四股半腱肌腱重建兔前交叉韧带后束间结构转归过程的实验研究

Histological Study of Remodel Progress of Inter-bundle of Four-band HamstringTendon Used for Anterior Cruciate Ligament Reconstruction in A Rabbit Model

目的:通过动物实验研究观察四股半腱肌腱重建兔前交叉韧带术后,移植物改建塑形过程中束间结构的转归过程。方法:以20只新西兰白兔为研究对象,取自体双侧半腱肌腱单骨道四束重建前交叉韧带,分别于术后第3、6、12、26、52周按时间段处死动物,从大体及组织学两方面观察移植物束间结构转归过程。结果:第3周时移植物组织内部呈坏死状态,周边细胞开始长入,束间界限清楚;第6周时大量滑膜开始覆盖移植物,表面间隙被滑膜填充、融合,有分束存在;第12周时各束改建塑形进一步进行,程度不同步,被滑膜填充的间隙已基本融合,距离较远的仍呈分束状态;第26周～第52周各束改建塑形基本完成,有些束间结构完全融合,有些虽然融合但有结缔组织相隔,有些束仍呈分离状态。结论:四股半腱肌腱作为前交叉韧带的移植物,与单股肌腱一样需经历坏死、再血管化、韧带化的改建塑形过程。不同的是,各束改建塑形的过程不十分平行,束间可发生融合或部分融合,有些塑形改建的束之间仍有结缔组织相隔,不同束也可发生不融合而呈分束状态,可能更多的与它们之间的相对运动有关。

Objective To investigate the histological change in the remodel progress of the inter- bundle of the four- band hamstring tendon used for reconstruction of anterior cruciate ligament （ACL） on the rabbit. Methods Reconstruction of the ACL of rabbit with its own bilateral four- band semitendinosus tendons was performed. The specimens of reconstructed the four - band tendon were collected at 3rd, 6th, 12th, 26th, 52nd week, respectively after the operation. The gross morphology and histological change in the inter - bundle of the four - band tendon were observed. Results Necrosis of the graft was evident, the peripheral cell started ingrowing, and the grafts were separated at 3rd week. The hyperplastic synovium was evident and enveloped the graft, some parts of the outer gaps were fill with the synovium and fused with the graft, but the inner parts were still separated at 6th week. The remodeling of the graft was under progress, but the extent of the remodeling in various bundles was different, and some parts of the inter- bundle were fused, some bundles with “big” interval were still separated at 12th week. The graft remodel progress was almost completed, some inter- bundle gap were not clear anymore, some bundles were connected with connective tissue, and some separated bundles were still existed at 26th and 52nd week. Conclusions As any graft for reconstruction of the ACL, the four- band hamstring tendons also had to pass through the necrosis, revascularization, and ligamentation progresses. However, unlike the single bundle graft, the different bundles were not remodeling synchronously. The inter- bundle might completely be fused, partially fused, fused in connection with connective tissue, and might still be separated. These different situations could be depended mostly on the relative movement among bundles.