掌骨受轴向压力作用下的腕部生物力学分析

Biomechanical Analysis of Wrist under Axial Static Compressive Force on Metacarpals

目的研究正常腕部载荷传递及关节接触应力分布情况,以及腕横韧带切除对腕部生物力学的影响。方法通过CT扫描图像数据对腕部进行三维有限元建模,计算并分析掌骨受轴向压力作用下正常腕部载荷传递及接触应力的分布,以及腕横韧带切开前后腕骨运动的变化情况。结果腕部载荷传递及关节接触应力分布情况与前人实验数据相当接近;腕横韧带的切除导致舟骨发生向桡侧和掌侧的偏移,以及掌向屈曲和向桡侧的转动,而整个腕管结构则产生更大的桡侧偏移。结论立体构架了包括整个腕管结构、远端尺骨和桡骨以及近端掌骨的腕部整体三维有限元模型。本模型可以较好地模拟腕管和桡腕关节载荷传递与接触应力的分布情况,为进一步探讨腕部结构的力学行为提供了一个可操作的平台。通过计算分析腕管松解术对腕骨运动的影响,为腕管综合征的临床手术、术后康复等提供了相关的理论依据。

Objective To study the force and pressure transmission through normal wrist, and the effect of transverse carpal ligament release on the biomechanics of carpal tunnel, Methods A 3-D finite element model of the wrist based on CT scan images was established. The load transmission of carpus and the distribution of contact stress on radiocarpal joint under axial compressive force on metacarpals as well as the effect of transverse carpal ligament （TCL） release on the displacement of carpal bones were computed and analyzed. Results The computational results of force and pressure transmission through normal carpus matched well with previous studies. The release of TCL resulted in radial and palmar displacement of the scaphoid, flexion and radial rotation of radiocarpal joint as well as a further radial deviation of the whole carpal tunnel. Conclusion A 3-D finite element model of the wrist that includes the carpal tunnel ,distal radius and ulna and proximal metacarpals is developed. This model may simulate the load transmission better and contact stress distribution of carpal tunnel and radiocarpal joint,as well as provide an operational plateform for further deeply studing on biomechanical behavior of carpal structure. The computed and analyzed results of the effect of TCL release on the displacements of carpal bones can be served as related theoratic base on carpal tunnel syndrome ,carpal tunnel release surgery and recovery after operation.