Bao H R C, Zhu D, Gong H, Gu G S
Department of Joint Surgery, First Hospital of Jilin University, 71 Xinmin Street, Changchun 130021, China.
J Orthop Sci. 2013 Mar;18(2):256-63. doi: 10.1007/s00776-012-0334-5. Epub 2012 Nov 17.
In recent years, with technological advances in arthroscopy and magnetic resonance imaging and improved biomechanical studies of the meniscus, there has been some progress in the diagnosis and treatment of injuries to the roots of the meniscus. However, the biomechanical effect of posterior lateral meniscus root tears on the knee has not yet become clear. The purpose of this study was to determine the effect of a complete radial posterior lateral meniscus root tear on the knee contact mechanics and the function of the posterior meniscofemoral ligament on the knee with tear in the posterior root of lateral meniscus.
A finite element model of the knee was developed to simulate different cases for intact knee, a complete radial posterior lateral meniscus root tear, a complete radial posterior lateral meniscus root tear with posterior meniscofemoral ligament deficiency, and total meniscectomy of the lateral meniscus. A compressive load of 1000 N was applied in all cases to calculate contact areas, contact pressure, and meniscal displacements.
The complete radial posterior lateral meniscus root tear decreased the contact area and increased the contact pressure on the lateral compartment under compressive load. We also found a decreased contact area and increased contact pressure in the medial compartment, but it was not obvious compared to the lateral compartment. The lateral meniscus was radially displaced by compressive load after a complete radial posterior lateral meniscus root tear, and the displacement took place mainly in the body and posterior horn of lateral meniscus. There were further decrease in contact area and increases in contact pressure and raidial displacement of the lateral meniscus in the case of the complete posterior lateral meniscus root tear in combination with posterior meniscofemoral ligament deficiency.
Complete radial posterior lateral meniscus root tear is not functionally equivalent to total meniscectomy. The posterior root torn lateral meniscus continues to provide some load transmission and distribution functions across the joint. The posterior meniscofemoral ligament prevents excessive radial displacement of the posterior root torn lateral meniscus and assists the torn lateral meniscus in transmitting a certain amount of stress in the lateral compartment.
近年来，随着关节镜和磁共振成像技术的进步以及半月板生物力学研究的改进，半月板根部损伤的诊断和治疗取得了一些进展。然而，外侧半月板后根部撕裂对膝关节的生物力学影响尚未明确。本研究的目的是确定外侧半月板后根部完全放射状撕裂对膝关节接触力学的影响以及后半月板股骨韧带在外侧半月板后根部撕裂的膝关节中的作用。
建立膝关节有限元模型，模拟完整膝关节、外侧半月板后根部完全放射状撕裂、外侧半月板后根部完全放射状撕裂合并后半月板股骨韧带缺失以及外侧半月板全切除等不同情况。所有情况下均施加1000 N的压缩载荷，以计算接触面积、接触压力和半月板位移。
外侧半月板后根部完全放射状撕裂在压缩载荷下减小了外侧间室的接触面积并增加了接触压力。我们还发现内侧间室的接触面积减小且接触压力增加，但与外侧间室相比并不明显。外侧半月板后根部完全放射状撕裂后，外侧半月板在压缩载荷下发生径向位移，且位移主要发生在外侧半月板的体部和后角。外侧半月板后根部完全撕裂合并后半月板股骨韧带缺失时，外侧半月板的接触面积进一步减小，接触压力和径向位移增加。
外侧半月板后根部完全放射状撕裂在功能上不等同于外侧半月板全切除。外侧半月板后根部撕裂仍继续提供一些跨关节的载荷传递和分布功能。后半月板股骨韧带可防止外侧半月板后根部撕裂后的过度径向位移，并协助撕裂的外侧半月板在外侧间室传递一定量的应力。
