100 Orthopedic MCQs: Trauma, Spine, Peds & Arthroplasty | Comprehensive ABOS Review

Unilateral sacralization of the fifth lumbar vertebra was first described by Bertolotti in 1917. Bertolotti's syndrome is present in 12% to 21% of the population. The altered biomechanics have been postulated to cause low back pain by placing increased stress on the adjacent cephalad disk, thus contributing to accelerated degenerative disk disease at this level. It has also been found that the neoarticulation between the enlarged transverse process and the sacrum and/or ilium may be a source of neural impingement on the exited L5 nerve root and results in radicular pain syndrome. Brault and associates reported on a case treated surgically at the Mayo Clinic, in which the pain generator was found to be the contralateral facet joint. Brault JS, Smith J, Currier BL: Partial lumbosacral transitional vertebra resection for contralateral facetogenic pain. Spine 2001;26:226-229. Quinlan JF, Duke D, Eustace S: Bertolotti's syndrome: A cause of back pain in young people. J Bone Joint Surg Br 2006;88:1183-1186.

Articular cartilage is a highly organized viscoelastic material, and load transmission depends on the specific composition of the extracellular matrix. Articular cartilage is devoid of neural, lymphatic, and blood vessel tissue. The extracellular matrix consists of water, proteoglycans, and collagen. Water comprises most of the wet weight (65% to 80%). Type II collagen comprises 95% of the collagen. The collagen and proteoglycan (keratan sulfate and chondroitin sulfate) matrix and its high water content are responsible for the mechanical properties of the articular cartilage. Buckwalter JA, Mankin HJ: Articular cartilage: Degeneration and osteoarthritis, repair, regeneration, and transplantation. Inst Course Lect 1998;47:487-504.

The main consequence of tumor invading the bone is activation of both osteoblasts and osteoclasts. However, the osteoclastic effect predominates in the majority of tumors early after the invasion of bone by tumor cells, causing resorption of bone. Cramer SF, Fried L, Carter KJ: The cellular basis of metastatic bone disease in patients with lung cancer. Cancer 1981;48:2649-2660.

Prepubescent athletes gain strength through neurogenic adaptations, including recruitment of motor units, reduced inhibition, and learned motor skills. Myogenic adaptations (muscle hypertrophy) occur after puberty and include increased contractile proteins, thickening of the connective tissue, and increased short-term energy sources such as creatine phosphate. Grana WA: Strength training, in Stanitski CL, DeLee JC, Drez D Jr (eds): Pediatric and Adolescent Sports Medicine. Philadelphia, PA, WB Saunders, 1994, pp 520-526.

This is a classic C6 nerve injury, and it is most likely the result of a herniated nucleus pulposus at C5-6. The C5 nerve root controls the elbow flexors, shoulder abductors, and external rotators. The C7 nerve root controls the elbow extensors, wrist pronators, and the triceps reflex. Standaert CJ: The patient history and physical examination: Cervical, thoracic and lumbar, in Herkowitz HN, Garfin SR, Eismont FJ, et al (eds): Rothman-Simeone The Spine, ed 5. Philadelphia, PA, Saunders Elsevier, 2006, vol 1, pp 171-186.

The radiographs reveal marked lateral subluxation of the patella in a patient who has recurrent patellar instability. The medial patellofemoral ligament is the main restraint to lateral subluxation of the patella. Boden BP, Pearsall AW: Patellofemoral instability: Evaluation and management. J Am Acad Orthop Surg 1997;5:47-57.

This child has the potential to walk and therefore should have all the contracted structures in the feet released as necessary to place the feet in a plantigrade position for fitting of ankle-foot orthoses. Physical therapy, manipulation, and casting may provide some benefit in a newborn with flexible feet but are not effective in an older infant with rigid clubfeet. Botulinum injections and tendon transfers are of no use because there are no muscles functioning below the knee. Tendon releases are more effective than tendon transfers in children with myelomeningocele. Mazur JM: Management of foot and ankle deformities in the ambulatory child with myelomeningocele, in Sarwark JR, Lubicky JP (eds): Caring for the Child with Spina Bifida. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2001, pp 155-160.

Exposure of polyethylene to radiation and then heating it to quench the free radicals leads to a cross-linked material. It converts a high molecular weight polyethylene macromolecule to an interpenetrating network structure of polymer chains. The ductility of the material is decreased, hence the greater risk of fracture. While the wear rate (measured as fewer and smaller particles) against a smooth counterface is markedly reduced, cross-linked polyethylene has shown a larger increase in wear rate when a rougher counterface is used compared to noncross-linked material. Due to reduced mechanical strength, highly cross-linked polyethylene is less resistant to abrasive wear.

The patient has not undergone a trial of foot-specific patient education and accommodative/therapeutic shoe wear. He must use therapeutic shoe wear at all times, as even the occasional use of pressure-concentrating shoe wear has a high likelihood of leading to the development of a diabetic foot ulcer. Pinzur MS, Kernan-Schroeder D, Emmanuele NV, et al: Development of a nurse-provided health system strategy for diabetic foot care. Foot Ank Int 2001;22:744-746. Pinzur MS, Shields N, Goelitz B, et al: American Orthopaedic Foot & Ankle Society shoe survey of diabetic patients. Foot & Ankle Int 1999;20:703-707.

The radiographs reveal a large femoral metaphyseal lytic lesion with well-defined borders. Joint space narrowing medially is consistent with polyethylene wear. The most likely diagnosis is particle-mediated osteolysis. Metastatic tumors and primary sarcomas adjacent to an arthroplasty are extremely rare. In addition, malignant tumors and infection would more likely reveal a destructive lesion with poorly defined borders and increased uptake on a bone scan. Stress shielding with massive bone loss has not been described in knee arthroplasty literature, although this entity has been observed in fully porous-coated femoral implants in total hip arthroplasty. Robinson EJ, Mulliken BD, Bourne RB, et al: Catastrophic osteolysis in total knee replacement: A report of 17 cases. Clin Orthop Relat Res 1995;321:98-105. Archibeck MJ, Jacobs JJ, Roebuck KA, et al: The basic science of periprosthetic osteolysis. Instr Course Lect 2001;50:185-195.

Patella baja is commonly encountered when converting a high tibial osteotomy (HTO) to a TKA. Patella baja most likely occurs because of scarring. Meding and associates' study did not show an increased rate of lateral release when converting a knee that had undergone a previous HTO. Yoshino N, Shinro T: Total knee arthroplasty after failed high tibial osteotomy, in Callaghan JJ, Rosenberg AG, Rubash HE, et al (eds): The Adult Knee. Philadelphia, PA, JB Lippincott, 2003, vol 2, pp 1265-1271.

