大段同种异体骨移植愈合的实验研究

The Experimental Studies on the Healing of Massive Allografts

目的 研究大段同种异体骨移植愈合过程和特点。方法 采用新西兰大白兔股骨中段切除 1 5cm骨干和骨膜实验动物模型。将 36只兔随机分成实验组和对照组。实验组植入深低温保存的同种异体骨 ,对照组植入自体新鲜骨 ,均用直径 3mm的髓内针固定。于术后第 1、 2、 3个月分别行X线摄片、ECT、大体标本、组织学观察 (四环素荧光标记、HE染色 )以及BMP免疫组织化学染色。结果 深低温保存的同种异体骨移植愈合与自体骨相似 ,ECT显示术后第 1个月骨代谢活跃 ,2、 3个月趋于稳定。移植骨BMP表达阴性 ,新生骨及其周围类基质表达阳性。其愈合是从宿主骨向移植骨 ,从周围向中央 ,从哈佛氏管向其四周逐渐进行爬行替代的过程。结论 同种异体骨移植愈合过程是移植骨全方位活化的过程 ,即全方位再血管化、新骨形成和宿主与移植骨接连的过程。其主要通过骨传导实现成骨 。

Objective To study the mechanism and characteristic of bone-healing of massive allografts.Methods The bone massive defect animal models were made New Zealand white rabbits at the middle shaft of the femur which remove 1.5cm of diaphysis and periosteum.36 rabbits were randomly divided into experimental and control groups.The bone defect was filled by the similar segment from another rabbit which were frozen in bone bank in experimental group,and the bone defect was by replacement of the excised segment(autograft)in control group.Two group were fixed with 3mm intramedullary nailing.Obeservations were with X-ray,bone scintigraphy,gross specimen,histological examinations(labled with tetracycline,hemaloxylin and eoxin stain) as well as immunohistochemical staining of BMP at the 1,2,3 months postoperative.Results The frozen bone of atllograft was able to produce bone induction and the speed of the union is similar to that of autografts.ECT showed that bone metabolism were more active in the first month and it were stable in the 2,3 months postoperative.Bone allogeneic were negative against BMP,new bone(osteoblasts and osteoid)were positive against BMP.The processes of the creep-substitution was from united end to the allogenic bone,from periphery to the center of the allografts,and from Haversian cannals to its periphery.Conclusions The processes of bone-healing of massive allografts is generally activable of bone allogeneic,which company by revascularixation,new bone formation,and host-graft union in course of the allograft.The creep-substitution are most depend on osteoconduction,but osteoinduction are play a important role for the healing of bone allografts.