100 Orthopedic MCQs: Trauma, Spine & Joints | Comprehensive AAOS Board Review

By convention when determining the motor level, the key muscle must be at least 3/5. The next most rostral level must be 4/5. Therefore, this patient's functional level is C6.

Injuries involving brackish water and shellfish can have devastating consequences caused by Vibrio vulnificus infections. Patients may have a severe invasive infection, with three main clinical features: primary septicemia, wound infection, and gastroenteritis. Antibiotic administration is crucial because mortality rates of up to 50% have been observed with Vibrio septicemia. The current recommendation is to give a third-generation cephalosporin such as ceftazadime. Chiang SR, Chuang YC: Vibrio vulnificus infection: Clinical manifestations, pathogenesis, and antimicrobial therapy. J Microbiol Immunol Infect 2003;36:81-88.

Recent studies have shown a high rate of waste of autologous blood. Therefore, the Committee does not recommend autologous blood donation for procedures that carry a transfusion risk of 10% or less. Toy P, Beattie C, Gould S, et al: Transfusion alert: Use of autologous blood. National Heart, Lung, and Blood Institute Expert Panel on the use of autologous blood. Transfusion 1992;35:703-711.

Patellar clunk syndrome is associated with certain types of posterior stabilized knee arthroplasties. Arthroscopic resection of the band of inflammatory tissue inferior to the patellar component is effective in treating this condition. Arthroscopic lavage of infected knee arthroplasties is not associated with an acceptable success rate. Diagnostic arthroscopy for nonspecific pain following arthroplasty is not uniformly successful. Patellar component maltracking is frequently associated with component malposition and is not alleviated by an arthroscopic lateral release. Synovitis secondary to polyethylene wear is best treated by exchange of the polyethylene spacer and not arthroscopic synovectomy. Lucas TS, DeLuca PF, Nazarian DG, et al: Arthroscopic treatment of patellar clunk. Clin Orthop 1999;367:226-229.

Flexion contractures and angular deformities of a limb cause inaccurate limb-length measurement results with most clinical methods. A CT scanogram is more accurate than standard scanograms for determining limb length in patients with knee flexion contractures of 30 degrees or more. The cost and time necessary to complete the examinations are comparable, but the CT scanogram delivers only 20% of the radiation needed for standard scanograms. Aaron A, Weinstein D, Thickman D, Eilert R: Comparison of orthoroentgenography and computed tomography in the measurement of limb-length discrepancy. J Bone Joint Surg Am 1992;74:897-902.

The pectoralis major insertion is just lateral to the long head of the biceps tendon. Medial to the biceps is the insertion for the teres major and latissimus dorsi. The short head of the biceps originates on the coracoid process. The subscapularis inserts on the lesser tuberosity just medial to the biceps.

Even though the patient has a grade 3 ankle ligament injury, studies have shown that 95% of patients with a grade 3 injury that may include a complete tear of the ligaments will heal successfully with conservative functional management. Extensive diagnostic evaluation with stress radiographs, CT, and MRI is not indicated. Surgical reconstruction is not indicated because of the overwhelming success of conservative management; however, in the few patients where late instability develops, surgical reconstruction offers an excellent outcome. Carne P: Nonsurgical treatment of ankle sprains using the modified Sarmiento brace. Am J Sports Med 1989;17:253-257.

The overriding factor determining treatment in this case is the appearance of the surgical wound. Based on MacPhearson's work, this "C" wound is best managed with two-stage exchange. The functional outcome is markedly diminished following a knee arthrodesis compared to revision knee arthroplasty. Harwin SF: The diagnosis and management of infected total knee replacement. Seminars Arthroplasty 2002;13:9-22. Goldmann RT, Scuderi GR, Insall JN: 2-stage reimplantation for infected total knee replacement. Clin Orthop 1996;331:118-124.

The image shows a view of the radiocapitellar joint from an anterior medial portal. The radial nerve lies on the elbow capsule at the midportion of the capitellum. It is at risk for injury when capsular excision is performed in this region. Field LD, Altchek DW, Warren RF, et al: Arthroscopic anatomy of the lateral elbow: A comparison of three portals. Arthroscopy 1994;10:602-607.

There are a number of important technical details in performing a biopsy. Incisions should always be longitudinal in the extremity. Good hemostasis is important in avoiding contamination from hematoma. The approach should avoid neurovascular structures, and go through a single muscle belly when possible. Although a frozen section should be obtained to ensure adequate viable tissue has been obtained, definitive diagnosis is not necessary at the time of the frozen section. Vaccaro AR (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 197-215.

The patient has extensor tendon ruptures at the level of the wrist that are the result of synovitis at the distal radioulnar joint (Vaughn-Jackson syndrome). Extensor indius proprius transfer appropriately matches strength and excursion of the ruptured extensor digiti quinti and extensor digitorum communis tendons. An extensor tenosynovectomy with distal radioulnar joint resection decreases the synovitis, which if left untreated may cause additional tendon ruptures. Radial head resection is used for posterior interosseous nerve compression secondary to radial head synovitis, and in this patient only two fingers are involved, which rules out this diagnosis. Dynamic splinting is not indicated for ruptured tendons. Metacarpophalangeal arthroplasties and imbrication of the sagittal bands are used for metacarpophalangeal arthritis and extensor tendon subluxation. If this was the problem, the patient should be able to maintain the fingers in extension after they are passively extended. Total wrist arthrodesis prevents the tenodesis effect, thus limiting effective tendon excursion and making the proposed transfer less effective. Feldon P, Terrono AL, Nalebuff EA, et al: Rheumatoid arthritis and other connective tissue diseases: Tendon ruptures, in Green DP, Hotchkiss RN, Pederson WC (eds): Green's Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, pp 1669-1684. Moore JR, Weiland AJ, Valdata L: Tendon ruptures in the rheumatoid hand: Analysis of treatment and functional results in 60 patients. J Hand Surg Am 1987;12:9-14.

The radiographs show a distal third humerus fracture that is angulated, rotated, and not rigidly fixed. Rigid fixation is needed because mobilization is highly desirable to improve pulmonary function. The acetabular fracture is through the weight-bearing dome but is nondisplaced. Nonsurgical management of the acetabular fracture requires at least 6 weeks of touchdown weight bearing to minimize the forces across the hip joint. Open reduction and plate fixation would achieve anatomic reduction and immediate mobilization. A single posterolateral 4.5-mm plate or two 3.5-mm plates at 90 degrees are possible alternatives. Immediate weight bearing on a plated humerus fracture with the use of crutches or a walker has been shown to be safe and would allow touchdown weight bearing, protecting the hip. None of the other options would achieve this goal for this distal fracture.

The most likely diagnosis is acute osteomyelitis. She may also have a septic wrist; however, the lytic lesion in the distal radius has the typical presentation and radiographic appearance of metaphyseal osteomyelitis. In this area of sluggish vascular flow, low oxygen tension, and low pH, bacterial seeding is common and is the usual origin of metaphyseal osteomyelitis. Leukemia and Ewing's sarcoma can present as a lytic lesion with an elevated erythrocyte sedimentation rate, but they are much less common than osteomyelitis and are less focal and more destructive in appearance. Nonossifying fibroma is typically metaphyseal and eccentric; however, it is well circumscribed and uncommon in the upper extremity. Eosinophilic granuloma does not typically present with inflammatory indicies. Dormans JP, Drummond DS: Pediatric hematogenous osteomyelitis: New trends in presentation, diagnosis and treatment. J Am Acad Orthop Surg 1994;2:333-341.

