Oura Keiichiro, Oka Kunihiro, Kawanishi Yohei, Sugamoto Kazuomi, Yoshikawa Hideki, Murase Tsuyoshi
Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
J Orthop Res. 2015 Apr;33(4):496-503. doi: 10.1002/jor.22780. Epub 2014 Dec 9.
To investigate the cause of rupture of the flexor pollicis longus (FPL) after volar plate fixation of distal radius fractures, previous studies have examined the shape of the distal radius in the sagittal plane or in the lateral view. However, there are no reports on the anatomical shape of the volar surface concavity of the distal radius in the axial plane. We hypothesized that this concavity might contribute to the mismatch between the plate and the surface of the radius. To test this hypothesis, we constructed three-dimensional models of the radius and FPL based on computed tomography scans of 70 normal forearms. We analyzed axial cross-sectional views with 2 mm intervals. In all cases, the volar surface of the distal radius was concave in the axial plane. The concavity depth was maximum at 6 mm proximal to the palmar edge of the lunate fossa and progressively decreased toward the proximal radius. FPL was closest to the radius at 2 mm proximal to the palmar edge of the lunate fossa. The volar surface of the distal radius was externally rotated from proximal to distal. These results may help to develop new implants which fit better to the radius and decrease tendon irritation.
为了研究桡骨远端骨折掌侧钢板固定后拇长屈肌（FPL）断裂的原因，以往的研究已经在矢状面或侧位视图中检查了桡骨远端的形状。然而，关于桡骨远端掌侧表面在轴向平面上的解剖形状尚无报道。我们推测这种凹陷可能导致钢板与桡骨表面不匹配。为了验证这一假设，我们基于70例正常前臂的计算机断层扫描构建了桡骨和拇长屈肌的三维模型。我们以2毫米的间隔分析轴向横截面视图。在所有病例中，桡骨远端的掌侧表面在轴向平面上呈凹陷状。凹陷深度在距月骨窝掌侧边缘近端6毫米处最大，并向桡骨近端逐渐减小。拇长屈肌在距月骨窝掌侧边缘近端2毫米处最靠近桡骨。桡骨远端的掌侧表面从近端向远端向外旋转。这些结果可能有助于开发更适合桡骨的新型植入物，并减少肌腱刺激。
