后交叉韧带断裂对内侧半月板体部生物力学特性的影响

目的 探讨后交叉韧带(PCL)不同程度断裂对内侧半月板体部生物力学特性的影响.方法 新鲜成人正常膝关节标本12具(PCL完整组),膝关节0°、30°、60°、90°屈曲位,在200N载荷下,测试内侧半月板体部应变；然后将标本随机分为前外侧束(ALB)切断组和后内侧束(PMB)切断组,各6具,造模后,同法测试；再将12具标本的PCL完全切断(PCL全断组),同法测试.结果 膝0°屈曲位,内侧半月板体部应变在各实验组之间均差异无统计学意义(P＞0.05)；膝关节30°、60°屈曲位,内侧半月板体部应变在PCL完整组和PMB切断组之间差异无统计学意义(P＞0.05),在ALB切断组和PCL全断组之间差异无统计学意义(P＞0.05),PCL完整组和PMB切断组的应变绝对值均小于ALB切断组和PCL全断组的应变绝对值(均P＜0.05)；膝关节90°屈曲位,应变在各实验组之间均差并有统计学意义(P＜0.05),应变绝对值表现为PCL完整组＜PMB切断组＜ALB切断组＜PCL全断组.结论 PCL完全断裂,ALB断裂,PMB断裂对内侧半月板体部应变均产生影响,致半月板应力分布异常,为PCL断裂早期修复提供了理论依据.

Effects of PCL rupture on the biomechanics of medial meniscus

【Objective】 To investigate the effect of the PCL rupture on the biomechanics of medial meniscus.【Methods】 The straining of medial meniscus in all fresh normal adult knee joint specimens including 12 specimens of complete PCL,6 of anterolateral bundle(ALB) rupture,6 of posteromedial bundle(PMB) rupture and 12 of complete rupture PCL are tested when the knee joints loaded 200 N at 0°,30°,60° and 90° of flexion.【Results】 The straining of medial meniscus shows no significant difference among all the groups under the load of 200 N at 0° of flexion,P >0.05;the straining of medial meniscus shows no significant difference between ALB rupture group and PCL complete rupture group,between PCL complete group and PMB rupture group under the load of 200 N at 30°,60° of flexion,P >0.05,and the absolute value of straining in ALB rupture group and PCL complete rupture group were bigger than PCL complete group and PMB rupture group,P <0.05;the straining of medial meniscus shows significant difference among all groups under the load of 200 N at 90° of flexion,P <0.05,the correlation of the absolute value of medial meniscus straining increases in this way of complete PCL group < PMB rupture group < ALB rupture group < PCL complete rupture group.【Conclusions】 Abnormal straining of medial meniscus can be caused by the complete rupture of PCL,the rupture of anterolateral bundle(ALB) and the rupture of posteromedial bundle(PMB) rupture,this achievement may be used as the theoretical evidence to support the early reparation of the PCL rupture.