathophysiological spectrum in the bone stress injury. Imaging studies are needed to ensure an early and exact diagnosis. If the diagnosis is made early, most bone stress injuries heal well without complications.
REFERENCES: Mubarak SJ, Gould RN, Lee YF, et al: The medial tibial stress syndrome: A cause of shin splints. Am J Sports Med 1982;10:201-205.
Knobloch K, Yoon U, Vogt PM: Acute and overuse injuries correlated to hours of training in master running athletes. Foot Ankle Int 2008:29:671-676.
Kiuru MJ, Pihlajamaki HK, Ahovuo JA: Bone stress injuries. Acta Radiol 2004;45:317-326.

Question 51

A 72-year-old female presents to the office 5 weeks after distal radius fracture surgery with the findings seen in Figure A. She performed daily cleansing with soap and water and dry dressings. Which of the following has been shown to decrease the risk of developing this complication?

Explanation

There is no difference between daily showers with soap, water and dry dressings, and solutions comprising (1) saline and chlorhexidine, or (2) saline and hydrogen peroxide.
The risks of external fixation include cellulitis, pin-track drainage, osteomyelitis and pin loosening. The rate of complications is about 20%. Chlorhexidine gluconate has broad spectrum activity against gram-positive and negative bacteria by disrupting cell membranes. It is not affected by blood and has low skin irritancy. Studies show that simple pin-site care (showers, dry dressings) maintains a low infection rate.
Egol et al. performed a randomized trial examining external fixation pin tracts about the wrist. They compared (1) weekly dry dressings, (2) daily pin care with half normal saline (NS) and hydrogen peroxide (H2O2) and (3) chlorhexidine discs with weekly changes. They found pin-site complications in 19%, with no difference between the 3 groups. They do not recommend additional wound care beyond sterile dressings.
Stinner et al. performed a survey on the use of half-pins by the limb lengthening and reconstruction society. They found that most respondents preferred hydroxyapatite coating (81%) because of improved fixation and decreased loosening (less radiographic pin-tract rarefaction and greater extraction torque, which may lead to
lower infection rates). Most encouraged shower (60%) and washing solution (67%)(soap and water, peroxide or saline) for pin site care.
Figure A shows an external fixator around the wrist with cellulitis around the proximal half-pins.
Incorrect Answers

Question 52

A 16-year-old female dancer has persistent posterior ankle pain, particularly after a vigorous dancing schedule. Examination reveals tenderness both posteromedially and posterolaterally. MRI scans are seen in Figures 44a and 44b. What is the most likely diagnosis?

Explanation

DISCUSSION: Posterior ankle impingement or os trigonum syndrome is well described in dancers, and it is often associated with flexor hallucis longus tendinitis. High-quality MRI imaging will reveal the inflammation about the os trigonum and flexor hallucis longus tendinitis.
REFERENCES: Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont IL, American Academy of Orthopaedic Surgeons, 1998, pp 315-332.
Hamilton WG, Hamilton LH: Foot and ankle injuries in dancers, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 1225-1256.

Question 53

A 3-year-old child is referred for evaluation of bowed legs. History reveals no dietary deficiencies; however, family history is significant for several members with bowed legs. Examination reveals genu varum, and the child is in the 5th percentile for height and weight. Laboratory studies show normal renal function, a normal calcium level, a decreased phosphate level, and an elevated alkaline phosphatase level. A plain radiograph of the lower extremities is shown in Figure 22. What is the most likely diagnosis?

Explanation

DISCUSSION: The differential diagnosis of genu varum includes physiologic genu varum, Blount's disease, skeletal dysplasia, and metabolic bone disease. Children with Blount's disease are generally in the 95th percentile for height and weight, and usually multiple family members are not affected. The radiographs show widening of the physis and metaphyseal flaring. In Blount's disease, the characteristic radiographic changes involve only the tibia, and at this age, most commonly show beaking of the medial metaphysis. Skeletal dysplasias, such as chondrometaphyseal dysplasia, are associated with short stature, and the radiographic changes are similar to those seen here. However, laboratory studies in these children will be within normal limits. Children with chronic renal disease will often be of short stature, and the radiographic findings are again similar to those shown here. However, BUN and creatinine levels are elevated and phosphate levels are elevated rather than decreased in children with renal disease. The absence of dietary deficiencies and positive family history rules out vitamin D-deficient rickets. There are four types of vitamin D-resistant rickets: failure of production of 1,25-dihydroxy vitamin D, phosphate diabetes (hypophosphatemic rickets), end organ insensitivity to vitamin D, and renal tubular acidosis. All types of vitamin D-resistant rickets are resistant to treatment with physiologic doses of vitamin D. The patient’s clinical picture, family history, laboratory studies, and radiographs are most consistent with hypophosphatemic rickets. This entity is inherited as a sex-linked dominant trait.
REFERENCES: Evans GA, Arulanantham K, Gage JR: Primary hypophosphatemic rickets: Effect of oral phosphate and vitamin D on growth and surgical treatment. J Bone Joint Surg Am 1980;62:1130-1138.
Loeffler RD Jr, Sherman FC: The effect of treatment on growth and deformity in hypophosphatemic vitamin D-resistant rickets. Clin Orthop 1982;162:4-10.
Loder RT, Johnston CE II: Infantile tibia vara. J Pediatr Orthop 1987;7:639-646.
Bassett GS, Scott CI: The osteochondrodysplasias, in Morrissy RT (ed): Pediatric Orthopaedics, ed 3. Philadelphia, Pa, JB Lippincott, 1990, vol 1, pp 91-142.

Question 54

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

Explanation

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

Question 55

A 61-year-old man reports right hip pain and limited motion after undergoing total hip arthroplasty for posttraumatic arthritis 1 year ago. Figure 6 shows an AP radiograph of the pelvis. To improve motion and relieve pain, management should consist of

Explanation

DISCUSSION: The patient has symptomatic grade IV Brooker heterotopic ossification. Once the bone has matured, it can be excised. Surgical excision should be combined with postoperative irradiation to avoid recurrence. Pharmacologic and irradiation intervention are not successful beyond the perioperative period unless they are combined with surgical excision of mature heterotopic ossification.
REFERENCES: Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 417-451.
Iorio R, Healy WL: Heterotopic ossification after total hip and total knee arthroplasty: Risk factors, prevention, and treatment. J Am Acad Orthop Surg 2002;10:409-416.

Question 56

A 24-year-old athlete has a painful right shoulder. Figure 30 shows an intra-articular photograph that was obtained through a posterior portal during arthroscopy; the labrum is indicated by the arrow. Based on these findings, management should consist of

Explanation

DISCUSSION: The photograph shows a normal variant that is a sublabral hole beneath the anterosuperior labrum. In some instances, the labrum will become confluent with the middle glenohumeral ligament as a stout band. Because this variant is not abnormal, no treatment is necessary. Securing this portion of the labrum to the capsule may tighten the middle glenohumeral ligament complex and restrict external rotation of the arm.
REFERENCES: Andrews JR, Guerra JJ, Fox GM: Normal and pathologic arthroscopic anatomy of the shoulder, in Andrews JR, Timmerman LA (eds): Diagnostic and Operative Arthroscopy, ed 1. Philadelphia, PA, WB Saunders, 1997, pp 60-76.
Williams MM, Snyder SJ, Buford D Jr: The Buford complex: The “cord-like” middle glenohumeral ligament and absent anterosuperior labrum complex. A normal anatomic capsulolabral variant. Arthroscopy 1994;10:241-247.

Question 57

The mangled extremity severity score (MESS) utilizes all of the following variables EXCEPT:

Explanation

DISCUSSION: The MESS is a tool utilized to help predict limb salvage success versus primary amputation at the time of presentation. As a screening tool for amputation, this scoring system has a high specificity but low sensitivity, as scores lower than 7 may also ultimately need amputation. All of the variables except choice #5 are part of the scoring system.
The scoring system is as follows: 1. Skeletal / soft-tissue injury: Low energy = 1; Medium energy = 2; High energy = 3; very high energy = 4; 2. Limb ischemia: Pulse reduced or absent but perfusion normal = 1; Pulseless = 2; Cool, paralyzed, insensate = 3; 3. Shock: normotensive = 0; transient hypotension = 1; persistent hypotension = 2; 4. Age:
< 30 = 0; 30-50 = 1; >50 = 2. Limb category scores are doubled for ischemia > 6 hours. The system's original designers reported a cutoff of 7 as predicting amputation.
The referenced study by Ly et al found that the scoring system did not predict functional outcomes at 6 or 24 months. They also found that the Limb Salvage Index; the Predictive Salvage Index; the Nerve Injury, Ischemia, Soft-Tissue Injury, Skeletal Injury, Shock, and Age of Patient Score; and the Hannover Fracture Scale-98 all did not predict outcomes at 6 or 24 months.

Question 58

A 6-month-old child has the deformity seen in Figure 10. There are no other known associated problems. What is the etiology of this condition? Review Topic

Explanation

The radiograph demonstrates a type IV radial clubhand (radial dysplasia) with complete absence of the radius. This is a pre-axial deficiency usually with complete absence of the thumb. The condition is thought to be caused by an injury to the formation of the apical ectodermal ridge early in embryology. It is not an inherited condition unless it is associated with other syndromic problems. It is not known to be associated with specific teratogens. Fibroblast growth factor is involved in angiogenesis, wound healing, and embryonic development, but is not known to be associated with radial clubhand.

Question 59

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 60

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 61

Rupture of the distal biceps tendon is predictably identified by the hook test, which is performed by bringing a finger from lateral to medial across the antecubital fossa of a flexed elbow, feeling for a cord-like structure on which the examiner can "hook" a finger. Bringing the finger from medial to lateral can cause a false-negative result, hooking the lacertus fibrosus, which can remain intact even with a ruptured distal biceps tendon. The Yergason test (option 3) and the Speed test (option 4) are used to assist in diagnosing proximal, not distal, biceps and labral pathology. Even if the distal biceps tendon is ruptured, the supinator remains intact. Although supination weakness may be present, an inability to supinate should not be observed. When treating a closed long finger central slip tendon rupture conservatively, what is the most appropriate plan of care?

Explanation

EXPLANATION:
Closed central slip injuries treated nonsurgically require extension splinting of the PIP joint. DIP joint active range of motion is allowed during this time period. This allows the connections between the lateral bands and the central slip to pull the central slip distally with DIP joint active motion, minimizing the gap
across the central tendon injury and keeping the DIP joint from getting stiff as well.

Question 62

What is the most common causative bacteria in septic arthritis in children? Review Topic

Explanation

The spectrum of causative bacteria and frequency of occurrence of specific pathogens in septic arthritis are similar to those seen in osteomyelitis, with Staphylococcus aureus being the most common. Other common causative organisms include Kingella Kingae, Streptococcus pneumonia, Klebsiella species, Salmonella, Brucella melitensis, and Haemophilus influenzae.

Question 63

A 24-year-old man sustains the injury shown in Figures 19a through 19e in a paragliding accident. He is neurologically intact. He also sustained fractures of his left femur and right distal radius. Which of the following represents the best option for management of the spinal injury?

Explanation

DISCUSSION: The injury pattern is that of a burst fracture at L1 contiguous with a compression fracture at T12. There is associated kyphosis and slight spondylolisthesis of T12 on L1. Treatment of this type of burst fracture in neurologically intact patients is somewhat controversial, with at least one study demonstrating equal long-term results comparing nonsurgical treatment to surgical treatment. In this study, however, body casts were used initially in the nonsurgical group. Moreover, because this patient has multiple fractures, spinal fracture stabilization should be considered to facilitate early mobilization. Surgical stabilization and fusion via a posterior approach is the best treatment option in this patient. Anterior decompression is not necessary since the patient is neurologically intact.
REFERENCES: McLain RF, Benson DR: Urgent surgical stabilization of spinal fractures in polytrauma patients. Spine 1999;24:1646-1654.
Wood K, Butterman G, Mehbod A, et al: Operative compared with nonoperative treatment of a thoracolumbar burst fracture without neurological deficit: A prospective, randomized study.

J Bone Joint Surg Am 2003;85:773-781.
Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 201-216.

Question 64

Figure 28 is the lateral radiograph of a patient who sustained an intraarticular fracture of the calcaneus. The structure (*) depicted by the arrows most likely represents which osseous component of the calcaneus?

Explanation

Fractures of the calcaneus occur as a result of shear and compression forces. Foot position at the time of impact, the force of the impact, and bone quality all dictate the degree of comminution and fracture line orientation. Two primary fracture lines are consistently observed, one of which divides the calcaneus into medial and lateral portions. An essential feature of this fracture line is that it creates a fragment (sustentaculum tali) that remains attached to the talus by the interosseous ligament. This medial portion (constant fragment) of the posterior facet retains its normal anatomic position beneath the posterior talus. Its corresponding lateral component (labeled with an * in the figure), however, can be found displaced inferiorly within the body of the calcaneus. It is often rotated 90 degrees (as depicted in Figure 28) in relation to the remainder of the subtalar joint. This gives the appearance of what has been described as the "double-density" sign. The middle facet is more anterior and less commonly displaced. The lateral wall is nonarticular.

