BACKGROUND:Core decompression may provide insufficient support for the subchondral bone in the treatment of early avascular necrosis of the femoral head and increase the risk of fracture and colapse. Quadratus femoris implantation cannot only provide good biological support, but also promote the revascularization at necrotic regions, thus repairing the necrosis of femoral head. OBJECTIVE: To compare the clinical effects of core decompression with bone paste implantation and core decompression with quadratus femoris implantation on early and middle-stage avascular necrosis of the femoral head. METHODS:Eighty-three patients with early avascular necrosis of the femoral head (92 hips) admitted at the Department of Orthopedics, the First Affiliated Hospital of Zhengzhou University, China, from January 2009 to January 2012 were enroled and divided into groups of core decompression with bone paste implantation (46 cases, 49 hips) and core decompression with quadratus femoris implantation (37 cases, 43 hips) that were respectively injected with bone meal and autogenous bone and osteoinductive materials. RESULTS AND CONCLUSION: Al involved patients were folowed up. After 1 year of treatment, Harris scores in the two groups were both increased (P < 0.05). But the Harris score of core decompression with bone paste implantation group was lower than that of core decompression with quadratus femoris implantation group (P < 0.05). After 3 years of treatment, X-ray scores in the core decompression with quadratus femoris implantation group were significantly higher than those in the core decompression with bone paste implantation group (P < 0.05). These findings indicate that compared with core decompression with bone paste implantation, core decompression with quadratus femoris implantation is better to prevent femoral head colapse, improve hip function and delay the process of osteonecrosis of the femoral head.