Osteonecrosis of the Humeral Head.

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.