前十字韧带重建术后自体Hamstring腱的超微结构研究

摘要

Objective To observe the ultrastructural change of the reconstructed anterior cruciate ligament (ACL) with Hamstring autograft in vivo. Methods Biopsy specimens were obtained from the mid-zone of the Hamstring graft in 18 patients who underwent second look arthroscopic evaluation. The normal ACL and the tendons of the semitendinosus were set up to control. Patients were divided into 1-4 months(2 cases), 4-7 months(4 cases), 7-10 months(3 cases), 10-13 months(3 cases), 13-18 months(2 cases), 18-25 months (2 cases) and >25 months (2 cases) groups by postoperative time. After being done as routine electron microscopic section procedure, cells and collagen fibers in specimens were observed under transmis-sion electron microscopy. To describe and analyze the collagen fibrils, they were categorized as thin, medium, and thick, according to their diameter. The number and area of collagen fibrils in each case was evaluated by means of a digital imaging analysis system. Results In the early period (< 7 months), the number of cells increased and most were fibroblasts. Collagen fibers had different size arranged in disalignment, and the ma-jority was the thick one. In the middle period (7-13 months), the number of cells decreased and most were like-fibroblasts. Collagen fibers had similar size arranged parallelly, and the majority was the medium and thin one as the same as that in normal ACL. In the last period (>13 months), the number of ceils decreased, most were fibrocytes. Compact collagen fibers arranged parallelly, the majority was the thin one. But the number of thick type increased gradually, as the number of medium type decreased. Conclusion Hamstring autograft changes quickly in the early period. The histomorphology characteristic in the middle period almost has been mature, in which the number of the medium and thin fibers increase. The thin fibers increase grad-ually and become predominant with appearance of several thick ones simultaneously during the last period, and remodeling of autograft is gone on.%目的 观察自体Hamstring腱重建前十字韧带(anterior cruciate ligament,ACL)后在人体内超微结构的变化过程.方法 单侧关节镜下自体Hamstring腱重建ACL后再行关节镜手术患者18例,男10例,女8例;年龄21～43岁,平均27.3岁;其中16例因取内镶钉,2例因术后疼痛而行关节镜手术.取重建ACL术后Hamstring腱的部分组织块,以正常半腱肌腱和ACL作为对照组.取下的组织块依据重建术后时间分组:1～4个月组2例,4～7个月组4例,7～10个月组3例,10～13个月组3例,13～18个月组2例,18～25个月组2例和>25个月组2例.常规电镜技术制备组织块样品,透射电子显微镜下观察细胞和纤维;按纤维的直径分为细、中、粗三种,计算各纤维的平均数目(频率)和所占的相对面积.结果 显微镜下超微结构显示:植入体内早期(<7个月)细胞数多,主要为成纤维细胞,胶原纤维大小差异很大,以粗纤维为多;中期(7～13个月)细胞数目减少,类成纤维细胞居多,胶原纤维呈平行排列,纤维直径已趋均匀,中、细纤维占多数,且与正常ACL的中、细纤维接近,粗纤维罕见;后期(>13个月)细胞数少,主要为类纤维细胞,胶原纤维密集,聚集呈束状,纤维排列呈平行状,纤维直径不均匀,粗纤维增多,中纤维减少,细纤维占多数.结论 自体Hamstring腱组织重建ACL后在体内早期呈快速变化过程,中期组织以细、中纤维为主,已趋成熟,晚期以细纤维为主,且改建过程仍缓慢进行.