Because the man is only recently removed from his injury and is judged capable of returning to work with some restrictions, the term that best describes his work status is temporary partial disability.

The hypoglossal nerve exits from the ansa cervicalis at approximately the C2-3 level and can be injured during retraction up to the C2 level. The superior laryngeal nerve lies at about C4-5. The facial nerve is much higher. The vagus nerve runs with the internal jugular and carotid much more laterally. The phrenic nerve exits posteriorly. Chang U, Lee MC, Kim DH: Anterior approach to the midcervical spine, in Kim DH, Henn JS, Vaccaro AR, et al (eds): Surgical Anatomy and Techniques to the Spine. Philadelphia, PA, Saunders Elsevier, 2006, pp 45-54.

A knock-out mouse to the Vitamin D receptor would cause loss of vitamin D function, resulting in rickets. Renal failure would not occur; although Vitamin D is converted from 25 (OH) D to 1,25 (OH) D in the kidney, the active hormone acts on the gut and bone. Osteopetrosis can be seen as the phenotype for the c fos knock-out mouse; the Jansen-type metaphyseal dysplasia phenotype results from overactivation of the PTH/PTHrp receptor. Although compensatory hyperparathyroidism would occur, excessive PTH would not be able to rescue the skeletal loss and instead phosphoturia and phosphotasia would result. Glowacki J, Hurwitz S, Thornhill TS, et al: Osteoporosis and vitamin-D deficiency among postmenopausal women with osteoarthritis undergoing total hip arthroplasty. J Bone Joint Surg Am 2003;85:2371-2377.

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

The radiographic appearance of the joint is highly suspicious for neuropathic joint (Charcot's joint). Evidence of bone loss on both the tibial and the femoral sides may necessitate the use of metal and/or bone augments. Patients with a neuropathic joint often have excellent range of motion, and postoperative stiffness is not a problem. The main problem with these patients is instability that occurs secondary to ligamentous laxity. Use of a semiconstrained prosthesis prevents the latter complication. Parvizi J, Marrs J, Morrey BF: Total knee arthroplasty for neuropathic (Charcot) joints. Clin Orthop 2003;416:145-150.

Symptoms of activity-related low back pain, physical findings of pain with extension, lateral bending, and resuming an upright position, and relative hamstring tightness are consistent with spondylolysis. While the initial diagnostic work-up should include plain radiographs of the lumbosacral spine, the findings may be negative because it can take weeks or months for the characteristic changes to become apparent. SPECT has been a useful adjunct in the diagnosis of spondylolysis when plain radiographs are negative. Since the patient's pain is activity related and she is otherwise healthy, evaluation for infection is not indicated. Because the neurologic examination is normal, electromyography, nerve conduction velocity studies, and MRI are not indicated. CT can be used in those instances in which SPECT and bone scans are negative. Ciullo JV, Jackson DW: Pars interarticularis stress reaction, spondylolysis, and spondylolisthesis in gymnasts. Clin Sports Med 1985;4:95-110. Collier BD, Johnson RP, Carrera GF, et al: Painful spondylolysis or spondylolisthesis studied by radiography and single photon emission computed tomography. Radiology 1985;154:207-211. Jackson DW, Wiltse LL, Cirincione RT: Spondylolysis in the female gymnast. Clin Orthop 1976;117:68-73.

Chronic rotator cuff tears should be nonsurgically managed initially with a strengthening program. A cortisone injection may reduce inflammation. Surgery is reserved for patients who continue to have pain and lose sleep despite the use of physical therapy. Blood tests for infection or inflammation are nonspecific. Arthroscopy may play a role, but surgical replacement is reserved for advanced cases. Bokor DJ, Hawkins RJ, Huckell GH, et al: Results of nonoperative management of full-thickness tears of the rotator cuff. Clin Orthop 1993;294:103-110.

Fractures of the distal one third of the clavicle have a high incidence of delayed union (45% to 67%) and nonunion (22% to 33%) with nonsurgical management. Surgical stabilization with tension band techniques or a combination of plate and screw techniques is indicated, especially in young, active patients. In this patient, significant displacement of the fracture implies injury to the coracoclavicular ligaments with a higher risk of delayed union or nonunion. Various surgical treatments have been recommended, but the use of smooth wires is not indicated because of the potential for hardware migration. Jupiter JB, Ring D: Fractures of the clavicle, in Ianotti JP, Williams GR (eds): Disorders of the Shoulder: Diagnosis and Management, ed 1. Philadelphia, PA, Lippincott, Williams and Wilkins, 1999, pp 709-736.

Most patients lose elbow range of motion after open reduction and internal fixation of a distal humeral fracture. Ulnar nerve dysfunction, nonunion, and infection all occur less commonly. Webb LX: Distal humerus fractures in adults. J Am Acad Orthop Surg 1996;4:336-344.

The radiograph reveals a subchondral lesion in the metacarpophalangeal joint that is lytic and expansile. The MRI scans show a mass that is moderate in intensity on the T2-weighted image and has some gadolinium uptake. There are no cystic components in this lesion. The subchondral location and expansile nature are highly suggestive of giant cell tumor of bone. A lesion with this appearance might also represent an aneurysmal bone cyst, given the amount of expansion present. Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 113-118.

Certain medical procedures involving blood are specifically prohibited in the belief system of a Jehovah's Witness whereas others are not doctrinally prohibited. For procedures where there is no specific doctrinal prohibition, a Jehovah's Witness should obtain the details from medical personnel and make his or her own decision. Transfusions of allogeneic whole blood or its constituents or preoperative donated autologous blood are prohibited. Other procedures, while not doctrinally prohibited, are not promoted such as hemodilution, intraoperative cell salvage, use of a heart-lung machine, dialysis, epidural blood patch, plasmapheresis, white blood cell scans (labeling or tagging of removed blood returned to the patient), platelet gel, erythropoietin, or blood substitutes. The patient should not be given blood. Plasma expanders should be used first to restore hemodynamic stability. Cell saver blood from an open would is not recommended nor would there likely be enough from an open tibial fracture to salvage. The patient's family may be expressing their own beliefs rather than the patient's beliefs and it would be better to ask the patient when he or she is more alert to determine what procedures they would allow. A consult with the ethics committee will unnecessarily delay an intervention that should restore hemodynamic stability. Jimenez R, Lewis VO (eds): Culturally Competent Care Guidebook. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2007.

The patient has a scaphoid fracture involving the proximal pole. Surgical treatment is recommended for such fractures because of the prolonged period of cast immobilization necessary and the increased risk of delayed union, nonunion, and/or osteonecrosis with nonsurgical management. A cannulated compression screw, inserted in the central scaphoid via a dorsal approach, is biomechanically advantageous and provides greater stability for fracture healing than Kirschner wires. Recently, good outcomes have been reported with arthroscopic-assisted percutaneous fixation of nondisplaced or minimally displaced scaphoid fractures. Rettig ME, Raskin KB: Retrograde compression screw fixation of acute proximal pole scaphoid fractures. J Hand Surg Am 1999;24:1206-1210. Chan KW, McAdams TR: Central screw placement in percutaneous screw scaphoid fixation: A cadaveric comparison of proximal and distal techniques. J Hand Surg Am 2004;29:74-79. Bedi A, Jebson PJ, Hayden RJ, et al: Internal fixation of acute non-displaced scaphoid waist fractures via a limited dorsal approach: An assessment or radiographic and functional outcomes. J Hand Surg Am 2007;32:326-333.

