Orthopedic Surgery Board Review: 100 High-Yield MCQs (Set 348)

The radiograph reveals a "bony mallet injury." As the distal phalanx is not volarly subluxated, extension splinting, similar to a classic mallet injury without bony involvement, is appropriate. If there is volar subluxation associated with a large bony fragment, surgical intervention is appropriate. Baratz ME, Schmidt CC, Hughes TB: Extensor tendon injuries, in Green DP, Hotchkiss RN, Pederson WC, et al (eds): Green's Operative Hand Surgery, ed 5. Philadelphia, PA, Elsevier, 2005, p 192.

The status of the hips (located or dislocated) in children with thoracic-level myelomeningocele has no effect on the functional outcome of these patients. Management of unstable hips in this population should be limited to treatment of the contractures that may lead to poor limb positioning in either braces or a wheelchair. The use of the Pavlik harness and/or spica cast is contraindicated because they would promote flexion and abduction contractures. In the past, open reduction either through an anterior or medial approach had been performed with a high incidence of redislocation and other complications, with little functional gain for the child. Gabriel KG: Natural history of hip deformity in spina bifida, in Sarwark JR, Lubicky JP (eds): Caring for the Child With Spina Bifida. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2001, pp 89-103.

Intrafocal pinning allows the Kirschner wires to be placed through a site of comminution and then drilled through intact cortex. Generally Kapandji intrafocal pinning is done for dorsal comminuted extra-articular dorsal bending fractures, but it also may be used to elevate and buttress radial comminution. Simple intra-articular fractures can also be treated with pinning alone. Intrafocal pinning works best as a dorsal or radial buttress to prevent shortening. When there is volar comminution, the fracture is prone to shortening and supplemental external fixation or plating is recommended. Trumble TE, Wagner W, Hanel DP, et al: Intrafocal (Kapandji) pinning of distal radius fractures with and without external fixation. J Hand Surg Am 1998;23:381-394. Choi KY, Chan WS, Lam TP, et al: Percutaneous Kirschner-wire pinning for severely displaced distal radial fractures in children: A report of 157 cases. J Bone Joint Surg Br 1995;77:797-801.

The patient has a moderately displaced distal diaphyseal fracture of the fifth metatarsal, and the most appropriate treatment is brief immobilization and symptomatic management. Attempts at closed reduction are unlikely to appreciably alter the position of the fracture. Surgical techniques for either reduction of the fracture or fixation have not been shown to result in improved functional outcomes. O'Malley MJ, Hamilton WG, Munyak J: Fractures of the distal shaft of the fifth metatarsal: "Dancer's Fracture." Am J Sports Med 1996;24:240-243. DeLee JC: Fractures and dislocations of the foot, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, CV Mosby, 1993, pp 1465-1703.

Surgery is indicated for congenital kyphosis once the deformity reaches a certain size or if significant progression is documented. In a young patient with a relatively small deformity, the treatment of choice is isolated in situ posterior fusion and postoperative immobilization. If an adequate posterior fusion can be obtained, an epiphyseodesis effect can be generated, allowing the remaining anterior growth to cause some correction. Because there is no evidence of neurologic compression and the deformity is less than 50 degrees, anterior surgery is not indicated. There is no role for bracing in the management of congenital kyphosis. Winter RB: Congenital Deformities of the Spine. New York, NY, Thieme-Stratton, 1983, pp 229-261.

In a midterm (7 to 11 years) follow-up study of lumbar total disk arthroplasty, 5 of 55 patients had transient radicular leg pain without evidence of nerve root compression. Implant migration is rare. Deep venous thrombosis, incisional hernia, and retrograde ejaculation are less common complications of disk arthroplasty.

The contracture is too large for a Z-plasty, which allows a 75% increase in length. Excision of the scar with placement of a skin graft is prone to contracture. A posterior interosseous fasciocutaneous flap will provide enough well-vascularized tissue and is well suited to reach the first dorsal web space. Buchler U, Frey HP: Retrograde posterior interosseous flap. J Hand Surg Am 1991;16:283-292.

Numerous experimental studies have shown that vertical suture techniques are superior to all of the other noted methods. In fact, vertical sutures have been shown to be twice as strong as several of these techniques. DeHaven KE: Meniscus repair. Am J Sports Med 1999;27:242-250. Dervin GF, Downing KJ, Keene GC, McBride DG: Failure strengths of suture versus biodegradable arrow for meniscal repair: An in vitro study. Arthroscopy 1997;13:296-300.

The child has an up-to-date tetanus; therefore, a booster is not recommended. Pseudomonas coverage is most likely not needed because the child was barefoot. It is too early to evaluate for abscess or osteomyelitis with MRI, and a formal debridement is rarely indicated without signs of an abscess or a retained foreign body. Radiographs with soft-tissue penetration should be obtained to check for a retained foreign body. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 199-205.

14b 14c 14d 14e Although the imaging reveals generalized lumbar spondylosis and stenosis, in particular at L4-5, the MRI scan of the left hip clearly reveals a stress fracture of the femoral neck. Therefore, the treatment of choice is non-weight-bearing of the left lower extremity. During the evaluation of acute back pain, clinicians must include other possibilities within the differential diagnosis that may mimic mechanical axial back pain; thus, potential complications from a missed diagnosis can be avoided. Wong DA, Transfeldt E: Macnab's Backache, ed 4. Philadelphia, PA, Lippincott Williams and Wilkins, 2007, pp 339-361.

When comparing closed reduction and pinning to ligament reconstruction, the reconstruction group had slightly better abduction and pinch strength. The volar oblique ligament usually tears off the first metacarpal in a subperiosteal fashion. In this young patient, motion-sparing procedures are preferred. Simonian PT, Trumble TE: Traumatic dislocation of the thumb carpometacarpal joint: Early ligamentous reconstruction versus closed reduction and pinning. J Hand Surg Am 1996;21;802-806.

Essex-Lopresti injuries affect axial stability of the forearm. Injury to the interosseous membrane or the triangular fibrocartilage complex can result in proximal migration of the radius. Morrey BF, Chao EY, Hui FC: Biomechanical study of the elbow following excision of the radial head. J Bone Joint Surg Am 1979;61:63-68.

The saphenous nerve is located on the posterior medial aspect of the knee and must be protected when performing an inside-out repair of the medial meniscus. The peroneal nerve is most at risk with lateral meniscal repairs. The other structures usually are not at risk with meniscal repair. Cannon WD Jr, Morgan CD: Meniscal repair: Arthroscopic repair techniques. Instr Course Lect 1994;43:77-96.

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.

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.

