OBJECTIVE To investigate clinical therapeutic effect on early stage femoral head necrosis managed with allogeneic cortical bone cage support combining with autologous cancellous bone grafting through core decompression tunnel, and to discuss its effect on preventing femoral head collapse and influence factors. METHODS From January 2002 to December 2005, 40 patients (42 hips) with femoral head necrosis underwent core decompression and an allogeneic threaded cortical bone supporting cage which was loaded with autologous cancellous bone inside. There were 26 males and 14 females, aging 27-45 years (mean 35.6 years). The disease course was 6-28 months (mean 18.3 months). All the cases underwent X-ray, CT and MRI examination to confirm the diagnosis and necrosis area. Twelve hips were at Ficat stage I, 29 hip at stage II, and 1 hips at stage III. Harris hip score system was used to evaluate the hip function pre- and post-operatively. X-ray films were taken regularly after operation. RESULTS All the wound healed by first intention without any complications such as infection, fracture, nerve and vascular injury, and deep vein thrombosis. Thirty-six patients (38 hips) were followed up for 24-58 months with an average of 38 months. All the patients had different degrees of improvement in clinical symptoms. According to Harris hip score system, the Harris score was 63.1 +/- 6.4 before operation and 82.3 +/- 16.5 at the last follow-up, showing significant difference (P < 0.001). The results were excellent in 24 hips, good in 11 hips, fair in 2 hips and poor in 1 hips. The X-ray films showed femoral head repairing and no advancement of osteonecrosis and collapsing in 23 patients (24 hips) 24 months after operation. CONCLUSION Allogeneic cortical bone cage support combining with autologous cancellous bone grafting is suitable for managing early stage femoral head necrosis and its short- and middle-term effect is satisfactory.