JAAOS, Volume 5, No. 6

Fatigue fractures of the femoral neck are potentially disabling injuries if the diagnosis is missed or delayed and proper treatment is not provided. Previously considered primarily an injury of military personnel, femoral-neck fatigue fractures are becoming increasingly more common among nonmilitary athletes. The pathogenesis of this condition is multifactorial. Ultimately, fracture is thought to be caused by repetitive submaximal stresses that occur with a frequency that exceeds the adaptive ability of the bone. The clinical hallmark of a femoral-neck fatigue fracture in an impact-loading athlete is nonspecific, activity-related hip pain that is relieved by rest. Plain radiographs obtained initially are often negative. Radionuclide imaging is useful but not specific. Magnetic resonance imaging has demonstrated better specificity, sensitivity, and accuracy than are available with other modalities in the diagnosis of this injury. Treatment of compression-side injuries is generally conservative. Treatment of tension-side injuries remains controversial. The authors recommend aggressive treatment of tension-side injuries to prevent the potentially catastrophic sequelae of displacement, which include osteonecrosis, malunion, and coxarthrosis.

Fractures about the elbow are very common in children, but the anatomy of the child's elbow may make the diagnosis less obvious than in a mature skeleton. An understanding of the ossification and fusion of the secondary growth centers about the elbow is essential to avoid overlooking these injuries and to optimize treatment. If plain radiographs are equivocal, an arthrogram of the elbow may clarify the anatomy and diagnosis. Early neurologic and vascular complications are not uncommon and must be recognized before fracture reduction. Many late complications, such as malunion, osteonecrosis, and physeal bridging, are largely preventable by correct early diagnosis and treatment. Anatomic reduction of articular surfaces, restoration of physeal anatomy, and near-anatomic alignment of fracture fragments in the frontal plane are the corner-stones of successful treatment of pediatric elbow fractures.

The diagnosis and treatment of pain are among the most challenging problems facing orthopaedic surgeons, and reflex sympathetic dystrophy is probably the most frustrating and difficult pain syndrome to manage. Pain, swelling, and autonomic dysfunction are cardinal signs of the condition. Although the pathogenesis is still unclear, many theories have been proposed. Because reflex sympathetic dystrophy is sympathetically mediated, diagnosis can be confirmed on the basis of response of the pain to sympathetic blockade. Treatment may include an appropriate exercise program, a-adrenergic blocking agents, mood-elevating drugs, calcium channel blockers, intravenous regional blocks, and stellate ganglion blocks. Recent additions to therapy include electroacupuncture, transcutaneous electrical nerve stimulation, and biofeedback. Prognosis is, at best, guarded with this perplexing condition, but the best response is obtained when diagnosis is made early (within the first 2 or 3 weeks after injury) and treatment is initiated during the first stage of the disease.

Patellar fractures are a diverse group of injuries with a variety of fracture patterns. The surgical goals are anatomic reconstruction of the articular surface and stable fixation to allow early motion. Contemporary methods of treatment include screws, the modified tension band, and a combination of the two. Screws and wires have demonstrated specific failure patterns in experimental models, and biomechanical studies suggest that the combination of screws and wires provides more secure fixation. Partial patellectomy is the procedure of choice in comminuted fractures that cannot be anatomically reduced. Optimal treatment of patellar fractures requires individualization of surgical technique. The postoperative rehabilitation program should be based on the intraoperative findings and the stability of fixation.

The hip joint may be affected in 15% to 28% of all patients with rheumatoid arthritis. Radiographic evidence of involvement includes periarticular osteopenia, cystic changes, and a variable amount of progressive protrusio acetabuli. Histomorphometric study has shown increased bone turnover in acetabular biopsy specimens from rheumatoid patients undergoing total hip arthroplasty. Due to the relative fragility of bone in these patients, there is an increased risk of fracture of the proximal femur due to minor trauma, and a high rate of loss of fixation has been reported. Total hip arthroplasty has been successful in the treatment of severe rheumatoid arthritis of the hip in patients of all ages. Special attention should be paid to the cervical spine and the patient's medical treatment regimen during the preoperative evaluation. Cemented total hip arthroplasty has been associated with a higher prevalence of late infection and acetabular component loosening in rheumatoid patients than in osteoarthritic patients. Loosening of cemented components is accelerated in patients with juvenile rheumatoid arthritis. Several short-term studies have documented successful early results with noncemented components in patients with rheumatoid arthritis; however, longer-term studies are necessary to determine whether the improvements in function and survival are greater than with cemented components.

Current understanding of osteonecrosis of the humeral head is largely based on previous studies of the femoral head. Similarities between the two sites are numerous, but the shoulder has many unique characteristics. The anatomy of the glenohumeral joint, motion at the scapulothoracic joint, the rich vascular supply of the surrounding soft tissues, and the accommodations for the different forces (shear, compression) exerted across the glenohumeral joint all allow the shoulder to tolerate a greater amount of deformity. A number of pathologic agents can cause bone death by disrupting the blood supply, among them corticosteroid use, trauma, dysbarism, hemoglobinopathies, and various systemic diseases that disrupt the vascular system, such as Gaucher's disease and systemic lupus erythematosus. Management is similar to that of femoral osteonecrosis; the earlier stages respond well to nonoperative approaches, and the more advanced stages require surgical intervention. Hemiarthroplasty and total shoulder arthroplasty have produced good outcomes. Surgical intervention with core decompression, vascular flaps, and arthroscopic debridement have also shown promise, but further studies are necessary to define their optimal use.