同种异体骨复合带血管自体骨移植修复大段骨缺损的实验研究

目的研究同种异体骨与带血管自体骨镶嵌式复合骨移植修复骨肿瘤切除后大段骨缺损的疗效。方法采用健康6月龄山羊12只于尺桡骨中段建立尺桡骨双缺损动物模型。实验组6只：将自体截取的带血管蒂尺骨与同种异体骨镶嵌后，嵌插入桡骨缺损处，用外固定架加石膏固定。对照组6只：仅将同种异体骨植入骨缺损区，同法固定。术后12、24周分别行X线片、Micro CT及组织学观察。结果X线示实验组较同时期对照组新骨形成明显，第24周实验组骨缺损愈合率达100％，对照组骨缺损未愈合或愈合不良。Micro CT重建后显示，实验组可见骨缺损区远近端已完全修复，骨性连接，植入异体骨与带血管自体骨间形成大量新生骨，与异体骨形成新的管状骨和髓腔，对照组缺损区异体骨骨密度下降，吸收明显。组织学观察：实验组较同期对照组成骨活动显著，实验组骨缺损远近端及中间部均有不同程度的新骨爬行替代，对照组异体骨吸收明显，新骨形成很少。结论大段同种异体骨复合带血管自体骨移植修复骨缺损效果良好，带血管自体骨在快速愈合的同时能促进大段同种异体骨的爬行替代过程，加快骨折愈合。此方法有望应用于骨肿瘤切除后遗留大段骨缺损的修复。

Experimental research on the repair of massive bone defects by using vascular-attached ulna autograft combined with bone allografts

Objective To investgate the therapeutic effect of the treatment of vascular-attached autograft combining with allograft for repairing massive bone defects after bone tumor resection. Methods Twelve 6-month old goats were chosen as the experimental animals. A 6.0 cm bone defect of diaphysis and periosteum was made at the shaft of the ulna and the radius. The defects of the experimental group were frepaired with ipsilateral vascular-attached ulna combining with aUograft bone. In the control group, the defects were filled with allografts only. External fixation and plaster were used tostabilize the grafts. X-ray, micro-CT and histological observations were taken after operation or 12, 24 weeks post-operatively. Results In week 12, plenty of new bones were found in the group of experimental group and the defects were completely repaired by the grafts in week 24. The healing rate of the bone defects was 100%. On the contrary, no evidence of bone repairing was found in the control group. After the Micro-CT reconstruction, the proximal and distal end of the defects were repaired completely and many new bones were formed between the implanted allograft and vascularized autografts in the experimental group. Moreover, the defects of allografts were filled with new bone and medullary cavity were formed. The density of bone mineral of the allografts bone in the control group declined, and obvious bone absorption were found. The bone formation of experimental group was obviously higher than that of the control group. Creep substitutions occured in the proximal and distal end or the middle of the bone defects in the experimental group according to histological investigation. Conclusions The treatment of vascular-attached autograft combining with allograft for repairing massive bone defects was very effective. The vascularized autograft was found to accelerate the healing and promote the creep substitution of allograft which was useful to the healing. The method used in the experiment may be carried out to repair massive bone defect after the resection of bone tumor.