Question 65

A 38-year-old man has winging of the ipsilateral scapula after undergoing a transaxillary resection of the first rib 3 weeks ago. What is the most likely cause of this finding?

Explanation

DISCUSSION: During transaxillary resection of the first rib, the long thoracic nerve is at risk as it passes either through or posterior to the middle scalene muscle. Injury to this nerve may occur as the result of overly aggressive retraction of the middle scalene during the procedure.
REFERENCES: Leffert RD: Thoracic outlet syndrome. J Am Acad Orthop Surg 1994;2:317-325.
Todd TW: The descent of the shoulder after birth: Its significance in the production of pressure-symptoms on the lowest brachial trunk. Anat Anz 1912;41:385-397.

Question 66

The subcutaneous nerve most at risk for transection during an anterior surgical exposure of the ankle is the

Explanation

DISCUSSION
The dorsal medial cutaneous nerve arising from the superficial peroneal nerve crosses the inferior extent of a routine extensile surgical exposure to the ankle joint. The extensile anterior incision develops the interval between the tibialis anterior and extensor hallucis tendons, and, although the deep peroneal nerve is lateral and posterior to the extensor hallucis longus, the nerve most at risk during this exposure is the cutaneous branch supplying the dorsal medial foot to the great toe. Ankle replacement surgery is becoming more common; consequently, surgeons must be familiar with this anatomic landmark and risks related to its transection during surgery.
The medial plantar nerve is at risk when medial hindfoot incisions are made through the
abductor hallucis muscle during tarsal tunnel release and harvest of the flexor hallucis tendon for transfer. The dorsal cutaneous branch of the sural nerve supplies the lateral dorsal

Question 67

A 61-year-old man with a body mass index of 31 had a 6-month gradual onset of right medial knee pain. Examination revealed a small effusion, stable ligaments, a normally tracking patella, and mild medial joint line tenderness. Standing radiographs show mild medial joint space narrowing. Effective treatment at this stage of early medial compartmental osteoarthritis includes

Explanation

DISCUSSION:
According to the 2008 AAOS Clinical Practice Guideline, Treatment of Osteoarthritis of the Knee (Nonarthroplasty), level 1 evidence confirms that weight loss and exercise benefit patients with knee osteoarthritis. The other responses have either inclusive evidence (a valgus-directing brace) or no evidence to support their use (glucosamine 1,500 mg/day and chondroitin sulfate 800 mg/day as well as
arthroscopic debridement and lavage).

Question 68

A B C What is the appropriate first step when confirming the diagnosis of a neurologically intact, 73-year-old man who has the images shown in Figures 25a through 25c?

Explanation

DISCUSSION
The radiograph and MR images show an osteoblastic lesion in the T9 and T8 vertebral bodies. In an older man, this finding most likely reveals metastatic prostate cancer. The first and least invasive diagnostic step is to order a PSA level. Gleave and associates found in a retrospective review of patients with prostate cancer that isolated levels of PSA lower than 10 to 20 micrograms per liter are rarely associated with bone metastasis. Vis and associates documented that 10-year prostate cancer survival in a screened population was higher than 60%, and in an unscreened population it was 24%. In a neurologically intact patient with no evidence of neural compression or instability, surgery is not indicated. Fine-needle aspiration may be performed, but the diagnostic yield in a blastic lesion is low. A bone scan may be indicated to complete the metastatic workup, but it will not aid in the diagnosis of tissue source.
RECOMMENDED READINGS
Gleave ME, Coupland D, Drachenberg D, Cohen L, Kwong S, Goldenberg SL, Sullivan LD. Ability of serum prostate-specific antigen levels to predict normal bone scans in patients with newly diagnosed prostate cancer. Urology. 1996 May;47(5):708-12. PubMed PMID: 8650870. View Abstract at PubMed
Vis AN, Roemeling S, Reedijk AM, Otto SJ, Schröder FH. Overall survival in the intervention arm of a randomized controlled screening trial for prostate cancer compared with a clinically diagnosed cohort. Eur Urol. 2008 Jan;53(1):91-8. Epub 2007 Jun 12. PubMed PMID: 17583416. View Abstract at PubMed
Cronen GA, Emery SE. Benign and malignant lesions of the spine. In: Spivak JM, Connolly PJ, eds. Orthopaedic Knowledge Update: Spine 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:351-366.
CLINICAL SITUATION FOR QUESTIONS 26 THROUGH 29

Figures 26a and 26b are the MR images with gadolinium enhancement of a 40-year-old man who arrives at the emergency department with a 4-day history of fevers and severe back pain without radiation. He is normotensive at presentation with a heart rate of 86 beats per minute. Upon examination he is neurologically intact with normal sensory and motor function. He has a history of alcohol and cocaine abuse. His white blood cell (WBC) count is 12000 (reference range [rr], 4500-11000 /µL) and his C-reactive protein (CRP) level is 100 mg/L (rr, 0.08-3.1 mg/L)

Question 69

Which of the following methods best aids in diagnosis of an interdigital neuroma?

Explanation

DISCUSSION: History and physical examination are still the gold standard for diagnosis of an interdigital neuroma. Ultrasound and MRI may be helpful adjuncts but are dependent on equipment and operator expertise. Web space injection may be helpful for diagnostic and therapeutic purposes. Electromyography and nerve conduction velocity studies are of little benefit for distal lesions.
REFERENCES: Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 145-147.
Bennett GL, Graham CE, Mauldin DM: Morton’s interdigital neuroma: A comprehensive treatment protocol. Foot Ankle Int 1995;16:760-763.

Question 70

What preoperative factor correlates best with the outcome of rotator cuff repair?

Explanation

DISCUSSION: The size of the rotator cuff tear in both anteroposterior and mediolateral dimensions has been found to correlate best with outcome. Older patient age and rupture of the long head of the biceps tend to be associated with larger tears and, therefore, may be associated indirectly with a poorer outcome.
REFERENCES: Iannotti JP: Full-thickness rotator cuff tears: Factors affecting surgical outcome. J Am Acad Orthop Surg 1994;2:87-95.
Iannotti JP, Bernot MP, Kuhlman JR, Kelley MJ, Williams GR: Postoperative assessment of shoulder function: A prospective study of full-thickness rotator cuff tears. J Shoulder Elbow Surg 1996;5:449-457.

Question 71

Figure 28 shows an AP radiograph of a 54-year-old woman who underwent lumbar laminectomy and fusion at the L4 and L5 levels with placement of a bone stimulator 8 years ago. She also underwent a left total hip arthroplasty 2 years ago; aspiration of that joint now reveals that it is infected with a gram-positive cocci organism. History is also significant for IV drug use and human immunodeficiency virus (HIV). The patient reports fever, chills, and left flank and abdominal pain. Examination reveals significant pain with resisted left hip flexion and passive hip extension. She also has lumbar hyperlordosis. Which of the following studies would best identify the underlying cause of her infection?

Explanation

DISCUSSION: The patient’s clinical signs (fever and flank, hip, and abdominal pain) suggest a primary iliopsoas abscess. With an increased patient population who abuse drugs and/or who are HIV-positive, iliopsoas abscess may be more prevalent because of systemic bacterial seeding and may be potentially unrecognized. Diagnostic imaging studies provide a better understanding of the anatomic magnitude of the infection, give concrete confirmation of the diagnosis, and may suggest an underlying cause. Neither standard abdominal radiographs nor ultrasound studies are sensitive enough to be diagnostic of this disease process. CT has been established as the standard study for identifying the underlying cause of this abscess. The hip infection has most likely developed as a result of hematogenous spread from an infected skin lesion from the patient’s IV drug use.
REFERENCES: Santaella RO, Fishman EK, Lipsett PA: Primary vs secondary iliopsoas abscess: Presentation, microbiology, and treatment. Arch Surg 1995;130:1309-1313.
Malhotra R, Singh KD, Bhan S, Dave PK: Primary pyogenic abscess of the psoas muscle. J Bone Joint Surg Am 1992;74:278-284.

Question 72

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 73

Figure 4a shows the radiograph of a 20-year-old man who has an injury to the right shoulder. Figure 4b shows an arthroscopic view (posterior portal). The arrow points to a Review Topic

Explanation

The radiograph shows an anterior dislocation of the shoulder. A frequently encountered sequela of this is a compression fracture of the posterolateral humeral head, commonly referred to as a Hill-Sachs defect. The arthroscopic view of the glenohumeral joint visualizes the posterior aspect of the humeral head. In the image, the area devoid of cartilage to the right is the bare area. The indentation seen to the left is a Hill-Sachs defect.

Question 74

A 23-year-old woman has had vague left knee pain for the past 6 months. A radiograph and CT scan are shown in Figures 50a and 50b. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographic appearance of the lesion emanating from the posterior cortex of the left distal femur is consistent with a surface bone-producing lesion; therefore, the most likely diagnosis is a parosteal osteosarcoma. In an osteochondroma, the cortex and medullary cavity of the lesion are in continuity with that of the native bone. A dedifferentiated chondrosarcoma has histologic components of a high-grade sarcoma plus a benign or low-grade malignant cartilage tumor. Tumoral calcinosis is characterized by amorphous calcium in the soft tissues and does not emanate from the bone itself. While often confused with parosteal osteosarcoma, myositis ossificans is usually more mature at the periphery of the lesion rather than the center. In addition, myositis ossificans does not involve the underlying cortex but remains separate from the bone.
REFERENCES: Unni KK: Dahlin’s Bone Tumors: General Aspects and Data on 11,087 Cases, ed 5. Philadelphia, PA, Lippincott-Raven, 1996, pp 185-196.
Okada K, Frassica FJ, Sim FH, Beabout JW, Bond JR, Unni KK: Parosteal osteosarcoma. A clinicopathological study. J Bone Joint Surg Am 1994;76:366-378.

Question 75

Acute redislocation of the glenohumeral joint is a complication that occurs following a first-time dislocation. This is most often seen with

Explanation

DISCUSSION: Redislocation following acute dislocation occurs in approximately 3% of patients. This redislocation tends to occur in middle-aged and elderly patients. A higher incidence of redislocation occurs when there are accompanying fractures of the glenoid rim and the greater tuberosity.
REFERENCES: Robinson CM, Kelly M, Wakefield AE: Redislocation of the shoulder during the first six weeks after a primary anterior dislocation: Risk factors and results of treatment.

J Bone Joint Surg Am 2002;84:1552-1559.
Bigliani LU, Newton PM, Steinmann SP, et al: Glenoid rim lesions associated with recurrent anterior dislocation of the shoulder. J Sports Med 1998;26:41-45.

Question 76

A 20-year-old man reports painless snapping about the lateral aspect of the right hip. He denies any history of trauma. Examination reveals no limp or tenderness. Hip range of motion is full, and there is good strength. Radiographs are normal. What anatomic structure is most likely causing these symptoms?

Explanation

DISCUSSION: Coxa saltans (snapping hip syndrome) can occur in two forms: external/lateral or interior/medial/anterior. This patient has the external/lateral form. The external/lateral form involves the iliotibial band, tensor fascia, or gluteus medius, which snaps over the greater trochanter. The external form usually can be treated with physical therapy alone; however, several recent studies report satisfactory results with surgical treatment. Faraj and associates reported good results from surgical Z-plasty in a series of 10 patients. White and associates reported good results in a series of 16 patients with 17 hips who underwent surgical release of an external snapping hip. The interior/medial/anterior form can involve the iliopsoas tendon, acetabular labrum, subluxation of the hip, and loose bodies.
REFERENCES: White RA, Hughes MS, Burd T, et al: A new operative approach in the correction of external coxa saltans: The snapping hip. Am J Sports Med 2004;32:1504-1508.
Faraj AA, Moulton A, Sirivastava VM: Snapping iliotibial band: Report of ten cases and review of the literature. Acta Orthop Belg 2001;67:19-23.
Choi YS, Lee SM, Song BY, et al: Dynamic sonography of external snapping hip syndrome.
J Ultrasound Med 2002;21:753-758.

Question 77

Figures 42a and 42b shows the radiographs of a 20-year-old man who sustained a hyperextension injury to his little finger. Multiple attempts at closed reduction have been unsuccessful. Management should now consist of

Explanation

DISCUSSION: The radiographs show a complex dislocation of the little finger metacarpophalangeal joint. This is characterized by obvious dislocation on the AP and lateral views and a type of bayonet apposition best visualized on the lateral view. Irreducibility of this injury is caused by displacement of the volar plate that has been traumatically avulsed from its origin on the metacarpal, with subsequent displacement into the metacarpophalangeal joint. This abnormal position of the volar plate causes irreducibility that can be corrected only by open reduction. This can be effected either by dorsal or palmar approaches.
REFERENCES: Stern PJ: Fractures of the metacarpals and phalanges, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, 1999,

pp 711-771.
Becton JL, Christian JD Jr, Goodwin HN, Jackson JG III: A simplified technique for treating the complex dislocation of the index metacarpophalangeal joint. J Bone Joint Surg Am 1975;57:698-700.
Green DP, Terry GC: Complex dislocation of the metacarpophalangeal joint: Correlative pathological anatomy. J Bone Joint Surg Am 1973;55:1480-1486.

