大段异体骨关节移植后长期转归的观察

目的观察大段人异体骨关节移植后的转归。方法取植入４～６５个月的大段异体骨关节标本,采用组织学及ＢＭＰ分子原位杂交及免疫组化方法,结合随访Ｘ线片及骨核素扫描进行研究。结果外骨痂由宿主骨皮质向异体骨皮质侧生长连接愈合,皮质骨爬行替代相当缓慢,５年时仍大量死骨与活骨共存。异体骨骨松质内可见新骨、骨髓及新生血管,但骨小梁有吸收。非主要负重区的关节软骨细胞部分存活。４个月时异体骨皮质浅层及骨痂ＢＭＰ免疫组化染色及分子原位杂交阳性。植入１２个月至６５个月骨皮质浅、深层及活骨ＢＭＰ表达均呈阴性。结论（１）骨痂由自体骨向异体骨侧生长连接以达到骨性愈合。异体骨关节血运可重建。（２）非负重区关节软骨可部分存活。关节塌陷与骨小梁吸收有关。（３）异体骨内ＢＭＰ在移植后早期的新骨替代及愈合中起作用,１２个月后则主要是靠骨传导而不是骨诱导。（４）坏死骨单位的排除不完全,是异体骨皮质新骨替代慢的原因。

Fate of massive retrieved human bone allografts

Objectives To study retrieved massive human allograft specimen after they had been in situ for four to sixty five months,and to investigate the changes union,bone replacement and degradation of articular cartilage. Method BMP gene expression in the specimen was also studied with in situ hybridization,immunohistochemical methods, and the observations were correlated with the clinical and isotope scan date. Result The union between the allograft and the host was achieved by the formation of an external callus derived from the cortex of the host.New bone replacement took place slowly.Analysis of the articular cartilage revealed evidence that some chondrocytes had survived in non bearing area of the articular.The expression of BMP in the surface of the cotex and unioned callus was positive 4 months after implantion. But it was negtive in the center of cortex after it had been implanted for over 12 months.An external callus formed from the cortex of the host.Some chondrocytes survived in nonbearing area of the articular. Neovasculature penetrated into osteoarticular. Conclusion Bone absorption may be the cause of collapse of articular surface.The results suggest that large allografts in humans are osteoconductive rather than inductive.Incomplete repairment of osteon may be related to slowed replacement of massive human allograft.