Proprionobacter acnes has been a leading cause of indolent shoulder infections. During shoulder arthroscopy, the arthroscopic fluid may actually dilute the shoulder preparation and lead to a higher rate of infection during subsequent mini-open rotator cuff repair surgery. The remaining bacteria listed are rarely associated with shoulder infections after arthroscopy. Herrera MF, Bauer G, Reynolds F, et al: Infection after mini-open rotator cuff repair. J Shoulder Elbow Surg 2002;11:605-608.

Osteochondritis dissecans of the capitellum is seen most commonly in adolescent athletes. It should be distinguished from osteochondrosis of the capitellum (Panner's disease), a self-limiting condition seen in younger patients. Lesions are graded I through V based on radiographic and arthroscopic appearance. Grade I lesions show intact but soft cartilage. Grade II lesions show fissuring of the overlying cartilage. Grade III lesions show exposed bone or an attached osteoarticular flap that is not loose. Grade IV lesions show a loose but nondisplaced osteoarticular flap. Grade V lesions show a displaced fragment. Simple excision of the loose osteoarticular flap is the treatment of choice for grade IV and V lesions. More complex procedures such as drilling of the in situ lesion, bone grafting, or internal fixation are associated with significantly worse results. While some authors advocate abrasion chondroplasty, the long-term benefits of the procedure are yet to be proven. Baumgarten TE: Osteochondritis dissecans of the capitellum. Sports Med Arthroscopy Rev 1995;3:219-223.

A thoracotomy in an adult with idiopathic scoliosis causes a reduction in pulmonary function that often does not return to preoperative levels. What pulmonary function that does recover, recovers over many months. Long-term improvement in pulmonary function, compared to preoperative function, is rarely seen. This should be considered in planning surgical intervention in adults with scoliosis. Graham EJ, Lenke LG, Lowe TG, et al: Prospective pulmonary function evaluation following open thoracotomy for anterior spinal fusion in adolescent idiopathic scoliosis. Spine 2000;25:2319-2325.

The patient has a type IIIB patellar fracture (inferior pole fracture with an intact patellar tendon). Nonsurgical management is the treatment of choice if there is little displacement and the extensor mechanism is intact. Brown TE, Diduch DR: Fractures of the patella, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 3. Philadelphia, PA, Churchill Livingstone, 2001, vol 2, pp 1290-1312.

Chronic or neglected Achilles tendon ruptures can present a surgical problem. Ideally, end-to-end apposition of tendon should be attempted, but this should be accomplished without placing the foot in marked equinus. A defect of greater than 5 cm requires the use of a tendon transfer either alone or in combination with a V-Y advancement of the gastrocnemius. Because of its proximity to the Achilles tendon and its strength as a plantar flexor, the flexor hallucis longus is an ideal choice for this task. Studies have shown that early active range-of-motion exercises after an Achilles tendon repair is beneficial for tendon healing and improved clinical outcomes. Myerson M: Achilles tendon ruptures. Instr Course Lect 1999;48:219-230.

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

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.

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.

Persistent or recurrent symptoms after lumbar diskectomy are troublesome and can be difficult to assess. Gadolinium-enhanced MRI scans may be helpful. The images show enhancement about the left S1 root, a finding that is most consistent with perineural (epidural) fibrosis. The root itself does not enhance. Root enhancement has been associated with compressive radicular symptoms. A disk herniation does not enhance with gadolinium. A neurilemmoma enhances with gadolinium, but the involved root would be enlarged. There is no evidence of a fluid collection which would be consistent with an epidural abscess. Babar S, Saifuddin A: MRI of the post-discectomy lumbar spine. Clin Radiol 2002;57:969-981. Kikkawa I, Sugimoto H, Saita K, et al: The role of Gd-enhanced three-dimensional MRI fast low-angle shot (FLASH) in the evaluation of symptomatic lumbosacral nerve roots. J Orthop Sci 2001;6:101-109.

The patient has patellofemoral stress and a tight lateral retinaculum that has failed to respond to nonsurgical management; therefore, the most appropriate treatment includes an arthroscopic lateral retinacular release. A patellar restraining brace may aggravate the peripatellar pain by increasing pressure on the lateral facet. There is no evidence of patellar instability or significant malalignment; therefore, medial retinacular repair or a tibial tubercle transfer is not indicated. A modified Maquet tibial tubercle elevation would be considered only for significant patellofemoral arthrosis. Gambardella RA: Techical pitfalls of patellofemoral surgery. Clin Sports Med 1999;18:897-903.

The patient has macrodactyly involving the second ray, with significant enlargement of the width and height of the foot. The radiographs show widening of the interval between the first and second metatarsal and between the second and third metatarsal. With this degree of involvement, amputation of the second ray with excision of the overgrowth of affected soft tissue provides the most consistent desired reduction in foot size. A threaded Steinmann pin should be inserted across the remaining metatarsals until healing has occurred. Patients with macrodactyly should be examined to exclude neurofibromatosis type 1 and Klippel-Trenaunay-Weber syndrome.

In this age group of patients with arthrogryposis, open reduction through a medial approach is generally recommended. Open reduction through an anterior approach is reserved for patients in which a medial approach has failed or for older patients who require simultaneous femoral shortening and/or pelvic osteotomy. Closed treatment of unilateral hip dislocation in association with arthrogryposis is rarely successful. In bilateral hip dislocation associated with arthrogrypsis, the consensus is that the hips are best left unreduced because of the difficulty in obtaining excellent clinical and radiographic results bilaterally. Staheli LT, Chew DE, Elliot JS, Mosca VS: Management of hip dislocations in children with arthrogryposis. J Pediatr Orthop 1987;7:681-685. Szoke G, Staheli LT, Jaffe K, Hall JG: Medial-approach open reduction of hip dislocation in amyoplasia-type arthrogryposis. J Pediatr Orthop 1996;16:127-130.

The arrow points to the biceps femoris, which is inserted onto the fibula. The biceps femoris lies at the posterolateral aspect of the thigh. The semimembranosus and the semitendinous lie at the posterior medial aspect of the thigh. Gray H: Anatomy of the Human Body. Philadelphia, PA, Lea and Febiger, 1918, 2000.

Although this patient had a hemothorax, the bleeding has stopped and he has been resuscitated to a euvolemic status with a small base deficit and good urine output. External fixation of both femurs is an option but an unnecessary step in the treatment algorithm. Nork SE, Agel J, Russell GV, et al: Mortality after reamed intramedullary nailing of bilateral femur fractures. Clin Orthop Relat Res 2003;415:272-278.