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's history, examination, and radiographs are classic for locked posterior dislocation of the glenohumeral joint. Posterior dislocation of the shoulder remains the most commonly missed dislocation of a major joint. Up to 80% are missed on initial presentation. The primary cause for failure to accurately diagnose this injury is inadequate radiographic evaluation. The typical presentation is a shoulder locked in internal rotation with loss of abduction. An axillary view not only will make the definitive diagnosis but will help assess the size of the articular surface defect and help plan treatment. This view can be done expediently as part of every trauma series. The AP view is suspicious for a posteriorly dislocated humerus with loss of the humeral neck profile, a vacant glenoid sign, and an anterior humeral head compression fracture (reverse Hill-Sachs lesion). Hawkins RJ, Neer CS II, Pianta RM, Mendoza FX: Locked posterior dislocation of the shoulder. J Bone Joint Surg Am 1987;69:9-18. Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow. Rosement, IL, American Academy of Orthopaedic Surgeons, 1997, pp 181-189.

Tuberculosis of the spine is seen in 50% to 60% of skeletal disease and is most commonly found in the lower thoracic or upper lumbar spine. Typically two or more adjacent bodies are involved as seen in this MRI scan. The disk space is narrowed but still relatively preserved as opposed to pyogenic infections (black arrow). Epidural extensions often spread from vertebrae to vertebrae (white arrow); however, the posterior elements are not frequently involved (arrowhead). Tumors rarely spread to adjacent vertebrae. The anterior and posterior spread of the infectious process rules out trauma. Boachie-Adjei O, Squillante RG: Tuberculosis of the spine. Orthop Clin North Am 1996;27:95-103.

Secondary chondrosarcomas are most common in patients with multiple hereditary exostosis. Dedifferentiated chondrosarcoma is less common and refers to bone lesions in which a high-grade spindle cell sarcoma component is located immediately adjacent to a low-grade cartilage neoplasm. Mesenchymal chondrosarcoma, clear cell chondrosarcoma, and periosteal osteosarcoma are no more common in patients with multiple hereditary exostosis than in the general population. Mirra JM: Bone Tumors: Clinical, Radiologic, and Pathologic Correlations. Philadelphia, PA, Lea and Febiger, 1989, pp 1660-1669.

The distal oblique shortening (Weil) metatarsal osteotomy has not been associated with transfer lesions to the extent of other shortening osteotomies, and malunions and nonunions are unusual complications. Recurrent dorsal contracture of the toe has been reported. Recommendations to reduce this problem include release of the dorsal capsule and tendons, as well as a flexor tendon transfer. A potential cause suspected for this phenomenon is the relatively dorsal positioning of the intrinsic tendons after plantar displacement of the metatarsal head. Trnka HJ, Nyska M, Parks BG, Myerson MS: Dorsiflexion contracture after the Weil osteotomy: Results of cadaver study and three-dimensional analysis. Foot Ankle Int 2001;22:47-50. Trnka HJ, Muhlbauer M, Zettl R, Myerson MS, Ritschl P: Comparison of the results of the Weil and Helal osteotomies for the treatment of metatarsalgia secondary to dislocation of the lesser metatarsophalangeal joints. Foot Ankle Int 1999;20:72-79.

The findings are characteristic of hemangioma. When the hemangioma is large enough, vertical striations may be visible on plain radiographs. Axial CT scans commonly reveal a speckled appearance. Metastatic lesions are typically hypointense on T1-weighted images because they replace the fatty marrow. Bony islands, like cortical bone, are dark on T1- and T2-weighted images. Intravertebral disk herniation would have characteristics similar to the disk and be in continuity with the disk. Osteoporosis is more diffuse. Ross JS, Masaryk TJ, Modic MT, Carter JR, Mapstone T, Dengel FH: Vertebral hemangiomas: MR imaging. Radiology 1987;165:165-169.

In an acute first-time dislocation, arthroscopy has been shown to reveal a Bankart lesion in most shoulders. The classic finding of labral detachment from the anterior inferior glenoid along with occasional hemorrhage within the inferior glenohumeral ligament is the most common sequelae of a traumatic anterior inferior dislocation. Acute treatment, if chosen, is repair of the labral tissue back to the glenoid plus or minus any capsular plication to address potential plastic deformation of the glenohumeral ligament. Acute treatment of a patient sustaining a first-time dislocation remains controversial. The potential indications may be patients whose dislocation occurs at the end of a season and when the desire to minimize risk of future instability outweighs the risks of surgical intervention. Taylor DC, Arciero RA: Pathologic changes associated with shoulder dislocations: Arthroscopic and physical examination findings in first-time, traumatic anterior dislocations. Am J Sports Med 1997;25:306-311. DeBerardino TM, Arciero RA, Taylor DC, et al: Prospective evaluation of arthroscopic stabilization of acute, initial anterior shoulder dislocations in young athletes: Two- to five-year follow-up. Am J Sports Med 2001;29:586-592.

Congenital dislocation of the radial head is often confused with posttraumatic dislocation. The distinguishing feature here is the dome-shaped radial head. Some patients with congenital anomalies fail to recognize their limitations until an injury occurs. Soft-tissue contractures do not cause radial head dislocation nor do they usually cause this pattern of motion restriction (mainly flexion and rotation without significant loss of extension). There is no deformity of the ulna to suggest an old Monteggia lesion. Morrey BF (ed): The Elbow and Its Disorders, ed 2. Philadelphia, PA, WB Saunders, 1993, p 196.

Quadrilateral space syndrome is a rare condition and is the result of compression of the contents of the quadrilateral space. The contents of the quadrilateral space include the posterior circumflex vessels and the axillary nerve. Cahill BR, Palmer RE: Quadrilateral space syndrome. J Hand Surg 1983;8:65-69.

The sciatic nerve is formed by the roots of the lumbosacral plexus. It exits the pelvis through the greater sciatic notch and appears in the buttock anterior to the piriformus. From that point, the sciatic nerve passes posteriorly over the superior gemellus, obturator internus, inferior gemellus, and quadratus femoris before it passes deep to the biceps femoris. The tendon of the obturator internus passes through the lesser sciatic notch. Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach. Philadelphia, PA, JB Lippincott, 1984, p 347. Anderson JE: Grant's Atlas of Anatomy, ed 7. Baltimore, MD, Lippincott Williams & Wilkins, 1978, pp 4-34, 4-36.

The patient has the classic symptoms, examination findings, and radiographs for a painful accessory navicular. Initial treatment should always be nonsurgical, specifically cast immobilization. Surgery should be reserved for those patients who fail nonsurgical management. Corticosteroids should not be injected into a posterior tibial tendon or insertion point because they can weaken the tendon and possibly cause tendon rupture. Triple arthrodesis and biopsy have no role in the management of a painful accessory navicular.

The epiphyseal location on the radiograph and MRI scan and the histologic findings of polyhedral cells separated by a chondroid matrix with pericellular, lattice-like "chicken wire" calcification all suggest chondroblastoma. Although giant cell tumors of bone typically occupy an epiphyseal location, they are rare in children and when present are often metaphyseal in skeletally immature patients. Enchondromas and osteoblastomas are generally metaphyseal and, along with giant cell tumors, have very different histology than seen here. Chondromyxoid fibromas are typically metaphyseal in location. Huvos AG: Bone Tumors: Diagnosis, Treatment, and Prognosis. Philadelphia, PA, WB Saunders, 1991, pp 295-313.

