Orthopedic Board Review MCQs (2026 Edition) - Part 8

The radiographs show an oblique periprosthetic distal femoral fracture. Of the options listed, open reduction and internal fixation is the most appropriate surgical option because a well-fixed, posterior stabilized closed box femoral component is present. Nonsurgical methods are not favored because of the highly displaced, unstable fracture pattern and prolonged immobility. Revision with a stemmed component is an option but would sacrifice more bone stock in this younger patient. Moran MC, Brick GW, Sledge CB, et al: Supracondylar femoral fracture following total knee arthroplasty. Clin Orthop 1996;324:196-209. Raab GE, Davis CM III: Early healing with locked condylar plating of periprosthetic fractures around the knee. J Arthroplasty 2005;20:984-989.

Polyethylene wear debris can result in significant synovitis and subsequent cloudy appearing synovial fluid. Typically, laboratory studies show a WBC of less than 30,000/mm3 no left shift. Cytologic examination can reveal intra-articular polyethylene particles. Infected total knee arthroplasty is extremely uncommon in a healthy, immune-competent patient who has a normal preoperative erythrocyte sedimentation rate and C-reactive protein level.

The sympathetic chain approaches the lateral border of the longus coli muscle at C6 and is more vulnerable to injury at this level. Injury to the chain will cause Horner's syndrome, usually seen as unilateral ptosis.

The more severe the trauma, the higher the rate of subsequent clavicular nonunion. Neither duration nor type of immobilization has been clearly demonstrated to be a causative factor in the development of nonunion. Similarly, closed reduction has not been found to alter the healing course in midshaft clavicular fractures. Lazarus MD, Seon C: Fractures of the clavicle, in Bucholz RW, Heckman JD, Court-Brown C (eds): Fractures in Adults. Philadelphia, PA, Lippincott Williams and Wilkins, 2006, vol 2, pp 1241-1242.

The CT scan is an important test to help determine the extent of involvement of the talocalcaneal facet in a talocalcaneal coalition. In a young patient with no arthritis and joint involvement of less than 50%, resection of the coalition and fat pad interposition has been shown to be successful. A calcaneal osteotomy does not address the coalition. Subtalar arthroereisis has been used for treatment of a flexible flatfoot; tarsal coalition patients have a rigid-type flatfoot deformity. Sullivan JA: The child's foot, in Morrissy RT, Weinstein SL (eds): Lovell and Winter's Pediatric Orthopaedics, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 2, pp 1077-1135.

The radiograph reveals a metaphyseal lesion with some stippled mineralization suggesting a chondroid tumor. The bone scan shows increased uptake, beyond what is expected for a simple enchondroma, and beyond the limits of the lesion. The MRI sequences shows a lobular lesion on the T1- and T2-weighted (bright on the T2 sequence) images with inhomogeneous uptake of gadolinium; both findings are typical for a chondroid lesion. The history of pain, the positive bone scan, the age of the patient, the size of the lesion, and the central location (enostotic) of the lesion all suggest a malignant cartilage tumor. The images are not consistent with the other diagnoses. In particular, plasmacytoma is more uniformly bright on T2-weighted images and often has a negative bone scan. Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 187-194.

While it is recommended that a patient gain full range of motion, pain-free function, and symmetric strength prior to returning to vigorous activities, it is absolutely essential that radiographs of the fracture site reveal a circumferential external bridging callus to prevent refracture. This is particularly important for comminuted femoral fractures with various sized fragments. It is also recommended that a return to rodeo riding be postponed for at least 1 year. Brumback RJ, Ellison TS: Intermedullary nailing of femoral stress fractures. J Bone Joint Surg Am 1992;74:106-112. Bucholz RW, Jones A: Fractures of the shaft of the femur. J Bone Joint Surg Am 1991;73:1561-1566.

The sympathetic trunk runs longitudinally along the medial border of the psoas. The ilioinguinal nerve emerges along the upper lateral border of the psoas and travels to the quadratus lumborium, and the genitofemoral nerve lies more laterally on the psoas. The ureter is adherent to the posterior peritoneum and falls away from the psoas and the spine in the dissection, as does the aorta. Watkins RG (ed): Surgical Approaches to the Spine. New York, NY, Springer-Verlag, 1983, p 107.

Malrotation of the foot is frequently overlooked in this clinical setting. This can be judged by evaluating and comparing the transmalleolar axes of the affected and unaffected legs. The rotation occurs through the physis and frequently is not recognized until the patient has been walking for a few months. The other conditions are not expected to occur in the clinical setting described. Phan VC, Wroten E, Yngve DA: Foot progression angle after distal tibial physeal fractures. J Pediatr Orthop 2002;22:31-35.

The patient has a displaced intra-articular tibial tuberosity fracture; therefore, the treatment of choice is open reduction and internal fixation. Periosteum is often interposed between the fracture fragments and prevents satisfactory closed reduction. Fortunately, most patients with this injury are close to skeletal maturity and therefore, growth arrest and recurvatum are unusual. Nondisplaced fractures can be treated with a cast, but displaced fractures are best treated with open reduction and internal fixation. Intra-articular fractures can disrupt the joint surface and are sometimes associated with a meniscal tear; therefore, arthroscopy may be needed at the time of open reduction and internal fixation. McKoy BE, Stanitski CL: Acute tibial tubercle avulsion fractures. Orthop Clin North Am 2003;34:397-403.

Cauda equina syndrome is a medical emergency that must be quickly diagnosed and treated to avoid long-term complications. Cauda equina syndrome typically presents with low back pain, unilateral or usually bilateral sciatica, saddle sensory disturbances, bladder and bowel dysfunction, and variable lower extremity motor and sensory loss. Although a number of pathologies can cause cauda equina syndrome, in a patient with a history of chronic back pain, disk pathology is the most common cause of acute onset cauda equina syndrome. Whereas radiographs may be useful in a traumatic onset of symptoms, MRI is the most appropriate study. Cauda equina syndrome should be evaluated on an emergent basis and admission for work-up is appropriate. Ahn UM, Ahn NU, Buchowski JM, et al: Cauda equina syndrome secondary to lumbar disc herniation: A meta-analysis of surgical outcomes. Spine 2000;25:1515-1522.

It is generally accepted that reconstructions of the proximal tibia are associated with the highest incidence of failure, probably because of poor soft-tissue coverage, the need for extensor mechanism reconstruction, and other anatomic issues. It also may be related to the fact that patients with tumors of the proximal tibia, in general, have a better prognosis and better survival rates than patients with tumors located elsewhere in the body. Reconstructions of the proximal humerus may be more durable because they are not involved in weight-bearing activities.

Elastofibroma is a rare tumor that most commonly occurs in adults who are older than age 55 years. The lesions usually grow between the chest wall and the scapula, and 10% are bilateral. Histologic analysis shows that they are composed of equal amounts of elastin and collagen with occasional fibroblasts. Briccoli A, Casadei R, Di Renzo M, Favale L, Bacchini P, Bertoni F: Elastofibroma dorsi. Surg Today 2000;30:147-152.

