Joint-preserving operations for idiopathic avascular necrosis of the femoral head. Results of core decompression, grafting and osteotomy.

We have reviewed 54 hips in 46 patients from 2 to 14 years after a joint-preserving operation for idiopathic avascular necrosis of the femoral head. The choice between core decompression (17 hips), bone grafting (18), rotation osteotomy (15) or varus osteotomy (4) was determined by the stage and location of the area of necrosis. The overall success rate was unexpectedly low at 60%. Core decompression and bone grafting by our techniques gave poor long-term results, but those of rotation or varus osteotomies, performed with care for the correct indications, were better. The indications for each procedure are discussed: osteotomy is best when the area of necrosis is shallow and localised in the medial or anterior portion of the femoral head.