Using the traditional concussion grading scale, the patient sustained a grade I concussion because he did not lose consciousness and his abnormal cognitive level lasted less than 1 hour. If this was the player's first concussion, theoretically he could return to play later in the game provided that he had no confusion, headache, or associated symptoms. However, because it was the third concussion for the year, participation in contact sports should be terminated for the season. Guskiewwicz KM, Barth JT: Head injuries, in Schenk RC Jr (ed): Athletic Training and Sports Medicine. Rosemont, IL, American Academy of Orthopedic Surgeons, 1999, pp 143-167.

With a gap of less than 4 cm, a V-Y repair would be appropriate without a tendon transfer. For gaps greater than 5 cm, a lengthening with augmentation is the most appropriate treatment. Therefore, the treatment of choice is an Achilles tendon turndown with flexor hallucis longus tendon transfer. The plantaris tendon is not a strong enough repair, and direct repair is not possible given the large defect in the Achilles tendon. Continued use of the ankle-foot orthosis will not provide adequate relief for this patient.

Peak embolization is observed during femoral stem insertion. Embolization is also observed during acetabular preparation and hip reduction. Lewallen DG, Parvizi J, Ereth MH: Perioperative mortality associated with hip and knee arthroplasty, in Morrey BF (ed): Joint Replacement Arthroplasty, ed 3. Philadelphia, PA, Churchill-Livingstone, 2003, pp 119-127.

3b 3c 3d Because the patient has an apparent compressive neuropathy secondary to the metallic fragments, removal of the fragments in this incomplete lesion at the cauda equina level can be expected to improve her sensory dysesthesias and pain. Steroids are not indicated in a root lesion secondary to a penetrating injury. MRI will have significant artifact effect and will not provide much additional information. The posterior bony elements are not significantly injured; therefore, stabilization is not indicated. Bracken MB, Shepard MJ, Holford TR: Administration of methylprednisolone for 24 or 48 hours or tirilazad mesylate for 48 hours in the treatment of acute spinal cord injury. JAMA 1997;277:1597-1604. Waters RL, Adkins RH: The effects of removal of bullet fragments retained in the spinal canal: A collaborative study by the National Spinal Cord Injury Model Systems. Spine 1991;16:934-939.

The figure shows an intractable plantar keratosis (IPK). The keratoma usually forms beneath a bony prominence. This can occur under the sesamoids, most commonly the tibial sesamoid, or under the fibular condyle of a prominent metatarsal head. The initial treatment of an IPK consists of paring down the callused lesion and placing a metatarsal pad proximal to the lesion to provide posting to unload the bony prominence.

In the treatment of ankle fractures, the superficial peroneal nerve is most commonly injured by the use of a direct lateral approach to the ankle. The superficial peroneal nerve and its branches exit the fascial hiatus approximately 9 cm to 10 cm proximal to the tip of the distal fibula with a range of 4 cm to 13 cm, and their course is typically anterior to the midlateral plane of the fibula. However, small branches may course across the surgical plane directly laterally. A posterior-lateral approach diminishes the risk of injury to the superficial peroneal nerve and its branches; however, by moving farther posterior, the sural nerve and its branches may be at increased risk. Cast immobilization may injure the cutaneous nerves about the ankle; however, the risks are greater with surgical intervention. A medial or anterior-medial approach to the ankle will not injure the superficial peroneal nerve at the ankle level. Redfern DJ, Sauve PS, Sakellariou A: Investigation of incidence of superficial peroneal nerve injury following ankle fracture. Foot Ankle Int 2003;24:771-774.

Ganglion cysts are the most common mass or mass-like lesions seen in the hand and wrist. They arise in a variety of locations, including synovial joints or tendon sheaths. The most common location is the dorsal/radial wrist arising from the dorsal scapholunate interosseous ligament.

Skin cancers far outnumber primary musculoskeletal malignancies of the hand and the most common of these is squamous cell carcinoma. Metatastic lung carcinoma, while classic for the carcinoma that metastasizes to the hand, does so at an extremely low rate. Fink JA, Akelman E: Nonmelanotic malignant skin tumors of the hand. Hand Clin 1995;11:255-264.

Salvage of a total elbow arthroplasty is possible with early aggressive management of acute infection (symptoms for less than 30 days) with serial irrigation and debridement and antibiotic bead placement. This form of treatment is indicated when there are no radiographic or intraoperative signs of loosening. However, successful treatment is largely dependent on the organism. Staphylococcus epidermidis is associated with persistent infection because it is an encapsulating organism, and it is best treated with implant removal and IV antibiotics. Yamaguchi K, Adams RA, Morrey BF: Infection after total elbow arthroplasty. J Bone Joint Surg Am 1998;80:481-491.

The patient has a displaced fracture of the apophysis of the olecranon for which most authorities recommend surgical treatment. In older children, stability of the reduction may be achieved by the use of two parallel medullary Kirschner wires and a figure-of-8 tension band loop of either stainless steel wire or absorbable suture. The use of an absorbable suture does not require removal of the implant. Absorbable suture alone is best used in very young patients who have this type of injury. An intramedullary screw would pose an unnecessary risk of future growth disturbance. A displaced, isolated fracture of the apophysis of the olecranon is an unusual injury in a child. It has been suggested by several authors that children who have osteogenesis imperfecta may be especially prone to this injury. One study reported seven of these fractures occurring in five children who had the mild form of osteogenesis imperfecta (Sillence type IA). The authors of this study suggest that the diagnosis of osteogenesis imperfecta be considered in any child who has a displaced fracture of the apophysis of the olecranon, especially when the injury is associated with relatively minor trauma. Stott NS, Zionts LE: Displaced fractures of the apophysis of the olecranon in children who have osteogenesis imperfecta. J Bone Joint Surg Am 1993;75:1026-1033. Gaddy BC, Strecker WB, Schoenecker PL: Surgical treatment of displaced olecranon fractures in children. J Pediatr Orthop 1997;17:321-324.

Localized PVNS is a form of the disease in which synovial proliferation is restricted to one area of a joint and causes the formation of a small mass-like lesion. The true incidence of this is unknown but is probably less common than the diffuse form of the disease. PVNS presents as a usually painful discrete mass. The anterior compartment of the knee is the most common location. Tyler WK, Vidal AF, Williams RJ, et al: Pigmented villonodular synovitis. J Am Acad Orthop Surg 2006;14:376-385.

The patient has no clinical or observed signs of sepsis. The skin just proximal to the gangrenous tissue appears somewhat hyperemic and is clearly viable. These wounds should be managed much like burn wounds. Moist dressings should be used until the tissue clearly demarcates. Much of the insult may simply be superficial and only require late debridement. McAdams TR, Swenson DR, Miller RA: Frostbite: An orthopedic perspective. Am J Orthop 1999;28:21-26.

The patient has a perilunate dislocation. A volar dislocation of the lunate is often associated with median nerve dysfunction. This injury to the wrist is often overlooked because of its benign clinical appearance and the presence of other injuries, as it is caused by high-energy mechanisms. Ruby LK, Cassidy C: Fractures and dislocations of the carpus, in Browner BD (ed): Skeletal Trauma, ed 3. Philadelphia, PA, WB Saunders, 2003, pp 1297-1300.