Question 78

A 74-year-old man reports progressive left hip pain with weight-bearing activities. A radiograph is shown in Figure 30. What is the most likely underlying diagnosis?

Explanation

DISCUSSION: The radiograph shows enlargement of the bone, coarse trabeculation, a blastic appearance, and thickening of the cortex, revealing the classic appearance of Paget’s disease in the sclerotic phase, the most common presentation. While lymphoma may present as a blastic lesion, it will not have the same enlargement, coarse trabeculation of bone, and the significant sclerosis seen here.
REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 211-215.
Resnick D (ed): Diagnosis of Bone and Joint Disorders. Philadelphia, PA, WB Saunders, 2002, pp 1947-2000.

Question 79

An active 23-year-old man has right groin pain that increases with sports activity. Examination reveals decreased internal rotation of the affected hip. He has a positive impingement test and radiographs reveal no crossover sign. An MRI scan is most likely to reveal which of the following? Review Topic

Explanation

Young patients with hip pain and a positive impingement test are likely to have femoroacetabular impingement. The triad seen in these patients is a reduced concavity at the femoral head-neck junction, which leads to an increase in alpha angle and a chondrolabral tear. MR-arthrogram is the cross-sectional imaging modality of choice. These patients usually have reduced internal rotation and a positive impingement sign. The other findings, though possible, are not the most likely scenario in this young and active patient.

Question 80

During right knee anterior cruciate ligament (ACL) reconstruction, after drilling an appropriately positioned and referenced tibial tunnel, the surgeon finds that the transtibial guide is placing the femoral tunnel at 11:30 within the intercondylar notch. Which of the following choices will best enable appropriate graft placement in this clinical scenario? Review Topic

Explanation

Anatomic placement of the femoral tunnel is best achieved in this clinical scenario by drilling the femoral tunnel through the anteromedial portal or via a two-incision technique. Several recent studies have demonstrated the difficulty that may be encountered in restoring true ACL anatomy on the femoral side when placing a femoral tunnel through a transtibial technique. While this is not always the case and this technique may be reasonable and sufficient, it is important for orthopaedic surgeons to critically assess tunnel placement intraoperatively and postoperatively to
minimize errant tunnel placement, demonstrated in the literature as the most common cause of ACL failure and need for revision. In this not uncommon clinical scenario, simply converting to a two-incision ACL technique or drilling through the anteromedial portal with the knee hyperflexed will permit accurate femoral tunnel placement and increase the likelihood of an optimal clinical outcome. Femoral tunnel accuracy with these techniques is enhanced by a lower starting point in the intercondylar notch. Familiarity with these techniques is valuable for surgeons performing ACL reconstruction. Revising the tibial tunnel in this scenario would likely lead to bone compromise of the proximal tibia and may interfere with graft fixation and incorporation. Converting to a double-bundle ACL with a transtibial technique would not correct the vertical femoral tunnel. Hyperflexion of the knee may improve femoral tunnel placement to some extent, but is unlikely to allow anatomic placement of a femoral tunnel when the transtibial guide lies in a clearly excessive vertical position.

Question 81

An MRI scan

Explanation

Treatment is based on the probability of curve progression. Major factors that influence curve progression are skeletal maturity, curve magnitude and curve type. Candidates for bracing are Risser 0, 1, or 2 and have a curve in the range of 20-40 degrees. Patients who present with curves between 30-40 degrees should be braced on presentation. Acceptable frequency of follow-up visits are at 4-6 month intervals. MRI scan would be indicated to evaluate a patient with atypical scoliosis, the patient described is a fairly typical scoliosis patient. Scoliosis treatment by electrical stimulation or physical therapy has not been shown to be effective.

Question 82

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

Explanation

DISCUSSION: SIS is a devastating but preventable complication of head injury. It occurs when return to activities is allowed prior to complete resolution of the symptoms of the first head injury. A second, sometimes trivial, head injury can lead to a devastating series of events that can result in sudden death. The symptoms tend to progress rapidly and often involve the brain stem. The prognosis is poor.
REFERENCES: Cantu RC: Second-impact syndrome. Clin Sports Med 1998;17:37-44.
Saunders RL, Harbaugh RE: Second impact in catastrophic contact-sports head trauma. JAMA 1984;252:538-539.
Stevenson KL, Adelson PD: Pediatric sports-related head injuries, in Delee JC, Drez D (eds): Orthopaedic Sports Medicine: Principles and Practice, ed 2. Philadelphia, PA, WB Saunders, 2003, vol 1, p 781.

Question 83

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 84

What portion of the pitching phase creates forces approaching the tensile limit of the medial ulnar collateral ligament of the elbow? Review Topic

Explanation

The late cocking and early acceleration phases are often combined when discussing medial stress on the elbow of the overhand thrower. This is when the greatest valgus moment across the medial elbow occurs and the forces reach the tensile limits of the medial ulnar collateral ligament.
Fleisig et al. were among the first to elucidate the elbow and shoulder kinetics in healthy adult pitchers using high-speed motion capture analysis. Inability to generate sufficient elbow varus torque may result in medial tension, lateral compression, or posteromedial impingement injury.
According to Lynch et al. the late cocking phase of the overhand throw places a marked valgus moment across the medial elbow. This repetitive force reaches the tensile limits of the medial collateral ligament, subjecting it to microtraumatic injury and attenuation. The anterior bundle of the medial collateral ligament has been identified as the primary restraint to valgus load and is the focus of reconstruction.
Incorrect Responses:
1,4,5: The medial elbow forces are less during these phases. 4: Ball release is not one of the 5 phases of throwing and marks the end of the acceleration and beginning of deceleration phase.

Question 85

Surgical arthroscopy performed 1 week after injury presents increased risk for

Explanation

DISCUSSION
The MR images show injuries to the ACL, PCL, and PLC consistent with a knee dislocation. The optimal timing of surgery after multiligament knee injury remains unclear. Two systematic reviews demonstrated superior clinical outcome scores after early treatment, including higher mean Lysholm scores and a higher percentage of good/excellent International
Knee Documentation Committee scores. Early treatment was associated with increased residual anterior knee instability but no difference in posterior instability, varus laxity, or valgus laxity. Although numbers were limited, the average range of motion and rate of extension loss of at least 5 degrees was similar between groups. More patients in the early-treatment group demonstrated a higher rate of flexion loss of 10 or more degrees and an increased need to undergo a second procedure to address arthrofibrosis, including manipulation under anesthesia and arthrolysis. Return to work did not significantly differ between groups, but return to sports was lower in the early-treatment group. Evidence demonstrates a higher rate of low-energy mechanisms resulting in multiligament knee injury and an increased odds ratio for complications among obese (= 30 degrees kg/m2 patients, including wound complications and neurovascular injury. The complication rate increased 9.2% for every 1-point increase in body mass index. There is no association between complication rate and age, injury mechanism, or timing of surgery. Orthopaedic surgeons performing arthroscopy during the early postinjury period must be mindful of the extensive soft-tissue damage present in these patients, including potential capsular defects. Use of high-pressure irrigation can lead to substantial fluid extravasation into the thigh or lower leg compartments, placing patients at increased risk for compartment syndrome. In addition to avoiding high-pressure irrigation, some orthopaedic surgeons have advocated the creation of generous capsular incisions during portal establishment to allow for ready egress of irrigation fluid from the portal sites rather than into soft tissues.
RESPONSES FOR QUESTIONS 85 THROUGH 88
Excessive medial placement of coracoid autograft
Excessive lateral placement of coracoid autograft
Excessive inferior dissection during the procedure
Excessive retraction and dissection of the medial portion of the conjoint tendon
A 20-year-old right-hand-dominant football player sustained a traumatic shoulder dislocation during a tackle. He has had multiple recurrent dislocations, and radiographs reveal anterior glenoid bone loss. He underwent a Latarjet procedure. Match the most likely complication described below with the surgical error listed above.

Question 86

A 40-year-old man reports an enlarging soft-tissue mass in his right shoulder. Based on the MRI scan and biopsy specimens shown in Figures 40a through 40c, what is the most likely diagnosis?

Explanation

DISCUSSION: Nodular fasciitis is a pseudosarcomatous, self-limiting reactive process composed of fibroblasts and myofibroblasts. Most patients give a history of a rapidly growing mass that has been present for only a few weeks. Many have pain associated with the mass and can recall a specific traumatic event predating the presence of the lesion. It can occur at any age but is most commonly seen in adults who are 20 to 40 years of age. Histologically, the lesion is composed of predominantly plump, immature-appearing fibroblasts that bear a close resemblance to the fibroblasts found in granulation tissue. Characteristically, the fibroblasts

are arranged in short, irregular bundles and fascicles and are adjacent to collagen and reticulin. The lesions can appear to be more myxoid or more fibrotic in nature and this correlates to the duration of symptoms. The lesions with a short duration of symptoms have a more myxoid appearance in contrast to those of longer duration characterized by hyaline fibrosis.
REFERENCES: Weiss SW, Goldblum JR, Enzinger FM: Enzinger and Weiss’s Soft Tissue Tumors, ed 4. Philadelphia, PA, Elsevier, 2001, pp 250-266.
Wang XL, De Schepper AM, Vanhoenacker F, et al: Nodular fasciitis: Correlation of MRI findings and histopathology. Skeletal Radiol 2002;31;155-161.

Question 87

What genetic defect is responsible for achondroplasia? Review Topic

Explanation

In achondroplasia the defect is always in the same location on this gene (a defect in FGFR-3), and most children share a very similar clinical phenotype. Achondroplasia is not caused by a defect in the gene for FGF-3, the growth factor itself, but rather the gene coding for the receptor. Trisomy of chromosome 21 is responsible for Down syndrome. Defects in the COL1A1 gene are found in some types of osteogenesis imperfecta. Unlike achondroplasia, the defects occur throughout the gene, with more than 200 mutation sites reported.

Question 88

Which of the following best describes athletic pubalgia?

Explanation

DISCUSSION: Athletic pubalgia refers to a distinct syndrome of lower abdominal and adductor pain that is mostly commonly seen in high performance male athletes. This condition must be distinguished from others such as painful inflammation of the symphysis pubis, referred to as osteitis pubis. Symptoms attributable to the iliopsoas tendon are most commonly associated with snapping of the tendon. Stress fracture of the pubic ramus may cause symptoms in this area, but it is usually confirmed by imaging studies. Neurapraxia of the pudendal nerve is associated with pressure from the seat in cycling sports and also as a complication associated with traction during surgical procedures.
REFERENCES: Meyers WC, Foley DP, Garrett WE, Lohnes JH, Mandlebaum BR: Management of severe lower abdominal or inguinal pain in high-performance athletes: PAIN (Performing Athletes with Abdominal or Inguinal Neuromuscular Pain Study Group). Am J Sports Med 2000;28:2-8.
Albers SL, Spritzer CE, Garrett WE Jr, Meyers WC: MR findings in athletes with pubalgia. Skeletal Radiol 2001;30:270-277.

Question 89

A 13-year-old patient has foot drop and lateral knee pain. AP and lateral radiographs and an MRI scan are shown in Figures 49a through 49c. A biopsy specimen is shown in Figure 49d. What is the preferred method of treatment?

Explanation

DISCUSSION: The “sunburst” radiographic appearance suggests an osteosarcoma, and the histologic findings confirm the diagnosis with malignant cells surrounded by pink osteoid. MRI scans are not particularly helpful in the diagnosis of osteosarcoma but are mandatory for surgical planning. Osteosarcomas are high-grade sarcomas that are best treated with chemotherapy and wide resection. Even though the peroneal nerve is involved, limb salvage is indicated. Survival after limb salvage is equivalent to amputation, with better function.
REFERENCES: Goorin AM, Abelson HT, Frei E: Osteosarcoma: Fifteen years later. N Engl J Med 1985;313:1637.
Link MP, Goorin AM, Miser AW, et al: The effect of adjuvant chemotherapy on relapse-free survival in patients with osteosarcoma of the extremity. N Engl J Med 1986;314:1600.
Davis AM, Bell RS, Goodwin PJ: Prognostic factors in osteosarcoma: A critical review. J Clin Oncol 1994;12:423.

