Experimental Study Of Implanting Orbital Bone Allografts In Rabbits

ObjectiveTo evaluate the effectiveness of bone allografts as implanted materials for restoring orbital bone defect and investigate the feasibility of implanting orbital bone defect with orbital bone allografts in rabbits,which provides experimental foundation for choosing an ideal repair materials of the orbital bone defect in clinic.MethodsTwenty-four Japanese White rabbits were selected as experimental animal,eight were the suppliers of bone allografts stored in deep freezing.The other 16 Japanese White rabbits were established 15mm×5mm×1mm bone defect models in the double superior orbital wall and respectively implanted frozen bone allografts and autogenous bone.Group A was the experiment and the orbit of being implanted frozen orbital bone allografts.Group B was the control and the other orbit of being implanted autogenous orbital bone.After surgery,gross specimen,CT scan,histological examinations as well as immunohistochemistry staining of BMP-2 were performed at 2,4,8,12 weeks respectively.ResultNo complication was observed. After 2,4 weeks,there was no different the degree of bone healing in Group A,B,after 8,12 weeks,implanted bone connected with the host bone formed a whole body except for two cases weren't healed.Group B was better than Group A in bone healing. CT scan : average CT numerical value of implanted bone connected with the host bone was measured at 2,4,8,12 weeks respectively.Group B exceeded Group A in average CT numerical value. Histological examinations:after 2,4 weeks,there were a lot of inflammatory cell and fresh callus in implanted bone connected with the host bone,and there was no different in Group A,B. After 8,12 weeks ,Group B formed more fresh bone than Group A . Immunohistochemistry staining of BMP-2:After 2,4 weeks,the expressions of surrounding callus in bone allografts were positive.After 8,12 weeks, the expressions of cortical bone and surrounding mature osteon in bone allografts were positive.ConclusionThe degree of forming bone healing between orbital bone allografts and autogenous bone in repair of the orbital bone defect was similar,which was rather effective in repair of orbital bone defect in rabbits.