Temporary bed rest (less than 4 days) with gradual resumption of activities can be efficacious. Epidural steroid injections may be indicated for acute low back pain with radiculopathy. Acupuncture, facet joint injections, or ligamentous (sclerosant) injections are not indicated. Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, Appendix A15.

41b The radiographs show tunnel enlargement, which is seen after ACL reconstruction, particularly with allografts. Occasionally, there will be formation of an associated subcutaneous pretibial cyst. It has been proposed that the tunnel enlargement and cyst are the result of incomplete incorporation of allograft tissues within the bone tunnels. There may be residual graft necrosis, allowing synovial fluid to be transmitted through the tunnel to collect in the pretibial area, manifesting as a synovial cyst. In the absence of cyst formation, the presence of tunnel enlargement does not appear to adversely affect the clinical outcome. Based on studies by Fahey and associates, continued tunnel expansion does not occur. Victoroff and associates report good results with curettage and bone grafting of the tibial tunnel if a pretibial cyst is present. Because this patient does not have a pretibial cyst, observation with activity modification is the preferred treatment. Fahey M, Indelicato PA: Bone tunnel enlargement after anterior cruciate ligament replacement. Am J Sports Med 1994;22:410-414.

The radioscaphocapitate ligament is the most radial of the extrinsic volar ligaments of the wrist. It has a mean attachment to the radius 4 mm from the tip of the radial styloid. Nakamura T, Cooney WP III, Lui WH, et al: Radial styloidectomy: A biomechanical study on the stability of the wrist joint. J Hand Surg Am 2001;26:85-93.

The prevalence of postoperative ileus associated with total joint arthroplasty has been reported to be as high as 3%. Metabolic abnormalities such as hypokalemia are believed to contribute to the onset of ileus and Ogilvie's syndrome (acute pseudo-obstruction of the colon). Prolonged bed rest also has been associated with the development of ileus and Ogilvie's syndrome. Untreated Ogilvie's syndrome can result in cecal perforation. Ileus usually is not accompanied by mechanical obstruction. Antibiotic administration and the type of anesthesia used have not been correlated with development of ileus. Administration of warfarin has been associated with elevated prothrombin time/partial thromboplastin time and international normalized ratio levels when ileus is managed with a nasogastric tube and suction. Metabolic imbalances must be corrected to reverse the ileus process. Iorio R, Healy WL, Appleby D: The association of excessive warfarin anticoagulation and postoperative ileus after total joint replacement surgery. J Arthroplasty 2000;15:220-223.

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

The radiographs show early ectopic bone formation originating between the ulna and the radius. The development of ectopic bone in this area following a two-incision approach for anatomic repair of the distal biceps tendon is thought to be related to exposure of the periosteum of the lateral ulna during surgery. This can be avoided by the use of a muscle-splitting incision between the extensor carpi ulnaris and common extensor muscles. Full pronation of the forearm allows for the necessary exposure of the radial tuberosity during the procedure and for fixation of the tendon at its maximal length. Morrey BF: Tendon injuries about the elbow, in Morrey BF (ed): The Elbow and Its Disorders, ed. 2. Philadelphia, PA, WB Saunders, 1993, pp 492-503.

Slipped capital femoral epiphysis is the most common pathology involving the hip in adolescents. While patients with acute slips may report severe pain and are unable to ambulate, those with chronic slips often have pain during ambulation, a limp, and increased external rotation of the hip. While 60% of the patients specifically report hip pain, the remainder have pain in the thigh or knee. The initial diagnostic study of choice is AP and frog-lateral radiographs of the pelvis; bilateral involvement is frequently seen. Boyer DW, Mickelson MR, Ponseti IV: Slipped capital femoral epiphysis: Long-term follow-up study of one hundred and twenty-one patients. J Bone Joint Surg Am 1981;63:85-95.

The patient has a stable bony fracture that will heal with immobilization in a rigid collar. Flexion-extension radiographs may be obtained at 6 weeks to verify that there is no instability; mobilization may then be begun.

Arthrodesis of the failed infected total knee arthroplasty may be accomplished by external fixation, intramedullary rod fixation, and dual plates and screws. External fixation runs the risk of pin tract infection, although after its removal, there are no metal surfaces left in place. Intramedullary rods have been used successfully in the treatment of infected total knees, although they also leave metal within the region of the infection. The dual plate technique of knee fusion is useful in patients with rheumatoid arthritis who require fusion in the absence of infection because it provides good initial stability and avoids the use of external pins. However, in the face of infection, the large surface area of the screws and plates may serve as a site for bacteria to hide within a glycocalyx and make eradication of the infection almost impossible.

The development of arthritis in SLAC wrist follows a consistent pattern. Beginning at the radial styloid to the scaphoid articulation, it progresses through the entire radioscaphoid joint and the midcarpal joint. In all stages, the radiolunate joint is spared, which is the basis for a scaphoid excision and four-corner fusion performed as a motion-sparing procedure for treatment of this condition. Wyrick JD: Proximal row carpectomy and intercarpal arthrodesis for the management of arthritis. J Am Acad Orthop Surg 2003;11:277-281. Watson HK, Ballett FL: The SLAC wrist: Scapholunate advanced collapse pattern of degenerative arthritis. J Hand Surg Am 1984;9:358-365.

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.

Several cutting studies have evaluated the primary static restraints and the role of the glenohumeral ligaments in providing static stability. With the arm at the side in adduction, the superior glenohumeral ligament and coracohumeral ligament are the primary restraints to inferior translation. The middle glenohumeral ligament functions with the arm in 45 degrees of abduction and resists anterior translation. The inferior glenohumeral ligament is the primary restraint to anterior translation at 90 degrees of abduction. Warner JJ, Deng XH, Warren RF, et al: Static capsuloligamentous restraints to superior-inferior translation of the glenohumeral joint. Am J Sports Med 1992;20:675-685.

10b 10c Based on these findings, the patient has an aneurysmal bone cyst. Frequently, fluid-fluid levels can be detected on MRI or CT images. The histologic results show a lesion that consists of cavernous spaces filled with blood. The lining of the cavity contains spindle cells, multinucleated giant cells, and reactive bone. Curettage and bone grafting is the preferred treatment method. Without treatment, these lesions can become quite large and destructive. Radiation therapy is not recommended for resectable lesions. Chemotherapy is not required for these benign lesions. Simon MA, Springfield DS, et al: Common Benign Bone Tumors: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 194-200.

Most of these injuries occur in young, active patients. Success rates for nonsurgical management are only marginally better than 50%. The treatment of choice is early surgery for patients who desire a quick return to a sport or active lifestyle. Subluxation of the peroneal tendons leads to longitudinal tears over time. McLennan JG: Treatment of acute and chronic luxations of the peroneal tendons. Am J Sports Med 1980;8:432-436.

