复合rhBMP_2的异种骨(rhBMP_2/BCB)与骨膜联合移植修复兔桡骨节段性骨缺损

目的　探讨复合基因重组人ＢＭＰ２ 的异种骨（ｒｈＢＭＰ２／ＢＣＢ） 移植及其与骨膜联合移植修复节段性骨缺损的效果。方法　将ｒｈＢＭＰ２ 与去抗原牛松质骨载体（ＢＣＢ）复合，制成ｒｈＢＭＰ２／ＢＣＢ；并采用兔桡骨干１．５ ｃｍ 缺损的动物模型，通过Ｘ线、生物力学、骨密度、组织学等检测手段，比较单纯ｒｈＢＭＰ２／ＢＣＢ移植、ｒｈＢＭＰ２／ＢＣＢ 与带血运骨膜联合移植及ｒｈＢＭＰ２／ＢＣＢ 与游离骨膜联合移植修复节段性骨缺损的疗效。结果　（１） 单纯ｒｈＢＭＰ２／ＢＣＢ 移植，可在１６ 周使节段性骨缺损基本修复，其修复机制与过程和重组异种骨相似；（２）ｒｈＢＭＰ２／ＢＣＢ与带血运骨膜联合移植，８ 周即可修复骨缺损，其修复机制与骨折修复相仿，包括膜内成骨和软骨成骨两种机制；（３）ｒｈＢＭＰ２／ＢＣＢ与游离骨膜联合移植，在骨缺损修复早期（ ≤１２ 周） ，其成骨速度及成骨质与量均优于单纯ｒｈＢＭＰ２／ＢＣＢ移植，约在１２ 周使骨缺损基本修复。结论　上述三种方法均可有效地修复节段性骨缺损，但以ｒｈＢＭＰ２／ＢＣＢ与带血运骨膜联合移植较为理想。该方法同时具有良好的骨生成、骨传导和骨诱导作用。

Combined Use of rhBMP 2/BCB and Periosteum in Repairing Segmental Defects in Radii of Rabbits

Objective\ To study the efficacy of combined use of rhBMP 2/BCB and periosteal graft in repairing segmental bony defects.Methods\ A new grafting material (rhBMP 2/BCB) was made by combining recombinant human BMP 2(rhBMP 2) and an antigen free bovine cancellous bone (BCB) as a carrier. rhBMP 2/BCB was used alone, in conjunction with vascularized or free periosteal graft to repair a 1.5 cm defect in the radius of the rabbits. The defect repairing capability for each of the treatment modalities was assessed radiographically, biomechanically, bonydensitometry and histological studies. Results\ 1) rhBMP 2/BCB used alone was basically capable of healing the defect by 16 weeks, with a similar repair process and mechanism to that seen with RBX. 2) the use of rhBMP 2/BCB in conjunction with vascularized periosteal graft exhibited the strongest defect repairing power, apparent healing of the defect by 8 weeks. The repair process consisted of intramembranous and endochondral ossification resembling the physiological repair during the fracture healing. 3) combined use of rhBMP 2/BCB and free periosteal graft is superior in terms of increased amount and quality of the new bone formed at the early stage of the repair process (within 12 weeks) to rhBMP 2/BCB used in alone, with the defect basically healed by 12 weeks. Conclusion\ All three methods are effective in repairing segmental bony defects, with rhBMP 2/BCB used in conjunction with vascularized periosteal graft being most preferred, considering the satisfactory osteogenesis, osteoconduction and osteoinduction seen with this method.