Sexual dysfunction is a common condition after extensive anterior lumbar surgical dissection. Erectile dysfunction usually is nonorganic but may be related to parasympathetic injury. The parasympathetic nerves are deep in the pelvis at the level of S2-3 and S3-4 and usually are not involved in the surgical field for anterior L4-5 and L5-S1 procedures. Retrograde ejaculation is the result of injury to the sympathetic chain on the anterior surface of the major vessels crossing the L4-5 level and at the L5-S1 interspace. Erectile function and orgasm are not affected by sympathetic injury. The pudendal nerve is primarily a somatic nerve and is not located in the surgical field. Flynn JC, Price CT: Sexual complications of anterior fusion of the lumbar spine. Spine 1984;9:489-492.

Numerous studies have documented the poor performance of heat-pressed ultra-high molecular weight polyethylene used in the porous-coated anatomic tibial inserts of both total knee and unicompartmental arthroplasty. The other processing and sterilization methods have not been associated with significantly high failure rates. Wright TM, Rimnac CM, Stulberg SD, et al: Wear of polyethylene in total joint replacements: Observations from retrieved PCA knee implants. Clin Orthop 1992;276:126-134. Landy MM, Walker PS: Wear of ultra-high molecular-weight polyethylene components of 90 retrieved knee prostheses. J Arthroplasty 1988;3:S73-S85.

In the skeletally mature individual, this mechanism of injury will often result in a sprain of the medial collateral ligament. In skeletally immature patients, the same mechanism can cause a fracture of the distal femoral physis. If the fracture is nondisplaced, the plain radiographs may show only soft-tissue swelling or effusion. While the MRI scan may show edema in the soft tissues on the medial side of the knee and even an abnormality of the physis, stress radiographs provide a quicker and less expensive means of making the diagnosis. Arthroscopy and arthrography would not be helpful in making the diagnosis. Arthroscopy may result in further displacement of the injury. Smith L: Concealed injury to the knee. J Bone Joint Surg Am 1962;44:1659-1660.

Anterolateral bowing of the tibia is normally associated with congenital pseudarthrosis of the tibia. This, in turn, is associated with neurofibromatosis. Posterior bowing is more benign and usually corrects spontaneously. However, anterolateral bowing also corrects spontaneously, and the limb-length discrepancy may be the only remaining sequela when associated with duplication of the great toe. Lisch nodules and axillary freckling are pathognomonic findings in neurofibromatosis but would not be expected in this patient because this type of tibial deformity is not associated with neurofibromatosis.

Boden and associates' recent article presents significant evidence that patients with rheumatoid arthritis, neurologic deterioration, and C1-2 instability are more likely to improve after surgery if the posterior alanto-odontoid interval is greater than 10 mm preoperatively. The accepted safe range for the posterior atlanto-odontoid interval is 14 mm. This measurement is believed to better represent the space available for the cord than the anterior alanto-odontoid interval. Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 273-279. Boden SD, Dodge LD, Bohlman HH, Rechtine GR: Rheumatoid arthritis of the cervical spine: A long-term analysis with predictors of paralysis and recovery. J Bone Joint Surg Am 1993;75:1282-1297.

The median nerve has an intimate association with the palmaris longus and the flexor carpi radialis at the proximal aspect of the carpal canal. The median nerve lies just ulnar and dorsal to the flexor carpi radialis tendon. Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 118-131.

Ewing's sarcoma is the second most common bone tumor in children with an incidence of three per one million Caucasian children younger than 21 years of age. Ewing's sarcoma is rare in African Americans. Osteosarcoma is the most common bone tumor in children. Rhabdomyosarcoma is the most common soft-tissue sarcoma in children. Fibrosarcoma is a rare primary bone tumor most commonly seen in adults. Adamantinoma is a rare primary bone malignancy also most commonly seen in adults in the tibia. Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 195.

Patients with a mutation of the retinoblastoma gene (RB) have an increased likelihood for the development of osteosarcoma. The EWS-FLI1 gene is the fusion product of a chromosomal translocation of 11:22. EGF-R and IGF-R are growth factor receptors, but mutations in these genes have not been correlated with osteosarcoma. VEGF is a proangiogenic molecule that is involved in tumor formation in multiple sites but not the development of osteosarcoma. Scholz RB, Kabisch H, Delling G, et al: Homozygous deletion within the retinoblastoma gene in a native osteosarcoma specimen of a patient cured of a retinoblastoma of both eyes. Pediatr Hematol Oncol 1990;7:265-273.

The MRI scans show a complete disruption of the sesamoid complex with proximal retraction of the medial sesamoid and high signal originating from the site normally occupied by the plantar plate (metatarsophalangeal ligament). This injury is the result of a hyperextension injury and is a severe variant of a turf toe. Watson TS, Anderson RB, Davis WH: Periarticular injuries to the hallux metatarsophalangeal joint in athletes. Foot Ankle Clin 2000;5:687-713.

One possible reason for improved efficacy of LMWHs is the relative improved bioavailability compared with that of unfractionated heparin. This is, in part, the result of a more predictable dose response and a longer half-life. There is no alteration of venous flow, and the rate of bleeding complications is the same or slightly higher than that of other prophylactic agents. Colwell CW Jr, Spiro TE, Trowbridge AA: Use of enoxaparin, a low-molecular weight heparin, and unfractionated heparin for the prevention of deep venous thrombosis after elective hip replacement: A clinical trial comparing efficacy and safety. J Bone Joint Surg Am 1994;76:3-14. Bara L, Billaud E, Kher A, Samama M: Increased anti-Xa bioavailability for a low-molecular weight heparin (PK 10169) compared with unfractionated heparin. Semin Thromb and Hemost 1985;11:316-317.

In the 2004 ACCP guidelines, there were three prophylactic regimens that received a grade 1A favorable recommendation. These included low-molecular-weight heparin, warfarin, or fondaparinux, as long as they are used for at least 10 days. If warfarin is used, the target INR should be 2.0 to 3.0, according to the guidelines. Pneumatic compression sleeves have gained popularity in the orthopaedic community but have not received a grade 1A rating from the ACCP at this time. Use of aspirin by itself is discouraged by the ACCP.

Although this is a fracture of the medial and lateral malleoli, the degree of displacement and comminution of the medial dome indicate that this injury is similar to a pilon fracture. Initial management should consistent of stabilization to allow for soft-tissue healing. The use of temporizing spanning external fixation should be the initial step, followed by limited or more extensive open reduction and internal fixation when the soft-tissue status will allow. Initial placement in either a short or long leg cast does not provide the needed stability and does not allow for care and monitoring of soft tissues. In addition, maintaining reduction of the talus may be very difficult. Immediate open reduction and internal fixation through an injured soft-tissue envelope adds the risk of difficulties with incision healing and a higher risk of deep infection. In the acute setting, a primary ankle fusion through this soft-tissue envelope is not indicated. Marsh JL, Bonar S, Nepola JV, et al: Use of an articulated external fixator for fractures of the tibial plafond. J Bone Joint Surg Am 1995;77:1498-1509. Wyrsch B, McFerran MA, McAndrew M, et al: Operative treatment of fractures of the tibial plafond: A randomized, prospective study. J Bone Joint Surg Am 1996;78:1646-1657.

