持续被动活动对兔重建前交叉韧带生物力学特性的影响

目的:采用半腱肌腱重建兔前交叉韧带(ACL),探讨持续被动活动(CPM)对移植物生物力学特性的影响。方法:对30只8月龄雄性新西兰大白兔右侧后肢膝关节行自体双股半腱肌腱移植重建前交叉韧带手术。术后随机分为CPM组和非CPM组两组:CPM组术后第2天开始采用自制兔膝关节CPM器进行持续被动活动,共6周;非CPM组仅笼养。分别于术后第6、12、24周取材,每组每次取5只行生物力学观察。结果:与非CPM组相比,CPM组大部分标本两束融合成一体。从术后6周到24周,所有移植物的最大载荷、最大应力、弹性模量以及这些指标和其对照侧ACL的比值逐渐增加。在术后6、12、24周时,CPM组移植物最大载荷分别为22.72N、79.56N、122.20N,最大应力分别为4.58MPa、13.62MPa、21.79MPa;非CPM组移植物最大载荷分别为16.00N、70.68N、96.20N,最大应力分别为3.07MPa、11.58MPa、17.89MPa。3个时间点两组间上述指标差异均具有统计学意义(P<0.05)。结论:半腱肌腱重建兔前交叉韧带术后早期进行持续被动活动可明显提高移植物的生物力学性能。

Effects of Continuous Passive Motion on Biomechanical Properties of the Tendon Autograft Used for Anterior Cruciate Ligament Reconstruction in a Rabbit Model

Objective To study the effects of continuous passive motion(CPM)on the biomechanical properties of the semitendinous tendon autograft used for anterior cruciate ligament(ACL)reconstruction in rabbits.Methods Thirty rabbits were underwent ACL reconstruction using double semitendinous tendon autograft in right posterior limb knee joint and were treated by either continuous passive motion or cage activity(non-CPM)postoperatively.The biomechanical properties of ACL were tested bilaterally,at 6,12,24 weeks post operation.Results The maximum load,maximum stress and elastic modulus of tendon autograft showed a continuous improving from 6 to 24 weeks in both groups,compared with their own controls.In the CPM specimens,the maximum load of graft was 22.72N,79.56N,122.20N and the maximum stress was 4.58MPa,13.62MPa,21.79MPa in 6,12,24 weeks respectively,with statistically significant difference from non-CPM specimens(P<0.05).Conclusion Early rehabilitation program with integration of CPM exercise could help the restructuring process of the graft after reconstruction.