关节软骨下骨移植后对关节软骨影响的实验研究

目的：探讨关节软骨下大块骨缺损骨移植后，局部成骨活动的发生与演变、关节软骨的活性变化及术后关节面塌陷、关节软骨退变等并发症的原因。方法：在家兔胫骨上端内侧，模拟临床骨肿瘤刮除，建立关节软骨下大块骨缺损动物模型，采用新鲜自体骨与同种异体脱钙骨移植后，通过大体观察、组织学观察、放射自显影方法进行动态观察。结果：模型建立２周后，软骨下骨完全坏死，出现吸收腔；４周时吸收腔内出现新的毛细血管，新骨开始沉积；到１２周时，坏死软骨下骨中毛细血管完全恢复，有８２５％的死骨被新骨替代。结论：（１）关节软骨下骨移植时，大量刮除软骨下骨，会增高术后关节软骨退变的发生率。（２）在关节软骨下骨移植时，如果大量刮除软骨下骨，将引起软骨下骨的缺血坏死，坏死的软骨下骨将逐渐被新生骨爬行替代。（３）用新鲜自体骨与异体脱钙骨移植修复关节软骨下大块骨缺损相比较，均经历了被吸收、血管长入、新骨形成取代移植骨的过程，愈合及修复程度均无显著差异。

Effect of articular subchondral bone replacement on the articular cartilage

Objective: Experiments were designed to find the reason of articular surface collapse and degeneration after subchondral bone replacement.Methods:The authors established the animal model of articular subchondral bone defect of tibial in rabbits and observed leg gross,histological examination and radioautography after bone replacements .Results:There was completely necrosis in subchondral bone at 2 weeks.New bone cells were found in necrotic bone after 4 weeks.At 12 weeks,82 5% necrotic bone were replaced by new bone.Conclusions:Extensive curettage of subchondral bone will carry a high risk of postoperative cartilage degeneration .