Question 90

Linazolid exerts its antimicrobial action by inhibiting bacterial

Explanation

DISCUSSION: Linazolid is the first agent of the oxazolidinone group of antibiotics and is very active against methicillin-sensitive Staphylococus aureus, S epidermidis, and vancomycin-resistant enterococci. The drug has no gram-negative activity. Linazolid inhibits protein synthesis by blocking formation of the 70S ribosomal translation complex. This mechanism of action is unique to the oxazolidinones.
REFERENCES: Rybak MJ, Cappelletty DM, Moldovan T, et al: Comparative in vitro activities and postantibiotic effects of the oxazolidinone compounds eperezolid (PNU-100592) and linezolid (PNU-100766) versus vancomycin against Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus faecalis, and Enterococcus faecium. Antimicrob Agents Chemother 1998;42:721-724.
Sweeney MT, Zurenko GE: In vitro activities of linezolid combined with other antimicrobial agents against Staphylococci, Enterococci, Pneumococci, and selected gram-negative organisms. Antimicrob Agents Chemother 2003;47:1902-1906.

Question 91

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

Explanation

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

Question 92

To prevent injury to the posterior interosseous nerve during the approach for reduction and fixation of a fracture of the radial head, anterior retraction should be performed with the forearm

Explanation

Position of the patient-Place supine on the operating table, with the affected arm positioned over the chest. Pronate the forearm.
Deep surgical dissection-Fully pronate the forearm to move the posterior interosseous nerve away from the operative field. Incise the capsule of the elbow joint longitudinally to reveal the underlying capitulum, the radial head, and the annular ligament. Do not incise the capsule too far anteriorly; the radial nerve runs over the front of the anterolateral portion of the elbow capsule. Do not continue their dissection below the annular ligament or retract vigorously, distally, or anteriorly, because the posterior interosseous nerve lies within the substance of the supinator muscle and is vunerable to injury.
Dangers: Nerves-The posterior interosseous nerve is in no danger as long as the dissection remains proximal to the annular ligament. Pronation of the forearm keeps the nerve as far from the operative field as it possible can be. To ensure the safety of the nerve, take great care to place the retractors directly on the bone and be careful in their placement. Because the posterior interosseous nerve actually may touch the bone of the radial neck, directly opposite the bicipital tuberosity, placing retractors behind it poses a risk.

Question 93

Figures 75a and 75b are the radiographs after attempted reduction of an injury in a 9-year-old girl. Which anatomic structure is most likely to be interposed?

Explanation

DISCUSSION
The injury shown is a flexion-type supracondylar humerus fracture. The most commonly interposed anatomic structure is the ulnar nerve. The brachialis muscle is often interposed in extension-type fractures, as are the median nerve and radial artery. The radial nerve is at risk for entrapment in a humeral shaft fracture or distal third humeral fracture.

CLINICAL SITUATION FOR QUESTIONS 76 THROUGH 80
Figure 76 is the clinical photograph of an infant with foot deformities.

Question 94

Which of the following statements best describes the typical early presentation of osteochondritis dissecans of the elbow? Review Topic

Explanation

This condition is the result of repetitive valgus overload of the radiocapitellar joint in the immature elbow. The clinical presentation is of lateral elbow pain and loss of extension in a juvenile older than age 10 years. Panner's disease typically affects the capitellum in boys younger than age 10 years. Osteochondritis dissecans (OCD) of the elbow affects the capitellum and occasionally the radial head. Fracturing of the OCD region can lead to an unstable fragment with margins outlined on an MR arthrogram and can progress to loose bodies that cause clinical catching or locking. These are typically late signs with a poorer prognosis.

Question 95

below show the radiographs, and the CT obtained from a 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 96

A 34-year-old man presents to clinic with 4 months of right elbow pain. He began going to the gym and playing squash about 3 months ago. On exam, he is tender over the lateral aspect of the elbow and has pain with resisted wrist extension. Which of the following choices lists the correct compartment of the muscle typically involved in this disease and then lists its antagonist muscle? Review Topic

Explanation

The patient presents with lateral epicondylitis, which typically involves the origin of the extensor carpi radialis brevis (ECRB). ECRB is in the mobile wad compartment and its antagonist muscle is flexor carpi ulnaris.
Lateral epicondylitis is an overuse injury, typically secondary to repetitive pronation and supination motion in extension, that leads to inflammation of the ECRB origin at the elbow. Histological analysis typically shows vascular hyperplasia and disorganized collagen. Clinically, patients will have pain over the lateral elbow exacerbated by resisted wrist extension. ECRB, the most commonly involved muscle origin, is innervated by the deep branch of the radial nerve and inserts on the base of the 3rd metacarpal. As it is radial wrist extensor, its antagonist is the ulnar sided wrist flexor.
Brummel et al. reviewed the clinical presentation and management options for lateral epicondylitis. They report acute symptoms in younger patients and chronic symptoms in older patients. NSAIDs, extensor stretching and activity modification are the mainstay of nonsurgical treatment.
Bunata et al. studies 85 cadavar elbows to determine anatomic factors contributing to tennis elbow. They found that the ECRB undersurface rubs against the lateral capitellium in elbow extension leading to tendinosis.
Illustration A is cross-sectional diagram of the forearm with muscle bellies labeled. Notice the location of ECRB in the mobile wad. Illustration B is a coronal T2 MRI showing fluid signal and undersurface tearing near the extensor origin as can be seen in lateral epicondylitis.
Incorrect Answers:
1-4: The ECRB is in the mobile wad and its antagonist is flexor carpi ulnaris. All other answers are incorrect.

Question 97

Figures below show the clinical photograph and radiograph obtained from a 62-year-old man who has deformity and pain 1 year after primary total hip arthroplasty. What is the reason for the observed deformity?

Explanation

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

Question 98

A 70-year-old woman who underwent total knee replacement 18 months ago has had 3 weeks of moderate drainage from a previously healed wound. What is the most appropriate treatment?

Explanation

DISCUSSION:
This situation represents a definitively and chronically infected knee replacement. Antibiotic therapy alone might suppress the infection but would not eradicate it. Debridement and polyethylene exchange would be appropriate treatment for an early postoperative infection. The treatment of choice is to perform a two-stage debridement and reconstruction. Although not among the listed choices, an aspiration or culture could be done presurgically and might help clinicians identify the best antibiotics to treat the condition. Antibiotic selection would not affect the need for the two-stage reconstruction, however.

Question 99

Increased hip intracapusular pressures can lead to diminished femoral head perfusion. What leg position has been shown to create the lowest intracapsular hip pressures after femoral neck fracture?

Explanation

DISCUSSION: In the referenced study by Bonnaire et al, extension and internal rotation had the highest intercapsular pressure. They found that the greatest decrease in pressure was found with flexion, abduction and external rotation. This is a possible etiology to the common position in which these patients will present to the emergency room. Traction was shown to increase pressure in the joint capsule.

Question 100

Figure 56 is the radiograph of an otherwise healthy 3-year-old boy who fell and sustained the isolated injury shown. What is the best treatment modality?

Explanation

DISCUSSION
At 3 years of age, children do well with nonsurgical treatment with early spica casting and early mobilization. There is no indication to perform surgical stabilization in such a closed isolated injury. The fracture is not shortened unacceptably according to clinical practice guidelines, and traction for this fracture is unnecessary. Traction also may be problematic for the family and healthcare system.
RESPONSES FOR QUESTIONS 57 THROUGH 62
Cortical thickening in the region of the lesion
Erosive metaphyseal lesion with loss of cortical integrity
Normal bony anatomy on radiographs
Diffuse articular erosion with loss of joint space
Round, expansive, well-circumscribed metaphyseal lesion with thinning of the cortex
Eccentric well-circumscribed metaphyseal lesion with a scalloped border
Match the orthopaedic condition described below with the expected radiographic finding listed above.

Full Question & Answer Text (for Search Engines)

Question 1:

A 56-year-old woman sustained the fracture shown in Figures 30a and 30b in a motor vehicle accident. What mechanism is most likely responsible for the injury?

Options:

Flexion distraction
Vertical shear
Extension distraction
Flexion compression
Axial load

Correct Answer: Axial load

Explanation:

DISCUSSION: The CT scans show a burst fracture that results from an axial load injury. The radiographic hallmark of a burst fracture is compression of the posterior cortex of the vertebral body with retropulsion of bone into the spinal canal. AP radiographs often show widening of the interpedicular distance with a fracture of the lamina.
REFERENCES: Theiss SM: Thoracolumbar and lumbar spine trauma, in Stannard JP, Schmidt AH, Kregor PJ (eds): Surgical Treatment of Orthopaedic Trauma. New York, NY, Thieme, 2007, pp 179-207.
Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 201-216.

Question 2:

Options:

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

Correct Answer: observation.

Explanation:

Question 3:

Options:

Electromyography and nerve conduction velocity studies of bilateral lower extremities
Multilevel lumbar laminectomy
MRI of the thoracic and cervical spine
MRI of the brain
Epidural steroid injections

Correct Answer: Electromyography and nerve conduction velocity studies of bilateral lower extremities

Explanation:

The patient is having gait problems suspicious for spinal cord compression. MRI of the thoracic and cervical spine should be performed to evaluate for spinal cord compression. Reports of leg weakness in the absence of discrete motor weakness on manual testing, and the appearance of an unsteady wide-based gait are more consistent with myelopathy as a cause of the gait difficulty rather than lumbar stenosis. Although the MRI scan of the lumbar spine shows multilevel spinal stenosis that is mild to moderate, it does not clearly explain the patient's signs and symptoms. Electromyography and nerve conduction velocity studies of the lower extremities are unlikely to add significantly to the diagnosis. Epidural steroid injections are not indicated. Lumbar decompression is unlikely to help the patient because the source of the patient's problem does not originate in the lumbar spine. MRI of the brain could be considered as a secondary imaging study if the cervical and thoracic MRI scans fail to identify an obvious cause for gait instability.
(SBQ12SP.92) A 36-year-old man presents to the emergency department after being involved in a motor vehicle collision. He is complaining of back pain and imaging shows the findings in Figure A. On neurological examination, he does not have any deficits. MRI shows approximately 25% canal encroachment and no evidence of injury to the posterior ligamentous complex. Which of the following is the most appropriate course in management?
Review
Topic
Strict bedrest for six weeks then progressive weightbearing
Ambulation as tolerated with or without a TLSO
Surgical decompression and anterior stabilization
Surgical decompression and posterior stabilization
Surgical decompression and combined anterior/posterior stabilization
The patient has a L1 burst fracture with minimal retropulsion of bony fragments in the spinal canal. In the absence of neurological deficits and injury to the PLC, the most
appropriate treatment is ambulation as tolerated with or without a thoracolumbrosacral orthosis (TLSO).
Thoracolumbar burst fractures are typically caused by an axial load with flexion and commonly found in this location due to increased motion at these segments. With an intact posterior ligamentous complex (PLC) and no neural compromise, TLSO is the mainstay of treatment. If there is evidence of neurological deficit and/or PLC injury, decompression and fusion are indicated. The degree of acceptable kyphosis is controversial. The choice of anterior versus posterior approach is based on ease of decompression.
Vaccaro et al. introduced a new classification system for thoracolumbar injuries, TLICS, based on morphological appearance, integrity of the posterior ligamentous complex, and neurological status. They advocate use of the system for nonoperative versus operative decision making and communication between surgeons.
Bailey et al. completed a randomized, nonblinded controlled trial to determine the efficacy of bracing for AO type A0-A3 thoracolumbar burst fractures. Both groups were encouraged to ambulate as tolerated and the no brace group had bending restrictions for 8 weeks. They found no difference in the Roland Morris Disability Questionnaire (RMDQ) score at 3 months after injury.
Figure A is sagittal CT scan of the lumbar spine showing a burst fracture of L1 with minimal retropulsion. Illustration A is the TLICS classification with score of 4 being the branch point for nonoperative versus operative management.
Incorrect Answers:

Question 4:

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

Options:

Elbow stiffness
Nonunion
Osteonecrosis
Varus malunion from overgrowth
Fishtail deformity

Correct Answer: Nonunion

Explanation:

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

Question 5:

For halo traction, what is the preferred site for anterior pin placement?

Options:

Below the head equator, above the supraorbital ridge, and 3.5 cm lateral to the midline
Below the head equator, above the supraorbital ridge, and 4.5 cm lateral to the midline
Below the head equator, below the supraorbital ridge, and 4.5 cm lateral to the midline
Above the head equator, above the supraorbital ridge, and 3.5 cm lateral to the midline
Above the head equator, above the supraorbital ridge, and 4.5 cm lateral to the midline

Correct Answer: Below the head equator, above the supraorbital ridge, and 4.5 cm lateral to the midline

Explanation:

Question 6:

Options:

Recurrence of the deformity
Hallux varus
back answer
Transfer metatarsalgia
Nonunion of the first metatarsal osteotomy
Osteonecrosis of the first metatarsal osteotomy 77.03

Correct Answer: Recurrence of the deformity

Explanation:

Coglin’s referenced paper is a study out of Idaho. 11 year retrospective study of 45 patients (60 feet). A multiprocedural approach was used to surgically correct the deformity. There were 6 recurrences of the deformities and eight
complications (6 cases of hallux varus, one case of wire breakage and one case of undercorrection.) So according to their reference this question has two correct answers.
Postoperative complications have been frequently reported following juvenile hallux valgus corrections. Recurrence following surgery is probably the most frequently reported complication and is likely due to the high rate of congruency associated with a
juvenile hallux valgus deformity.
OKU Foot and Ankle 2 Rosemont IL., American academy of orthopaedic surgeons, pp135-150.
back to this question next question

Question 7:

Options:

adhesive wear.
abrasive wear.
fatigue wear.
creep.