The average location of the anterior portal is 6.3 cm distal to the anterior superior iliac spine. The lateral femoral cutaneous nerve typically has divided into three or more branches at the level of the anterior portal. The portal usually passes within several millimeters of the most medial branch. Injury to the nerve can lead to meralgia paresthetica. The femoral nerve lies an average minimum distance of 3.2 cm from the anterior portal. The ascending branch of the lateral circumflex artery lies approximately 3.7 cm inferior to the anterior portal. Neither the ascending branch of the medial circumflex artery nor the superior gluteal nerve are at risk. Byrd JWT: Operative Hip Arthroscopy. New York, NY, Thieme Medical Publishers, 1998, pp 83-91.

Pitchers tend to have a decrease in internal rotation and an increase in external rotation. The increase in external rotation is felt to be multifactorial. An increase in humeral retroversion occurs from repeated throwing. This results in increased soft-tissue stretching and results in a posterior capsular contracture. Meister K, Buckley B, Batts J: The posterior impingement sign: Diagnosis of rotator cuff and posterior labral tears secondary to internal impingement in overhand athletes. Am J Orthop 2004;33:412-415.

Microvascular studies have shown that the majority of the blood supply to the cruciate ligaments comes from the middle geniculate artery, although there is collateral flow through the other geniculates and from bone. Arnoczky SP: Blood supply to the anterior cruciate ligament and supporting structures. Orthop Clin North Am 1985;16:15-28.

Compression plating remains the treatment of choice for most established humeral nonunions. Autograft is felt to be superior to allograft. Electrical stimulation has not been found to improve healing rates in patients with nonunion after intramedullary nailing. Retrograde nailing with flexible nails gives inadequate rotational control to promote healing in this patient. Adding cancellous graft alone will not stabilize the nonunion site. Dynamic locking has been successful only in the lower extremity because the bone can be loaded axially. McKee MD, Miranda MA, Riemer BL, et al: Management of humeral nonunion after the failure of locking intramedullary nails. J Orthop Trauma 1996;10:492-499.

The Canale view, which visualizes the talar neck, is taken with the ankle in maximum plantar flexion and the foot pronated 15 degrees. The radiograph is directed at a 75 degree angle from the horizontal plane in the anteroposterior plane. The Broden view, which is different from the Canale view, is best for imaging the posterior facet of the subtalar joint. Canale ST, Kelly FB Jr: Fractures of the neck of the talus: Long-term evaluation of seventy-one cases. J Bone Joint Surg Am 1978;60:143-156.

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.

Fatigue from repetitive loading of the stem with the distal aspect well-fixed resulted in stem failure. If the stem had loosened, it would not have broken. Crevice corrosion occurs at a taper interface; galvanic corrosion occurs at the junction of two metals of differing electrochemical potentials, not along a uniform portion of the implant. Simon SR (ed): Orthopaedic Basic Science. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 449-486.

Transfer of the flexor digitorum longus tendon is a common technique combined with other procedures to treat patients with posterior tibial tendon insufficiency. However, it is contraindicated in patients with a fixed hindfoot deformity, hypermobility, or neuromuscular compromise. It is relatively contraindicated in patients who are obese, and those older than age 60 to 70 years. Pedowitz WJ, Kovatis P: Flatfoot in the adult. J Am Acad Orthop Surg 1995;3:293-302.

The MRI scan reveals a laceration through the abductor hallucis musculature and lateral plantar nerve, producing numbness along its distribution. There is no evidence of a foreign body on the MRI scan. Baxter's nerve, or nerve to the abductor digiti quinti muscle, is the first branch off the lateral plantar nerve and impingement of this nerve typically produces a Tinel's sign along the nerve branch deep to the abductor hallucis muscle. Interdigital neuroma would be suggested by the presence of a Mulder's click. A digital nerve laceration would exhibit isolated numbness more distally. Baxter DE, Pfeffer GB: Treatment of chronic heel pain by surgical release of the first branch of the lateral plantar nerve. Clin Orthop Relat Res 1992;279:229-236.

This is a nonplantigrade deformity in a patient with a Charcot foot deformity. Longitudinal studies have shown that recurrent ulceration/infection is likely unless the deformity is corrected. Achilles tendon lengthening is advised for simple forefoot ulcers. The current approach to this problem is best managed with surgical correction of the deformity, Achilles tendon lengthening, and therapeutic footwear. Bevan WP, Tomlinson MP: Radiographic measures as a predictor of ulcer formation in diabetic charcot midfoot. Foot Ank Int 2008;29:568-573. Simon SR, Tejwani SG, Wilson DL, et al: Arthrodesis as an early alternative to nonoperative management of Charcot arthropathy of the diabetic foot. J Bone Joint Surg Am 2000;82:939-950.

Very large corrections of tibial deformity can be achieved at or just below the tibial tubercle. This level of osteotomy maintains the relationship between the tubercle and the rest of the joint, does not alter patellofemoral mechanics, and avoids complicating possible future conversion to total knee arthroplasty. High tibial osteotomy is contraindicated for large corrections because of excessive elevation of the tibial tubercle and overhang of the lateral plateau. Correction in the tibial diaphysis creates a zig zag pattern in the tibia by correcting below the deformity and risks nonunion in cortical bone. There is no evidence that the femur is deformed; therefore, femoral osteotomy is not indicated.

High-level pitchers with symptomatic UCL tears require reconstruction, with autograft being the best studied graft selection. With concomitant ulnar nerve symptoms, a simultaneous ulnar nerve transposition provides good results. Ligament "repairs" and allograft reconstructions have not shown good long-term results. Azar FM, Andrews JR, Wilk KE, et al: Operative treatment of ulnar collateral ligament injuries of the elbow in athletes. Am J Sports Med 2000;28:16-23.

Zirconia as a bearing surface is "metastable," meaning that, in the microstructure of the material the zirconia molecules are ordered in a tetragonal fashion, but they can easily transform to a monoclinic microstructure that is less wear resistant. Transformation can occur with input of enough energy (eg, thermal energy imparted by steam sterilization or mechanical energy at the bearing surface). Zirconia was introduced as an alternative to alumina because it has a higher toughness, making it less susceptible to gross fracture (ceramics do not undergo fatigue fracture, but rather fail from a process of slow crack growth). Zirconia is highly biocompatible (as are many ceramics) and is essentially immune to corrosive processes that can plague metallic alloys such as stainless steel. Clarke IC, Manaka M, Green DD, et al: Current status of zirconia used in total hip implants. J Bone Joint Surg Am 2003;85:73-84. Haraguchi K, Sugano N, Nishii T, et al: Phase transformation of a zirconia ceramic head after total hip arthroplasty. J Bone Joint Surg Br 2001;83:996-1000.

The risk of synostosis is imminent with any technique for repairing a distal biceps tendon rupture. However, the risk is quite low for all approaches that avoid exposure of the ulna, including the muscle-splitting two-incision technique.

Excision of the fracture fragment typically leads to rapid return to function. Fixation techniques are difficult to perform because of the size of the bone; hardware prominence is common. Nerve deficits are not typically noted in this injury. The motor branch of the ulnar nerve in Guyon's canal must be protected during the surgical approach. Kulund DN, McCue FC III, Rockwell DA, et al: Tennis injuries: Prevention and treatment: A review. Am J Sports Med 1979;7:249-253.