The superficial portion of the MCL contributes 57% and 78% of medial stability at 5 degrees and 25 degrees of knee flexion, respectively. The deep MCL and posteromedial capsule act as secondary restraints at full knee extension. The anterior cruciate ligament and PCL also provide secondary resistance to valgus loads.

Humeral arthroplasty provides excellent pain relief and function for stage IV osteonecrosis with humeral collapse. In late disease with glenoid involvement (stage V), total shoulder arthroplasty is preferred. Some authors have reported satisfactory results with core decompression of the humeral head for early stages of osteonecrosis, but results for stage IV osteonecrosis are less satisfactory when compared with those for humeral arthroplasty. Cruess RL: Steroid-induced avascular necrosis of the head of the humerus: Natural history and management. J Bone Joint Surg Br 1976;58:313-317. LePorte DM, Mont MA, Mohan V, Pierre-Jacques H, Jones LC, Hungerford DS: Osteonecrosis of the humeral head treated by core decompression. Clin Orthop 1998;355:254-260.

The patient has a solitary lesion that is at high risk for fracture. While metastatic lesions are most common in this age group, a stabilization procedure is contraindicated until results of a biopsy confirm the presence of a metastasis. Because of the lytic lesion and the associated calcification shown on the radiograph, the most likely diagnosis is a chondrosarcoma. Therefore, any type of stabilization procedure with a rod or plate would compromise a wide surgical excision to remove the entire proximal femur. Radiation therapy and chemotherapy are also contraindicated until biopsy results are obtained. Because of these factors, obtaining a frozen section biopsy specimen is considered the next most appropriate step in management. If a metastatic lesion is confirmed on the frozen section, a stabilization procedure could then be performed under the same anesthetic. Therefore, it is important to have a pathologist available at the time of a biopsy. Frassica FJ, Frassica DA, McCarthy EF, Riley LH III: Metastatic bone disease: Evaluation, clinicopathologic features, biopsy, fracture risk, nonsurgical treatment, and supportive management. Instr Course Lect 2000;49:453-459.

Tuberculosis is uncommon in the cervical spine but has a relatively greater incidence in young children. In a review of 40 patients with lower cervical spine involvement (C2 to C7), 24 were younger than age 10 years at presentation. In children, the disease is characterized by more extensive involvement with the formation of large abscesses. In older patients with lower cervical tuberculosis, the disease is more localized but is more likely to cause paraplegia. Four-drug antituberculosis therapy should be used. For patients with pain or neurologic dysfunction, anterior excision of diseased bone and grafting are indicated. Whether vertebral body excision and grafting should be done in an asymptomatic 10-year-old child is debatable. The CT scan shows a large "cold" abscess that is partially calcified. Hsu LC, Leong JC: Tuberculosis of the lower cervical spine (C2 to C7): A report on 40 cases. J Bone Joint Surg Br 1984;66:1-5.

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

The imaging studies show a permeative lytic destructive lesion in the proximal radius with "hair-on-end" periosteal reaction and a large soft-tissue mass most consistent with Ewing's sarcoma. The pathology reveals monotonous sheets of "round blue" cells. This limits the differential diagnosis to primary lymphoma of bone versus Ewing's sarcoma. These are best differentiated by immunohistochemistry, cytogenetics, and flow cytometry. Lymphoma of bone is typically CD34 positive and CD99 negative; whereas, the reverse is true of Ewing's sarcoma, CD34 negative and CD99 positive. The most common cytogenetic translocation with Ewing's sarcoma is 11; 22; 21; 22 and 7; 22 translocations have also been reported in Ewing's sarcomas. The X; 18 translocation is most commonly associated with synovial cell sarcomas; the 12; 22 translocation is most commonly associated with clear cell sarcomas; the 2; 13 translocation is most commonly associated with alveolar rhabdomyosarcomas, and the 12; 16 translocation is most commonly associated with myxoid liposarcomas. Flow cytometry is used to characterize the cell types of lymphomas. Womer R: The cellular biology of bone tumors. Clin Orthop Relat Res 1991;262:12-21. Yamaguchi U, Hasegawa T, Morimoto Y, et al: A practical approach to the clinical diagnosis of Ewing's sarcoma/primitive neuroectodermal tumour and other small round cell tumours sharing EWS rearrangement using new fluorescence in situ hybridisation probes for EWSR1 on formalin fixed, paraffin wax embedded tissue. J Clin Pathol 2005;58:1051-1056.

The standard approach to the volar aspect of the distal radius is the Henry approach. Following incision of the skin and subcutaneous tissues, the forearm fascia is incised. The radial artery and venae comitantes lie in the interval between the tendons of the flexor carpi radialis muscle and the brachioradialis muscle. This interval is developed, and the radial artery and veins are retracted in a radial direction. Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 118-131.

Arthroscopic capsular release is an effective means of treating stiffness that is the result of capsular contractures, such as in the case of a tight Bankart repair. Open release allows lengthening of a surgically shortened subscapularis, such as after a tight Putti-Platt repair. Additional physical therapy is unlikely to be effective because 8 months of treatment has failed to result in improvement. Accepting this degree of asymptomatic limited motion is not advisable because of the functional limitations for the patient and the increased risk of postoperative degenerative arthritis. Warner JJ, Allen AA, Marks PH, Wong P: Arthroscopic release of postoperative capsular contracture of the shoulder. J Bone Joint Surg Am 1997;79:1151-1158.

Patellar fractures that occur after a total knee arthroplasty are usually stress fractures. Integrity of the extensor mechanism precludes the need for surgical repair or internal fixation, while stability and fixation of the patellar component determine whether revision is indicated. A cylindrical cast and full weight bearing for 6 weeks is recommended for transverse fractures with an intact extensor mechanism and a stable component. A similar fracture, if vertical, may be treated with earlier motion. Rorabeck CH, Angliss RD, Lewis PL: Fractures of the femur, tibia, and patella after total knee arthroplasty: Decision making and principles of management, in Cannon WD Jr (ed): Instructional Course Lectures 47. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 449-458. Hozack WJ, Goll SR, Lotke PA, Rothman RH, Booth RE Jr: The treatment of patellar fractures after total knee arthroplasty. Clin Orthop 1988;236:123-127.

The patient has chronic posterolateral instability with a varus knee alignment; therefore, the most effective treatment is a valgus-producing HTO. A repeat soft-tissue reconstruction without correction of the varus alignment will most likely fail. An ACL reconstruction is not indicated with a normal Lachman's test. Physical therapy and bracing will have little effect. Naudie DD, Amendola A, Fowler PJ: Opening wedge high tibial osteotomy for symptomatic hyperextension-varus thrust. Am J Sports Med 2004;32:60-70.

The findings are consistent with an aneurysmal bone cyst. The MRI scan demonstrates a lesion involving the posterior elements of the vertebrae with fluid-fluid levels and neural compression. Fibrovascular tissue with multinucleated giant cells surrounding a vascular lake is seen on the histology. The most appropriate treatment is a marginal resection of the involved posterior elements. Although the recurrence rate can be as high as 25% to 30%, wide surgical resection could result in permanent neurologic injury and is not necessary. Aspiration and steroid injection have been advocated but would not relieve the nerve compression in this patient. Radiation therapy and chemotherapy are not indicated. Mankin HJ, Hornicek FJ, Ortiz-Cruz E, et al: Aneurysmal bone cyst: A review of 150 patients. J Clin Oncol 2005;23:6756-6762.