Correct Answer: fatigue wear.

Explanation:

Question 8:

Options:

above-knee amputation.
preoperative chemotherapy, wide resection of the distal femur, and reconstruction.
preoperative chemotherapy and above-knee amputation.
wide resection of the distal femur and subsequent reconstruction, followed by chemotherapy.
curettage and placement of methylmethacrylate.

Correct Answer: preoperative chemotherapy, wide resection of the distal femur, and reconstruction.

Explanation:

Question 9:

Which of the following enzymes is used to resorb bone by mature osteoclasts?

Options:

Alkaline phosphatase
Cathepsin K
Tissue inhibitor of metalloproteinase (TIMP)
Osteonectin
Osteopontin

Correct Answer: Cathepsin K

Explanation:

Question 10:

Options:

Female gender
Use of skin graft
Ability to return to work
Retained plantar sensation
Initial treatment by amputation

Correct Answer: Ability to return to work

Explanation:

The LEAP study is a multicenter prospective study evaluating multiple aspects of reconstruction versus amputation in the treatment of mangled extremity injuries. With regard to patient satisfaction, treatment variables such as decision for reconstruction versus amputation, or initial presence or absence of plantar sensation have little impact. In addition, demographic factors such as age, gender, socioeconomic status,
and education level do not predict patient satisfaction. Instead, the most important predictors of patient satisfaction at 2 years after injury include the ability to return to work, absence of depression, faster walking speed, and decreased pain.
(SBQ12TR.26) A 44-year-old male presents after being struck by a car. He is hypotensive, and has an obvious open tibia and a closed femoral shaft fracture. A pelvic radiograph is obtained and shown in Figure A. A representative CT scan image in shown in Figure B. The patient is placed in a pelvic binder, and his blood pressure normalizes with crystalloid and a blood transfusion. He then undergoes pelvic angiography, and his internal iliac artery is embolized. Which of the following definitive treatment options is most appropriate in this case?
Review
Topic
Anterior pelvic external fixation with pins placed in the AIIS and a posterior sacroiliac screw
Open reduction and internal fixation of the pubic symphysis with a two hole plate and posterior fixation with a iliosacral screw
Open reduction and internal fixation of the pubic symphysis with a non-locking multi-hole plate and posterior fixation with a iliosacral screw
Anterior pelvic external fixation and posterior triangular osteosynthesis
Open reduction and internal fixation of the pubic symphysis with a locked multi-hole plate and posterior sacral plate fixation
The radiographs and CT scan show a fracture pattern consistent with an APC-III injury. This is most appropriately treated with pubic symphysis ORIF with a multi-hole plate and posterior iliosacral screw fixation.
APC-III pelvic ring injuries are associated with with disruption of the anterior and posterior SI ligaments (SI dislocation) as well as disruption of sacrospinous and sacrotuberous ligaments. They are commonly associated with vascular injury and retroperitoneal bleeding.
Sagi et al studied the radiographic and clinical outcome of symphyseal plating techniques, specifically comparing two hole (THP) vs multi-hole plating (MHP). Retrospective review of charts and radiographs immediately after the index procedure to latest follow-up was performed. When comparing the 2 different methods of anterior fixation, they found that the rate of fixation failure was greater in group THP (33%) than group MHP (12%). When evaluating the presence of a malunion as a result of these 2 treatment methods, there were more present in the THP group (57%) than in the MHP group (15%). On the basis of these findings, the authors recommended multi-hole plating of unstable pubic symphyseal disruptions.
Grimshaw et al performed a biomechanical study to determine the failure risk and potential benefit to use of locked fixation constructs in simulated pelvic ring injuries. The authors used a six-hole 3.5-mm plate specifically designed for the symphysis pubis with the capability of fixation in locked or unlocked mode, six pelves were fixed with locked screws and six pelves were fixed standard unlocked bicortical screws. Biomechanical testing was performed, and no abrupt failures were noted. However, locked plating of the pubic symphysis did not appear to offer any advantage over the standard unlocked technique
Illustrations A, B, and C show the AP, outlet, and inlet postoperative radiographs. Incorrect Answers:
1,4-Anterior pelvic fixation is typically not used as definitive treatment of these
injuries unless performed in a damage-control setting. The patient in this case is stable.
2-Multi-hole plate fixation of the pubic symphysis is preferred over 2-hole plate fixation.
5-Posterior sacral plating is not indicated in this fracture pattern, as there is no significant sacral comminution of vertical shear component. Furthermore, no distinct advantage has been found with locked symphyseal plating.

Question 11:

Options:

excision of the fracture fragment.
radial head replacement.
closed reduction and cast immobilization.
open reduction and internal fixation of the radial head.
open reduction and internal fixation of the capitellum.

Correct Answer: open reduction and internal fixation of the capitellum.

Explanation:

Question 12:

Which of the following is considered a specific advantage of using COX-2 inhibitors over COX-1 inhibitors?

Options:

Conversion of arachidonic acid to prostaglandins
Higher degree of efficacy
Does not affect platelet function and can be used during the perioperative period
Can be used in patients with congestive heart failure and renal disease
High levels of COX-2 (cyclooxygenase) found in normal tissue

Correct Answer: Does not affect platelet function and can be used during the perioperative period

Explanation:

DISCUSSION: Inflammation is mediated through two isoforms of cyclooxygenase that convert arachidonic acid to prostaglandins. Selectivity, but not specificity, is one of the unique characteristics of this process that has been able to provide more protection from the effects of gastric mucosal alterations using the COX-2 selective inhibitors. The use of COX-1 selective inhibitors is associated with side effects such as ulcerative conditions and platelet interference, both of which have been difficult to control in the past until the advent of the COX-2 inhibitors. PGE
2
inhibition by COX-1 in the intestinal track can then be bypassed, thereby reducing ulceration complications associated with use of nonsteroidal anti-inflammatory drugs.
REFERENCES: Lane JM: Anti-inflammatory medications: Selective COX-2 inhibitors. J Am Acad Orthop Surg 2002;10:75-78.
Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002.
Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000.

Question 13:

Options:

Inlet and outlet views of the pelvis to better delineate the injury
Angiography
Laparotomy
Open reduction and internal fixation of the pelvis
Placement of a pelvic binder around the patient

Correct Answer: Placement of a pelvic binder around the patient

Explanation:

DISCUSSION: This hypotensive patient has an obvious open book injury of the pelvic ring on the AP pelvis radiograph and further radiographs are not needed prior to the initiation of treatment. Although angiography may be indicated if he does not respond to stabilization of his pelvis and fluid/blood administration, temporary stabilization of the pelvis with a sheet or binder should be performed first because it is simple, quick, and has been shown to be effective. This patient does not need a laparotomy at this point since the FAST examination did not show any free intra-abdominal fluid and his chest radiograph was unremarkable, leaving the most likely source of bleeding the pelvic fracture. Open reduction with internal fixation of a pelvic injury is not indicated in an acutely ill patient.
REFERENCES: Kreig JC, Mohr M, Ellis TJ, et al: Emergent stabilization of pelvic ring injuries by controlled circumferential compression: A clinical trial. J Trauma 2005;59:659-664.
Croce MA, Magnotti LJ, Savage SA, et al: Emergent pelvic fixation in patients with exsanguinating pelvic fractures. J Am Coll Surg 2007;204:935-942.
Routt ML Jr, Falicov A, Woodhouse E, et al: Circumferential pelvic antishock sheeting:
A temporary resuscitation aid. J Orthop Trauma 2002;16:45-48.

Question 14:

A 25-year-old student sustains the injury shown in Figures 13a through 13c after falling off a curb. Initial management should consist of

Options:

weight bearing as tolerated in a hard-soled shoe.
weight bearing as tolerated in an ankle lacer.
weight bearing as tolerated in a short leg cast.
non-weight-bearing in a hard-soled shoe.
non-weight-bearing in a short leg cast.

Correct Answer: non-weight-bearing in a short leg cast.

Explanation:

Question 15:

Options:

Continued IV antibiotics for 4 weeks
Continued oral antibiotics for 6 weeks
Bone scan, biopsy, and metastatic work-up
Surgical débridement along with antibiotics

Correct Answer: Surgical débridement along with antibiotics

Explanation:

EXPLANATION:
This patient has a septic distal interphalangeal joint, which was treated with antibiotics alone. As a result, the patient developed osteomyelitis with bone destruction and abscess. The best way to treat this problem is to perform surgical débridement of bone and soft tissue, along with abscess drainage and an appropriate antibiotic regimen. Antibiotic treatment without surgery would not be successful in eliminating this particular infection. Bone scan with biopsy is not the correct option, because this problem is an infection
and not a tumor, and MRI already has provided enough diagnostic information.

Question 16:

The use of multiagent adjuvant chemotherapy is associated with a clear survival benefit in which of the following diseases?

Options:

Renal carcinoma
Osteosarcoma
Dedifferentiated chondrosarcoma
Adult soft-tissue sarcoma
Melanoma

Correct Answer: Osteosarcoma

Explanation:

Question 17:

Options:

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

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

Explanation:

Question 18:

Which of the following findings is seen in the chest radiograph shown in Figure 13?

Options:

Fracture-dislocation at T2-3
Sternoclavicular fracture-dislocation
Proximal humerus fracture
Pneumothorax
Distal clavicle osteolysis

Correct Answer: Proximal humerus fracture

Explanation:

Question 19:

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

Options:

Allograft
Tricalcium phosphate
Calcium phosphate
Calcium sulfate
Bone morphogenetic protein

Correct Answer: Bone morphogenetic protein

Explanation:

Question 20:

In a patient with rheumatoid arthritis of the wrist, which of the following extensor tendons is most at risk of rupture?

Options:

Extensor digiti quinti
Abductor pollicis longus
Extensor pollicis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris

Correct Answer: Extensor digiti quinti

Explanation:

DISCUSSION: The tendon most prone to rupture in a patient with rheumatoid arthritis of the wrist is the extensor digiti quinti. It can be a silent injury since the extensor digitorum communis can provide extension to the fifth finger. The extensor digiti quinti is at high risk since it is overlying the ulnar head where it is prone to attritional rupture (Vaughan-Jackson syndrome).
REFERENCES: Vaughan-Jackson OJ: Rupture of extensor tendons by attrition at the inferior radioulnar joint: A report of two cases. J Bone Joint Surg Br 1948;30:528-530.
Papp SR, Athwal GS, Pichora DR: The rheumatoid wrist. J Am Acad Orthop Surg
2006;14:65-77.

Question 21:

What is the most common malignant bone tumor seen in patients with multiple hereditary exostosis?

Options:

Dedifferentiated chondrosarcoma
Mesenchymal chondrosarcoma
Secondary chondrosarcoma
Clear cell chondrosarcoma
Periosteal osteosarcoma

Correct Answer: Secondary chondrosarcoma

Explanation:

Question 22:

During a dual incision fasciotomy of the leg, the soleus is elevated from the tibia to allow access to which of the following compartments?

Options:

Superficial posterior
Deep posterior
Lateral
Anterior
Mobile wad

Correct Answer: Superficial posterior

Explanation:

Question 23:

Options:

methylprednisolone and observation.
posterior laminectomy and spinal fusion.
anterior spinal fusion.
halo vest immobilization.
posterior laminectomy followed by halo vest immobilization.

Correct Answer: posterior laminectomy and spinal fusion.

Explanation:

Question 24:

Options:

Posterior interosseous nerve entrapment
Extensor pollicis longus rupture
Extensor pollicis longus entrapment
Distal radius malunion
Intersection syndrome

Correct Answer: Posterior interosseous nerve entrapment

Explanation:

Question 25:

Options:

orthotic stabilization.
removal of the components with resection arthroplasty.
revision total elbow arthroplasty with an unconstrained prosthesis and ulnar allograft.
revision total elbow arthroplasty with a semiconstrained long-stemmed ulnar prosthesis.
elbow arthrodesis with bone grafting.

Correct Answer: revision total elbow arthroplasty with a semiconstrained long-stemmed ulnar prosthesis.

Explanation:

Question 26:

Options:

immobilization.
arthroscopic evaluation of fragment stability.
transarticular drilling of the lesion with 0.045 Kirschner wire.
arthroscopic excision of the fragment and microfracture of underlying cancellous bone.
excision of the fragment and mosaicplasty.

Correct Answer: immobilization.