At present, radiologists perform multiple MRI images to rule out all possible diagnoses. The ability to specify the anticipated changes on MRI should become more important as a means of reducing costs. MRI is sensitive to changes in free water (or hemorrhage) and thus this will appear dark on T1 and bright on T2. Miller MD: Review of Orthopaedics, ed 3. Philadelphia PA, WB Saunders, 2000, p 116.

The modified Brostrom lateral ankle ligament stabilization procedure uses the remnants of the anterior talofibular and the calcaneofibular ligaments, supplemented by the inferior retinaculum and the transferred talocalcaneal ligament to stabilize the lateral ankle. Chrisman and associates described the use of one half of the peroneus brevis. Watson-Jones and Evans used the entire peroneus brevis. The peroneus longus has been taken by mistake. The plantaris has been used in triligamentous reconstruction. Gould N, Seligson D, Gassman J: Early and late repair of lateral ligament of the ankle. Foot Ankle 1980;1:84-89. Hamilton WG, Thompson FM, Snow SW: The modified Brostrom procedure for lateral ankle instability. Foot Ankle 1993;14:1-7. Chrisman OD, Snook GA: Reconstruction of lateral ligament tears of the ankle: An experimental study and clinical evaluation of seven patients treated by a new modification of the Elmslie procedure. J Bone Joint Surg Am 1969;51:904-912. Evans DL: Recurrent instability of the ankle: My method of surgical treatment. Proc R Soc Med 1953;46:343. Watson-Jones R: Fractures and Joint Injuries, ed 3. Baltimore, MD, Williams and Wilkins, 1946, p 234.

The radiographs show an eccentric metaphyseal lesion with a well-defined reactive rim of bone that is consistent with a nonossifying fibroma. Pathologic fractures through benign lesions should be treated as appropriate for the fracture, allowing the fracture to heal. Biopsy is not needed when the radiographic diagnosis is benign. MRI, in the presence of a fracture, is not particularly helpful because of the hematoma. If radiographic findings reveal that the lesion appears aggressive, a biopsy should be performed, obtaining tissue away from the fracture site. Marks KE, Bauer TW: Fibrous tumors of bone. Orthop Clin North Am 1989;20:377.

The greatest risk factor for local recurrence is an inadequate surgical margin. The tumor grade, histologic subtype, and size are predictive of systemic relapse. Sarcomas that arise in some anatomic sites, such as the forearm or retroperitoneum, may be more difficult to completely resect compared with other sites. The optimum margin is generally considered to be a cuff of normal tissue beyond the tumor. Bell RS, O'Sullivan B, Liu FF, et al: The surgical margin in soft-tissue sarcoma. J Bone Joint Surg Am 1989;71:370-375. Sadoski C, Suit HD, Rosenberg A, Mankin H, Efird J: Preoperative radiation, surgical margins, and local control of extremity sarcomas of soft tissues. J Surg Oncol 1993;52:223-230.

Gunshot wounds to the spine present relatively little risk of infection in most cases. When there has been an injury to the colon, the risk of infection can be minimized with a 7-day course of broad-spectrum antibiotics. Fragment removal is not indicated. Roffi RP, Waters RL, Adkins RH: Gunshot wounds to the spine associated with a perforated viscus. Spine 1989;14:808-811.

The patient has bowlegs associated with very wide physes, particularly noted at the hips. The widening of the growth plates is a classic sign of rickets; however, the normal levels of calcium, phosphorus, and alkaline phosphatase rule out both nutritional and hypophosphatemic rickets. Patients with nutritional rickets or hypophosphatemic rickets have hypophosphatemia and increased alkaline phosphatase levels. Jansen metaphyseal dysostosis has very severe radiographic findings that are not found in this patient; however, these radiographic findings are classic for Schmid metaphyseal dysostosis. This disorder is caused by a mutation in the gene for type X collagen, which is found only in the growth plates of growing children. Lachman RS, Rimoin DL, Spranger J: Metaphyseal chondrodysplasia - Schmid type: Clinical and radiographic delineation with a review of the literature. Pediatr Radiol 1988;18:93-102.

Adequate decompression of the cervical cord can be achieved in a variety of ways depending on the pathoanatomy of the compression, but kyphosis is a relative contraindication to laminectomy alone. For laminectomy to be effective, the lordosis must be maintained so the cord can displace posteriorly away from the anterior structures. In addition, removing the posterior tension band increases the probability that the kyphosis will progress, therefore increasing the force against the front of the cord as it tents across the kyphosis. Albert TJ, Vaccaro A: Postlaminectomy kyphosis. Spine 1998;23:2738-2745. Truumees E, Herkowitz HN: Cervical spondylotic myelopathy and radiculopthy. Instr Course Lect 2000;49:339-360.

Tibial tubercle avulsion is an injury of the adolescent knee that most often occurs just before the end of growth. The fracture usually occurs with jumping, either at push-off or landing. This patient has a type III injury. In type III injuries, the articular surface is disrupted, and meniscal injury and compartment syndrome can occur. Open reduction is the treatment of choice, and anterior fasciotomy should be considered prophylactically at the time of surgery. Although the fracture heals with an anterior epiphysiodesis of the proximal tibia, little growth remains in this patient and no special handling of the physis is warranted. Ogden JA, Tross RB, Murphy MJ: Fractures of the tibial tuberosity in adolescents. J Bone Joint Surg Am 1980;62:205-215.

5b A significant bunionette deformity that fails to respond to conservative management is best addressed surgically, in this case with the bunion deformity. The radiograph reveals a prominent lateral condyle at the fifth metatarsal head without a significant increase in the intermetatarsal angle. Simple exostectomy is preferred with less risk of complications. Complete excision would risk transfer lesions to the medial metatarsals. Mann RA, Coughlin MJ: Adult hallux valgus, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 415-435.

Bilateral joint replacement, chronic disease, and preoperative autologous donation all increase the risk of needing blood. Young patients and a high hemoglobin level (greater than 15 g/dL) are considered clinical parameters that decrease the risk for requiring allogenic blood. Bierbaum BE, Callaghan JJ, Galante JO, Rubash HE, Tooms RE, Welch RB: An analysis of blood management in patients having a total hip or knee arthroplasty. J Bone Joint Surg Am 1999;81:2-10.

The peroneus brevis and peroneus longus muscles are the main evertors of the hindfoot. As they descend along the posterior fibula, they pass through the retromalleolar sulcus, formed by the concavity of the retromalleolar fibula. This sulcus is deepened by a fibrocartilaginous rim. The superior peroneal retinaculum covers the fibular groove and stabilizes the peroneal tendons within the retromalleolar sulcus. It originates from the posterolateral ridge of the fibula and inserts onto the lateral calcaneus. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2003, pp 81-89.

Teres minor originates from the middle third of the dorsal surface of the lateral border of the scapula. It is supplied by the axillary nerve (C5). Williams PL, Warwick R, Dyson M, Bannister LH: Myology, in Gray's Anatomy, ed 37. Edinburgh, Scotland, Churchill Livingstone, 1989, pp 611-615.