The athlete has a corneal abrasion. Fluorescein staining identifies the break in the epithelium when examined with ultraviolet light. Topical antibiotics are used as prophylaxis against secondary bacterial infection, and the patch, applied with the lid closed, is used for comfort and to promote epithelial healing. The accompanying symptoms, including pain, tearing, and photophobia, are usually too intense to allow a return to play. Surgery is reserved for a corneal laceration with associated loss of the anterior chamber. While a proper fundoscopic examination may be a consideration, increased intraocular pressure is not typically associated with this injury. Traumatic hemorrhage in the anterior chamber (hyphema) necessitates strict bed rest during the early phases of healing; examination will most likely reveal the red fluid level of blood settling inferiorly in the anterior chamber. It is often associated with increased intraocular pressure. Brucker AJ, Kozart DM, Nichols CW, et al: Diagnosis and management of injuries to the eye and orbit, in Torg JS (ed): Athletic Injuries to the Head, Neck, and Face. St Louis, MO, Mosby-Year Book, 1991, pp 650-670.

Femoral acetabular impingement usually presents in active young adults with the slow onset of groin pain that often starts after a minor trauma. Physical examination reveals limitation of motion with a positive impingement test which consists of forceful internal rotation with flexion and adduction. Femoral acetabular impingement is a mechanism for the development of early osteoarthritis in nondysplastic hips. Surgical debridement of the impinging, nonspherical portion of the femoral head restores offset and improves the clearance of the head, thus preventing abutment of the neck against the acetabular rim. The patient has no evidence of osteonecrosis, developmental dysplasia of the hip, rheumatoid arthritis, or femoral neck fracture. Ganz R, Parvizi J, Beck M, et al: Femoroacetabular impingement: A cause for osteoarthritis of the hip. Clin Orthop 2003;417:112-120.

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

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.

In an infant younger than age 6 months with a complete dislocation of the hip that is not initially reducible, the Pavlik harness may be used for a trial of guided reduction. When the harness is used in these patients, the infant should be followed at weekly intervals to see if reduction has been achieved. If the hip does not reduce after 3 to 4 weeks of harness wear, the harness should be discontinued, and closed or open reduction should be considered to avoid secondary deformation of the posterolateral acetabulum, also known as Pavlik harness pathology. Changing to other abduction braces is not indicated. Jones GT, Schoenecker PL, Dias LS: Developmental hip dysplasia potentiated by inappropriate use of the Pavlik harness. J Pediatr Orthop 1992;12:722-726. Atar D, Lehman WB, Grant AD: Pavlik harness pathology. Isr J Med Sci 1991;27:325-330.

Although the patient has sustained a complete spinal cord injury, an anterior decompression, even performed late, can gain an additional level of root function. In the quadriplegic patient, this can mean the difference between dependent and independent function. Posterior procedures do not afford adequate access to the retropulsed bony fragments compromising the canal. Bohlman HH, Anderson PA: Anterior decompression and arthrodesis of the cervical spine: Long-term motor improvement. Part I: Improvement in incomplete traumatic quadriparesis. J Bone Joint Surg Am 1992;74:671-682.

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.

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.

The paravertebral musculature, the intervertebral disks, and the normal lordotic curvature of the cervical spine can absorb much of the imparted energy of collision. However, when the neck is flexed approximately 30 degrees, the normal lordotic curvature is flattened and the forces applied to the vertex of the head are directed at a straight segmented column. In this situation, the cervical spine is less able to absorb the applied force. With mounting axial load, compressive deformation occurs within the intervertebral disks, causing angular deformation and buckling. The spine will fail in flexion, with resultant fracture, subluxation, or dislocation. A rotatory component added to axial compression can cause concomitant extension, rotation, and shear injury patterns. The National Football Head and Neck Injury Registry has made two recommendations to the NCAA Football Rules Committee to minimize the risk of such injuries: (1) No player should intentionally strike an opponent with the crown or top of the helmet; and (2) No player should deliberately use his helmet to butt or ram an opponent. Thomas BE, McCullen GM, Yuan HA: Cervical spine injuries in football players. J Am Acad Orthop Surg 1999;7:338-347.

Most patients with a significant recurrent neuroma will not obtain relief with conservative methods. Pain results from a stump neuroma at the weight-bearing area from too short of a resection of the nerve or from regrowth of the remaining nerve end. Although steroid injection may be helpful in localizing symptoms or providing temporary relief, it rarely cures a stump neuroma. Orthotics with a metatarsal pad will likely increase pressure and pain at the neuroma site. Physical therapy could temporize the symptoms but will not address the underlying problem. Similarly, bone decompression alone will not alter the location of the neuroma stump. Revision of the nerve to a more proximal level off of the weight-bearing area is the most likely method to succeed. A plantar approach facilitates identification and ability to revise the nerve to a more proximal level. 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. Johnson JE, Johnson KA, Unni KK: Persistent pain after excision of an interdigital neuroma: Results of reoperation. J Bone Joint Surg Am 1988;70:651-657. Beskin JL, Baxter DE: Recurrent pain following interdigital neurectomy: A plantar approach. Foot Ankle 1988;9:34-39.

CMT is characterized by a cavovarus foot position that increases weight-bearing stresses along the lateral border. Removal of the fifth metatarsal head carries the risk of creating a transfer lesion at the fourth metatarsal head, particularly with a cavovarus foot. Claw toes are common in CMT, but the fifth toe would be flail in this situation. Ulceration is unlikely given the lack of underlying bone. Peroneal atrophy is associated with CMT but would not be a complication of this procedure. Charcot arthropathy is a neuropathic process frequently seen in individuals with diabetes mellitus. Kitaoka HB, Holiday AD Jr: Metatarsal head resection for bunionette: Long-term followup. Foot Ankle 1991;11:345-349.

Dense pods of ingrowth into the porous coating of cementless ingrowth sockets are seen. Channels through the non-ingrown portion allow access to the trabecular bone of the ilium. Polyethylene wear debris can enter these areas through screw holes. Expansile, lytic lesions can result, which can become large without compromising implant fixation. Loosening is late and results from catastrophic loss of bone. A well-fixed acetabular component with a modular design, a well-designed locking mechanism, and a good survivorship history is a candidate for exchange of the liner and grafting of the osteolytic lesion. Ries MD: Complications in primary total hip arthroplasty: Avoidance and management. Wear. Instr Course Lect 2003;52:257-265. Dumbleton JH, Manley MT, Edidin AA: A literature review of the association between wear rate and osteolysis in total hip arthroplasty. J Arthroplasty 2002;17:649-661.

The motor dysfunction in Charcot-Marie-Tooth disease involves the tibialis anterior muscle. Charcot-Marie-Tooth disorders most commonly cause distal motor dysfunction in the foot intrinsics, anterior compartment musculature, and peroneals. There is evidence that the peroneus brevis is affected selectively and the peroneus longus is spared. This is based on clinical muscle testing, muscle cross-sections on MRI, and electrodiagnostic testing. Mann RA, Missirian J: Pathophysiology of Charcot-Marie-Tooth disease. Clin Orthop 1988;234:221-228.

