Nomoto Takashi, Matsuura Yusuke, Yamazaki Takahiro, Suzuki Takane, Ohtori Seiji
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Chiba Perfecture, Japan.
Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, Chiba, Chiba Perfecture, Japan.
J Hand Surg Glob Online. 2025 May 23;7(4):100747. doi: 10.1016/j.jhsg.2025.100747. eCollection 2025 Jul.
This study aimed to evaluate the effects of wrist joint angles during flexion-extension and radioulnar deviation on stress distribution using finite element analysis.
Eight fresh-frozen upper limb specimens were analyzed using computed tomography. Finite element models were developed to simulate grip postures in flexion-extension (five positions ranging from 30° flexion to 30° extension) and radioulnar deviation (eight positions from 15° radial deviation to 20° ulnar deviation). Stress distributions (equivalent stress, minimum principal stress, and maximum principal stress) in the distal radius, ulnar head, and proximal carpal bones were assessed.
In the flexion-extension model, stress was concentrated in the central area of the distal radius and increased with an increase in flexion-extension angles. Stress values in the ulnar head and triquetrum increased during flexion and extension, whereas stress changes were minimal in the scaphoid and lunate. The scaphoid fossa experienced higher stress than the lunate fossa, with the volar aspect of the distal radius under greater stress during extension and the dorsal aspect during flexion. In the radioulnar deviation model, radial deviation decreased the load on the lunate fossa while increasing the load on the ulnar head, triquetrum, and dorsal lunate. Conversely, ulnar deviation reduced the load on the ulnar head but increased the load on the volar aspect of the lunate fossa.
Finite element analysis demonstrated dynamic changes in wrist joint stress distribution at various motion angles.
These findings enhance the understanding of wrist biomechanics and provide insights into the pathomechanics of degenerative wrist conditions.
本研究旨在通过有限元分析评估屈伸和桡尺偏斜过程中腕关节角度对应力分布的影响。
使用计算机断层扫描分析8个新鲜冷冻的上肢标本。建立有限元模型以模拟屈伸（从30°屈曲到30°伸展的5个位置）和桡尺偏斜（从15°桡偏到20°尺偏的8个位置）时的抓握姿势。评估桡骨远端、尺骨头和近端腕骨的应力分布（等效应力、最小主应力和最大主应力）。
在屈伸模型中，应力集中在桡骨远端的中央区域，并随屈伸角度的增加而增加。尺骨头和三角骨的应力值在屈曲和伸展时增加，而舟骨和月骨的应力变化最小。舟骨窝的应力高于月骨窝，桡骨远端掌侧在伸展时承受更大的应力，背侧在屈曲时承受更大的应力。在桡尺偏斜模型中，桡偏减少了月骨窝的负荷，同时增加了尺骨头、三角骨和月骨背侧的负荷。相反，尺偏减少了尺骨头的负荷，但增加了月骨窝掌侧的负荷。
有限元分析表明腕关节在不同运动角度下应力分布的动态变化。
这些发现增强了对腕关节生物力学的理解，并为退行性腕关节疾病的发病机制提供了见解。