Forearm rotation results from a complex interaction of osseous articulations and soft tissues including the radiocapitellar articulation, proximal and distal radioulnar joints, the interosseous membrane, and the adjacent forearm muscles. The rotation occurs around a longitudinal forearm axis extending from the center of the radial head proximally through the foveal region of the ulnar head distally. Werner FW, An KN: Biomechanics of the elbow and forearm. Hand Clin 1994;10:357-373.

Following a severe crush injury, the patient has an acute compartment syndrome. Even though there is an open fracture, this is not sufficient to decompress the compartment syndrome. Therefore, splinting and observation are not appropriate. The surgical treatment of choice is fasciotomy with fixation of the multiple fractures. A primary amputation is not indicated because there is potential for salvage of this devastating injury. Fakhouri AJ, Manoli A II: Acute foot compartment syndromes. J Orthop Trauma 1992;6:223-228. Myerson MS: Management of compartment syndromes of the foot. Clin Orthop 1991;271:239-248.

Results of treatment of subscapularis rupture are best when immediate repair is performed. When the cause of the anterior instability is the result of rupture of the subscapularis tendon and the component position is acceptable, revising the position of the component is unnecessary. Restoring the coracoacromial arch and subacromial decompression are related to superior instability and rotator cuff pathology, respectively, and would not correct the instability caused by subscapularis rupture. Moeckel BH, Altchek DW, Warren RF, Wickiewicz TL, Dines DM: Instability of the shoulder after arthroplasty. J Bone Joint Surg Am 1993;75:492-497.

15b The radiographs reveal severe arthritic changes with no joint space, and the AP view shows a progressive malalignment secondary to the radial head resection. A prosthetic arthroplasty is indicated given the severe arthritis (Larsen grade III). Unconstrained arthroplasties have not performed as well as semiconstrained arthroplasties after previous radial head resections. However, both types of arthroplasties performed better in native elbows. Synovectomies should be reserved for less advanced disease states. Whaley A, Morrey BF, Adams R: Total elbow arthroplasty after previous resection of the radial head and synovectomy. J Bone Joint Surg Br 2005;87:47-53. Maenpaa HM, Kuusela PP, Kaarela KK, et al: Reoperation rate after elbow synovectomy in rheumatoid arthritis. J Shoulder Elbow Surg 2003;12:480-483.

Generally, patients cannot tolerate more than 5 degrees of hindfoot posting. Donatelli RA, Hurlbert C, Conaway D, et al: Biomechanics foot orthotics: A retrospective study. J Orthop Sports Phys Ther 1988;10:205-212. Michaud TM: Foot Orthoses and Other Forms of Conservative Foot Care. Baltimore, MD, Williams & Wilkins, 1993, pp 61-65, 186.

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.

50b 50c 50d 50e 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.

Treatment of shoulder instability with thermal devices has lead to numerous complications including recurrent instability, chondrolysis, stiffness, and capsular necrosis. This patient's findings are consistent with a heat-induced axillary nerve injury. Normal radiographs exclude extensive chondrolysis. Levine WN, Bigliani LU, Ahmad CS: Thermal capsulorrhaphy. Orthopedics 2004;27:823-826.

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

The appropriate placement of the anterolateral portal provides access to the lateral gutter of the joint while avoiding the superficial peroneal nerve. The safest location for the portal is approximately 4 mm lateral to the peroneus tertius tendon, the closest of the tendons listed to the anterolateral portal. Because the superficial peroneal nerve location is variable, attempts to visualize, palpate, or transilluminate the nerve are mandatory.

Documenting the status of recovery at this time is appropriate; therefore, repeat EMG studies should be conducted to check for early signs of reinnervation. Timing of nerve exploration in this setting is debated, with authors suggesting exploration if there is no sign of recovery at 6 to 9 months. Perlmutter GS: Axillary nerve injury. Clin Orthop 1999;368:28-36. Artico M, Salvati M, D'Andrea V, et al: Isolated lesions of the axillary nerves: Surgical treatment and outcome in twelve cases. Neurosurgery 1991;29:697-700. Vissar CP, Coene LN, Brand R, et al: The incidence of nerve injury in anterior dislocation of the shoulder and its influence on functional recovery: A prospective clinical and EMG study. J Bone Joint Surg Br 1999;81:679-685.

Posterior screw fixation of the upper cervical spine has gained a great deal of popularity due to its stable fixation, obviating the use of halo vest immobilization, and its high fusion rates. The use of screws in this location, however, has introduced a whole new set of potential complications. Vertebral artery injury is one of the most feared complications associated with screws in the C1/C2 region. This structure, however, is lateral and posterior at the C2 level and then penetrates the foramen transversarium of C1 to lie cephalad to the arch of C1 before entering the foramen magnum. It is the internal carotid artery that lies immediately anterior to the arch of C1 that is particularly at risk by anterior penetration of C1 lateral mass or C1-C2 transarticular screws as demonstrated by Currier and associates. The internal carotid artery lies posterior to the pharynx. The external carotid artery and the glossopharyngeal nerve are not at risk with this method of fixation. Currier BL, Todd LT, Maus TP, et al: Anatomic relationship of the internal carotid artery to the C1 vertebra: A case report of cervical reconstruction for chordoma and pilot study to assess the risk of screw fixation of the atlas. Spine 2003;28:E461-E467. Grant JC: Grant's Atlas of Anatomy, ed 6. Baltimore, MD, Williams & Wilkins, 1972.

Ackland and associates demonstrated that the failure to achieve early spinal clearance in an unconscious blunt trauma patient predisposed the patient to increased morbidity secondary to the prolonged used of cervical immobilization. They demonstrated that the four significant predictors of collar-related ulcers were ICU admission, mechanical ventilation, the necessity for cervical MRI, and the time to cervical spine clearance and collar removal. The risk of pressure-related ulceration increased by 66% for every 1-day increase in Philadelphia collar time and this highlights the need for definitive C-spine clearance. Ackland HM, Cooper DJ, Malham GM, et al: Factors predicting cervical collar-related decubitus ulceration in major trauma patients. Spine 2007;32:423-428.

The most common complication is anterior knee pain (57%). The knee pain is activity related (92%) and exacerbated by kneeling (83%). Although knee pain is the most common complication, most patients rate it as mild to moderate and only 10% are unable to return to previous employment. Some authors report less knee pain with a peritendinous approach when compared to a tendon-splitting approach. In one study, nail removal resolved pain in 27%, improved it in 70%, and made it worse in 3%. The incidence of the other complications was: infection 0% to 3%, nonunion 0% to 6%, and malunion 2% to 13%. Compartment syndrome is rare after nailing. Court-Brown CM: Reamed intramedullary tibial nailing: An overview and analysis of 1106 cases. J Orthop Trauma 2004;18:96-101. McQueen MM, Gaston P, Court-Brown CM: Acute compartment syndrome: Who is at risk? J Bone Joint Surg Br 2000;82:200-203.