The history and physical examination are consistent with a monoarticular joint condition but not typical of joint sepsis. The arthroscopic appearance of brownish proliferative synovium is typical of PVNS. PVNS is a monoarticular synovial disease of unknown etiology and is treated with total synovectomy. The proliferative synovitis is not consistent with chondromalacia. Synovial cell sarcoma is an extracapsular disease. Rheumatoid arthritis typically is polyarticular, and the synovial appearance is not associated with hemosiderin deposition. Flandry FC, Hughston JC, Jacobson KE, Barrack RL, McCann SB, Kurtz DM: Surgical treatment of diffuse pigmented villonodular synovitis of the knee. Clin Orthop 1994;300:183-192.

Incomplete cord syndromes have variable neurologic findings with partial loss of sensory and/or motor function below the level of injury. Incomplete cord syndromes include the anterior cord syndrome, the Brown-Séquard syndrome, central cord syndrome, and posterior cord syndrome. Central cord syndrome is characterized with greater motor weakness in the upper extremities than in the lower extremities. The pattern of motor weakness shows greater distal involvement in the affected extremity than proximal muscle weakness. Anterior cord syndrome involves a variable loss of motor function and pain and/or temperature sensation, with preservation of proprioception. The Brown-Séquard syndrome involves a relatively greater ipsilateral loss of proprioception and motor function, with contralateral loss of pain and temperature sensation. Posterior cord syndrome is a rare injury and is characterized by preservation of motor function, sense of pain, and light touch, with loss of proprioception and temperature sensation below the level of the lesion. Spinal shock is the period of time, usually 24 hours, after a spinal injury that is characterized by absent reflexes, flaccidity, and loss of sensation below the level of the injury. Penrod LE, Hegde SK, Ditunno JF: Age effect on prognosis for functional recovery in acute, traumatic central cord syndrome. Arch Phys Med Rehab 1990;71:963-968.

Studies have shown that when compared with fixation to the sacrum alone, the success rate of fusion across the lumbosacral junction increases when both the sacrum and ilium are included in the posterolateral construct. Curve correction, coronal balance, and pelvic balance are all attended to within the thoracolumbar spine and are not directly related to the pelvic fixation. Fretting and corrosion are a byproduct of metal-to-metal connections. Islam NC, Wood KB, Transfeldt EE, et al: Extension of fusions to the pelvis in idiopathic scoliosis. Spine 2001;26:166-173.

The patient has the classic signs of Little Leaguer's shoulder, with findings that include pain localized to the proximal humerus during the act of throwing and radiographic evidence of widening of the proximal humeral physis. Examination usually reveals tenderness to palpation over the proximal humerus, but the presence of any swelling, weakness, atrophy, or loss of motion is unlikely. The treatment of choice is rest from throwing for at least 3 months, followed by a gradual return to pitching once the shoulder is asymptomatic. Carson WG Jr, Gasser SI: Little Leaguer's shoulder: A report of 23 cases. Am J Sports Med 1998;26:575-580.

Although the degeneration of an isolated benign cartilaginous lesion into a chondrosarcoma is rare, it occurs in roughly 10% of patients with Ollier's disease. Pain is the most common symptom of chondrosarcoma. The treatment of low-grade chondrosarcoma ranges from intralesional excision to wide amputation. The intent of the surgery is to remove all the disease to decrease the chance of local recurrence. Lee FY, Mankin HJ, Fondren G, et al: Chondrosarcoma of bone: An assessment of outcome. J Bone Joint Surg Am 1999;81:326-338.

A calcaneal deformity of the foot may occur in children who have low lumbar myelomeningocele. Strong dorsiflexors overcome a weak or absent gastrocnemius-soleus complex, leading to downward growth of the calcaneal apophysis. The deformity is usually progressive and does not respond to nonsurgical management. Most authorities recommend transfer of the tibialis anterior muscle through the interosseous membrane to the posterior aspect of the calcaneus. This procedure has been reported to be effective in limiting progression of the deformity. An extra-articular subtalar arthodesis, a treatment option for valgus deformity of the hindfoot, is not indicated. Similarly, Achilles tendon tenodesis to the fibula, an option for managing valgus of the ankle, is not indicated. Calcaneal osteotomy may be used in older children with severe calcaneal deformity. Stott NS, Zionts LE, Gronley JK, Perry J: Tibialis anterior transfer for calcaneal deformity: A postoperative gait analysis. J Pediatr Orthop 1996;16:792-798.

Surgical margins are classified according to the plane of dissection in relation to the tumor. An intralesional procedure is where the plane of dissection passes through the tumor. A marginal resection involves a resection where the plane of dissection is through the reactive zone of the tumor. A wide resection is through completely normal tissue outside of the reactive zone. A radical resection removes all of the muscles and/or bone of the compartment that are involved by the tumor.

Humeral arthroplasty is indicated for chronic posterior dislocations when the impression defect in the humeral head is greater than 45% to 50%. If the condition remains undiagnosed for more than 9 to 12 months, secondary degenerative changes on the glenoid may occur, necessitating total shoulder arthroplasty. Open reduction and transfer of the subscapularis and lesser tuberosity are used for impression defects that consist of 20% to 40% of the humeral articular surface. Closed reduction and immobilization with the arm in slight extension and external rotation is useful when the posterior dislocation is diagnosed within the first 6 weeks and the articular defect is less than 20%. Hawkins RJ, Neer CS II, Pianta RM, Mendoza FX: Locked posterior dislocation of the shoulder. J Bone Joint Surg Am 1987;69:9-18.

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

The clinical result in this patient has been good, with no dislocations, suggesting that the components are in reasonably good position. The radiograph and examination at the time of surgery suggest that the acetabular component is well fixed. The surrounding bone of the acetabulum is osteopenic and there would most likely be considerable bone loss if the acetabular component is removed. Access to the osteolytic lesions is possible. Cementing an acetabular component into the retained socket will cause the least amount of bone loss, shorten the procedure, and most likely result in a functional hip. Maloney WJ: Socket retention: Staying in place. Orthopedics 2000;23:965-966.

The photograph shows the characteristic attitude of the hand when an anterior interosseous nerve palsy is present. The patient is unable to flex the interphalangeal joint to the joint of the thumb. Anterior interosseous nerve palsies are often misdiagnosed as tendon ruptures. Schantz K, Reigels-Nielsen P: The anterior interosseous nerve syndrome. J Hand Surg Br 1992;17:510-512.

Patients with diabetes mellitus should be screened for the presence of protective foot sensation. In the absence of protective foot sensation, patients are at increased risk for the development of neuropathic ulcerations and neuropathic arthropathy. The most reliable screening tool for the presence of protective sensation is the ability to feel the 5.07 Semmes-Weinstein monofilament. Pinzur MS, Shields N, Trepman E, Dawson P, Evans A: Current practice patterns in the treatment of Charcot foot. Foot Ankle Int 2000;21:916-920.

Synovectomy of the knee prior to loss of articular cartilage has been shown to consistently relieve pain in patients with rheumatoid arthritis. Partial knee replacement will not arrest the process of joint destruction. Osteotomy of the hip has not been found to be a successful procedure in patients with rheumatoid arthritis. Hip arthrodesis should not be considered because of the multiarticular involvement in patients with rheumatoid arthritis. Core decompression of the hip has not been shown to save the femoral head because the necrosis appears to occur simultaneously with the inflammatory joint process. Granberry WM, Brewer EJ Jr: Early surgery in juvenile rheumatoid arthritis, in Calundruccio RA (ed): Instructional Course Lectures XXIII. St Louis, MO, CV Mosby, 1974, pp 32-37.

