Abstract:
Anterior cruciate ligament (ACL) rupture is a very common knee joint injury. Torn ACLs are currently reconstructed using tendon autografts. However, half of the patients develop osteoarthritis (OA) within 10 to 14 years postoperatively. Proposedly, this is caused by altered knee kine(ma)tics originating from changes in graft mechanical properties during the in vivo remodeling response. Therefore, the main aim was to use subject-specific finite element knee models and investigate the influence of decreasing graft stiffness and/or increasing graft laxity on knee kine(ma)tics and cartilage loading. In this research, 4 subject-specific knee geometries were used, and the material properties of the ACL were altered to either match currently used grafts or mimic in vivo graft remodeling, i.e., decreasing graft stiffness and/or increasing graft laxity. The results confirm that the in vivo graft remodeling process increases the knee range of motion, up to >300 percent, and relocates the cartilage contact pressures, up to 4.3 mm. The effect of remodeling-induced graft mechanical properties on knee stability exceeded that of graft mechanical properties at the time of surgery. This indicates that altered mechanical properties of ACL grafts, caused by in vivo remodeling, can initiate the early onset of osteoarthritis, as observed in many patients clinically.
摘要:
前交叉韧带(ACL)断裂是一种非常常见的膝关节损伤。目前使用自体肌腱移植重建撕裂的ACL。然而,一半的患者在术后10~14年内发展为骨关节炎(OA).提议,这是由改变的kneekine(ma)Tics源于在体内重塑反应过程中移植物机械特性的变化引起的。因此,主要目的是使用特定受试者的有限元膝关节模型,并研究降低移植物刚度和/或增加移植物松弛对膝关节运动(ma)和软骨负荷的影响。在这项研究中,使用了4种受试者特定的膝盖几何形状,ACL的材料特性被改变以匹配当前使用的移植物或模拟体内移植物重塑,即,降低移植物硬度和/或增加移植物松弛度。结果证实,体内移植物重塑过程增加了膝关节的运动范围,高达>300%,并重新定位软骨接触压力,高达4.3毫米。手术时,重塑诱导的移植物机械性能对膝关节稳定性的影响超过了移植物机械性能。这表明ACL移植物的机械性能改变,由体内重塑引起,可以引发骨关节炎的早期发作,正如在许多临床患者中观察到的那样。