Steroid-associated osteonecrosis of the knee: a comprehensive review.

Steroid-associated osteonecrosis of the knee is a disease of young patients (generally younger than 45 years old) who often have underlying immunocompromising disorders. Although many theories have been postulated, the exact pathophysiology of the disorder is still unknown. Precollapse lesions can be treated with core decompression for prolonged symptomatic relief. Later-stage lesions are treated with total knee replacements, which have less than optimal results reported to date.