Explanation:

DISCUSSION: This skeletally immature patient has a small OCD lesion that appears stable, and he has not undergone any treatment. Therefore, a trial of immobilization until pain resolves is the best initial choice. Thereafter, cessation of sport activities for 4 to 6 months may allow healing of the lesion. Surgical treatment of juvenile OCD lesions is reserved for unstable lesions, patients who have not shown radiographic evidence of healing and are still symptomatic after 6 months of nonsurgical management, or patients who are approaching skeletal maturity. Good results with stable in situ lesions that have failed to respond to nonsurgical management have been reported with both transarticular and retroarticular drilling. Results after excision alone are poor at 5-year follow-up, and it is unclear if microfracture will improve the long-term outcome. Mosaicplasty may be the next best option for patients who remain or become symptomatic after excision of the fragment and microfracture.
REFERENCES: Wall E, Von Stein D: Juvenile osteochondritis dissecans. Orthop Clin North Am 2003;34:341-353.
Kocher MS, Micheli LJ, Yaniv M, et al: Functional and radiographic outcome of juvenile osteochondritis dissecans of the knee treated with transarticular arthroscopic drilling.
Am J Sports Med 2001;29:562-566.

Question 27:

Options:

Dorsalis pedis artery
Perforating peroneal artery
Lateral tarsal artery
Artery of the tarsal canal
Artery of the tarsal sinus

Correct Answer: Artery of the tarsal canal

Explanation:

Question 28:

When reconstructing the anterior cruciate ligament (ACL) with autograft, what is the most common source of surgical failure?

Options:

Graft choice
Tunnel position
Tibial fixation
Femoral fixation

Correct Answer: Tunnel position

Explanation:

Question 29:

Treatment should include

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:

Question 30:

Options:

skeletal traction.
immediate application of a cast brace.
a retrograde supracondylar nail.
revision total knee replacement.
resection arthrodesis.

Correct Answer: a retrograde supracondylar nail.

Explanation:

Question 31:

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

Options:

4 mm
8 mm
12 mm
16 mm
20 mm

Correct Answer: 8 mm

Explanation:

Question 32:

Options:

insertion of a thicker cement mantle and a thicker patellar insert to achieve a total patellar thickness of 24 mm.
a lateral release after inserting a standard patella.
a distal femoral augmentation to maximize the moment-arm on a standard patellar insert.
leaving the patella alone and performing a lateral release, if necessary, for proper patellar tracking.
an oversized femoral component to improve the moment-arm on a standard patellar insert.

Correct Answer: leaving the patella alone and performing a lateral release, if necessary, for proper patellar tracking.

Explanation:

Question 33:

A 42-year-old woman underwent an instrumented posterior spinal fusion at L3-S1 with transforaminal lumbar interbody fusion. She had an excellent

Options:

Observation
Oral antibiotics only
IV antibiotics only
Irrigation and debridement of the surgical site
Irrigation and debridement of the surgical site with hardware removal

Correct Answer: Irrigation and debridement of the surgical site

Explanation:

Question 34:

Options:

Extended medial parapatellar approach
Quadriceps snip
Extended tibial tubercle osteotomy
Medial epicondyle osteotomy

Correct Answer: Extended tibial tubercle osteotomy

Explanation:

Question 35:

Options:

Ewing’s sarcoma
Lymphoma of bone
Metastatic neuroblastoma
Langerhans cell histiocytosis
Osteomyelitis

Correct Answer: Langerhans cell histiocytosis

Explanation:

Question 36:

Options:

Decreased joint penetration of distal screws
Increased rigidity
Decreased need for delayed hardware removal
Decreased peroneal irritation
Improved distal fixation

Correct Answer: Decreased joint penetration of distal screws

Explanation:

Question 37:

Options:

Tear size
Pain scale score
Strength deficit
Patient expectations The MRI reveals a large full thickness supraspinatus tear. A large, prospective study showed that physical therapy can be effective in the treatment of atraumatic full-thickness rotator cuff tears. Patient expectations regarding the role of rehabilitation were the strongest predictor of surgery. Other factors associated with surgery were higher activity level and not smoking. Anatomic features of the rotator cuff tear and the severity of patient’s reported pain did not predict failure of nonoperative treatment. Patients who have low expectations regarding the effectiveness of physical therapy are more likely to fail nonoperative treatment.

Correct Answer: Patient expectations The MRI reveals a large full thickness supraspinatus tear. A large, prospective study showed that physical therapy can be effective in the treatment of atraumatic full-thickness rotator cuff tears. Patient expectations regarding the role of rehabilitation were the strongest predictor of surgery. Other factors associated with surgery were higher activity level and not smoking. Anatomic features of the rotator cuff tear and the severity of patient’s reported pain did not predict failure of nonoperative treatment. Patients who have low expectations regarding the effectiveness of physical therapy are more likely to fail nonoperative treatment.

Explanation:

Question 38:

Options:

Functional rehabilitation and return to play when he has pain-free range of motion
Immobilization in internal rotation for 6 weeks
Immobilization in internal rotation for 3 weeks, followed by 3 weeks of supervised rehabilitation
Immobilization with the arm in neutral rotation
Immobilization with the arm in 30 degrees of external rotation

Correct Answer: Immobilization with the arm in 30 degrees of external rotation

Explanation:

Question 39:

Options:

Anterior lumbar interbody fusion L4-5
L4-5 hemilaminotomy and diskectomy
Lumbar laminectomy L4-L5 posterior fusion
Lumbar laminectomy at L4-5

Correct Answer: Lumbar laminectomy L4-L5 posterior fusion

Explanation:

DISCUSSION
This patient has symptoms consistent with neurogenic claudication secondary to lumbar spinal stenosis and degenerative spondylolisthesis. Her symptoms are chronic and she has undergone an appropriate course of nonsurgical care. Nevertheless, her symptoms are worsening and surgical intervention is a
reasonable consideration. Studies have shown that patients with lumbar spinal stenosis with associated degenerative spondylolisthesis benefit most from decompression of the neural elements that are stenotic and subsequent fusion across the degenerative slip. Anterior lumbar interbody fusion likely will not address stenosis at the level of the slip and may not result in adequate neurologic decompression. Partial laminotomy and diskectomy likely will not provide adequate neural decompression because these procedures would only address unilateral compression and this patient has bilateral issues. Lumbar laminectomy without fusion could be performed but has been associated with results inferior to lumbar laminectomy with fusion when addressing stenosis with spondylolisthesis.
RECOMMENDED READINGS
Weinstein JN, Lurie JD, Tosteson TD, Zhao W, Blood EA, Tosteson AN, Birkmeyer N, Herkowitz H, Longley M, Lenke L, Emery S, Hu SS. Surgical compared with nonoperative treatment for lumbar degenerative spondylolisthesis. four-year results in the Spine Patient Outcomes Research Trial (SPORT) randomized and observational cohorts. J Bone Joint Surg Am. 2009 Jun;91(6):1295-304. PubMed PMID: 19487505.
View Abstract at
PubMed
Herkowitz HN, Kurz LT. Degenerative lumbar spondylolisthesis with spinal stenosis. A prospective study comparing decompression with decompression and intertransverse process arthrodesis. J Bone Joint Surg Am. 1991 Jul;73(6):802-8. PubMed PMID: 2071615.
View
Abstract at PubMed
Lombardi JS, Wiltse LL, Reynolds J, Widell EH, Spencer C 3rd. Treatment of degenerative spondylolisthesis. Spine (Phila Pa 1976). 1985 Nov;10(9):821-7. PubMed PMID: 4089657.
View Abstract at PubMed
RESPONSES FOR QUESTIONS 66 THROUGH 69
Deep surgical-site infection
Adjacent segment degeneration
Pressure ulcers
Iatrogenic neurologic injury
Incidental durotomy
Hardware failure
Match the frequently encountered complication listed above with the appropriate clinical scenario below.

Question 40:

Compared with cobalt-chromium, the biomechanical properties of titanium on polyethylene articulation in total hip replacement result in

Options:

an increased rate of volumetric wear.
increased stability.
decreased frictional force.
a decreased rate of acetabular loosening.
a decreased rate of femoral stem loosening.

Correct Answer: an increased rate of volumetric wear.

Explanation:

Question 41:

Options:

placement of a chest tube.
insertion of a large gauge needle into the second intercostal space.
cardiopulmonary resuscitation.
administration of adrenaline.
immediate transfer to the emergency department.

Correct Answer: insertion of a large gauge needle into the second intercostal space.

Explanation:

Question 42:

Options:

Emergent CT of the abdomen and pelvis
Insertion of a Swan-Ganz catheter to monitor the cardiac index
Administration of albumin solution
Emergent laparotomy in the operating room
Application of a pneumatic antishock garment

Correct Answer: Emergent laparotomy in the operating room

Explanation:

Question 43:

Options:

casting in flexion.
observation.
arthroscopic drilling and pinning of the lesion.
removal and reattachment of the osteochondral lesion.
allograft transplantation for the lesion.

Correct Answer: casting in flexion.

Explanation:

Question 44:

An otherwise healthy 50-year-old man who is a smoker undergoes a posterior spine fusion with instrumentation for spondylolisthesis. What can the patient do to minimize his risk for pseudarthrosis?

Options:

Increase calcium and vitamin D intake
Avoid all nonsteroidal anti-inflammatory drugs (NSAIDs)
Maintain smoking cessation
Engage in early physical therapy to strengthen the trunk musculature

Correct Answer: Maintain smoking cessation

Explanation:

Question 45:

Options:

repeat closed reduction and buddy taping.
closed reduction and percutaneous pin fixation, followed by casting.
open reduction and plate fixation, followed by casting.
open reduction and screw fixation, followed by splinting and early motion.
open reduction and intramedullary fixation with absorbable implants.

Correct Answer: closed reduction and percutaneous pin fixation, followed by casting.

Explanation:

DISCUSSION: The patient has an unstable oblique fracture of the proximal phalanx that is easily reducible but unstable; therefore, the treatment of choice is closed reduction and percutaneous pin fixation, followed by casting. Closed reduction and percutaneous pin fixation offers a better functional result than open reduction and plate fixation. Repeat closed reduction and buddy taping is inadequate because of the inherently unstable fracture pattern. Buddy taping will allow the dislocation to recur. The other options represent more aggressive surgical techniques than are necessary to treat this fracture.
REFERENCES: Stern PJ: Fractures of the metacarpals and phalanges, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, 1999,
pp 711-771.
Green DP, Anderson JR: Closed reduction and percutaneous pin fixation of fractured phalanges. J Bone Joint Surg Am 1973;55:1651-1653.

Question 46:

Options:

rest from throwing activities.
a subacromial corticosteroid injection.
open reduction and internal fixation.
arthroscopic labral repair.
biopsy of the proximal humerus.

Correct Answer: rest from throwing activities.

Explanation:

Question 47:

Options:

Closed reduction and percutaneous pinning
Reconstruction of the ulnar collateral ligament using palmaris tendon autograft
Open reduction and internal fixation
Splinting for 1 week and observation of the nerve injury
Ulnar nerve exploration and transposition

Correct Answer: Closed reduction and percutaneous pinning

Explanation:

The radiographs reveal an incarcerated medial epicondyle fracture apparently associated with an elbow dislocation. The incarcerated position of the fragment warrants open reduction and internal fixation. Due to the close proximity of the ulnar nerve, percutaneous pinning of a medial epicondyle fracture is not recommended. Ulnar nerve symptoms secondary to this fracture usually do not require a formal transposition.
(SBQ13PE.97) A 3-year-old boy presents to your office for evaluation. On physical examination, the patient has large calves and uses his hands to assist in rising from the floor. Laboratory results from the pediatrician reports notably high creatinine kinase of 43000 IU/L. What is the most likely inheritance pattern?
Review Topic
Autosomal recessive
Autosomal dominant
X-linked recessive
X-linked dominant
Mitochondrial inheritance
Duchenne's muscular dystrophy (DMD) has an X-linked recessive inheritance pattern.
Duchenne's muscular dystrophy is characterized by a lack of dystrophin on muscle biopsy. Gower's sign is a typical physical exam finding (child uses hands to assist in rising from sitting), along with pseudohypertrophy of the calves. Notable laboratory values include elevated creatinine kinase (CK), typically above 25,000 IU/L.
Sussman et al. provide a comprehensive review of DMD, highlighting characteristic findings, including pseudohypertrophy of the calves (due to replacement of skeletal muscle with adipose tissue), Gower's sign, as well as CK levels typically above 25,000 IU/L. CK levels can aid in distinguishing between Becker's dystrophy which has levels less than 25,000 IU/L.
Figure A exhibits a muscle biopsy (calf) at low power of DMD; note the replacement of muscle with adipose tissue.
Incorrect answers:
(SBQ13PE.47) Figure A shows an ultrasound of a 2 week old infant being evaluated for developmental dysplasia of the hip. Which of the labels depict the alpha angle, and what anatomic landmarks define this angle?
Review Topic
Angle A, ilium and cartilaginous acetabulum
Angle A, ilium and bony acetabulum
Angle B, ilium and cartilaginous acetabulum
Angle B, ilium and bony acetabulum
Angle B, bony acetabulum and acetabular labrum
The alpha angle is subtended by (1) a line drawn down the ilium to a point where it intersects with the bony and cartilaginous confluence of the acetabulum and (2) a line drawn along the roof of the bony acetabulum.
The coronal flexion view (as depicted in figure A) of the infant hip is perhaps more familiar if rotated 90 degrees to view as one would view an anterior posterior radiograph of the pelvis. Acetabular development is evaluated primarily by the alpha angle, indicating the morphology of the developing acetabulum, and the percentage of the femoral head that is covered by the bony acetabulum. These are each readily apparent on ultrasound. Normal hips should have an alpha angle of at least 60 degrees by 6-8 weeks of age.
Harcke et al. provide a current concepts review on the state of ultrasound in the diagnosis and management of developmental dysplasia of the hip (as of 1991). They report, since that time, ultrasound has become the mainstay for diagnostic confirmation and management of DDH.
LeBa et al. performed a study to look at whether ultrasound screening would increase in effectiveness if targeted toward infants with established risk factors for developmental dysplasia of the hip and normal findings on physical examination. They found dynamic ultrasound evaluation showed developmental dysplasia in 7.8% of patients who had normal physical exams and led to a change in treatment in 8%. They conclude selective ultrasound screening in infants with risk factors and normal
findings on physical examination is effective and leads to more effective treatment.
Figure A shows an ultrasound exam of a 2 week old infant. The alpha angle is labeled 'B'. The beta angle is lableled 'A'. Illustration A is a diagram from Tachdjian's illustrating diagrammatically the elements of these angles.
Incorrect answers.