The ulnar nerve is more prone to neuropathy than the radial or median nerves for many reasons. It has the greatest longitudinal excursion required to accommodate elbow range of motion, subjecting it to potential traction forces. The dimensions of the entrance of the cubital tunnel change with elbow motion, potentially causing compression in flexion. For these two reasons, the ulnar nerve is subjected to both compression and traction during elbow motion. Although it passes between two muscle heads as it enters the forearm, so do the median and radial nerves. Finally, the vascular supply is adequate because of the anastamoses between the superior ulnar collateral artery, the posterior ulnar recurrent artery, and the inferior ulnar collateral artery. Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 369-378. Prevel CD, Matloub HS, Ye Z, Sanger JR, Yousif NJ: The extrinsic blood supply of the ulnar nerve at the elbow: An anatomic study. J Hand Surg Am 1993;18:433-438.

Activity levels do not affect cobalt and chromium ion levels, which are the bulk of serum ion levels. The majority of ions are produced in the run-in period in the first several years. A gradual reduction in ion levels occurs thereafter. The kidneys are responsible for the bulk of clearance from the serum, and to date there is no relationship of cancer to ion levels in the serum.

Local control of malignant fibrous histiocytoma of bone typically consists of wide excision. Curettage and bone grafting is a procedure with an intralesional surgical margin, with an unacceptable rate of local recurrence. Prophylactic fixation is considered for patients with metastatic disease. Radiation therapy alone is not adequate for local control of this tumor. Neoadjuvant chemotherapy is often used primarily for systemic tumor control.

The patient has a transscaphoid dorsal perilunate dislocation. The radiographs clearly define a dorsal dislocation of the capitolunate joint, and the scaphoid fracture component is easily visible on the AP view. A scaphoid fracture alone is an unlikely diagnosis because of the midcarpal dislocation component. The radiocarpal joint is not dislocated because the lunate is sitting in the lunate fossa of the radius. Isolated radiocarpal dislocations are not associated with a midcarpal disruption. While a midcarpal dislocation is a component of a dorsal perilunate dislocation, this diagnosis does not address the scaphoid fracture. A volar lunate dislocation is not seen because the lunate is reduced in the lunate fossa of the distal radius. Volar lunate dislocations are in the spectrum of injury of perilunate dislocations and fracture-dislocations; however, the radiographs show a transscaphoid dorsal perilunate dislocation. Mayfield JK, Johnson RP, Kilcoyne RK: Carpal dislocations: Pathomechanics and progressive perilunar instability. J Hand Surg Am 1980;5:226-241.

Half pins placed in the AIIS are an alternative to pins placed in the iliac crest. A strong pillar of bone runs from the AIIS to the posterior iliac crest and less soft tissue is typically present in this area. The starting point is best seen on an obturator outlet view. The obturator outlet view is a combination of the pelvic outlet view and the obturator view of Judet and Letournel. The beam is rotated "over the top" of the patient since the iliac wing is externally rotated as well as cephalad to best visualize this column of bone running from the AIIS to the posterior iliac spine. This corridor of bone will appear as a teardrop. Once the correct view is obtained, the pin should be started at least 2 cm proximal to the hip joint to avoid placing a pin within the hip capsule. Blunt dissection and a guide sleeve should be used to prevent damage to the lateral femoral cutaneous nerve. An iliac oblique view is used after the pin has been partially inserted to make sure the pin is passing superior to the superior gluteal notch, and an obturator inlet view can be used at the completion of the procedure to make sure the pin is contained within the bone for its entire length. Gardner MJ, Nork SE: Stabilization of unstable pelvic fractures with supra-acetabular compression external fixation. J Orthop Trauma 2007;21:269-273. Haidukewych GJ, Kumar S, Prpa B: Placement of half-pins for supra-acetabular external fixation: An anatomic study. Clin Orthop Relat Res 2003;411:269-273.

The most important criteria in determining the need for surgery following a nondisplaced or minimally displaced tibial plateau fracture is knee stability to varus/valgus stress. Soft-tissue injury noted on MRI may be addressed at a later time following fracture healing. This fracture pattern is amenable to nonsurgical management. Decisions regarding surgical intervention may be made up to 2 weeks after injury.

These lesions are extremely vascular and can cause uncontrolled intraoperative bleeding; therefore embolization is the appropriate first treatment. Because the radiograph and CT scan show a lytic lesion in the supra-acetabular region that affects the weight-bearing dome and medial wall, the next step in treatment would most likely be a total hip arthroplasty and acetabular reconstruction. Treatment with bisphosphonates and radiation therapy will not prevent an acetabular fracture. Cementoplasty is an emerging technique in which cement is injected percutaneously into a lesion, but no long-term results have been reported. Radiofrequency ablation of bone metastases is also an emerging technique that provides palliative pain control. Layalle I, Flandroy P, Trotteur G, Dondelinger RF: Arterial embolization of bone metastases: Is it worthwhile? J Belge Radiol 1998;81:223-225.

Acetabular protrusion in patients with rheumatoid arthritis moves the center of hip rotation medially and posteriorly. Positioning of the acetabular component in a patient with protrusion is best accomplished in the normal (anterior and inferior) position and not in a protruded position. This has been shown both clinically and in a finite-element analysis. Any medial positioning will produce impingement of the prosthesis neck on the rim, and superior placement produces improper hip mechanics. Crowninshield RD, Brand RA, Pedersen DR: A stress analysis of acetabular reconstruction in protrusio acetabuli. J Bone Joint Surg Am 1983;65:495-499.

Numerous clinical and basic science investigations have evaluated meniscal tear characteristics to identify factors that either promote or mitigate against meniscal healing. Complex tears have been noted to heal poorly, while longitudinal tears heal more predictably. Tear length, time from injury to repair, medial versus lateral meniscal tears, and the use of a fibrin clot have not been shown to consistently affect meniscal healing. However, rim width, the distance of the tear site from the peripheral meniscocapsular junction (vascular supply), has been shown to have a significant role in the ability of a meniscus repair to heal. DeHaven KE, Arnoczky SP: Meniscus repair: Basic science, indications for repair, and open repair. Instr Course Lect 1994;43:65-76.

The plain radiographs show an eccentric metaphyseal lesion involving a long bone in a skeletally immature patient. The lesion is longer than it is wide, with distinctly lobular outer edges that are sclerotic. These findings are characteristic of a nonossifying fibroma. Small asymptomatic lesions may be followed clinically. Larger lesions that occupy greater than two thirds of the width of the shaft and are located in areas of high mechanical stress such as the femur are more prone to fracture than smaller lesions. Pain is often a sign of impending fracture or the presence of a small fracture that may not be apparent on radiographs. The natural history of the lesion is to resolve over a period of years. The procedure that would allow the patient to return to contact sports is curettage and bone grafting. Intralesional steroid injection has been advocated in the treatment of unicameral bone cysts and eosinophilic granuloma but not nonossifying fibromas. En block resection is not indicated for a benign lesion. Low-dose radiation therapy has been used for eosinophilic granuloma but not for nonossifying fibromas. Walker RN, Green NE, Spindler KP: Stress fractures in skeletally immature patients. J Pediatr Orthop 1996;16:578-584.