Patellar problems currently constitute the largest number of complications after total knee arthroplasty, affecting between 8% and 35% of patients. These problems include patellar instability, fracture, component loosening, surface erosion, and pain. Malalignment, as an isolated reason for revision, is uncommon, yet it contributes to accelerated wear of the components. Joint instability affects up to 6% of patients, and the infection rate in knee arthroplasty is around 1% to 2%. Blasier RB, Matthews LS: Complications of prosthetic knee arthroplasty, in Epps CH (ed): Complications in Orthopaedic Surgery. Philadelphia, PA, JP Lippincott, 1994, pp 1066-1069. Rand JA: The patellofemoral joint in total knee arthroplasty. J Bone Joint Surg Am 1994;76:612-620.

The patient has a chronic unrecognized volar lunate dislocation. Median nerve compression is the result of the lunate displaced into the carpal tunnel. The diagnosis can be made by radiographs; MRI is not necessary. A volar approach allows median nerve decompression with excision of the lunate, whereas a dorsal approach facilitates excision of the scaphoid and triquetrum. Rettig ME, Raskin KB: Long-term assessment of proximal row carpectomy for chronic perilunate dislocations. J Hand Surg Am 1999;24:1231-1236.

The MRI scan reveals a full-thickness rotator cuff tear with retraction and increased signal in the subacromial space indicating joint fluid. Herzog RJ: Magnetic resonance imaging of the shoulder. Instr Course Lect 1998;47:3-20.

The motorized shaver is adjacent to the acetabular labrum, which is torn. The femoral head and acetabulum are normal in appearance. Neither the fat pad nor a loose body is identified.

The rate of wound complications is significantly increased after total knee arthroplasty in obese patients. Knee scores and the rate of aseptic loosening or patellar subluxation do not appear to be significantly altered. Winiarsky R, Barth P, Lotke P: Total knee arthroplasty in morbidly obese patients. J Bone Joint Surg Am 1998;80:1770-1774. Stern SH, Insall JN: Total knee arthroplasty in obese patients. J Bone Joint Surg Am 1990;72:1400-1404.

The patient has a chronic unrecognized volar lunate dislocation. Median nerve compression is the result of the lunate displaced into the carpal tunnel. The diagnosis can be made by radiographs; MRI is not necessary. A volar approach allows median nerve decompression with excision of the lunate, whereas a dorsal approach facilitates excision of the scaphoid and triquetrum. Rettig ME, Raskin KB: Long-term assessment of proximal row carpectomy for chronic perilunate dislocations. J Hand Surg Am 1999;24:1231-1236.

Mortality following trauma that requires surgical intervention for head, chest, and abdominal injury exceeds 90%. The type of pelvic fracture is a predictor of associated injury, blood requirements, and overall mortality. AP III pelvic fractures require the most blood, and are associated with significant abdominal trauma and shock. Lateral compression pelvic fractures are more associated with head, chest, and occasionally abdominal trauma, and mortality often occurs from associated injuries. Dalal SA, Burgess AR, Siegel JH, et al: Pelvic fracture in multiple trauma: Classification by mechanism is key to pattern of organ injury, resuscitative requirements and outcome. J Trauma 1989;29:981-1000. Eastridge BJ, Burgess AR: Pedestrian pelvic fractures: 5-year experience of a major urban trauma center. J Trauma 1997;42:695-700.

Unopposed action of the tibialis anterior with weakness of the peroneus longus will lead to a dorsal bunion and supination deformity. Overpull of the gastrocnemius-soleus complex and posterior tibialis with weakness of the peroneus brevis will cause equinovarus deformity. A strong posterior tibialis with weakness of the peroneals will cause varus of the hindfoot. Unopposed peroneus brevis and incompetence of the posterior tibialis will lead to a flatfoot deformity. The etiology of a cavus foot is complex, but findings usually include a contracted plantar fascia and weakness of the tibialis anterior. Drennan JC (ed): The Child's Foot and Ankle. New York, NY, Raven Press, 1992, pp 289-302.

The semitendinosus and gracilis tendons lie beneath the superficial fascia and superficial to the medial collateral ligament. The semitendinosus is located more inferior to the gracilis tendon. The sartorius is more posterior and distal as is the medial collateral ligament. The semimembranosus is posterior. Pagnani MJ, Warner JJ, O'Brien SJ, Warren RF: Anatomic considerations in harvesting the semitendinosus and gracilis tendons and a technique of harvest. Am J Sports Med 1993;21:565-571.

In patients older than age 40 years, a high suspicion of a rotator cuff tear should be kept in those patients with weakness after shoulder dislocation. Both posterior rotator cuff and subscapularis injuries have been documented. The next most appropriate step in management should be MRI. If the findings are negative, suspicion of nerve injury should lead to electromyography. Stayner LR, Cumming J, Andersen J, et al: Shoulder dislocations in patients older than 40 years of age. Orthop Clin North Am 2000;31:231-239.

The pathology demonstrates a very cellular chondroid matrix with multinucleated forms, atypia, and myxomatous regions. This is most consistent with a myxoid chondrosarcoma. The radiograph shows a well-circumscribed lesion in the superior and medial aspect of the right acetabulum. The CT and MRI scans confirm these same findings with no evidence of matrix mineralization or significant surrounding edema. Unfortunately, in this location with this appearance, the radiographic differential diagnosis includes all the diagnoses listed. Terek RM: Recent advances in the basic science of chondrosarcoma. Orthop Clin North Am 2006;37:9-14. Donati D, El Ghoneimy A, Bertoni F, et al: Surgical treatment and outcome of conventional pelvic chondrosarcoma. J Bone Joint Surg Br 2005;87:1527-1530.

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.

Because the radiograph shows that the femoral stem is loose within the femoral canal and there is a fracture in the distal cement mantle, the stem should be revised. The Ogden-type plate and the allograft bone plates will reconstruct the femur but will not restore stability to the stem. Similarly, traction may allow the femur to heal but will not restore stability to the femoral stem within the femur. Resection arthroplasty is considered a salvage option following failure of the other procedures. Lewallen DG, Berry DJ: Periprosthetic fracture of the femur after total hip arthroplasty: Treatment and results to date, in Cannon WD Jr (ed): Instructional Course Lectures 47. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 243-249.

During osteolysis, IL-6 is secreted by fibroblasts in the membrane surrounding the prosthesis. IL-6 also can be secreted by osteoblasts in other settings, but they are not the predominant source of IL-6 in particle-induced osteolysis. The remaining cells are not major sources of IL-6.

The deformity is long-standing, the hindfoot is immobile, and the radiographs reveal severe degenerative arthritis involving the entire hindfoot, severe deformity, and talonavicular dislocation. The "exostosis" responsible for the callus is the talar head; resection would severely destabilize the foot. Degenerative arthritis and fixed deformity preclude lateral column lengthening, medial slide calcaneal osteotomy, and talonavicular arthrodesis. Triple arthrodesis is the only viable option. Johnson JE, Yu JR: Arthrodesis techniques in the management of Stage II and III acquired adult flatfoot deformity. Instr Course Lect 2006;55:531-542.

