三种肌腱重建前交叉韧带的组织学比较

Histological comparison of three grafts for anterior cruciate ligament reconstruction in rabbit

[目的]比较三种肌腱移植物重建前交叉韧带(ACL)的组织学早期愈合过程。[方法]新西兰兔60只,随机分为三组,分别用自体肌腱(自体组)、深低温冷冻同种异体肌腱(深冻组)、冷冻干燥同种异体肌腱(冻干组)重建ACL,每组20只。于术后3、8、12、24周时取材,行组织学观察。[结果]移植物关节内段:术后3周各组移植物内细胞结构消失;术后8周移植物浅层有成纤维细胞增殖,但深层为无细胞纤维;术后12周各组移植物浅层细胞数增多,由浅入深逐渐长入移植物;术后24周各组移植物浅层与深层细胞密度均匀一致,深层无细胞区域消失。移植物腱骨界面:术后3周腱骨界面成纤维细胞增殖;术后8周各组腱骨界面软骨细胞出现,出现散在斜形sharpey纤维;术后12周各组软骨细胞增多,各组斜形sharpey纤维数量增多,自体组出现垂直形sharpey纤维,有连续性"潮线"结构;术后24周垂直形sharpey纤维比例增多,连续性"潮线"结构范围扩大。随时间推移,三组移植物关节内段和腱骨界面内的细胞数均显著增加(P<0.05)。细胞数排序为自体组>深冻组>冻干组,术后8周和12周时,三组间差异有统计学意义(P<0.05),而术后24周时,三组间差异已无统计学意义(P>0.05)。[结论]冻干异体肌腱和深冻异体肌腱早期组织学愈合过程较自体肌腱延迟,但24周后三种肌腱移植物的愈合程度趋同。

[Objective]To compare the early histological healing process of three grafts for anterior cruciate ligament(ACL)reconstruction in rabbits.[Methods]A total of 60 New Zealand rabbits were randomly divided into three groups.ACL reconstruction was simulated in 20 rabbits with tendon autograft,20 animals with deep-frozen tendon allograft(DF allograft),and 20 rabbits with frozen-dried tendon allograft(FD allograft).The rabbits were sacrificed and the knee were harvested at 3,8,12 and 24 weeks postoperatively.Histological assessment of the early healing process of the grafts on the intraarticular part and tendon-bone interface were compared among the three groups.[Results]In term of the intraarticular part of grafts,the cellular structure disappeared in the deep layers at 3 weeks postoperatively in all the 3 groups,while the surface was covered by synovial tissue with scanty fibroblasts proliferation.As time went,cells gradually grew into the graft from superficial layer to the deep layer,on the contrary,the acellular area in the deep layer disappeared progressively.Regarding to tendon-bone interface,proliferation of fibroblast was noted at 3 weeks,chondrocytes appeared at 8 weeks postoperatively,and increased over time,associated with increasing Sharpey fibers formation in oblique,and then perpendicular directions,followed by continuous tidemark structure expanded.With regard to cell counting,the number of proliferative cells significantly increased over time in all the 3 groups(P<0.05),and was ranked in the sequence of autograft>DF allograft>FD allograft,which proved statistically significant at 8 and 12 weeks pos tope rati vely(P<0.05),whereas became not significant at 24 weeks among the 3 groups(P>0.05).[Conclusion]The frozen-dried allograft and deepfrozen allograft do have significant delays in histological healing process in contrast to the autograft at early stage.However,it becomes comparable at 24 weeks among the three kinds of graft.