Hamstring腱在体内重塑与转归的组织学研究

目的探讨游离Hamstring腱作为替代腱重建前十字韧带（anterior cruciate ligament，ACL）后在体内的重塑与转归过程，初步确定其术后在体内成熟的时间。方法33例关节镜下自体同侧游离4-5股Hamstring腱重建ACL的患者在行关节镜下再视手术时，于移植腱体中下段取活检组织进行组织学观察。重建术至再视手术的平均时间为11．9个月。替代腱依据重建术至再视手术的时段分为1月～、4月～、7月～、10月～、13月～、18月～和25月～组。将替代腱与正常ACL和半腱肌腱组织进行对比。结果重建ACL的Hamstring腱随植入时间延长，组织结构呈现其胶原纤维由不规则排列逐步向同向排列，排列不规则的菱形成纤维细胞逐步向较规则排列的椭圆形类纤维细胞转变，且细胞数目逐渐减少，血管腔数目也不断减少。上述的重塑变化主要发现在7月～组以前，其后各组重塑变化过程缓慢。结论自体游离Hamstring腱重建ACL术后具有良好的早期存活、加快再血管化和重塑过程的组织特性。其术后的重塑与成熟过程与自体髌腱相似，自体Hamstring腱在体成熟的时间为7-9个月。

Histological study on remodeling and maturation of hamstring autograft in postoperative patients

Objective To probe into the remodeling and maturity process along with extension of time in anterior cruciate ligament (ACL) reconstruction with hamstring autograft in order to confirm the date of maturity postoperatively. Methods Thirty-three patients after arthroscopic ACL reconstruction with hamstring autograft, were undergone second-look arthroscopical surgery. Meantime, biopsy specimens were obtained from the mid-zone of the hamstring graft. As a control group, specimens of normal ACL were obtained from total knee replacement of four cases, and specimens of semitendinous tendons obtained from ACL reconstruction of the four cases. The interval from initial reconstruction to second-look arthroscopy ranged from 2 to 36 months(mean 11.9 months). Patients were divided into different groups by postoperative time such as 1-, 4-, 7-, 10-, 13-, 18- and 25- month group. Thirty-three specimens were ordinarily sliced up into longitudinal sections. The sections were stained with hematoxylin and eosin so that cell and collagen fibrils were observed under light microscope, then compared the results with those of control group. Results Under microscopical observation, it was showed that tissue of hamstring graft was remodeled from more blood vessels and cellular amount to normal one, and from an irregular orientated crimp pattern of collagen to regular orientated crimp pattern of collagen in a time-dependent manner. Decreasing cellular amount, changing cell type, and a regular orientated crimp pattern of collagen of the hamstring graft were observed in 7- month group primarily, comparing with the original ACL. However, there existed a slower process in the other groups that are older than that of 7- month. Conclusion There are well histological features in the process of remodeling and maturation of the hamstring autograft after operation following extension of time, such as better survival of early period, and remodel of vessels and collagen. The process of remodeling and maturation in the hamstring autograft is similar to BPB autograft. The maturation period of the hamstring autograft after ACL reconstruction in human patients appears between 7 month and 9 month postoperatively.