Anterior coverage of the hip may be best estimated by the anterior center edge angle of Lequesne and de Seze (analogous to Wiberg's angle), which is measured on the well-defined faux profil view. Evaluation with CT scans also has been described. Klaue K, Wallin A, Ganz R: CT evaluation of coverage and congruency of the hip prior to osteotomy. Clin Orthop 1988;232:15-25.

Retrograde ejaculation is a sequela of injury to the superior hypogastric plexus. The structure needs protection, especially during anterior exposure of the lumbosacral junction. The use of monopolar electrocautery should be avoided in this region. The ideal exposure starts with blunt dissection just to the medial aspect of the left common iliac vein, sweeping the prevertebral tissues toward the patient's right side. Although erectile dysfunction can be seen after spinal surgery, it is not typically related to the surgical exposure because erectile function is regulated by parasympathetic fibers derived from the second, third, and fourth sacral segments that are deep in the pelvis and are not at risk with the anterior approach. The other choices are complications of spinal surgery but are not uniquely associated with an anterior L5-S1 exposure. Flynn JC, Price CT: Sexual complications of anterior fusion of the lumbar spine. Spine 1984;9:489-492. Watkins RG (ed): Surgical Approaches to the Spine, ed 1. New York, NY, Springer-Verlag, 1983, p 107.

45b Because the radiographs reveal poor regenerate bone, especially anteriorly and laterally, the first step in management is to slow the distraction rate. If this does not solve the problem, temporary reversal of the distraction, or "accordionization," can be used to induce a greater healing response. Maintaining the same distraction rate will further impair regenerate formation and delay healing. Bone grafting should be reserved as an option if decreasing the distraction rate or alternating a week of compression with a week of distraction fails to improve the callus formation. Repeat corticotomy is performed in patients with premature consolidation. Raney EM: Limb-length discrepancy, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 1519-1526.

Pediatric intracapsular hip fractures are challenging because of the high rates of complications, including osteonecrosis and varus malunion. These patients should be treated as emergencies. Principles of treatment include anatomic reduction with internal fixation. Screw fixation short of the physis is preferred and may need to be supplemented with spica cast immobilization. Fixation may be achieved with smooth pins across the physis when little metaphyseal bone is available. Fixation across the physis with threaded screws is acceptable only when the patient is close to skeletal maturity. Pediatric hip screws are appropriate if immediately available. Emergent open reduction, capsulotomy, or joint aspiration may decrease the rate of osteonecrosis. Cheng JC, Tang N: Decompression and stable internal fixation of femoral neck fractures in children can affect the outcome. J Pediatr Orthop 1999;19:338-343. Azouz EM, Karamitsos C, Reed MH, et al: Types and complications of femoral neck fractures in children. Pediatr Radiol 1993;23:415-420. Song KS, Kim YS, Sohn SW, et al: Arthrotomy and open reduction of the displaced fracture of the femoral neck in children. J Pediatr Orthop B 2001;10:205-210.

The patient has a distal biceps rupture. While the distal biceps contributes to elbow flexion, its main function is forearm supination. Baker BE, Bierwagen D: Rupture of the distal tendon of the biceps brachii: Operative versus non-operative treatment. J Bone Joint Surg Am 1985;67:414-417. D'Arco P, Sitler M, Kelly J, et al: Clinical, functional, and radiographic assessments of the conventional and modified Boyd-Anderson surgical procedures for repair of distal biceps tendon ruptures. Am J Sports Med 1998;26:254-261.

Glenoid dysplasia is an uncommon anomaly that usually has a benign course but may result in shoulder pain, arthritis, or multidirectional instability. Shoulder pain and instability often improve with shoulder strengthening exercises. Wirth MA, Lyons FR, Rockwood CA Jr: Hypoplasia of the glenoid: A review of sixteen patients. J Bone Joint Surg Am 1993;75:1175-1184.

Co-planing the distal clavicle may lead to painful acromioclavicular joints in up to 35% of patients; this is felt to be related to destabilizing the distal clavicle. Intra-articular diagnosis of synovitis, degenerative joint disease, and superior labrum anterior and posterior lesions would have been identified at initial arthroscopy (not necessarily seen in open surgery). Ganglions are seen on MRI. Fischer BW, Gross RM, McCarthy JA: Incidence of acromioclavicular joint complications after arthroscopic subacromial decompression. Arthroscopy 1999;15:241-248. Hazel RM, Tasto JP, Klassen J: Arthroscopic subacromial decompression: A 9-year follow-up. Arthroscopy 1998;14:419.

A concern in the multiply injured patient who has a pulmonary contusion is the potential for further pulmonary compromise because of embolization of marrow, blood clot, or fat during manipulation of the medullary canal. Recent evidence has shown that the presence of a lung injury is the most important determining factor in future deterioration. However, despite the lung injury and its potential consequences, this patient's femur fracture needs stabilization. Because damage control in the multiply injured patient requires a technique that can be performed rapidly and consistently, the treatment of choice is application of an external fixator. By placing two pins above and below the fracture and with longitudinal traction, the fracture is quickly realigned and stabilized. This allows the patient to be resuscitated and treated at a later date when definitive management of the fracture can be carried out. There is little difference between plate fixation and intramedullary nailing. Bosse MJ, MacKenzie EJ, Riemer BL, et al: Adult respiratory distress syndrome, pneumonia, and mortality following thoracic injury and a femoral fracture treated with either intramedullary nailing with reaming or with a plate: A comparative study. J Bone Joint Surg Am 1997;79:799-809. Scalea TM, Boswell SA, Scott JD, Mitchell KA, Kramer ME, Pollak AN: External fixation as a bridge to intramedullary nailing for patients with multiple injuries and with femur fractures: Damage control orthopedics. J Trauma 2000;48:613-623.

The maximum stress in a bone occurs at the periosteal surface (the greatest distance from the center of the bone). The magnitude of the stress is equal to the magnitude of the applied moment (M) multiplied by the distance to the surface (roughly the radius of the bone, r) divided by the area moment of inertia (I), so that stress = Mr/I. Of the possible answers, only area moment of inertia of the cross section contains any of these three items. The stress can also depend on the length of the bone, but it cannot be determined without knowing the location at which the bending load is applied, information that was not given in the problem. The type of structural support may influence local stresses where the support contacts the bone, but it has little effect on the maximum stress in the bone. The cross-sectional area is not as important as the area moment of inertia because the stress is not evenly distributed over the cross-section. Plastic modulus is a material property, not a geometric or structural property, and it does not affect stress. Hayes WC, Bouxsein ML: Biomechanics of cortical and trabecular bone: Implications for assessment of fracture risk, in Mow VC, Hayes WC (eds): Basic Orthopaedic Biomechanics, ed 2. New York, NY, Lippincott-Raven, 1997, pp 76-82.