The MRI scan shows a massive tear of the supraspinatus tendon with medial retraction to the level of the glenoid. This is most likely an attritional tear with a high risk of failure of the repair. The preferred treatment is nonsurgical management for pain and stiffness. Acromioplasty and coracoacromial ligament release in this setting are controversial, as they can result in the devastating complication of anterosuperior subluxation of the humerus. Rockwood CA Jr, Williams GR Jr, Burkhead WZ Jr: Debridement of degenerative, irreparable lesions of the rotator cuff. J Bone Joint Surg Am 1995;77:857-866.

The structure labeled "A" is a peroneus quartus, a supernumary muscle arising most commonly from the peroneus brevis. The presence of peroneus quartus is not uncommon, with an incidence of up to 21%, and is associated with lateral ankle pain and peroneal tendon symptoms, theoretically as a result of mass effect within the peroneal tendon sheath. Zammit J, Singh D: The peroneus quartus muscle: Anatomy and clinical relevance. J Bone Joint Surg Br 2003;85:1134-1137.

Cotler and associates reported on the use of awake skeletal traction to reduce facet fracture-dislocations in 24 patients. Seventeen patients required more than 50 pounds of traction (the "traditional" limit) to achieve reduction. More than 100 pounds of traction was safely used in one-third of the patients in this study. A cadaver study has supported the safe use of traction with weights in excess of 100 pounds. Cotler JM, Herbison GJ, Nasuti JF, et al: Closed reduction of traumatic cervical spine dislocation using traction weights up to 140 pounds. Spine 1993;18:386-390.

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

The patient has sustained a low-velocity, low-caliber gunshot wound to the foot. Because the injury occurred within a period of 8 hours, this is classified as a type I wound. Several studies support the use of surface debridement, cleansing, and sterile dressings as the treatment of choice. More aggressive measures are reserved for high-velocity injuries and shotgun injuries. Brettler D, Sedlin ED, Mendes DG: Conservative treatment of low velocity gunshot wounds. Clin Orthop 1979;140:26-31. Hampton OD: The indications for debridement of gunshot bullet wounds of the extremities in civilian practice. J Trauma 1961;1:368-372.

Indications for surgery in spinal infections include progressive destruction despite antibiotic treatment, an abscess requiring drainage, neurologic deficit, need for diagnosis, and/or instability. This patient has a progressive neurologic deficit. Debridement performed at the site of the abscess should effect canal decompression. Once the debridement is complete back to viable bone, the defect can be reconstructed with a strut graft. Additional posterior stabilization is used as deemed necessary by the degree of anterior destruction. CT-guided needle aspiration, while occasionally useful in the earliest phases of an infection, produces frequent false-negative results and would provide little useful information in the management of this patient. Emery SE, Chan DP, Woodward HR: Treatment of hematogenous pyogenic vertebral osteomyelitis with anterior debridement and primary bone grafting. Spine 1989;14:284-291. Lifeso RM: Pyogenic spinal sepsis in adults. Spine 1990;15:1265-1271.

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.

The patient has a stress fracture of the olecranon; therefore, the most appropriate management is modification of activities below the threshold of symptoms to allow for healing. Ultrasound provides no benefit, and immobilization is not necessary. MRI is not necessary because there is no associated ligamentous injury. Arthroscopy is not indicated. Cabanela ME, Morrey BF: Fractures of the olecranon, in Morrey BF (ed): The Elbow and Its Disorders. Philadelphia, PA, WB Saunders, 2000, pp 365-379.

The patient has a single-level deficit by clinical examination but an adjacent level that may be pathologic. Hilibrand and associates, in a review of 374 patients with myeloradiculopathy treated with single-level or multilevel anterior cervical diskectomy and fusion, showed that 25% of patients had an occurrence of new radiculopathy or myelopathy at an adjacent level within 10 years after surgery. Reoperation rates were highest in those patients where the adjacent nonfused segment was C5-6 or C6-7. Those patients who had multilevel fusions had a lower incidence of adjacent segment disease. The authors recommended incorporating an adjacent level in the initial procedure in patients with myelopathy or radiculopathy when significant disease was noted. Posterior keyhole foraminotomy is an excellent procedure for single-level radiculopathy but is not effective in relieving myelopathy. Anterior cervical diskectomy without fusion has an increased incidence of hypermobility and neck pain on long-term follow-up. In a later review, these authors reported improved fusion rates and better clinical outcomes with the use of strut fusions instead of multilevel interbody grafts. Hilibrand AS, Carlson GD, Palumbo MA, Jones PK, Bohlman HH: Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrodesis. J Bone Joint Surg Am 1999;81:519-528. Henderson CM, Hennessy RG, Shuey HM Jr, Shackelford EG: Posterior-lateral foraminotomy as an exclusive operative technique for cervical radiculopathy: A review of 846 consecutively operated cases. Neurosurgery 1983;13:504-512.

Over the past three decades, gamma irradiation and air has been the most common method of sterilizing polyethylene used in total joint arthroplasty. This method of sterilization results in breakage of the chemical bonds within the polymer. While this promotes cross-linking, it also leaves the polyethylene vulnerable to oxidation, especially if packaged in an air environment. Oxidation has been shown to decrease polyethylene's molecular weight, ultimate tensile strength, elongation, and toughness which results in a stiffer, more brittle material that is less resistant to wear. Severity of oxidation and a decrease in mechanical properties have been shown to be related to the length of time that the component is exposed to air (the shelf life). Currier and associates studied the clinical performance of gamma irradiated in air polyethylene components that had been shelf aged. They demonstrated that for the first 5 years of shelf life, polyethylene oxidized rather slowly. However, polyethylene components with a shelf life of more than 5 years would be expected to have minimal mechanical toughness and would likely fail rapidly if implanted. Bohl and associates evaluated 135 patients who had undergone total knee arthroplasty. Survivorship at 5 years was 100% for components with a shelf life of less than 4 years, 89% for components with a shelf life of 4 to 8 years, and 79% for components with a shelf life of more than 8 years. Sychterz and associates reported no correlation between shelf life and true wear rates for components with a shelf life of less than 3 years. In summary, both in vivo and in vitro data suggest that shelf life in excess of 3 to 5 years has a direct effect on wear of polyethylene. Currier BH, Currier JH, Collier JP, et al: Shelf life and in vivo duration: Impacts on performance of tibial bearings. Clin Orthop 1997;342:111-122. Bohl JR, Bohl WR, Postak PD, et al: The Coventry Award: The effects of shelf life on clinical outcome for gamma sterilized polyethylene tibial components. Clin Orthop 1999;367:28-38.

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.

Urbaniak and Harvey reported donor site morbidity following free vascularized fibular graft in 198 consecutive patients. At a 5-year follow-up, they reported overall complications in 24% of the patients. The most common complication was a sensory deficit (11.8%), followed by motor weakness (2.7%), flexor hallucis longus contracture (2%), and deep venous thrombosis (less than 1%).