Question 48:

Options:

a shoulder spica cast with the upper extremity in the salute position.
a sling and swathe for 3 weeks, followed by gradual motion and strengthening.
closed reduction and antegrade intramedullary pinning.
closed reduction and retrograde intramedullary nailing.
open reduction and internal fixation with small plates and screws.

Correct Answer: a sling and swathe for 3 weeks, followed by gradual motion and strengthening.

Explanation:

DISCUSSION: In this age group, bayonet apposition can produce very good results. Healing occurs rapidly, and remodeling usually is complete in less than 1 year. All of the other methods have significant risks of complications and are unnecessary for this fracture.
REFERENCES: Martin RF: Fractures of the proximal humerus and humeral shaft, in Letts RM (ed): Management of Pediatric Fractures. New York, NY, Churchill Livingstone, 1994,
pp 144-148.
Sanders JO, Rockwood CA Jr, Curtis RJ: Fractures and dislocation of the humeral shaft and shoulder, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 937-939.

Question 49:

What is the most common bacteria cultured from dog and cat bites to the upper extremity?

Options:

Pasteurella
Streptococcus
Staphylococcus
Bacteroides
Moraxella

Correct Answer: Pasteurella

Explanation:

DISCUSSION: To define bacteria responsible for dog and cat bite infections, a prospective study yielded a median of five bacterial isolates per culture. Pasteurella is most common from both dog bites (50%) and cat bites (75%). Pasteurella canis was the most frequent pathogen of dog bites, and Pasteurella multocida was the most common isolate of cat bites. Other common aerobes included streptococci, staphylococci, moraxella, and neisseria.
REFERENCE: Talan DA, Citron DM, Abrahamian FM, et al: Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group. N Engl J Med 1999;340:85-92.

Question 50:

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

Options:

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

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

Explanation:

Question 51:

Options:

A solution of 0.45% sodium chloride and hydrogen peroxide
A solution of 0.9% sodium chloride and hydrogen peroxide
A solution of 0.45% sodium chloride and chlorhexidine
A solution of 0.9% sodium chloride and chlorhexidine
None of the above, as specialized cleansing solutions do not decrease the risk this complication

Correct Answer: A solution of 0.45% sodium chloride and hydrogen peroxide

Explanation:

Question 52:

Options:

Posterior tibial tendinitis
Tarsal tunnel syndrome
Os trigonum impingement syndrome
Insertional tendinitis of the Achilles tendon
Osteochondritis dissecans of the talus

Correct Answer: Os trigonum impingement syndrome

Explanation:

Question 53:

Options:

Blount’s disease
Chondrometaphyseal dysplasia
Renal osteodystrophy
Vitamin D-deficient rickets
Vitamin D-resistant rickets

Correct Answer: Vitamin D-resistant rickets

Explanation:

Question 54:

Options:

Early mobilization and a guided proprioceptive and strengthening
Extended immobilization in a cast
Surgical intervention
Weight bearing as tolerated in an ankle brace for 6 weeks

Correct Answer: Early mobilization and a guided proprioceptive and strengthening

Explanation:

Question 55:

Options:

surgical excision of heterotopic ossification and ethyl hydroxydiphosphonate at a dose of 20 mg/kg of body weight for 3 months.
surgical excision of heterotopic ossification and irradiation of the right hip in a single dose of 400 Gy postoperatively.
surgical excision of heterotopic ossification and irradiation of the right hip in a single dose of 700 Gy postoperatively.
ethyl hydroxydiphosphonate at a dose of 20 mg/kg of body weight for 3 months.
25 mg of oral indomethacin administered three times a day for 10 days.

Correct Answer: surgical excision of heterotopic ossification and irradiation of the right hip in a single dose of 700 Gy postoperatively.

Explanation:

Question 56:

Options:

stabilization with suture anchors.
debridement only.
no treatment.
stabilization using absorbable tacks with the arm in external rotation.
release of the attachment to the middle glenohumeral ligament, followed by stabilization with any device.

Correct Answer: no treatment.

Explanation:

Question 57:

The mangled extremity severity score (MESS) utilizes all of the following variables EXCEPT:

Options:

Limb ischemia
Shock
Patient age
Skeletal and soft tissue injury
Time from admission to surgery

Correct Answer: Limb ischemia

Explanation:

Question 58:

A 6-month-old child has the deformity seen in Figure 10. There are no other known associated problems. What is the etiology of this condition? Review Topic

Options:

Exposure to teratogens
Multifactorily inherited
A defect of the apical ectodermal ridge
Excess production of fibroblast growth factor
Inherited as an autosomal dominant

Correct Answer: A defect of the apical ectodermal ridge

Explanation:

Question 59:

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 60:

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 61:

Options:

Splint the proximal interphalangeal (PIP) joint in flexion with early motion of the distal interphalangeal (DIP) joint
Allow early motion of the PIP joint with DIP extension joint splinting
Splint both the PIP and DIP joints in full extension
Splint the PIP joint in extension with early motion of the DIP joint

Correct Answer: Splint the PIP joint in extension with early motion of the DIP joint

Explanation:

Question 62:

What is the most common causative bacteria in septic arthritis in children? Review Topic

Options:

Staphylococcus aureus
Brucella melitensis
Haemophilus influenzae
Kingella kingae
Streptococcus pneumonia

Correct Answer: Staphylococcus aureus

Explanation:

Question 63:

Options:

Bed rest for 6 weeks, followed by mobilization in a thoracolumbosacral orthosis (TLSO) until the fracture has healed
Immediate mobilization in a TLSO, continuing until the fracture has healed
Anterior corpectomy with strut grafting and placement of anterior fixation
Anterior corpectomy and strut grafting followed by posterior spinal fusion and instrumentation
Posterior spinal fusion and instrumentation

Correct Answer: Posterior spinal fusion and instrumentation

Explanation:

DISCUSSION: The injury pattern is that of a burst fracture at L1 contiguous with a compression fracture at T12. There is associated kyphosis and slight spondylolisthesis of T12 on L1. Treatment of this type of burst fracture in neurologically intact patients is somewhat controversial, with at least one study demonstrating equal long-term results comparing nonsurgical treatment to surgical treatment. In this study, however, body casts were used initially in the nonsurgical group. Moreover, because this patient has multiple fractures, spinal fracture stabilization should be considered to facilitate early mobilization. Surgical stabilization and fusion via a posterior approach is the best treatment option in this patient. Anterior decompression is not necessary since the patient is neurologically intact.
REFERENCES: McLain RF, Benson DR: Urgent surgical stabilization of spinal fractures in polytrauma patients. Spine 1999;24:1646-1654.
Wood K, Butterman G, Mehbod A, et al: Operative compared with nonoperative treatment of a thoracolumbar burst fracture without neurological deficit: A prospective, randomized study.
J Bone Joint Surg Am 2003;85:773-781.
Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 201-216.

Question 64:

Options:

Middle facet
Sustentaculum tali
Extruded lateral wall
Medial portion of the posterior facet
Lateral portion of the posterior facet

Correct Answer: Lateral portion of the posterior facet

Explanation:

Question 65:

A 38-year-old man has winging of the ipsilateral scapula after undergoing a transaxillary resection of the first rib 3 weeks ago. What is the most likely cause of this finding?

Options:

Persistent thoracic outlet syndrome
Injury to the upper trunk of the brachial plexus
Injury to the long thoracic nerve
Injury to the lower trunk of the brachial plexus
Injury to the spinal accessory nerve

Correct Answer: Injury to the long thoracic nerve

Explanation:

Question 66:

The subcutaneous nerve most at risk for transection during an anterior surgical exposure of the ankle is the

Options:

dorsal cutaneous branch of the sural nerve.
deep peroneal nerve.
medial plantar nerve.
medial branch of the superficial peroneal nerve.

Correct Answer: medial branch of the superficial peroneal nerve.

Explanation:

Question 67:

Options:

glucosamine 1,500 mg/day and chondroitin sulfate 800 mg/day.
weight loss through dietary management and low-impact aerobic exercises.
arthroscopic debridement and lavage.
a valgus-directing brace.

Correct Answer: weight loss through dietary management and low-impact aerobic exercises.

Explanation:

Question 68:

A B C What is the appropriate first step when confirming the diagnosis of a neurologically intact, 73-year-old man who has the images shown in Figures 25a through 25c?

Options:

Order a prostate-specific antigen (PSA) level
Perform a 2-level corpectomy and reconstruction with tissue sent for pathologic analysis
Fine-needle aspiration
Bone scan

Correct Answer: Order a prostate-specific antigen (PSA) level

Explanation:

DISCUSSION
The radiograph and MR images show an osteoblastic lesion in the T9 and T8 vertebral bodies. In an older man, this finding most likely reveals metastatic prostate cancer. The first and least invasive diagnostic step is to order a PSA level. Gleave and associates found in a retrospective review of patients with prostate cancer that isolated levels of PSA lower than 10 to 20 micrograms per liter are rarely associated with bone metastasis. Vis and associates documented that 10-year prostate cancer survival in a screened population was higher than 60%, and in an unscreened population it was 24%. In a neurologically intact patient with no evidence of neural compression or instability, surgery is not indicated. Fine-needle aspiration may be performed, but the diagnostic yield in a blastic lesion is low. A bone scan may be indicated to complete the metastatic workup, but it will not aid in the diagnosis of tissue source.
RECOMMENDED READINGS
Gleave ME, Coupland D, Drachenberg D, Cohen L, Kwong S, Goldenberg SL, Sullivan LD. Ability of serum prostate-specific antigen levels to predict normal bone scans in patients with newly diagnosed prostate cancer. Urology. 1996 May;47(5):708-12. PubMed PMID: 8650870.
View
Abstract at PubMed
Vis AN, Roemeling S, Reedijk AM, Otto SJ, Schröder FH. Overall survival in the intervention arm of a randomized controlled screening trial for prostate cancer compared with a clinically diagnosed cohort. Eur Urol. 2008 Jan;53(1):91-8. Epub 2007 Jun 12. PubMed PMID: 17583416.
View
Abstract at PubMed
Cronen GA, Emery SE. Benign and malignant lesions of the spine. In: Spivak JM, Connolly PJ, eds. Orthopaedic Knowledge Update: Spine 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:351-366.
CLINICAL SITUATION FOR QUESTIONS 26 THROUGH 29
Figures 26a and 26b are the MR images with gadolinium enhancement of a 40-year-old man who arrives at the emergency department with a 4-day history of fevers and severe back pain without radiation. He is normotensive at presentation with a heart rate of 86 beats per minute. Upon examination he is neurologically intact with normal sensory and motor function. He has a history of alcohol and cocaine abuse. His white blood cell (WBC) count is 12000 (reference range [rr], 4500-11000 /µL) and his C-reactive protein (CRP) level is 100 mg/L (rr, 0.08-3.1 mg/L)

Question 69:

Which of the following methods best aids in diagnosis of an interdigital neuroma?

Options:

Ultrasound
MRI
Web space injection
Electromyography and nerve conduction velocity studies
History and physical examination

Correct Answer: History and physical examination

Explanation:

Question 70:

What preoperative factor correlates best with the outcome of rotator cuff repair?

