近排腕骨切除术后桡腕关节的解剖学及生物力学变化

目的研究近排腕骨切除术后新的桡腕-桡头关节的解剖学特点及生物力学变化，增强临床对这一术式的理解。方法6只福尔马林固定的尸体腕标本，模拟近排腕骨切除术后观测头状骨近端关节面；纵性剖开头状骨及月骨，描拓桡月关节和桡头关节的匹配曲线；选用6只新鲜标本牙托粉包埋后，用压敏片在双轴液压材料测试系统上测试正常和术后桡腕关节的接触面积和压力变化。数据进行统计学处理。结果正常桡月关节匹配曲线良好，腕骨切除术后头状骨近端关节面有4个子关节面，和桡骨远端的桡月窝匹配性差。腕中立位下，正常的平均腕单位面积负荷为（22．9±4．3）N／cm^2。近排腕骨切除术后为（136．4±30．7）N／cm。（P〈0．05）。结论近排腕骨切除术后形成的新桡腕关节-桡头关节其解剖学和生物力学都明显异常。

Anatomical and biomechanical changes of the wrist join after the proximal row carpectomy

Objective To evaluate the anatomical and biomechanical changes of the new wristradiocapitate joint after proximal row carpectomy and deepen the clinical understanding of this technique. Methods Proximal row carpectomy were performed on 6 formalin-fixed cadaver wrist specimens. The proximal ends of the capitate were observed and measured. The lunate, capitate and distal radius were longitudinally dissected to observe their joint surface curves and contact match. The normal and postoperational joint contact pressure and area changes were measured with pressure sensitive films and the material testing system on six fresh specimens.The information on the films was studied statistically. Results The normal radiolunate joint has perfect contact match. The four proximal articular surfaces of capitate have poor contact matching with the radiolunate fossa of the distal radius. Under the neutral position, the average pressure intensity of normal wrist is （22.9±4.3） N/cm. But the value reached （136.4±30.7）N/cm after proximal row carpectomy （P 〈0.05）. Conclusion There is significant anatomical and biomechanical changes of the new wris joint- radiocapitate joint after proximal row carpectomy.