The humerus was treated with an intramedullary nail. Findings from two prospective randomized studies of intramedullary nailing or compression plating of acute humeral fractures have shown approximately a 30% incidence of shoulder pain with antegrade humeral nailing. This is the most common complication in both of these series. Nonunions are present in approximately 5% to 10% of humeral fractures treated with an intramedullary nail. Infection has an incidence of approximately 1%. Elbow injury is unlikely unless the nail is excessively long. Rarely, injury to the radial nerve is possible if it is trapped in the intramedullary canal. Chapman JR, Henley MB, Agel J, et al: Randomized prospective study of humeral shaft fracture fixation: Intramedullary nails versus plates. J Orthop Trauma 2000;14:162-166.

The radiographs show a significant loss of the proximal anterior tibial cortex, consistent with an extensively damaged or deficient extensor mechanism. Such a deficit precludes insertion of another knee arthroplasty. Arthrodesis is the treatment of choice for this patient and is indicated for loss of the extensor mechanism and knee instability. A recent report on arthrodesis following removal of an infected prosthesis showed a union rate of 91% using a short intramedullary nail. Insertion of an antibiotic-impregnated PMMA spacer is not indicated because the rationale for using a spacer is to maintain a space for reinsertion of another prosthesis. Reconstruction of the extensor mechanism would not address the loss of the joint. Amputation is the final treatment option if the arthrodesis fails. Rand JA: Alternatives to reimplantation for salvage of the total knee arthroplasty complicated by infection. J Bone Joint Surg Am 1993;75:282-289. Lai KA, Shen WJ, Yang CY: Arthrodesis with a short Huckstep nail as a salvage procedure for failed total knee arthroplasty. J Bone Joint Surg Am 1998;80:380-388.

There is a spectrum of heat-related conditions. Heat cramps are the mildest form of heat illness. In heat exhaustion, cramps are associated with headache and weakness, and the skin is pale and moist. Treatment of heat cramps or heat exhaustion consists of removing and loosening excess clothing, applying ice to the axilla and groin, ingestion of cool water, and cool water sprays. This patient demonstrates symptoms of heat stroke which is a medical emergency. The core body temperature may be as high as 106 to 110 degrees F (41.1 to 43.3 degrees C). In heat stroke, the patient may no longer be sweating, and the skin may be hot and red. The athlete is usually confused, weak, nauseated, and may have seizure activity. Central nervous system depression has been called the most important marker of heat stroke, and progresses from confusion and bizarre behavior to collapse, delirium, and coma. Bizarre behavior is often the first sign of heat stroke. The patient needs to be treated and moved to a medical facility rapidly. During transfer, IV fluids and cooling of the athlete should be initiated. The best treatment of heat-related illness appears to be prevention with adequate hydration and monitoring of conditions (temperature and humidity), with cancellation of competition when conditions do not comply with guidelines. Griffin LY: Emergency preparedness: Things to consider before the game starts. J Bone Joint Surg Am 2005;87:894-902. Barker TA, Motz HA, Gersoff WK: Environmental factors in athletic performance, in Fu FH, Stone DA (eds): Sports Injuries, ed 2. Philadelphia, PA, Lippincott, 2001, pp 67-68.

Because the patient has a transverse midshaft fracture with no evidence of comminution, the treatment of choice is closed reduction and stabilization with flexible intramedullary nails. Transverse fractures treated with an external fixator heal with poor callus and have a high refracture rate. In addition, the pin tracks produce undesirable and excessive scarring. Femoral pin traction is safe and effective but results in considerable muscle wasting and a slow return to function. Interlocking nails run the risk of greater trochanteric growth disturbance and/or osteonecrosis of the femoral head in this age group. Plate fixation, while effective, requires considerable tissue dissection with large scar formation. It also requires a rather extensive dissection for later plate removal. Ligier JN, Metaizeau JP, Prevot J, Lascombes P: Elastic stable intramedullary nailing of femoral shaft fractures in children. J Bone Joint Surg Br 1988;70:74-77.

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.

Dislocation of the long head of the biceps tendon is the result of a defect in the region of the rotator cuff interval, coracohumeral ligament-superior glenohumeral ligament pulley, or an associated tear of the medial insertion of the subscapularis tendon. In the case of an intra-articular dislocation of the long head of the biceps tendon associated with a tear of the subscapularis tendon, stabilization of the biceps tendon is difficult in this situation; therefore, biceps release or tenodesis and repair of the subscapularis tendon is the treatment of choice. Eakin CL, Faber KJ, Hawkins RJ, et al: Biceps tendon disorders in athletes. J Am Acad Orthop Surg 1999;7:300-310. Sethi N, Wright R, Yamaguchi K: Disorders of the long head of the biceps tendon. J Shoulder Elbow Surg 1999;8:644-654.

In the design of tibial and femoral components, a compromise must be made between contact stresses and constraint. Increased conformity increases constraint, limits motion, and potentially increases stress on the knee-cement interface. By increasing conformity, the surface area over which force is applied is increased, resulting in decreased peak contact stresses and decreased component wear rates. 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 265-274.

Congenital anomalies of the spine, including failure of formation and failure of segmentation, are associated with other anomalies in other organ systems that develop at the same time. These include anomalies in the genitourinary system, cardiac anomalies, Sprengel's deformity, radial hypoplasia, and gastrointestinal anomalies including imperforate anus and trachealesophageal fistula. Spinal dysraphism is the most common associated abnormality. McMaster found an 18% incidence before the common use of MRI. Bradford and associates reported on 16 of 42 patients with congenital spinal anomalies and spinal dysraphism using MRI. Neural axis lesions may be associated with visible midline abnormalities such as a hairy patch or nevus. The child has already had a cardiac and renal work-up, and based on the findings of the hairy patch and congenital vertebral anomalies, MRI of the entire spine is prudent at this time. Spinal fusion is indicated for progressive congenital scoliosis or kyphosis. Physical therapy does not affect the natural history of congenital scoliosis. McMaster MJ: Occult intraspinal anomalies and congenital scoliosis. J Bone Joint Surg Am 1984;66:588-601. Bradford DS, Heithoff KB, Cohen M: Intraspinal abnormalities and congenital spine deformities: A radiographic and MRI study. J Pediatr Orthop 1991;11:36-41.

The modified Hardinger approach includes a partial anterior trochanteric osteotomy creating a trochanteric wafer (as seen on the radiograph) that is displaced anterior and medial in continuity with the gluteus medius and vastus lateralis. Failure of abductor reattachment, migration of the trochanter, nonunion of the osteotomy site, and excessive splitting of the gluteus medius muscle causing injury to the inferior branch of the superior gluteal nerve can result in weakness of the abductor mechanism. Abductor strength should be evaluated with the patient lying on the opposite side and elevating the affected limb. Although slight weakness may manifest itself as a limp only after prolonged muscular activity, significant weakness results in a constant limp without associated discomfort. Morrey BF (ed): Joint Replacement Arthroplasty. New York, NY, Churchill Livingstone, 1991, pp 512-526.

The first step in the treatment of an amputation residual limb (stump) ulcer is local wound care and adjustment of the residual limb-prosthetic interface, as well as adjusting prosthetic alignment. Surgical revision should be undertaken only when prosthetic modification is unsuccessful. Murnaghan JJ, Bowker JH: Musculoskeletal complications, in Smith DG, Michael JW, Bowker JH (eds): Atlas of Amputations and Limb Deficiencies, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 683-700.

