Repair of femoral head osteonecrosis using cancellous bone like nano-hydroxyapatite/collagen composite in rabbits / 中国组织工程研究

ABSTRACT

BACKGROUND: Autologous cancellous bone graft remains the most effective grafting material for bone defects because it provides the three elements required for bone regeneration: osteoconduction, osteoinduction, and osteogenic cell. OBJECTIVE: To determine the indications for a cancellous bone like nano-hydroxyapatite/collagen (nano-HA/CO) composite for treatment of osteonecrosis of the femoral head (ONFH). DESIGN, TIME AND SETTING: A randomized controlled animal study was performed at Guangdong Medical Laboratory Animal Center from May to August 2007. MATERIALS: Ten New-zealand rabbits, weighing 1.5-2.0 kg, were prepared into models of ONFH by injection of liquid nitrogen. METHODS: Ten rabbits were randomly, evenly divided into 2 groups: nano-HA/CO composites group, insertion of nano-HA/CO bone substitutes into bone defects, and control group, without any implantation. MAIN OUTCOME MEASURES: The healing processes were assessed with macroscopic examination, X-ray photography and histological examination at days 7 and 14 after surgery. RESULTS: In the nano-HA/CO composites group, osteonecrosis was halted, holes were repaired, and nano-HA/CO bone substitute was gradually degraded and absorbed; but in the control group, osteonecrosis was deteriorated and holes were not repaired, remained the same drilled at the beginning. CONCLUSION: These nano-HA/CO composites can not only replace autologous cancellous bone, but also can halt the progress of osteonecrosis insulted by liquid nitrogen. Experimental results show potent alternative of this nano-HA/CO composites in treatment of ONFH in stage II and earlier stage.