A complete review of the literature disclosed that there were 42 reports of 2025 hips treated by either core decompression (1206 hips) or nonoperative management (819 hips), excluding electrical stimulation, for osteonecrosis of the femoral head. The peer-reviewed published reports included general surveys, prospective studies, and multicenter studies, but excluded case reports. Satisfactory clinical results were reported in 63.5% of hips in 24 studies of core decompression and in 22.7% of hips in 21 studies of nonoperative management. When looking at only precollapse hips, there were 71% versus 34.5% good results, respectively. Recalculation excluding reports by the 4 centers that do the most core decompressions (and report the best results) showed a clinical success rate for core decompression of 53% versus 22.7% for the nonoperatively treated group. Investigators of multiple studies have reported that nonoperative management leads to extremely poor results. Core decompression has been reported to have a notable effect on the natural history and clinical progression in early stages of osteonecrosis of the femoral head. In view of the limitations of this data, further clarification of this effect only can be obtained by large prospective randomized studies.