自体肌腱与人工韧带联合应用重建兔前交叉韧带

Reconstructing anterior cruciate ligament in rabbits using autologous tendon combined with artificial ligament

背景：自体肌腱与人工肌腱是目前治疗前交叉韧带断裂的主要移植物，两者各有优缺点。目的：将自体肌腱与人工韧带联合重建兔前交叉韧带，观察其在不同时间段组织学反应及生物力学改变。设计、时间及地点：同体对照观察，于2007—09／2008—02在郑州大学骨科实验室和郑州大学生物实验室力学中心完成。材料：SPF成年健康新西兰大白兔28只由郑州大学动物实验中心提供，体质量2．4—31kg，平均2．8kg，雌雄不限。MB66编织线为上海施乐辉医用产品国际贸易有限公司产品。方法：①取兔的双下肢伸趾肌腱，一个伸趾肌腱完全包裹人工韧带，另一个伸趾肌腱单纯末端编织备用。②取兔双膝内侧髌旁切口暴露关节，切断并去除正常前交叉韧带，定位上下止点，分别钻股骨和胫骨骨道，一个膝关节穿入自体肌腱与人工韧带联合肌腱（联合肌腱组），另一个关节穿入单纯肌腱（单纯肌腱组），两端钻骨桥缝线固定。分别于术后第2，4，6，8周随机抽出的7只兔，麻醉后处死。主要观察指标：①两组兔重建的前交叉韧带大体观察和组织学观察结果。②两组移植物的最大拉断力。结果：移植后第2，4周，移植物内细胞消失，呈坏死状：联合肌腱之间有炎症细胞浸润，边缘开始有细胞向中心长入。移植后第6周，移植物表面滑膜增生明显；单纯肌腱有少许变形和松弛；联合肌腱部分间隙被滑膜填充，浸润的炎症细胞减少，内部仍有界限。增生的细胞由周围向中心推进明显。移植后第8周，移植物大部分组织被新长入的细胞替代，人工韧带被滑膜完全包裹，浸润的炎症细胞基本消失，部分接触面己融合，但部分面仍有间隙：联合肌腱无变形和松弛，移植物内细胞形态，数量接近正常前交叉韧带，但纤维细胞排列杂乱，纤维有了一定的纵向性。生物力学测试结果联合肌腱最大拉断力大于单纯肌腱（P〈0．05）。结论：联合肌腱与单纯肌腱都经历坏死、再血管化、韧带化的改建过程，与其生物力学经历由强到弱再逐渐增强的过程相一致。联合肌腱硬度或韧性均可弥补单纯肌腱早期易松弛的缺点，晚期自体肌腱成活可弥补人工肌腱被永久性拉长或断裂的缺点。

BACKGROUND： Autologous tendon and artificial tendon are both the important grafts that can reconstruct the ruptured anterior cruciate ligament, but each has their defects and excellents, OBJECTIVE： To investigate the blomechanical change and histological rejection of reconstructing the anterior cruciate ligament of the rabbits with autologous tendon and artificial ligament. DESIGN, TIME AND SETTING： A controlled observation was performed from September 2007 to February 2008 in the Orthopedics Laboratory and the Biological Laboratory of Zhengzhou University （Zhengzhou, Henan, China）. MATERIALS： Twenty-eight adult New Zealand rabbits of SPF grade were offered by Zhengzhou University Animal Experimental Center, weighing 2.4-3.1 kg with a mean of 2.8 kg, irrespective of genders. MB66 braid was produced by Smith ＆ Nephew Medical （Shanghai） Limited. METHODS： The tendons of extending toe were harvested in both lower extremities, one tendon was wrapped with artificial ligament, while the other was only processed into the terminal wove dovetail. Anterior cruciate ligament was excised from bilateral knee joints in rabbits through the parapatellar incision, then femoral and tibial bones were drilled to implant the autologous tendon and artificial ligament on one side （serving as combined tendon group）, whereas only autologous tendon on the other side （serving as pure tendon group）, Both sides were sutured through bone bridge. Every 7 rabbits were killed under anesthesia at 2, 4, 6, and 8 weeks postoperatively. MAIN OUTCOME MEASURES： Gross observation and histological determination were carried out in the reconstructed anterior cruciate ligament of rabbits. The maximal breaking force of both grafts were detected. RESULTS： At 2 and 4 weeks postoperatively, the cells of reconstructed grafts disappeared and showed necrosis. Inflammatory cells infiltrated between autologous tendon and artificial ligament, there were cells growing from the edge to the center. At 6 weeks postoperatively, the autologous tendon had a little loose and disfiguration. The synovial membrane and cells hyperplasia were obvious. The synovial membrane filled the combined tendon and the infiltrative inflammatory cells reduced. The proliferative cells remarkably trended to the center. At 8 weeks postoperatively, the grafts were mostly substituted by new cells, and the artificial ligament was completely parceled by the synovial membrane, but there were still some gaps; The combined tendon exhibited no loose or disfiguration, the infiltrative inflammatory cells disappeared. The cells in grafts were close to normal cells in anterior cruciate ligament, but fibrocytes arranged in disorder and fibers showed a verticality. Biomechanics test results demonstrated the maximal breaking force of combined tendon was more than that of pure tendon （P 〈 0.05）. CONCLUSION： Both combined tendon and pure tendon have experienced the necrosis, revascularization and religament, which are the same to the biomechanics change. The artificial ligament and autologous tendon can make up for each other＇s shortcoming, such as early loosening of autologous tendon and permanent rupture of artificial ligament.