Osteonecrosis of the femoral head. A prospective randomized treatment protocol.

Conservative treatment versus core decompression for cases of osteonecrosis (ON) of the femoral head was prospectively reviewed in 36 patients. A preoperative evaluation of the patients' history, physical examination, Harris Hip Score, roentgenograms, computed tomography, bone scan, magnetic resonance imaging, and measurement of the intraosseous pressure was used to grade the level of ON according to a rating system developed by Ficat. Hips were randomized to core decompression or conservative treatment groups. Fifty-five hips in 36 patients were randomized (29 surgical and 26 conservative). When success was gauged by Harris Hip Scores for Stage I hips, treatment was successful for seven of ten (70%) operatively treated hips and one of five (20%) non-operatively treated hips. Among Stage II hips, treatment was successful for five of seven (71%) decompressed hips and none of seven conservatively treated hips. Successful treatment was accomplished in eight of 11 hips (73%) and one of ten hips (10%) in decompression and conservative groups, respectively, for Stage III hips. Stages 0 and IV had groups too small for comparison. Less successful results were seen if roentgenographic criteria of success were used. Survival analysis showed more favorable results with surgical treatment. Core decompression produced better results than conservative treatment in the early stages of ON.