The patient has a valgus-supination triple arthrodesis malunion. Weight-bearing radiographs show excessive residual valgus through the subtalar joint, producing lateral subfibular impingement, and residual forefoot abduction and midfoot supination through the talonavicular joint, lateralizing the weight-bearing forces through the foot. The deformity is best managed with a medial displacement calcaneal osteotomy and transverse tarsal derotational osteotomy. Ankle arthroscopy and lateral ligament reconstruction are indicated in the event of ligament instability. Tendon transfer, lateral column lengthening, and heel cord lengthening are used for treatment of adult flatfoot from posterior tibial tendon insufficiency. Ankle arthrodesis and ankle arthroplasty are not indicated in this patient because the lateral ankle symptoms are the result of the underlying deformity in the hindfoot, the patient is young, and the ankle joint is relatively normal. Haddad SL, Myerson MS, Pell RF IV: Clinical and radiographic outcome of revision surgery for failed triple arthrodesis. Foot Ankle Int 1997;18:489-499.

Hypophosphatemia is a rare genetic disease usually inherited as an X-linked dominant trait. The fact that the woman has no skeletal manifestations would indicate that the husband has the X-linked mutation. The disease is more severe in boys than it is in girls. The husband will not transmit the disease to his sons. However, all of their daughters will be affected either with the disease or as carriers. If the woman has the disease or the trait, there is a 50% chance that her sons will inherit the disease and a 50% chance that her daughters will be carriers or have a milder form of the disease. Parents should be advised to have genetic counseling so they can be informed when deciding whether to have children. Herring JA: Metabolic and endocrine bone diseases, in Tachdjian's Pediatric Orthopaedics, ed 3. New York, NY, WB Saunders, 2002, pp 1685-1743. Sillence DO: Disorders of bone density, volume, and mineralization, in Rimoin DL, Conner JM, Pyerite RE, et al (eds): Principles and Practice of Medical Genetics, ed 4. New York, NY, Churchill Livingstone, 2002.

The MRI scans reveal a meso os acromiale with edema at the site in a skeletally mature patient. Sher JS: Anatomy, biomechanics, and pathophysiology of rotator cuff disease, in Iannotti JP, Williams GR (eds): Disorders of the Shoulder: Diagnosis and Management. Philadelphia, PA, Lippincott Williams & Wilkins, 1999, p 23.

The radiographs show classic hinge abduction. The diagnostic feature is the failure of the lateral epiphysis to slide under the acetabular edge with abduction, and the abduction view shows medial dye pooling because of distraction of the hip joint. Persistent hinge abduction has been shown to prevent femoral head remodeling by the acetabulum. Radiographic changes are characteristic of severe involvement with Legg-Calve-Perthes disease.The Catterall classification cannot be well applied without a lateral radiograph, but this degree of involvement would likely be considered a grade III or IV. Because the lateral pillar is involved, this condition would be classified as type C using the Herring lateral pillar classification scheme.

Lonner and associates conducted a prospective study to determine the reliability of analysis of intraoperative frozen sections for the identification of infection during 175 consecutive revision total joint arthroplasties (142 hips and 33 knees). The mean interval between the primary arthroplasty and the revision arthroplasty was 7.3 years (range, 3 months to 23 years). Of the 175 patients, 23 had at least 5 polymorphonuclear leukocytes per high-powered field on analysis of the frozen sections and were considered to have an infection. Of these 23 patients, five had 5 to 9 polymorphonuclear leukocytes per high-powered field and 18 had at least 10 polymorphonuclear leukocytes per high-powered field. The frozen sections for the remaining 152 patients were considered negative. On the basis of cultures of specimens obtained at the time of the revision surgery, 19 of the 175 patients were considered to have an infection. Of the 152 patients who had negative frozen sections, three were considered to have an infection on the basis of the results of the final cultures. Of the 23 patients who had positive frozen sections, 16 were considered to have an infection on the basis of the results of the final cultures; all 16 had frozen sections that showed at least 10 polymorphonuclear leukocytes per high-powered field. The sensitivity and specificity of the frozen sections were similar regardless of whether an index of 5 or 10 polymorphonuclear leukocytes per high-powered field was used. Analysis of the frozen sections had a sensitivity of 84% for both indices, whereas the specificity was 96% when the index was 5 polymorphonuclear leukocytes and 99% when it was 10 polymorphonuclear leukocytes. However, the positive predictive value of the frozen sections increased significantly (P < 0.05), from 70% to 89%, when the index increased from 5 to 10 polymorphonuclear leukocytes per high-powered field. The negative predictive value of the frozen sections was 98% for both indices. At least 10 polymorphonuclear leukocytes per high-powered field was predictive of infection, while 5 to 9 polymorphonuclear leukocytes per high-powered field was not necessarily consistent with infection. Less than 5 polymorphonuclear leukocytes per high-powered field reliably indicated the absence of infection. Feldman DS, Lonner JH, Desai P, Zuckerman JD: The role of intraoperative frozen sections in revision total joint arthroplasty. J Bone Joint Surg Am 1995;77:1807-1813. Lonner JH, Desai P, Dicesare PE, Steiner G, Zuckerman JD: The reliability of analysis of intraoperative frozen sections for identifying active infection during revision hip or knee arthroplasty. J Bone Joint Surg Am 1996;78:1553-1558. Spangehl MJ, Younger AS, Masri BA, Duncan CP: Diagnosis of infection following total hip arthroplasty, in Cannon WD Jr (ed): Instructional Course Lectures 47. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 285-295.

The prognosis for most patients with Osgood-Schlatter disease is good. When the secondary ossification center unites with the main body of the tibial tubercle, the patellar tendon has a more rigid anchor, and heterotopic ossification and its associated reaction often become quiescent. However, even after closure of the growth plates, some patients have persistent symptoms. Excision of the ossicle and prominence of the tibial tuberosity decompresses the patellar tendon and allows most patients to resume sports activities. Nonsurgical modalities are ineffective. Better results have been reported after excision than after drilling of the tubercle. Excision of the ossicle is not indicated prior to skeletal maturity because symptoms will resolve in most patients when the secondary ossification center unites. Flowers MJ, Bhadreshwar DR: Tibial tuberosity excision for symptomatic Osgood-Schlatter disease. J Pediatr Orthop 1995;15:292-297.

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.

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.

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

Achilles tendon tension is not affected by knee position when the ankle is in 20 degrees to 25 degrees of plantar flexion. Skin perfusion overlying the Achilles tendon is maximal in 20 degrees of plantar flexion and is reduced beyond 20 degrees of plantar flexion. Neutral flexion or any amount of dorsiflexion compromises the repair.

The use of nasotracheal intubation is less desirable in patients with respiratory arrest because placement of the tube is most reliable when the patient is breathing. Nasotracheal intubation is advantageous in patients with suspected cervical spine trauma because it does not require hyperextension of the neck. A nasotracheal tube may be more comfortable than an orally placed tube because it is fixed at several points and moves less freely within the larynx, subglottic area, and trachea. The presence of a hemothorax or pneumothorax does not affect the choice of airway control but does require placement of a chest tube. Colice GL: Prolonged intubation versus tracheostomy in the adult. J Intern Care Med 1987;2:85.