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

Chronic dislocation of the patella is occasionally seen in patients with Down syndrome. In early childhood, patellar realignment may restore stability of the patellae. In later childhood, bony changes in the patellar groove interfere with stability, even if surgical realignment is performed. Realignment can also lead to increased knee pain postoperatively. In asymptomatic patients who are able to extend their knees, continued observation is the management of choice. Dugdale TW, Renshaw TS: Instability of the patellofemoral joint in Down syndrome. J Bone Joint Surg Am 1986;68:405-413.

The steel shank is a flat 1-inch steel strip placed between layers of the shoe to extend the foot lever and prevent deformity at the toe break seen following a partial first ray amputation. A rocker sole may be added as well to facilitate transition from foot flat to the toe-off phase of gait. Proper shoe fit is important, but "snug" fitting shoes in a patient with peripheral neuropathy and likely fluctuations in volume from intermittent swelling are to be avoided. A custom shoe is an unnecessary expense. The patient has at least 10 degrees of dorsiflexion at the ankle with an intact anterior tibialis muscle; therefore, catching the sole on carpeting should not be a problem. Philbin TM, Leyes M, Sferra JJ, et al: Orthotic and prosthetic devices in partial foot amputations. Foot Ankle Clin 2001;6:215-228.

Displaced greater tuberosity fractures often will block abduction and/or external rotation by impinging on the underside of the acromion or posterior glenoid. The indications for open reduction and internal fixation are 1 cm of displacement or 45 degrees of rotation of the tuberosity fracture. Surgical treatment has recently been recommended for 0.5 cm of tuberosity displacement. Neer CS II: Displaced proximal humeral fractures: II. Treatment of three-part and four-part displacement. J Bone Joint Surg Am 1970;52:1090-1103.

Billote and associates compared patients with normal baseline hemoglobin levels who did and did not donate autologous blood prior to total hip arthroplasty. No patients received allogeneic blood perioperatively, and the autologous donors had significantly lower hemoglobin levels at the time of surgery and in the recovery room. Of the autologous donors, 69% received an autologous transfusion. The authors concluded that autologous donation was unnecessary in patients undergoing primary total hip arthroplasty who had a normal hemoglobin. Billote D, Glisson SN, Green D, Wixson RL: A prospective, randomized study of preoperative autologous donation for hip replacement surgery. J Bone Joint Surg Am 2002;84:1299-1304.

The axial views show fusion of the talus and calcaneus at the medial facet (talocalcaneal coalition). Peroneal spastic flatfoot is a descriptive term applying to the symptoms of painful flatfoot associated with apparent peroneal spasm and is sometimes caused by tarsal coalition; however, this is not the most appropriate diagnosis for this patient. Flexible flatfoot with a short Achilles tendon often causes symptoms similar to the ones listed above, but subtalar motion should be normal. A diagnosis of calcaneonavicular coalition can be made based on plain oblique views of the foot but is not seen in these views. Posterior tibial tendon dysfunction in the absence of other pathology is uncommon in children. Vincent KA: Tarsal coalition and painful flatfoot. J Am Acad Orthop Surg 1998;6:274-281.

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.

The majority of patients with thoracolumbar burst fractures without neurologic deficit can be effectively treated with a TLSO or a hyperextension body cast. Indications for surgery are neurologic deficit and/or significant deformity (greater than 50% loss of anterior vertebral body height or marked kyphosis). Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.

Traumatic posterior instability is a common finding in football players, especially in the blocking positions as well as in the defensive linemen and linebackers. A traumatic blow to the outstretched arm results in posterior glenohumeral forces. Labral detachment at the glenoid rim is common. Patients report slipping or pain with posteriorly directed pressure. Rarely do these patients have true dislocations that require reduction; however, recurrent episodes of subluxation or pain are not uncommon. Posterior repair has been shown to be successful in the treatment of traumatic instability. Bottoni CR, Franks BR, Moore JH, et al: Operative stabilization of posterior shoulder instability. Am J Sports Med 2005;33:996-1002. Williams RJ III, Strickland S, Cohen M, et al: Arthroscopic repair for traumatic posterior shoulder instability. Am J Sports Med 2003;31:203-209.

The CT scan reveals a hook of the hamate nonunion with irregular resorption at the fracture site, which is at the base of the hamate. Symptomatic relief of the pain and discomfort has been well documented after excision of the hook of the hamate. Ultrasound therapy will not provide long-term symptomatic relief or induce nonunion healing. MRI for further soft-tissue evaluation is inappropriate because this is a bony problem; the bony architecture of the wrist is best visualized by CT. Open reduction and internal fixation of the hook of the hamate does not provide the symptomatic relief that is found with excision of the hook of the hamate. In addition, the technical difficulties and relative risk of persistent nonunion after open reduction and internal fixation are not merited when hamate excision can be effected easily and causes no long-term untoward effects. Electrodiagnostic evaluation is inappropriate because there is no history of the persistent numbness and tingling that is found in peripheral compression neuropathies. Stark HH, Chao EK, Zemel NP, Rickard TA, Ashworth CR: Fracture of the hook of the hamate. J Bone Joint Surg Am 1989;71:1206-1207. Failla JM: Hook of hamate vascularity: Vulnerability to osteonecrosis and nonunion. J Hand Surg Am 1993;18:1075-1079. Carter PR, Easton RG, Littler JW: Ununited fracture of the hook of the hamate. J Bone Joint Surg Am 1977;59:583-588.

The patient has a nonunion at the subtalar joint because of poor preparation of the arthrodesis site with incomplete removal of the articular cartilage. Clinically, he has arthritis at the transverse tarsal joint. Casting with a bone stimulator is not expected to result in a union of the subtalar arthrodesis. To address both the subtalar nonunion and the transverse tarsal joint arthritis, revision of the subtalar arthrodesis and conversion to a triple arthrodesis is the preferred option. Graves SC, Mann RA, Graves KO: Triple arthrodesis in older adults: Results after long-term follow-up. J Bone Joint Surg Am 1993;75:355-362. Haddad SL, Myerson MS, Pell RF IV, Schon LC: Clinical and radiographic outcome of revision surgery for failed triple arthrodesis. Foot Ankle Int 1997;18:489-499. Sangeorzan BJ, Smith D, Veith R, Hansen ST Jr: Triple arthrodesis using internal fixation in treatment of adult foot disorders. Clin Orthop 1993;294:299-307. Sangeorzan BJ: Salvage procedures for calcaneus fractures. Instr Course Lect 1997;46:339-346.

This is a classic appearance for an osteosarcoma. The radiographs reveal a mixed osteolytic and osteoblastic lesion in a skeletally immature patient in the distal right femoral metaphysis. The pain pattern with progressive symptoms leading to the presence of night pain is also typical for this condition. The biopsy specimen reveals pleomorphic cells and the presence of osteoid. The current standard of care in the treatment of osteosarcoma is neoadjuvant chemotherapy followed by surgical resection or amputation followed by additional postoperative chemotherapy. Osteosarcoma is not radiosensitive. Wold LE, Adler CP, Sim FH, et al: Atlas of Orthopedic Pathology, ed 2. Philadelphia, PA, WB Saunders, 2003, p 179.