Options:

Size of the tear
Age of the patient
Arm dominance
Rupture of the long head of the biceps
Preoperative pain score

Correct Answer: Size of the tear

Explanation:

Question 71:

Options:

Abdominal and pelvic ultrasound
CT of the abdomen and pelvis
Technetium Tc 99m three-phase bone scan
Abdominal radiographic series
Gallium-67 citrate scan

Correct Answer: CT of the abdomen and pelvis

Explanation:

Question 72:

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 73:

Figure 4a shows the radiograph of a 20-year-old man who has an injury to the right shoulder. Figure 4b shows an arthroscopic view (posterior portal). The arrow points to a Review Topic

Options:

rotator cuff tear.
bare area.
Hill-Sachs defect.
Bankart tear.
glenoid fracture.

Correct Answer: Hill-Sachs defect.

Explanation:

Question 74:

A 23-year-old woman has had vague left knee pain for the past 6 months. A radiograph and CT scan are shown in Figures 50a and 50b. What is the most likely diagnosis?

Options:

Myositis ossificans
Osteochondroma
Parosteal osteosarcoma
Dedifferentiated chondrosarcoma
Tumoral calcinosis

Correct Answer: Parosteal osteosarcoma

Explanation:

Question 75:

Acute redislocation of the glenohumeral joint is a complication that occurs following a first-time dislocation. This is most often seen with

Options:

subglenoid dislocation.
subcoracoid dislocation.
fracture of the greater tuberosity.
fracture of the greater tuberosity and glenoid rim.
pediatric-age patients.

Correct Answer: fracture of the greater tuberosity and glenoid rim.

Explanation:

DISCUSSION: Redislocation following acute dislocation occurs in approximately 3% of patients. This redislocation tends to occur in middle-aged and elderly patients. A higher incidence of redislocation occurs when there are accompanying fractures of the glenoid rim and the greater tuberosity.
REFERENCES: Robinson CM, Kelly M, Wakefield AE: Redislocation of the shoulder during the first six weeks after a primary anterior dislocation: Risk factors and results of treatment.
J Bone Joint Surg Am 2002;84:1552-1559.
Bigliani LU, Newton PM, Steinmann SP, et al: Glenoid rim lesions associated with recurrent anterior dislocation of the shoulder. J Sports Med 1998;26:41-45.

Question 76:

Options:

Acetabular labrum
Iliopsoas
Loose body
Piriformis
Iliotibial band

Correct Answer: Iliotibial band

Explanation:

Question 77:

Options:

external traction.
open reduction and internal stabilization.
repeat closed reduction under general anesthesia.
open reduction.
percutaneous pin fixation in the current position.

Correct Answer: open reduction.

Explanation:

DISCUSSION: The radiographs show a complex dislocation of the little finger metacarpophalangeal joint. This is characterized by obvious dislocation on the AP and lateral views and a type of bayonet apposition best visualized on the lateral view. Irreducibility of this injury is caused by displacement of the volar plate that has been traumatically avulsed from its origin on the metacarpal, with subsequent displacement into the metacarpophalangeal joint. This abnormal position of the volar plate causes irreducibility that can be corrected only by open reduction. This can be effected either by dorsal or palmar approaches.
REFERENCES: Stern PJ: Fractures of the metacarpals and phalanges, in Green DP, Hotchkiss RN, Pederson WC (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, 1999,
pp 711-771.
Becton JL, Christian JD Jr, Goodwin HN, Jackson JG III: A simplified technique for treating the complex dislocation of the index metacarpophalangeal joint. J Bone Joint Surg Am 1975;57:698-700.
Green DP, Terry GC: Complex dislocation of the metacarpophalangeal joint: Correlative pathological anatomy. J Bone Joint Surg Am 1973;55:1480-1486.

Question 78:

A 74-year-old man reports progressive left hip pain with weight-bearing activities. A radiograph is shown in Figure 30. What is the most likely underlying diagnosis?

Options:

Infection
Lymphoma
Paget’s disease
Massive bone infarct
Old pelvic trauma

Correct Answer: Paget’s disease

Explanation:

DISCUSSION: The radiograph shows enlargement of the bone, coarse trabeculation, a blastic appearance, and thickening of the cortex, revealing the classic appearance of Paget’s disease in the sclerotic phase, the most common presentation. While lymphoma may present as a blastic lesion, it will not have the same enlargement, coarse trabeculation of bone, and the significant sclerosis seen here.
REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 211-215.
Resnick D (ed): Diagnosis of Bone and Joint Disorders. Philadelphia, PA, WB Saunders, 2002, pp 1947-2000.

Question 79:

Options:

Abnormal alpha angle and a chondrolabral tear
Acetabular retroversion
Heterotopic ossification
Ankylosing spondylitis
Coxa varum

Correct Answer: Abnormal alpha angle and a chondrolabral tear

Explanation:

Question 80:

Options:

Revise the tibial tunnel to be more oblique.
Revise the tibial tunnel to be more posterior.
Convert to a transtibial double-bundle ACL.
Prepare the femoral tunnel via an anteromedial portal or two-incision technique.
Hyperflex the knee and place the femoral tunnel with the transtibial guide.

Correct Answer: Prepare the femoral tunnel via an anteromedial portal or two-incision technique.

Explanation:

Question 81:

An MRI scan

Options:

Observation and repeat radiographs in 4 months
Application of a thoracolumbalsacral orthosis for 22 to 24 hours per day
Electrical stimulation at night
Physical therapy

Correct Answer: Electrical stimulation at night

Explanation:

Question 82:

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

Options:

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

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

Explanation:

Question 83:

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 84:

What portion of the pitching phase creates forces approaching the tensile limit of the medial ulnar collateral ligament of the elbow? Review Topic

Options:

Early cocking
Late cocking / Early acceleration
Ball release
Follow-through
Deceleration

Correct Answer: Late cocking / Early acceleration

Explanation:

Question 85:

Surgical arthroscopy performed 1 week after injury presents increased risk for

Options:

deep venous thrombosis.
popliteal artery dissection.
complex regional pain syndrome.
compartment syndrome.

Correct Answer: compartment syndrome.

Explanation:

Question 86:

A 40-year-old man reports an enlarging soft-tissue mass in his right shoulder. Based on the MRI scan and biopsy specimens shown in Figures 40a through 40c, what is the most likely diagnosis?

Options:

Nodular fasciitis
Fibrosarcoma
Intramuscular hemangioma
Schwannoma
Rhabdomyoma

Correct Answer: Nodular fasciitis

Explanation:

DISCUSSION: Nodular fasciitis is a pseudosarcomatous, self-limiting reactive process composed of fibroblasts and myofibroblasts. Most patients give a history of a rapidly growing mass that has been present for only a few weeks. Many have pain associated with the mass and can recall a specific traumatic event predating the presence of the lesion. It can occur at any age but is most commonly seen in adults who are 20 to 40 years of age. Histologically, the lesion is composed of predominantly plump, immature-appearing fibroblasts that bear a close resemblance to the fibroblasts found in granulation tissue. Characteristically, the fibroblasts
are arranged in short, irregular bundles and fascicles and are adjacent to collagen and reticulin. The lesions can appear to be more myxoid or more fibrotic in nature and this correlates to the duration of symptoms. The lesions with a short duration of symptoms have a more myxoid appearance in contrast to those of longer duration characterized by hyaline fibrosis.
REFERENCES: Weiss SW, Goldblum JR, Enzinger FM: Enzinger and Weiss’s Soft Tissue Tumors, ed 4. Philadelphia, PA, Elsevier, 2001, pp 250-266.
Wang XL, De Schepper AM, Vanhoenacker F, et al: Nodular fasciitis: Correlation of MRI findings and histopathology. Skeletal Radiol 2002;31;155-161.

Question 87:

What genetic defect is responsible for achondroplasia? Review Topic

Options:

Trisomy of chromosome 21
Defect in collagen, type 1, alpha 1 (COL1A1)
Defect in fibroblast growth factor 3 (FGF-3)
Defect in fibroblast growth factor receptor 3 (FGFR-3)

Correct Answer: Defect in fibroblast growth factor receptor 3 (FGFR-3)

Explanation:

Question 88:

Which of the following best describes athletic pubalgia?

Options:

A syndrome of lower abdominal and adductor pain
Painful symptoms emanating from the symphysis pubis
Painful symptoms associated with dysfunction of the iliopsoas tendon
Stress fracture of the pubic ramus
Entrapment of the pudendal nerve

Correct Answer: A syndrome of lower abdominal and adductor pain

Explanation:

Question 89:

Options:

Wide resection alone
Chemotherapy and radiation therapy
Chemotherapy and wide resection
Above-knee amputation
Through-knee amputation

Correct Answer: Chemotherapy and wide resection

Explanation:

Question 90:

Linazolid exerts its antimicrobial action by inhibiting bacterial

Options:

protein synthesis.
peptidoglycan wall synthesis.
DNA-gyrase activity.
mitochondrial enzymes.
oxidative phosphorylation.

Correct Answer: protein synthesis.

Explanation:

DISCUSSION: Linazolid is the first agent of the oxazolidinone group of antibiotics and is very active against methicillin-sensitive Staphylococus aureus, S epidermidis, and vancomycin-resistant enterococci. The drug has no gram-negative activity. Linazolid inhibits protein synthesis by blocking formation of the 70S ribosomal translation complex. This mechanism of action is unique to the oxazolidinones.
REFERENCES: Rybak MJ, Cappelletty DM, Moldovan T, et al: Comparative in vitro activities and postantibiotic effects of the oxazolidinone compounds eperezolid (PNU-100592) and linezolid (PNU-100766) versus vancomycin against Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus faecalis, and Enterococcus faecium. Antimicrob Agents Chemother 1998;42:721-724.
Sweeney
MT
, Zurenko GE: In vitro activities of linezolid combined with other antimicrobial agents against Staphylococci, Enterococci, Pneumococci, and selected gram-negative organisms. Antimicrob Agents Chemother 2003;47:1902-1906.

Question 91:

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

Options:

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

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

Explanation:

Question 92:

To prevent injury to the posterior interosseous nerve during the approach for reduction and fixation of a fracture of the radial head, anterior retraction should be performed with the forearm

Options:

Maximally pronated and elbow extended
Maximally pronated and the elbow flexed
Maximally supinated and the elbow flexed
Maximally supinated and the elbow extended
In neutral rotation, with the elbow extended

Correct Answer: Maximally pronated and the elbow flexed

Explanation:

Question 93:

Figures 75a and 75b are the radiographs after attempted reduction of an injury in a 9-year-old girl. Which anatomic structure is most likely to be interposed?

Options:

Brachialis muscle
Radial nerve
Median nerve
Ulnar nerve

Correct Answer: Ulnar nerve

Explanation:

Question 94:

Which of the following statements best describes the typical early presentation of osteochondritis dissecans of the elbow? Review Topic

Options:

Often associated with loss of elbow extension
Often associated with catching or locking
Involves the capitellum or lateral trochlea
Presents in boys younger than age 10 years
Outlining of the margins of the lesion on MR arthrogram is a good prognostic sign

Correct Answer: Often associated with loss of elbow extension

Explanation:

Question 95:

Options:

Trochanteric bursitis
Femoral component loosening
Iliopsoas tendonitis
Acetabular component loosening

Correct Answer: Iliopsoas tendonitis

Explanation:

Question 96:

Options:

posterior; flexor carpi radialis
posterior; flexor carpi ulnaris
posterior; flexor digitorum superficialis to the long finger
mobile wad; flexor carpi radialis
mobile wad; flexor carpi ulnaris

Correct Answer: mobile wad; flexor carpi ulnaris

Explanation:

Question 97:

Options:

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

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

Explanation:

Question 98:

A 70-year-old woman who underwent total knee replacement 18 months ago has had 3 weeks of moderate drainage from a previously healed wound. What is the most appropriate treatment?

Options:

Vacuum-assisted wound closure dressing
Intravenous antibiotics for 6 weeks, followed by long-term oral antibiotic administration
Irrigation and debridement, followed by polyethylene exchange
Two-stage debridement and reconstruction

Correct Answer: Two-stage debridement and reconstruction

Explanation:

Question 99:

Increased hip intracapusular pressures can lead to diminished femoral head perfusion. What leg position has been shown to create the lowest intracapsular hip pressures after femoral neck fracture?

Options:

flexion and internal rotation
extension and external rotation
flexion, abduction, and external rotation
extension, adduction, and internal rotation
there are no differences in hip pressures with any position

Correct Answer: flexion and internal rotation

Explanation:

Question 100:

Figure 56 is the radiograph of an otherwise healthy 3-year-old boy who fell and sustained the isolated injury shown. What is the best treatment modality?

Options:

Elastic intramedullary nailing
Submuscular plating
Early hip spica casting
Traction as definitive treatment

Correct Answer: Early hip spica casting

Orthopedic Surgery Board Review MCQs: Arthroplasty, Ligament & Spine | Part 149

Orthopedic Surgery Board Review MCQs: Spine, Arthroplasty & Trauma | Part 161

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 161

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index