The MRI scan reveals a laceration through the abductor hallucis musculature and lateral plantar nerve, producing numbness along its distribution. There is no evidence of a foreign body on the MRI scan. Baxter's nerve, or nerve to the abductor digiti quinti muscle, is the first branch off the lateral plantar nerve and impingement of this nerve typically produces a Tinel's sign along the nerve branch deep to the abductor hallucis muscle. Interdigital neuroma would be suggested by the presence of a Mulder's click. A digital nerve laceration would exhibit isolated numbness more distally. Baxter DE, Pfeffer GB: Treatment of chronic heel pain by surgical release of the first branch of the lateral plantar nerve. Clin Orthop Relat Res 1992;279:229-236.

For the fibula (or any bone) to bow, a long-standing process needs to be present. Pressure from a rapid process would cause erosion, not allowing the bone to remodel. The other features are helpful confirmatory findings but also may be associated with aggressive processes. In this patient, the fibular deformity is caused by a sessile osteochondroma of the tibia. Lodwick GS, Wilson AJ, Farrell C, Virtama P, Dittrich F: Determining growth rates of focal lesions of bone from radiographs. Radiology 1980;134:577-583.

Glassman and associates reported a significantly higher pseudarthrosis rate when ketorolac was used postoperatively compared to a similar group of patients who were not given ketorolac. Animal studies from the same institution support these clinical findings. To reduce narcotic dosage, nonsteroidal anti-inflammatory drugs (NSAIDs) have been promoted as an adjunct for postoperative analgesia in patients undergoing spinal fusion. However, a high failure rate of arthrodesis has been associated with postoperative use of NSAIDs. The analgesics oxycodone hydrochloride, hydrocodone/acetaminophen, and tramadol, as well as the tricyclic antidepressant imipramine, have not been shown to inhibit fusion. Glassman SD, Rose SM, Dimar JR, et al: The effect of postoperative nonsteroidal anti-inflammatory drug administration on spinal fusion. Spine 1998;23:834-838.

The radiograph shows myositis ossificans within the quadriceps muscle. This condition occurs as a complication of muscle injury. Initial treatment should include rest, ice, compression, and elevation. While gentle active range of motion is encouraged in the functional recovery from this injury, passive stretching is contraindicated as it can enhance hemorrhage and accentuate the development of myositis ossificans. Ultrasound is similarly contraindicated because it can enhance the development of myositis ossificans and has no proven efficacy in this patient; electrical stimulation also has no proven benefits. Massage is contraindicated in the initial management of this injury because of its influence on increasing local blood flow. Anderson JE (ed): Grant's Atlas of Anatomy. Baltimore, MD, Williams & Wilkins, 1978, pp 4.39-4.49. Brumet ME, Hontas RB: The thigh, in DeLee JC, Drez D Jr (eds): Orthopaedic Sports Medicine. Philadelphia, PA, WB Saunders, 1994, pp 1086-1112. Antao NA: Myositis of the hip in a professional soccer player: A case report. Am J Sports Med 1988;16:82-83.

The patient has bilateral subluxated hips, with nearly vertical neck shaft angles; therefore, the treatment of choice is varus derotation osteotomy. Shortening of the bone on one or both sides may be necessary to allow adequate range of motion postoperatively. In patients this age and with this degree of bony deformity, soft-tissue releases are not likely to lead to hip stability. Botulinum toxin has been shown to be effective in the treatment of ankle equinus, but its efficacy in other areas has not been demonstrated as yet. The indications for obturator neurectomy are unclear at present. Proximal femoral resection is a salvage procedure for long-standing hip dislocations that are symptomatic and not reconstructable. Tylkowski CM, Rosenthal RK, Simon SR: Proximal femoral osteotomy in cerebral palsy. Clin Orthop 1980;151:183-192.

Incarcerated fragments and nonconcentric reductions are best treated with urgent open reduction, retrieval of the fragments, and internal fixation. Delayed treatment increases the damage to the articular surface, even if traction is applied. There is no role for nonsurgical management with entrapped fragments and nonconcentric reduction of the hip. Epstein HC, Wiss DA, Cozen L: Posterior fracture dislocation of the hip with fractures of the femoral head. Clin Orthop Relat Res 1985;201:9-17.

The nerve roots of S2-5 are positioned dorsally and in the midline relative to the L5 and S1 nerve roots. The L5 nerve root is located lateral to S1 as it prepares to exit under the L5 pedicle. The S1 nerve root is located lateral and ventral to the S2-5 nerve roots. Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 3-17.

The injury mechanism involves a valgus load applied to the knee with the foot in external rotation. The primary stabilizer to valgus laxity is the medial collateral ligament. The secondary restraints to valgus rotation are the cruciate ligaments. Examination indicates disruption of the medial collateral and anterior cruciate ligaments. Valgus opening in extension should also arouse suspicion for an injury to the posterior cruciate ligament; however, in this patient, the valgus opening in extension is mild. The slight opening in extension and the increased anterior drawer, especially with external rotation, indicates disruption of the posteromedial capsule and posterior oblique ligament. Figure 21a shows complete disruption of the superficial and deep medial collateral ligaments involving the meniscofemoral ligament. Figure 21b shows a more posterior coronal section with a torn posterior oblique ligament. Figure 21c shows disruption of the anterior cruciate ligament, while the posterior cruciate ligament at the tibial insertion appears with a homogenous normal signal. Warren LA, Marshall JL, Girgis F: The prime static stabilizer of the medial side of the knee. J Bone Joint Surg Am 1974;56:665-674.

The bright signal on the T2-weighted MRI scan suggests fluid. The multiloculated appearance in proximity to the proximal tibiofibular joint suggests that the most likely diagnosis is a ganglion. They typically increase and decrease in size and can be diagnosed by the classic gelatinous fluid obtained through needle aspiration. Bianchi S, Abdelwahab IF, Kenan S, Zwass A, Ricci G, Palomba G: Intramuscular ganglia arising from the superior tibiofibular joint: CT and MR evaluation. Skeletal Radiol 1995;24:253-256.

Pigmented villonodular synovitis (PVNS) is a synovial proliferative disorder that remains a diagnostic difficulty. The most common clinical features are mechanical pain and limited joint motion. On radiographs, the classic finding is often a large lesion, associated with multiple lucencies. Other findings may include a normal radiographic appearance, loss of joint space, osteonecrosis of the femoral head, or acetabular protrusion. MRI is the imaging modality of choice and will show the characteristic findings of a joint effusion, synovial proliferation, and bulging of the hip. The synovial lining has a low signal on T1- and T2-weighted images, secondary to hemosiderin deposition. Copper deposition occurs in patients with Wilson's disease, which mainly affects the liver. Bhimani MA, Wenz JF, Frassica FJ: Pigmented villonodular synovitis: Keys to early diagnosis. Clin Orthop 2001;386:197-202.

Persistent pain following an ankle sprain can present a diagnostic dilemma. All of the injuries listed should be considered in the differential diagnosis. The superficial peroneal nerve courses in the lateral compartment and exits the crural fascia 12 to 15 cm above the level of the ankle. Muscle herniation through the fascial defect has been reported to be associated with entrapment of this nerve. The fascial hiatus also may serve as a potential tether in cases of inversion injuries causing injury to the superficial peroneal nerve. Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 101-111.