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

Intravenous fluid administration is the best first step to treat the hypercalcemia of malignancy. Many of these patients are dehydrated, and the increased serum calcium impairs the ability of the kidney to concentrate the urine. The decreased glomerular filtration rate secondary to the hypovolemia also leads to increased tubular resorption of calcium. The establishment of normovolemia will help promote increased urinary excretion of calcium. Lasix can also be used to help promote calciuria. Mithramycin is an antibiotic derived from Streptomyces plicatus. It is part of a group of drugs referred to as chromomycin antibiotics and is the only one of this group used clinically in the United States. It is rarely used in cancer chemotherapy because of its toxicity. A number of drug-related deaths have occurred from the use of mithramycin. Its use is now limited to the treatment of hypercalcemia associated with malignancy where it is used in lower dosage than that used for the treatment of tumors. Methotrexate has no role in the treatment of hypercalcemia of malignancy. While intravenous bisphosphonates are helpful in slowing progression of metastases and may help lower cerum calcium, they are not appropriate in the emergent treatment of hypercalcemia in the metastatic cancer patient.

Early mobilization and resumption of normal activities immediately after neck sprain has been shown to improve functional outcome and decrease subjective symptoms as measured 6 months after injury. Borchgrevink GE, Kaasa A, McDonagh D, Stiles TC, Haraldseth O, Lereim I: Acute treatment of whiplash neck injuries: A randomized trial during the first 14 days after a car accident. Spine 1998;23:25-31.

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

Scapular body fractures in children are rare and are often associated with other injuries of the chest and thorax. Management is generally nonsurgical, unless the injury is open, and usually consists of support with a sling and gentle range-of-motion exercises to minimize shoulder stiffness. Green N, Swiontkowski M: Skeletal Trauma in Children, ed 2. Philadelphia, PA, WB Saunders, 1998, vol 3, pp 319-341.

Osteochondritis dissecans occurs in the older child or adolescent (typically older than age 13 years). It involves the lateral compartment. The etiology is felt to be microtraumatic vascular insufficiency from repetitive rotatory and compressive forces. MRI typically shows separation of cartilage from the capitellum and chondral fissuring. Panner's disease is usually seen in children younger than age 10 years, involves the entire capitellar ossific nucleus, and resolves typically with no residual deformity or late sequelae. There is no evidence of ligamentous injury. Defelice GS, Meunier MJ, Paletta GA: Elbow injury in the adolescent athlete, in Altchek DW, Andrews JR (eds): The Athlete's Elbow. New York, NY, Lippincott Williams & Wilkins, 2001, pp 231-248.

The most common location of osteosarcoma is the knee area (50% to 55%), followed by the proximal humerus and iliac wing. The most commonly involved long bone is the femur (40% to 45%), followed by the tibia (15% to 25%). Within these bones, tumors are typically adjacent to the epiphyses in most patients. The flat bones of the pelvis and spine are less frequently involved. Malawer MM, Sugarbaker PH, Malawer M: Musculoskeletal Cancer Surgery: Treatment of Sarcomas and Allied Diseases. Kluwer Academic Publishers, 2001.

In a review of the practical applications of antibiotic-loaded bone cement for the treatment of the infected total joint arthroplasties, Hanssen and Spangehl described commercially available antibiotic-loaded bone cement as low-dose antibiotic cements. These cements generally contained 0.5 g of either tobramycin or gentamicin per 40 g of cement. They are indicated for use in prophylaxis and not for treatment of infected total joint arthroplasties. High-dose antibiotic-loaded bone cements are described as those containing greater than 1.0 g of antibiotic per 40 g of cement. Effective elution levels have been documented with 3.6 g tobramycin and 1.0 g vancomycin per 40 g of bone cement. This was documented by Penner and associates. Furthermore, it was shown that the combination of the two antibiotics in the bone cement improved the elution of both antibiotics. Hanssen AD, Spangehl MJ: Practical applications of antibiotic-loaded bone cement for treatment of infected joint replacements. Clin Orthop 2004;427:79-85.

The radiograph reveals developmental dysplasia of both hips. The patient has classic anterolateral undercoverage of the femoral head on the right side as demonstrated by a high acetabular index (measured at 27 degrees). Anterior undercoverage can be determined by drawing the marking for the anterior wall that fails to overlap the femoral head in this patient. Currently in North America, the most accepted surgical management for symptomatic dysplasia of the hip with good joint space is a Bernese (Ganz) periacetabular osteotomy. Surgical dislocation of the hip and femoroacetabular osteoplasty may be considered for patients with symptomatic femoroacetabular impingement of the hip. Ganz R, Klaue K, Vinh TS, et al: A new periacetabular osteotomy for the treatment of hip dysplasias: Technique and preliminary results. Clin Orthop 1988;232:26-36.

The radiograph shows a comminuted proximal ulnar fracture. The most reliable fixation is a posterior plate, acting as a tension band plate. The fracture involves the proximal shaft of the ulna; therefore, a 3.5-mm compression plate or one of similar size should be used to provide adequate stability. Kirschner wires and tension band wires do not provide axial stability of the comminution of the ulna. Compression screws alone will most likely fail and will not provide axial rotational stability to the construct. A medial plate will not resist the distraction forces across this fracture. McKee MD, Seiler JG, Jupiter JB: The application of the limited contact dynamic compression plate in the upper extremity: An analysis of 114 consecutive cases. Injury 1995;26:661-666.

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

The radiographs show an elbow dislocation associated with a comminuted radial head fracture. In the setting of comminution and instability, factures of the radial head are best managed with an arthroplasty rather than open reduction and internal fixation. Resection of the radial head will worsen the instability and is not recommended. Silastic radial head replacements are contraindicated. Hildebrand KA, Patterson SD, King GJ: Acute elbow dislocations: Simple and complex. Orthop Clin North Am 1999;30:63-79.

Although obesity can make brace or halo wear difficult, it has not been associated with an increased risk for nonunion. Carson GD, Heller JG, Abitbol JJ, et al: Odontoid fractures, in Levine AM, Eismont FJ, Garfin SR, et al (eds): Spine Trauma. Philadelphia, PA, WB Saunders, 1998, pp 235-238.

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.

Improved peak-to-load failure data have been demonstrated by reconstruction of the sternoclavicular joint using a semitendinosis graft in a figure-of-eight pattern through the clavicle and manubrium. Resection of the medial clavicle, which compromises the integrity of the costoclavicular ligament, results in medial clavicular instability. Rockwood CA, Wirth MA: Disorders of the sternoclavicular joint, in Rockwood CA, Matsen FA, Wirth MA, et al (eds): The Shoulder. Philadelphia, PA, WB Saunders, 2004, vol 2, pp 608-609.