This issue has been debated since Inman published his classic study on clavicular rotation in 1944. Subsequently, it has been shown by several authors that the clinical evaluation of patients with either coracoclavicular screws in place or with arthrodesis of the coracoclavicular reveals little to no loss of shoulder motion. This is most likely the result of synchronous motion of the scapula and clavicle in shoulder movements. Flatow EL: The biomechanics of the acromioclavicular, sternoclavicular, and scapulothoracic joints. Instr Course Lect 1993;42:237-245. Kenedy JC, Cameron H: Complete dislocation of the acromioclavicular joint. J Bone Joint Surg Br 1954;36:202-208. Rockwood CA Jr, Williams GR, Young CD: Disorders of the acromioclavicular joint, in Rockwood CA Jr, Matsen FA III (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1998, vol 1, pp 483-553.

A 30% to 50% loss of cervical range of motion is reported postoperatively in most patients following cervical laminoplasty. Inadvertent closure of the laminoplasty does occur but is rare. Laminoplasty is advocated in lieu of laminectomy to prevent progressive kyphosis and can effectively decompress the spinal cord. C5 nerve root palsies are a poorly understood but rare complication of surgical decompression for cervical spondylotic myelopathy. Emery SE: Cervical spondylotic myelopathy: Diagnosis and treatment. J Am Acad Orthop Surg 2001;9:376-388.

The patient has a proximal synostosis; therefore, resection of the synostosis is considered the best option to regain motion. While forearm osteotomy can place the hand in a more functional position, rotation will not be restored. Proximal radial excision can provide forearm rotation; however, this procedure is reserved for patients who have a proximal radioulnar synostosis that is too extensive to allow a safe resection, involves the articular surface, and is associated with an anatomic deformity. Motion will not be restored with dynamic splinting. Kamineni S, Maritz NG, Morrey BF: Proximal radial resection for posttraumatic radioulnar synostosis: A new technique to improve forearm rotation. J Bone Joint Surg Am 2002;84:745-751.

In a retrospective review of 10 patients treated with hemivertebra excision for hemivertebra in the levels of T12 to L3, the procedure was found to be safe and effective. The procedure provided an average curve correction of 67 degrees and was greatest in patients who were younger than age 4 years at the time of surgery. Long anterior and posterior fusion with instrumentation is not the treatment of choice at this age. Either anterior hemiepiphyseodesis or posterior hemiarthrodesis in this isolated hemivertebra setting would be inadequate. Brace treatment is ineffective in management of the primary curvature.

12b 12c The radiographs show a halo-like sclerotic margin around the tibial stem and lucency under the baseplate. The bone scan shows markedly increased uptake under the tibial component, particularly on the medial side (not diffusely through the knee as seen with infection). These studies indicate lack of bone ingrowth fixation of the cementless porous-coated tibial component. The recent report of Fehring and associates has identified failure of ingrowth of a porous-coated implant as a dominant mode of early failure of total knee arthroplasties. Fehring TK, Odum S, Griffin WL, Mason B, Nadaud M: Early failures of total knee arthroplasty. Clin Orthop 2001;392:315-318.

The annulus fibrosis has a multilayer lamellar architecture mode of type I collagen fibers. Each successive layer is oriented at 30 degrees to the horizontal in the opposite direction, leading to a "criss-cross" type pattern. This composition allows the annulus, which has the highest tensile modulus, to resist torsional, axial, and tensile loads.

In approximately 15% of children with Down syndrome, atlantoaxial instability develops because of ligament laxity, making them susceptible to spinal cord injury with relatively minor trauma. The American Academy of Pediatrics recommends lateral flexion-extension views of the cervical spine in any patient with Down syndrome who wishes to participate in sports. A normal ADI is up to 4 mm. Patients with Down syndrome with an ADI of more than 5 mm should not participate in contact sports or sports with a high risk for neck injury, such as diving, gymnastics, high jump, or butterfly stroke. Cervical fusion has a very high rate of complications in patients with Down syndrome and is recommended only for patients who have myelopathic signs or symptoms. Atlantoaxial instability in Down syndrome: Subject review. American Academy of Pediatrics Committee on Sports Medicine and Fitness. Pediatrics 1995;96:151-154. Tredwell SJ, Newman DE, Lockitch G: Instability of the upper cervical spine in Down syndrome. J Pediatr Orthop 1990;10:602-606.

39b 39c The MRI scans show coronal oblique and sagittal oblique views of a partial articular surface supraspinatus tear or tendon avulsion (PASTA lesion). The arthroscopic view is a posterior portal of the glenohumeral joint viewing the articular surface of the supraspinatus. These tears are a common source of shoulder pain and are often amenable to transtendon arthroscopic repair without detachment of the intact bursal surface. Sanders TG, Miller MD: A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the shoulder. Am J Sports Med 2005;33:1088-1105. McConville OR, Iannotti JP: Partial-thickness tears of the rotator cuff: Evaluation and management. J Am Acad Orthop Surg 1999;7:32-43.

The patient has spinal muscular atrophy, type 2. This type is intermediate in severity between the Werdnig-Hoffmann type (type 1) and the Kugelberg-Welander type (type 3). It normally manifests itself between the ages of 3 and 15 months. Survival until adolescence is common. All three types of spinal muscular atrophy have been linked to the SMN gene at the 5q12.2-13.3 locus. DNA testing is available and is preferred to muscle biopsy because it is less invasive and more definitive. Biros I, Forrest S: Spinal muscular atrophy: Untangling the knot? J Med Genet 1999;36:1-8.

Halo fixation is the most rigid form of cervical orthosis, but complications can arise from improper placement of the initial halo ring. A relatively safe zone for anterior pin placement is located 1 cm above the orbital rim and superior to the lateral two thirds of the orbit. This position avoids the supraorbital and supratrochlear nerves and arteries over the medial one third of the orbit. The more lateral positions in the temporal fossa have very thin bone and can interfere with the muscles of mastication. Posterior pin site locations are less critical; positioning on the posterolateral aspect of the skull, diagonal to the contralateral anterior pins, is generally desirable. Botte MJ, Byrne TP, Abrams RA, et al: Halo skeletal fixation: Techniques of application and prevention of complications. J Am Acad Orthop Surg 1996;4:44-53.

7b 7c 7d 7e The patient appears to be a borderline or unstable surgical patient following her initial trauma and spleenectomy (high base excess and low urine output). She needs continued resuscitation and minimal additional blood loss. This is best accomplished with irrigation and debridement of the ankle, external fixation of the ankle, foot, and femur, and splinting of the forearm. A traction pin for the femoral fracture will not control bleeding as well as an external fixator. Intramedullary nailing of the femur and open reduction and internal fixation of the forearm would be appropriate in patients that are euvolemic and stable. Pape HC, Hildebrand F, Pertschy S, et al: Changes in the management of femoral shaft fractures in polytrauma patients: From early total care to damage control orthopedic surgery. J Trauma 2002;53:452-461. Taeger G, Ruchholtz S, Waydhas C, et al: Damage control orthopedics in patients with multiple injuries is effective, time saving, and safe. J Trauma 2005;59:409-416. Harwood PJ, Giannoudis PV, van Griensven M, et al: Alterations in the systemic inflammatory response after early total care and damage control procedures for femoral shaft fracture in severely injured patients. J Trauma 2005;58:446-452.