Changing from a solid keel to a keel with a sagittal split allows an amputee to navigate uneven terrain more easily. Changing the length of the keel affects the responsiveness of the prosthesis but does not address the surface conditions for ambulation. The SACH is not used as frequently anymore, because overload problems to the nonamputated foot have been observed. Koval K (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 31-45.

MRI with gadolinium will best identify recurrent herniated nucleus pulposus or other root compression and distinguish scar from recurrent disk. CT is unable to distinguish scar from recurrent disk density, and the addition of myelogram dye can reveal compromise of the thecal sac but cannot distinguish the scar from recurrent disk as the source of compression. Although lateral flexion-extension radiographs may be important to rule out any instability, much of that information can be inferred from the associated disk and adjacent bony changes on MRI. Bone scan techniques may identify subtle stress fractures resulting from previous aggressive facet resection, but low back pain also would be expected. Mirowitz SA, Shady KL: Gadopentetate dimeglumine-enhanced MR imaging of the postoperative lumbar spine: Comparison of fat-suppressed and conventional T1-weighted images. Am J Roentgenol 1992;159:385-389.

The glenoid labrum receives its blood supply from the suprascapular, posterior humeral circumflex, and circumflex scapular arteries. The labral vessels arise from the capsular and periosteal vessels that penetrate the periphery of the labrum. The bone does not appear to be a source of vascularity. The posterior/superior and inferior labrum have a fairly robust vascular supply, whereas the anterior/superior labrum has relatively poor vascularity, which may influence the success of superior lateral repairs.

The juvenile Tillaux ankle fracture usually occurs because the lateral half of the distal tibial physis remains open. During an external rotational force, the anterior tibiofibular ligament holds the lateral tibial epiphysis, separating it through at the junction of the middle closed physis and lateral open physis.

The axillary nerve lies within millimeters of the anterior inferior capsule. The inferior capsule is of varying thickness, and thermal energy used in shortening the ligament can cause damage to the sensory fibers of the axillary nerve. Clinically, this is manifested as a burnt skin sensation in the axillary nerve distribution area. The motor branch of the axillary nerve is usually spared. The suprascapular nerve and the radial nerve are far from the shrinkage zone. The musculocutaneous nerve, frequently at risk with open procedures, lies well anterior. Fanton GS: Arthroscopic electrothermal surgery of the shoulder. Op Tech Sports Med 1998;6:157-160.

The patient is showing signs of vertebral artery stroke. The signs of Wallenberg syndrome include those listed above, as well as contralateral loss of pain and temperature sensation throughout the body, an ipsilateral Horner's syndrome, dysphagia, and ataxia. Vertebral artery injuries are not unusual in significant cervical facet injuries. A lesion in the cervical spinal cord is not associated with these symptoms, and an intracranial hemorrhage from trauma is unlikely to present in this manner. Young PA, Young PH: Basic Clinical Neuroanatomy. Baltimore, MD, Williams and Wilkins, 1997, pp 242-243. Hauop JS, et al: The cause of neurologic deterioration after acute cervical spinal cord injury. Spine 2001;26:340-346.

Injuries to the ulnar collateral ligament of the MCP joint of the thumb commonly occur in recreational skiers. Historically, this injury has been referred to as "gamekeeper's thumb." The ligament consists of the proper collateral ligament and the more volar accessory collateral ligament. In extension, the accessory ligament is taut, and in flexion, the proper ligament is taut. For a complete tear of the ligament complex to occur, there must be laxity in full extension. Incomplete tears respond well to thumb spica splinting or casting for 2 to 3 weeks and gradual resumption of range of motion. Prolonged immobilization of incomplete injuries leads to higher rates of MCP joint stiffness. Stener B: Displacement of the ruptured ulnar collateral ligament of the metacarpo-phalangeal joint of the thumb: A clinical and anatomical study. J Bone Joint Surg Br 1971;44:869.

Popliteal snapping syndrome represents the most likely diagnosis. Barnes and Scott noted that the popliteus tendon can be a potential source of internal derangement after total knee arthroplasty. They noted that it can be subluxated anteriorly and posteriorly over a retained lateral femoral condyle osteophyte. Allardyce and associates described the condition as a popliteus condition, snapping as it rolls over a retained lateral femoral condylar osteophyte. Patellar clunk syndrome is a distinct syndrome associated with the patella and has been reported in posterior stabilized knees. In addition to crepitation with range of motion, the patella literally snaps or jumps as the knee is taken from flexion to extension. Beight JL, Yao B, Hozack WJ, et al: The patellar "clunk" syndrome after posterior stabilized total knee arthroplasty. Clin Orthop 1994;299:139-142. Barnes CL, Scott RD: Popliteus tendon dysfunction following total knee arthroplasty. J Arthroplasty 1995;10:543-545.

The radiograph shows a type V acromioclavicular separation with greater than 100% superior elevation of the clavicle. This finding implies detachment of the deltoid and trapezius from the distal clavicle. Because of severe compromise of function and potential compromise to the overlying skin, surgery is the treatment of choice for type V acromioclavicular separations. During reduction and repair, meticulous repair of the deltotrapezial fascia will also aid in securing the repair. Nuber GW, Bowen MK: Acromioclavicular joint injuries and distal clavicle fractures. J Am Acad Orthop Surg 1997;5:11-18.

Functional bracing has been demonstrated to have a very high rate of healing without any functional limitations in a large series of patients. Surgery is reserved for "floating elbows," open injuries, neurovascular injuries, and those fractures that go on to nonunion. Sarmiento A, Zagorski JB, Zych GA, et al: Functional bracing for the treatment of fractures of the humeral diaphysis. J Bone Joint Surg Am 2000;82:478-486.

The supraspinatus tendon shows clear detachment and retraction from its greater tuberosity attachment by the absence of the normal dark subacromial signal extending to the attachment on the greater tuberosity. There is no anterior inferior glenoid labral detachment that usually is seen in a Bankart lesion. The acromioclavicular joint shows no evidence of separation. The humeral head is migrated cranially, indicating a chronic rotator cuff tear. Iannotti JP, Zlatkin MB, Esterhai JL, Kressel HY, Dalinka MK, Spindler KP: Magnetic resonance imaging of the shoulder: Sensitivity, specificity, and predictive value. J Bone Joint Surg Am 1991;73:17-29. Seeger LL, Gold RH, Bassett LW, Ellman H: Shoulder impingement syndrome: MR findings in 53 shoulders. Am J Roentgenol 1988;150:343-347.

Osteofibrous dysplasia frequently presents at a very young age, usually less than 10 years. In most patients, it involves the anterior cortex of the tibial shaft and minor anterior bowing of the tibia is frequently seen. The lesion is unpredictable in nature, but local recurrence is very high in patients who undergo surgery before 15 years of age. Campanacci M, Laus M: Osteofibrous dysplasia of the tibia and fibula. J Bone Joint Surg Am 1981;63:367-375.

Curettage and bone grafting typically are the preferred treatment of chondroblastoma, yielding acceptable local recurrence rates of less than 10%. Some surgeons advocate adjuvant therapies such as phenol, liquid nitrogen, or argon beam coagulation. Untreated, these lesions can destroy bone and invade the joint to a significant degree. Large intra-articular lesions may require major joint reconstruction. Wide local excision is rarely required to control the tumor. Radiation therapy is indicated only in unresectable lesions. Springfield DS, Capanna R, Gherlinzoni F, et al: Chondroblastoma: A review of seventy cases. J Bone Joint Surg Am 1985;67:748.