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.

The patient has a dislocation of the elbow with displaced coronoid process and radial head fractures. The elbow is extremely unstable after this injury, and recurrent dislocation in a splint is the most common early complication. Skeletal stabilization of the fractures is required to restore stability of the joint. Characteristics of the fractures will determine the techniques required to restore stability. Ring D, Jupiter JB, Zilberfarb J: Posterior dislocation of the elbow with fractures of the radial head and coronoid. J Bone Joint Surg Am 2002;84:547-551.

The history, examination, and MRI scan findings are consistent with a midsubstance partial rupture of the rectus femoris muscle. This is an injury masquerading as a "pseudo tumor." The lack of an appreciable mass effect on the T1-weighted MRI scan, the defined fluid signal on the T2-weighted scans, and the lack of significant contrast enhancement after gadolinium are all most consistent with injury rather than a neoplasm. Most of these injuries respond to nonsurgical management; a few will benefit from late debridement and repair if symptoms fail to resolve in 3 to 6 months. The treatment of choice is nonsurgical management with a follow-up MRI scan to verify that the findings are resolving. Hughes C IV, Hasselman CT, Best TM, et al: Incomplete, intrasubstance strain injuries of the rectus femoris muscle. Am J Sports Med 1995;23:500-506.

The patient has a fracture-dislocation of the radiocarpal joint. Attached to the large radial styloid fragment are the extrinsic wrist ligaments to the carpus. This injury should be treated with open reduction and internal fixation of the styloid fracture. Radiolunate fusion or extrinsic ligament repair is suggested when the extrinsic ligaments are ruptured, resulting in ulnar translocation of the carpus. Dumontier C, Meyer ZU, Reckendorf G, et al: Radiocarpal dislocations: Classification and proposal for treatment: A review of twenty-seven cases. J Bone Joint Surg Am 2001;83:212.

Posterior atlantoaxial arthrodesis predictably relieves pain associated with arthrosis of the atlantoaxial joints. Typically, these patients have pain at the base of the occiput and in the most cephalad portion of the posterior aspect of the neck. Associated headache is common and often severe. Pain is aggravated by rotation but usually not by flexion and extension. Diagnostic blocks of the C1-C2 joint and the greater occipital nerve may be helpful to confirm the diagnosis preoperatively. Ghanayem AJ, Leventhal M, Bohlman HH: Osteoarthrosis of the atlanto-axial joints: Long-term follow-up after treatment with arthrodesis. J Bone Joint Surg Am 1996;78:1300-1307.

The radiograph shows a complete acromioclavicular separation. Because the patient is a professional athlete who is unable to participate, surgery is indicated. Chronic separations, especially those with previous trauma from joint pinning, should be treated with resection of the distal clavicle and stabilization to the coracoid. Some type of biologic reconstruction of the coracoclavicular ligaments is generally recommended. Open repair of the ligaments is generally not possible in such a delayed fashion. Screw fixation alone will not provide a lasting solution as the screws usually need to be removed, leaving no fixation in place. Reconstruction using the coracoacromial ligament is generally recommended with coracoclavicular fixation to protect the repair while it heals. Nuber GW, Bowen MK: Disorders of the acromioclavicular joint: Pathophysiology, diagnosis and management, in Iannotti JP, Williams GR (eds): Disorders of the Shoulder: Diagnosis and Management. Philadelphia, PA, Lippincott Williams and Wilkins, 1999.

The radiographs show ankylosing spondylitis with sclerosis of the sacroiliac joints and a "bamboo spine" in the lumbar region. HLA-B27 is positive in 80% to 90% of patients with ankylosing spondylitis and in about 8% of the general population. The findings do not represent diffuse idiopathic skeletal hyperostosis (DISH), which is a radiographic diagnosis in which there are three consecutive levels of nonmarginated osteophytes without disk degeneration. Calin A: Ankylosing spondylitis. Clin Rheum Dis 1985;11:41-60. Booth R, Simpson J, Herkowitz H: Arthritis of the spine, in Herkowitz HH (ed): The Spine, ed 4. Philadelphia, PA, WB Saunders, 1992, p 431.

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.

Most closed simple dislocations are best managed with early range of motion. Posterior dislocation typically occurs through a posterolateral rotatory mechanism. When placed in pronation, the elbow has greater stability when the medial ligamentous structures are intact. In traumatic dislocations, MRI rarely provides additional information that will affect treatment. In elbows that remain unstable, primary repair is preferred over ligament reconstruction. Cast immobilization increases the risk of arthrofibrosis.

The radiographs confirm a slipped capital femoral epiphysis of the left hip, as well as a widened growth plate on the contralateral hip. This is considered a stable slip because the patient is able to walk. Treatment options for stable slips include in situ pinning, bone graft epiphysiodesis, and in some centers severe slips are treated with primary osteotomy and epiphyseal fixation. Percutaneous in situ fixation is the most popular and widely used method of treatment. This juvenile patient has an endocrine condition and a widened growth plate on the right side; therefore, strong consideration should be given to pinning the contralateral hip "pre-slip." Muscle strengthening, hip spica casting, and closed reduction have no place in the primary treatment of a stable slipped capital femoral epiphysis. Loder RT, Richards BS, Shapiro PS, et al: Acute slipped capital femoral epiphysis: The importance of physeal stability. J Bone Joint Surg Am 1993;75:1134-1140. Loder R, Wittenberg B, DeSilva G: Slipped capital femoral epiphysis associated with endocrine disorders. J Pediatr Orthop 1995;15:349-356.

Unlike malignant bone tumors, malignant soft-tissue tumors usually are asymptomatic and present with the presence of a mass. Malignant soft-tissue tumors enlarge by centrifugal growth, creating a mass while compressing surrounding tissue. Symptoms may develop as the result of direct compression on neurovascular structures as the tumor enlarges. This is especially true in the pelvis where the tumor can enlarge appreciably without being noticed. However, in the extremities, the tumor is most often apparent before neurologic symptoms develop. An asymptomatic mass is not necessarily benign; therefore, biopsy should not be delayed. It is uncommon for a malignant soft-tissue mass to be discovered incidentally. Soft-tissue tumors are not typically apparent on radiographs; they are best identified with MRI. Brouns F, Stas M, De Wever I: Delay in diagnosis of soft tissue sarcomas. Eur J Surg Oncol 2003;29:440-445. Rougraff B: The diagnosis and management of soft tissue sarcomas of the extremities in the adult. Curr Probl Cancer 1999;23:1-50.

