活动对兔前交叉韧带重建腱-骨愈合的影响

Effect of activities on tendon-bone healing of anterior cruciate ligament reconstruction in rabbits

[目的]观察不同术后活动对兔前交叉韧带(anterior cruciate ligament,ACL)重建术后腱骨愈合的影响。[方法]64只6月龄新西兰白兔随机分为4组,每16只,分别为固定(immobilization,IM)组、自由活动(free motion,FM)组、低强度活动(low-intensity motion,LIM)组以及高强度活动(high-intensity motion,HIM)组。所有动物均行右膝关节ACL切除,而后采用自体半腱肌腱行ACL重建术。IM组的动物术后2周石膏固定患膝于屈曲120°位;FM组术后置于饲养笼中自由活动;LIM组和HIM组分别在跑步台上,以0.2 m/s和0.5 m/s跑步,1次/3 d,每次持续0.5 h。8周后处死动物,行大体观察、组织学检查和生物力学测试。[结果]仅HIM组3只出现轻度跛行,处死后抽屉实验阳性,内固定失效,肌腱出现部分抽出,但隧道内仍存有一定长度的肌腱。组织学观察,与FM组相比,IM组腱骨界面仍存在较明显的界限、裂隙,更多的炎症细胞和血管组织,且未见任何软骨细胞。组织学评分由高至低依次为LIM组>HIM组>FM组>IM组,差异有统计学意义(P<0.05)。生物力学测试方面,最大损毁强度由高至低依次为LIM组>HIM组>FM组>IM组,差异有统计学意义(P<0.05)。最大位移由小至大依次为LIM组<HIM组<FM组<IM组,差异有统计学意义(P<0.05)。[结论]本研究表明,ACL重建术后适当活动有利于腱-骨愈合,而完全固定或高强度活动均不利于腱-骨愈合。

[Objective]To explore the effect of different postoperative activities on tendon-bone healing of anterior cruciate ligament(ACL)reconstruction in rabbits.[Methods]Sixty-four 6-month-old New Zealand white rabbits were randomly divided into 4 groups with16 rabbits in each group,including the immobilized(IM),free motion(FM),low-intensity motion(LIM),and high-intensity motion(HIM)groups.All the animals underwent right knee ACL resection followed by ACL reconstruction with autogenous semitendinosus tendon.The rabbits in the IM group had the knee fixed with plaster cast at 120°flexion after 2 weeks,those in the FM group were placed in free motion without restriction in the cage,whereas those in the LIM group and HIM group ran at 0.2 m/s and 0.5 m/s respectively on the running platform,once every 3 days for 0.5 hour each time.At 8 weeks after operation the animals were sacrificed for gross observation,histological examination and biomechanical tests.[Results]Only 3 animals in HIM group showed mild claudication,with positive drawer test,which proved internal fixation failure that the tendon was partially pulled out,but certain length of tendon remained in the tunnel.In term of histological observation,the tendon-bone interface in IM group still had more obvious boundaries and fissures,with more inflammatory cells and vascular tissues,while scanty chondrocytes compared with the FM group.Histological score was ranked from high to low as the LIM group>the HIM group>FM group>IM group with statistically significant differences among them(P<0.05).In terms of biomechanical tests,the maximum strength to failure was ordered from high to low as LIM group>the HIM group>FM group>IM group with statistically significant differences among them(P<0.05),whereas the maximum displacement was arranged from low to high as LIM group<the HIM group<FM group<IM group with statistically significant differences among them(P<0.05).[Conclusion]In this study,appropriate activities after ACL reconstruction are conducive to tendon-bone healing,whereas complete immobilization or high intensity activities are harmful to tendon-bone healing.