The arrows in the figure show the deep branch of the ulnar nerve (more radial) and the superficial branch of the ulnar nerve within Guyon's canal. Guyon's canal is approximately 4 cm long beginning at the proximal extent of the transverse carpal ligament and ends at the aponeurotic arch of the hypothenar muscles. Many structures comprise the boundaries of Guyon's canal. The floor, for example, consists of the transverse carpal ligament, the pisohamate and pisometacarpal ligaments, and the opponens digiti minimi. Within Guyon's canal, the ulnar nerve bifurcates into the superficial and deep branches. The ulnar artery is immediately adjacent and radial to the ulnar nerve. The median nerve is visualized within the carpal tunnel, and the palmar cutaneous branch is more radial to Guyon's canal and volar to the carpal tunnel. The radial and ulnar digital nerves to the little finger are branches off of the superficial branch of the ulnar nerve distal to its emergence from Guyon's canal. The ulnar artery is the round structure located radial to the branches of the ulnar nerve within Guyon's canal. Adjacent to the ulnar artery are two small veins. The dorsal cutaneous branch of the ulnar nerve branches from the ulnar nerve in the distal forearm, well proximal to Guyon's canal. The common digital artery to the fourth web branches from the superficial palmar arch distal to Guyon's canal. The hook of the hamate is clearly seen in the figure, orienting the observer to the ulnar side of the wrist. Gross MS, Gelberman RH: The anatomy of the distal ulnar tunnel. Clin Orthop Relat Res 1985;196:238-247.

The MRI scans show a rupture of the sternocostal portion of the pectoralis major tendon. This is the most common site of rupture and bench pressing is the most common etiology. Surgical repair yields better functional outcomes and patient satisfaction for tears not only at the tendon/bone interface but also at the myotendinous junction. Bak K, Cameron EA, Henderson IJ: Rupture of the pectoralis major: A meta-analysis of 112 cases. Knee Surg Sports Traumatol Arthrosc 2000;8:113-119.

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

Once degenerative changes have occurred, soft-tissue procedures are not indicated. Triple arthrodesis is the treatment of choice for adult-acquired flatfoot. Isolated fusion of the subtalar or talonavicular joint will not be sufficient to correct the problem. Lutter LD, Mizel MS, Pfeffer GB (eds): Orthopaedic Knowledge Update: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 269-282.

Serum lactate levels can be used to evaluate the effectiveness of the resuscitation of patients who have multiple injuries. Even after resuscitation, patients may have occult hypoperfusion as defined by a serum lactate level of greater than 2.5 mmol/L. The studies referenced indicate that these patients are at increased risk of perioperative complications such as organ failure or adult respiratory distress syndrome if definitive surgical fixation of the orthopaedic injuries is pursued prior to correction of the occult hypoperfusion. The other markers may be an indication of current physiology but have not been correlated with perioperative risks. Blow O, Magliore L, Claridge JA, et al: The golden hour and silver day: Detection and correction of occult hypoperfusion within 24 hours improves outcomes from major trauma. J Trauma 1999;47:964-977. Crowl A, Young JS, Kahler DM, et al: Occult hypoperfusion is associated with increased morbidity in patients undergoing early femur fracture fixation. J Trauma 2000;48:260-267.

Indications for open reduction of glenoid intra-articular fractures include those fractures with a 5-mm articular surface displacement or when the humeral head is subluxated with the fracture fragment. Kavanaugh and associates and Leung and Lam have shown that the posterior approach with plate fixation is best for most glenoid fractures, including the Ideberg type II fracture shown here. The anterior approach is best used for anterior rim and transverse fractures. Kavanagh BF, Bradway JK, Cofield RH: Open reduction and internal fixation of displaced intra-articular fractures of the glenoid fossa. J Bone Joint Surg Am 1993;75:479-484. Leung KS, Lam TP: Open reduction and internal fixation of ipsilateral fractures of the scapular neck and clavicle. J Bone Joint Surg Am 1993;75:1015-1018.

The patient has osteonecrosis of the humeral head. The radiographs show increased density in the superior subchondral region of the humeral head. The MRI scans reveal a central collapse of the humeral head. The patient's history of severe asthma and long-term prednisone use predisposes her to this condition. The MRI scans show no evidence of a full- or partial-thickness rotator cuff tear. Without a history of fevers, chills, or other systemic signs or symptoms, there is no indication of septic arthritis. The radiographs do not reveal periarticular erosions, commonly seen in rheumatoid arthritis. Matsen FA III, Rockwood CA Jr, Wirth MA, et al: Glenohumeral arthritis and its management, in Rockwood CA Jr, Matsen FA III (eds): Rockwood and Matsen The Shoulder, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 871-874.

The patient has a significantly angulated proximal humerus fracture with a high degree of varus angulation, and rotational malalignment is likely. Failure to correct the varus angulation will result in permanent loss of shoulder abduction because the patient's age limits bony remodeling. These fractures are inherently unstable due to the inability to control the proximal fracture alignment. Shoulder spica casts have a high rate of redisplacement after treatment. Adequate open or closed reduction and pin fixation in the operating room optimizes alignment and all but eliminates the chance of redisplacement. Dobbs MB, Luhmann SJ, Gordon JE, et al: Severely displaced proximal humerus epiphyseal fractures. J Pediatr Orthop 2003;23:208-215. Vaccaro AR (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, p 701.

This approach is criticized for the episodic limp associated with the muscle detachment and reattachment. Classically, two thirds of the gluteus medius is detached as a sleeve with the vastus lateralis. This exposes the gluteus minimus and the ligament of Bigelow. These must also be detached to allow dislocation of the hip and osteotomy of the femoral neck. The rectus femoris lies medially and anteriorly and does not need to be addressed. The piriformis and obturator internus are exposed during the posterior approach. Neither the gluteus maximus nor tensor fascia lata attach to the anterior femur. The sartorius and iliopsoas are not exposed during this dissection. Hoppenfeld S, deBoer P (eds): Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, pp 333-335.

The arterial supply to the hand is abundant and normally duplicated. The deep palmar arch as shown in this arteriogram typically receives its primary contribution from the radial artery which travels deep to the first dorsal compartment tendons and then returns to the volar aspect of the palm through the first web space. The superficial palmar arch receives its supply from the ulnar artery and is not visualized in this patient.

Developmental coxa vara develops in early childhood and results in a progressive decrease in the proximal femoral neck-shaft angle with growth. The characteristic radiographic features are seen in this patient and include a decreased neck-shaft angle, a more vertical position of the physeal plate, and a triangular metaphyseal fragment in the inferior femoral neck, surrounded by an inverted radiolucent Y pattern. The main goal of surgery is to correct the varus angulation into a more normal range. Valgus overcorrection is preferred. A recent study emphasized the importance of adequately correcting the Hilgenreiner physeal angle to less than 38 degrees to minimize the risk of recurrent angulation. No study has documented the use of any of the other listed radiographic measurements to the outcome of treating developmental coxa vara. Carroll K, Coleman S, Stevens PM: Coxa vara: Surgical outcomes of valgus osteotomies. J Pediatr Orthop 1997;17:220-224.

Histologic grade, the presence or absence of metastatic disease, and tumor size are important prognostic factors. Of the available choices, however, the size of the sarcoma is the most important prognostic indicator. A tumor size of greater than 5 cm is a more important prognostic factor than tumor location. Patients with sarcomas that measure 5 cm or less have nearly identical 3-year survival rates regardless of whether the tumor is subcutaneous or deep. Histologic grade (high versus low) is an important factor. However, histologic subtype frequently is not as important a factor as tumor size.