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

Local control of osteosarcoma consists of wide resection and reconstruction. Radiation therapy is not recommended except in unresectable lesions or for palliation. Curettage and bone grafting result in intralesional resection with an unacceptable high rate of local recurrence. Chemotherapy alone is not adequate for local control. Simon M, Springfield D, et al: Osteogenic Sarcoma: Surgery for Bone and Soft Tissue. Philadelphia, PA, Lippincott Raven, 1998, p 274.

The ground glass appearance on the radiograph, the hot bone scan, and histologic findings of bony spicules without osteoblastic rimming in a background of bland fibrous tissue all suggest fibrous dysplasia. Stress-related pain is common with activity because of the dysplastic bone. Parosteal osteosarcomas are surface lesions. Simple cysts, aneurysmal bone cysts, and eosinophilic granuloma are all possible radiographically; however, the histology is most consistent with fibrous dysplasia. Harris WH, Dudley HR Jr, Barry RS: The natural history of fibrous dysplasia: An orthopaedic, pathological and roentgenographic study. J Bone Joint Surg Am 1962;44:207.

The difference in the clinical results combined with the laboratory findings points to infection. While there is a significant risk of false-positive findings with aspiration, the fact that two successive aspirations grew the same organism strongly suggests infection. The radiograph shows that there is more radiolucency around the left acetabular component than the right component. White RE: Evaluation of the painful total hip arthroplasty, in Callaghan JJ, Rosenberg AG, Rubash HE (eds): The Adult Hip. Philadelphia, PA, Lippincott-Raven, 1998, vol 2, pp 1377-1385.

While difficult to appreciate on the AP radiograph of the shoulder, the increased physeal signal demonstrated on the axial MRI scan is consistent with a nondisplaced growth plate fracture. A comparison radiograph of the left shoulder also could be considered and the injured shoulder evaluated for physeal widening. Proximal humeral fractures in children are somewhat unusual, representing less than 1% of all fractures seen in children and only 3% to 6% of all epiphyseal fractures. Physeal injuries are classified according to the Salter-Harris classification scheme. Salter-Harris type I fractures represent approximately 25% of physeal injuries to the proximal humerus in adolescents. The proximal humeral physis is responsible for 80% of the longitudinal growth of the humerus; therefore, there is tremendous potential for remodeling of fractures in this region. Management for nondisplaced Salter-Harris type I fractures is limited to a short period of immobilization followed by a gradual return to activities as clinical symptoms resolve. Curtis RJ, Rockwood CA Jr: Fractures and dislocations of the shoulder in children, in Rockwood CA Jr, Matsen FA III (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1990, pp 991-1007.

The main arterial supply to the humeral head is provided by the ascending branch of the anterior humeral circumflex artery and its intraosseous continuation, the arcuate artery. There are significant intraosseous anastomoses between the arcuate artery, the posterior humeral circumflex artery through vessels entering the posteromedial aspect of the proximal humerus, the metaphyseal vessels, and the vessels of the greater and lesser tuberosities. Four-part fractures and dissection during exposure affect perfusion of the humeral head. Brooks CH, Revell WJ, Heatley FW: Vascularity of the humeral head after proximal humeral fractures: An anatomical cadaver study. J Bone Joint Surg Br 1993;75:132-136.

Most patients who undergo transmetatarsal amputation do not require custom shoe wear or an orthosis above the ankle. A molded toe filler is used to prevent excessive shear that can lead to ulceration. Use of a soft toe filler without stiffening of the sole results in excessive flexibility from the shortened lever arm, which reduces the efficiency of gait. A firm footplate or carbon fiber base adds rigidity to aid in push-off. A rocker bottom also may be added to the shoe. Philbin TM, Leyes M, Sferra JJ, Donley BG: Orthotic and prosthetic devices in partial foot amputations. Foot Ankle Clin 2001;6:215-228.

This is a classic situation for a distal phalanx tuft fracture with associated nail bed injury and subungual hematoma. In general, when the subungual hematoma is greater than 50% of the surface area under the nail plate, treatment should consist of nail plate removal, nail bed repair, oral antibiotics, and a fingertip splint. Oral antibiotics and fingertip splinting alone do not address the nail bed laceration, which will most likely lead to nail plate deformity if not repaired. Kirschner pin stabilization is not indicated because these fractures are nondisplaced and usually are inherently stable after nail bed repair. The use of IV antibiotics alone does not address the nail bed laceration surgically. Casting, followed by hydrotherapy and topical antibiotics, is not indicated because it does not address the nail bed laceration. Further, a nondisplaced distal phalangeal tuft fracture does not require cast immobilization. Stern PJ: Fractures of the metacarpals and phalanges, in Green DP, Hotchkiss RN, Pederson WC (eds): Green's Operative Hand Surgery, ed 4. Philadelphia, PA, 1999, pp 711-771.

Pediatric bony Chance fractures occur following severe flexion injuries as seen after motor vehicle accidents with lap belt restraints. There is a high rate of associated intra-abdominal injuries. In the absence of associated injuries, these fractures are best treated with immobilization. Bed rest is not necessary. Surgical fixation usually is not needed. Surgical stabilization and two-level fusion may be indicated in select individuals with progressive kyphosis of more than 25 degrees or other conditions that preclude cast or brace immobilization. Greenwald TA, Mann DC: Pediatric seatbelt injuries: Diagnosis and treatment of lumbar flexion-distraction injuries. Paraplegia 1994;32:743-751. Glassman SD, Johnson JR, Holt RT: Seatbelt injuries in children. J Trauma 1992;33:882-886.

Nearly all approaches to shoulder arthroplasty require detachment of the subscapularis tendon from the humerus and subsequent repair. Healing of this tenotomy is one of the limiting factors in postoperative recovery. Failure of the tenotomy repair must be recognized and treated early with repeat repair or pectoralis muscle transfer for optimal results. Failure of the subscapularis is diagnosed clinically as excessive external rotation and weakness, especially in the lift-off or belly press position. Muscle testing can be difficult in the postoperative period and may not be possible to assess in those positions. Although MRI might be useful to confirm the diagnosis, studies may be limited by artifact. CT or electromyography would not be diagnostic. Wirth MA, Rockwood CA Jr: Complications of total shoulder-replacement arthroplasty. J Bone Joint Surg Am 1996;78:603-616.

Injury to the spinal accessory nerve can occur after penetrating trauma to the shoulder. Blunt trauma may also cause loss of trapezius function. Most commonly, surgical dissection in the posterior triangle of the neck, such as lymph node biopsy, may expose the nerve to possible damage. Surgical repair of the nerve may be considered up to 1 year after injury; after this time muscle transfer is usually associated with a better functional outcome. Steinman SP, Spinner RJ: Nerve problems in the shoulder, in Rockwood CA, Matsen FA, Wirth MA, et al (eds): The Shoulder. Philadelphia, PA, WB Saunders, 2004, vol 2, pp 1013-1015.

