Nontraumatic avascular necrosis of the femoral head. Past, present, and future.

The history of research on avascular necrosis of the femoral head during the past 30 years includes clinical and radiologic data, etiology and epidemiology, histopathology, and other methods of exploration, pathophysiology and pathogenesis, and treatments. Preradiologic stages of the disease, its association with corticosteroid treatment, the use of core biopsy and magnetic resonance imaging for an early diagnosis, the pathogenetic significance of increased intramedullary pressure and of lipid metabolism and fat cell changes, and conservative surgical procedures such as core decompression and rotational osteotomy constitute important areas for further investigation as outlined in detail in this review.