Clubfoot (talipes equinovarus) in patients with arthrogryposis is a rigid and resistant deformity. However, multiple studies document limited success with nonsurgical management. Manipulation and casting are generally a preliminary treatment before surgery; successful correction will most like require a talectomy. Guidera KJ, Drennan JC: Foot and ankle deformities in arthrogryposis multiplex congenita. Clin Orthop 1985;194:93-98. Handelsman JE, Badalamente MA: Neuromuscular studies in clubfoot. J Pediatr Orthop 1981;1:23-32.

The primary carcinoma most likely to metastasize distal to the elbow and knees is lung carcinoma. Renal cell carcinoma can also metastasize to distal sites. Most metastatic bone disease occurs in the vertebral bodies, pelvis, and proximal long bones. Simon MA, Bartucci EJ: The search for the primary tumor in patients with skeletal metastases of unknown origin. Cancer 1986;58:1088-1095.

A Charcot flare in adjacent joints is not uncommon in patients with neuropathy who undergo surgery or other trauma. Venous thrombosis would present with swelling of the entire leg, while infection would present earlier in the postoperative period. The radiographs are pathognomonic of Charcot arthropathy, not an unrecognized fracture or gout. A compartment syndrome this late after injury is extremely rare, and there would be no bony distraction associated with compartment syndrome.

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. Wall E, Von Stein D: Juvenile osteochondritis dissecans. Orthop Clin North Am 2003;34:341-353.

The mainstay of early treatment of open fractures includes irrigation and debridement. Prior to the development of antibiotics, this was traditionally accomplished with some form of detergent irrigation. Antibiotic irrigation has been in favor more recently but has mixed scientific results related to its use. Results of at least one major study show the use of a nonsterile liquid soap additive (castile soap) is at least as effective as the use of bacitracin with regards to the rate of postoperative infection and fracture healing, and shows a significant decrease in problems with soft-tissue healing.

The diagnosis of an interdigital neuroma is best made by a thorough history and careful physical examination. Radiographs are helpful in excluding other pathologic processes such as a metatarsal stress fracture. MRI and ultrasound have both been reported to aid in the diagnosis of an interdigital neuroma. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2003, pp 145-151.

Pelvic osteotomies that redirect hyaline cartilage over the femoral head offer the potential for long-term preservation of the hip; however, salvage procedures such as the Chiari osteotomy are indicated in patients without a concentrically reducible hip. Ito and associates reported that moderate dysplasia and moderate subluxation without complete obliteration of the joint space and a preoperative center-edge angle of at least minus 10 degrees are desirable selection criteria. Ohashi H, Hirohashi K, Yamano Y: Factors influencing the outcome of Chiari pelvic osteotomy: A long-term follow-up. J Bone Joint Surg Br 2000;82:517-525.

The radiograph shows widening between the scaphoid and lunate. The normal variance is up to 5 mm. Although several ligaments may be torn, the scapholunate interosseous ligament must be torn for this widening to occur. Cooney WP, Linscheid RL, Dobyns JH: The Wrist: Diagnosis and Operative Treatment. St Louis, MO, Mosby-Year Book, 1998, vol 1, pp 503-506.

Epithelioid sarcoma is a rare soft-tissue sarcoma that most commonly arises in the hand or upper extremity, and it is frequently misdiagnosed as an infection or granuloma. It tends to have a higher incidence of lymph node metastasis than other soft-tissue sarcomas. The mainstay of treatment is wide surgical excision, even if amputation is necessary. Gupta TD, Chaudhuri P (eds): Tumors of the Soft Tissues, ed 2. Stamford, CT, Appleton and Lange, 1998, p 475.

The imaging studies are consistent with a chondrosarcoma. The radiograph shows a radiolucent lesion in the pelvis, and there are stippled calcifications on the CT scan. The histology shows a low-grade cellular hyaline cartilage neoplasm with stellate, occasionally binucleated chondrocytes. Enchondroma has a more benign histologic appearance.

Highly cross-linked polyethylene has gained widespread acceptance for joint arthroplasty components because of reported experimental and early clinical accounts of significant reductions in wear. Cross-linking is increased by imparting additional energy into the polymer (above that conventionally used for sterilization). The thermal treatments after cross-linking stabilize the material against oxidative degradation by quenching free radicals and also reduce the elastic modulus. One disadvantage of the increased cross-linking is a reduction in toughness that makes the polyethylene more susceptible to crack initiation and propagation. The reduced toughness raises concerns for gross component fracture and fracture at stress concentrations that can arise with the locking mechanisms used to secure polyethylene inserts into metallic backings. Nonconsolidated polyethylene particles have been associated with increased subsurface density secondary to oxidative degradation in conventional polyethylene implants. The quenching of free radicals by thermal treatment in highly cross-linked polyethylene should prevent this problem. Collier JP, Currier BH, Kennedy FE, et al: Comparison of cross-linked polyethylene materials for orthopaedic applications. Clin Orthop 2003;414:289-304. Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 203-208.

Calcaneal apophysitis (Sever's disease) is a common cause of heel pain in children who are active in sports. The symptoms are most commonly bilateral and will often respond to a gastrocnemius-soleus complex stretching program. In addition, rest, anti-inflammatory drugs, and heel pads for the shoe may be prescribed. There is no effect on the long-term growth of the calcaneus. Micheli LJ, Ireland ML: Prevention and management of calcaneal apophysitis in children: An overuse syndrome. J Pediatr Orthop 1987;7:34-38.

The radiograph reveals bilateral patchy sclerosis of the femoral heads without evidence of collapse. The MRI scan shows bilateral head involvement with a common serpentine-like low-intensity signal of the superior femoral head that is common to osteonecrosis. Changes confined to the femoral head effectively exclude rheumatoid arthritis and osteoarthritis. Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4. Philadelphia, PA, WB Saunders, 2002, vol 4, pp 3160-3162.

The recurrent laryngeal nerve provides innervation to the vocal cords and was the most common neurologic injury reported in a series of 36,000 patients. The nerve is felt to be more vulnerable during a right-sided approach because of its anatomic course. A recent study has also suggested a role for increased endotracheal cuff pressures in this nerve injury. Flynn TB: Neurologic complications of anterior cervical interbody fusion. Spine 1982;7:536-539.

Spondylolysis may develop as a stress fracture resulting from repetitive hyperextension during athletic activities. In young people, the pars interarticularis is thin, the neural arch has not yet reached maximum strength, and the intravertebral disk is less resistant to shear. While clinical symptoms may lead to the suspicion of spondylolysis, radiographic confirmation may be difficult in early cases. Plain radiographs may be negative initially, and the plain MRI scan may not offer good visualization of the pars. A bone scan with SPECT is very sensitive initially. CT scans with regular axial and reverse-gantry angled cuts may help determine the type of fracture and the course of treatment. Congeni J, McCulloch J, Swanson K: Lumbar spondylolysis: A study of natural progression in athletes. Am J Sports Med 1997;25:248-253.

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

Spinal shock typically ends after 48 hours with the return of reflexes, including the bulbocavernosus reflex. Lack of motor or sensory recovery in the lower extremities with the return of reflexes generally indicates a complete cord syndrome. Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 179-187.