Based on the history, examination, and radiograph, the patient has typical degenerative arthritis of the elbow. This condition is found almost exclusively in men, and there is almost universally a history of repetitive heavy use or overuse of the elbow. Patients report pain at terminal extension and usually have a flexion contracture. Radiographs reveal osteophytes on the coronoid and olecranon and in the coronoid and olecranon fossae. The osteophytes are often associated with loose bodies that sometimes are attached to the soft tissues. Treatment should consist of removal of all loose bodies and impinging osteophytes using open technique or by arthroscopy. The capsular contractures should be released at the same time. Kasser JR (ed): Orthopaedic Knowledge Update 5. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1996, pp 283-294. Morrey BF: Primary degenerative arthritis of the elbow: Treatment by ulnohumeral arthroplasty. J Bone Joint Surg Br 1992;74:409-413. Redden JF, Stanley D: Arthroscopic fenestration of the olecranon fossa in the treatment of osteoarthritis of the elbow. Arthroscopy 1993;9:14-16.

Chronic lateral instability is commonly associated with a longitudinal split tear of the peroneus brevis tendon. The interrelationship of lateral ankle instability with superior retinacular laxity and resultant peroneus brevis split can account for persistent lateral ankle pain in this patient. Surgical treatment must identify and correct the underlying tendon pathology and should attempt to repair or debride the peroneus brevis tendon, reconstruct the superior peroneal retinaculum, flatten the posterior edge of the fibula by removing the sharp bony prominence, or deepening the fibular groove, along with addressing lateral ankle ligamentous instability. The laboratory values are not consistent with infection. A negative anterior drawer test confirms stability of the repair. Ankle arthritis is not seen on radiographs and usually takes longer than 3 months to develop. Bonnin M, Tavernier T, Bouysset M: Split lesions of the peroneus brevis tendon in chronic ankle laxity. Am J Sports Med 1997;25:699-703.

The radiograph shows an anterior dislocation of the shoulder. A frequently encountered sequela of this is a compression fracture of the posterolateral humeral head, commonly referred to as a Hill-Sachs defect. The arthroscopic view of the glenohumeral joint visualizes the posterior aspect of the humeral head. In the image, the area devoid of cartilage to the right is the bare area. The indentation seen to the left is a Hill-Sachs defect. Matsen FA, Thomas SC, Rockwood CA, et al: Glenohumeral instability, in Rockwood CA, Matsen FA (eds): The Shoulder, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 611-754.

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 MRI scans show disruption of the fibers of the PCL. Patients sustaining an isolated acute PCL injury can present with only minimal discomfort and have full range of motion. When examination reveals a contusion over the tibial tubercle and discomfort with the posterior drawer examination, with or without instability, a possible injury to the PCL should be considered. In acute injuries, the reported accuracy of MRI imaging for diagnosing PCL tears ranges from 96% to 100%. Resnick D, Kang HS: Internal Derangement of Joints: Emphasis on MRI Imaging. Philadelphia, PA, WB Saunders, 1997, pp 699-700. Harner CD, Hoher J: Evaluation and treatment of posterior cruciate ligament injuries. Am J Sports Med 1998;26:471-482.

Bracing for spina bifida paraplegia provides both support and improved function of the movable limb. An orthosis has value in controlling unstable joints. The three-point pressure effect applies a force above and below the joint to prevent it from buckling. A four-point pressure effect is only required for a two-joint system (this patient has problems only at the ankle). A longer lever arm brace and a brace with a greater area of support provide better stability. Finally, a straighter limb, without contracture, applies less pressure to the brace and lessens overload to the skin. Gage JR: An overview of normal walking. Instr Course Lect 1990;39:291-303. Bleck EE: Current concepts review: Management of the lower extremities in children who have cerebral palsy. J Bone Joint Surg Am 1990;72:140-144.

The floating elbow is best managed with early open reduction and internal fixation of the humeral and forearm fractures, followed by early range of motion. These fractures predispose the elbow to stiffness, and early range of motion is recommended. Solomon HB, Zadnik M, Eglseder WA: A review of outcomes in 18 patients with floating elbow. J Orthop Trauma 2003;17:563-570.

The pelvic injury is a severe anterior-posterior compression III or Tile C injury. The vessel most likely injured is the superior gluteal artery, but several arterial bleeding sources are likely. Vertical shear injuries can also injure this vessel, but it is much less common. When arterial injury follows a lateral compression injury, it is usually related to injury of a more anterior vessel like the obturator artery or a branch of the external iliac artery. O'Neill PA, Riina J, Sclafani S, et al: Angiographic findings in pelvic fractures. Clin Orthop 1996;329:60-67.

The patient has a posterior dislocation. The radiograph reveals marked internal rotation, but fails to show whether the humeral head is posteriorly displaced. Therefore, an axillary radiograph should be obtained to help confirm the diagnosis. Transverse view CT or MRI scans also may be useful. The other studies will not help confirm the diagnosis. In addition to a direct posterior blow, a shoulder dislocation may be caused by a seizure disorder or electrocution. Bloom MH, Obata WG: Diagnosis of posterior dislocation of the shoulder with the use of Velpeau axillary and angle-up roentgenographic views. J Bone Joint Surg Am 1967;49:943-949.

The diagnosis is eosinophilic granuloma. The plain radiograph and MRI scan show a lesion in the midshaft of the femur. There is no soft-tissue mass. There is reactive bone about the lesion that suggests a less aggressive tumor. The histology reveals eosinophils in an otherwise bland cellular background with no evidence of mitotic figures or malignant cells to suggest sarcoma. The diagnostic elements are the amphophilic (ie, pale purple) histiocytes with cigar-shaped nuclei, some of which have linear longitudinal grooves. There is no histologic evidence of infection. Lymphoma of bone would be an unusual occurrence in this age group, and the histology is not consistent with that diagnosis.

In the study done by Pevny and associates, 35% of patients older than age 40 years sustained rotator cuff tears and 8% had axillary nerve palsies. All of the patients with axillary nerve palsy also had rotator cuff tears. Imaging of the rotator cuff is indicated in this age group. The incidence of recurrent instability in patients older than age 40 years is 10% to 15%. Pevny T, Hunter RE, Freeman JR: Primary traumatic anterior shoulder dislocation in patients 40 years of age and older. Arthroscopy 1998;14:289-294. Sonnabend DH: Treatment of primary anterior shoulder dislocation in patients older than 40 years of age: Conservative versus operative. Clin Orthop 1994;304:74-77.

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.

In osteopenic individuals, even those with excellent obtained or maintained balance, long instrumented fusions to the sacrum impart a high degree of strain, and the sacrum may fail in a transverse fracture or fracture-dislocation pattern. The risk of proximal functional kyphosis is unrelated to distal fixation as are coronal plane correction and rod contouring. Pubic ramus fractures have been shown to be associated with both fixation to the sacrum alone as well as to the ilium.