自固化磷酸钙复合BMP及同种异体骨修复兔股骨大段骨缺损

Repair of large segmental femur defects in rabbits with massive allograft combined with BMP and CPC

[目的]观察一种新型自固化磷酸钙(CPC)复合BMP与同种异体骨修复兔股骨节段性骨缺损的效果,为临床复合应用大段同种异体骨移植提供参考。[方法]54只新西兰大白兔随机分成3组,于一侧股骨中上段造成2 cm长皮质骨缺损模型,分别进行:A组复合BMP与CPC的新鲜冷冻同种异体骨移植;B组单纯新鲜冷冻同种异体骨移植;C组自体大段骨移植。移植骨均用直径3 mm三棱髓内针固定。于术后4、8、12周,进行影像学、组织学检查,对比各组移植骨愈合过程与修复效果。[结果]CPC复合BMP大段同种异体骨移植早期骨修复效果优于单纯异体骨移植(P<0.01),与自体骨移植修复效果相似,至12周3组均达骨性愈合,以A组及C组骨修复塑形较好。CPC复合BMP组骨痂量较多,分布于移植骨与宿主骨结合部及移植骨周围,形成皮质骨外骨桥,并较早在异体骨外表面形成破骨与成骨,异体骨内哈佛氏管扩大,衬垫细胞、成骨细胞、破骨细胞及血细胞较其它组多。CPC随着新骨的形成及改建塑形逐步缓慢降解。[结论]CPC复合BMP对大段同种异体骨移植的愈合及替代有增强和促进作用。

[ Objective ] To observe the bone repairing efficacy of large segmental femur defects in rabbits with calcium phosphate cement （CPC） combined with bone morphogenetic protein （BMP） and massive bone allograft, which may benefit the clinical application of large segmental bone allograft transplantation, [ Method ] Fifty-four New Zealand white rabbits were divided into three groups and a 2 cm femur defect was created on one side of each rabbit, followed by implantation with ： CPC combined with BMP and massive bone allograft （Group A ）, bone allograft only （Group B） and autograft transplantation （ Group C ）. Intramedullary nails with a 3 mm diameter fixed all the grafts transplanted. The bone defect repair efficacy was evaluated by radiology and histology exam at 4, 8 and 12 weeks after operation. [ Result] The bone reparation capacities of allograft with CPC/BMP complex was better than that of the allograft alone after 4 - 8 weeks of transplantation, which were similar to the result of autografi transplantation. Complete bone union was achieved for all the groups after 12 weeks of operation, with better bone remodeling for group A and group C transplantation. The healing process of CPC/BMP combined with allograft transplantation was featured with large amount of bone callus forming surrounding the graft-host bone union area and the surface of allograft, which composd the extra cortical bone bridge and ingrowth （EBBI）. Bone invasion, resorption as well as new bone genesis were seen in the surface of bone allograft at early stage, companied by expansion of Haversian＇s canal, with more lanner cells, osteoblasts, osteoclasts and blood cells inside the allograft. CPC was slowly biodegraded with the bone graft resorption and new bone regeneration. [ Conclusion] CPC combined with BMP can improve the bone reparation and substitution process in massive bone allograft transplantation for the treatment of large segmental bone defects.