BACKGROUND Most laboratory studies investigating scapholunate dissociations are based on normal cadaver arms with serially sectioned ligaments. It is assumed that the kinetic behavior of a ligament-sectioned wrist is similar to a scapholunate dissociation. We tested five cadaver wrists with real injuries. The goal of this research was to evaluate the biomechanical behavior of scapholunate advanced collapse wrists compared to an experimental group with simulated injuries. METHODS Using a magnetic 6-degree of freedom motion tracking device, changes in scaphoid alignment induced by isometric loading 5 wrist motor tendons in two groups of specimens were monitored. Twelve fresh cadaver wrists in which scapholunate injury was simulated by sectioning the scapholunate ligament were compared to 5 arms with chronic scapholunate dissociation. FINDINGS The behavior of the scaphoid is the same in both groups, but the magnitude of displacement is greater in chronic scapholunate dissociation wrists, although not statistically significant. The extensor carpi ulnaris is the only muscle that provokes scaphoid pronation; all other muscles induce its supination. INTERPRETATION Different factors may play a role in the amount of scaphoid rotation observed in wrists with chronic scapholunate dissociation. Ligament sectioning alone in the experimental setup can only partially replicate the behavior of real scapholunate dissociations. The extensor carpi ulnaris has a major role in destabilizing scapholunate advanced collapse wrists; therefore, isometric contraction of this muscle should be avoided in the conservative treatment. The experimental setup designed is useful to evaluate the biomechanical behavior of the carpus under traction load.

中文翻译：

---

慢性肩cap骨远端解离的腕部运动功能障碍。尸体研究。

背景技术大多数研究对肩cap骨解离的实验室研究是基于具有连续切成的韧带的正常尸体臂。假定韧带切开的腕部的动力学行为类似于肩cap骨的离解。我们测试了五具真正受伤的尸体手腕。这项研究的目的是评估与模拟受伤的实验组相比，肩cap骨高级塌陷手腕的生物力学行为。方法使用磁性6自由度运动跟踪装置，对两组标本中等轴负载5个腕部运动肌腱引起的舟突对齐变化进行监测。将十二个新鲜的尸体手腕（其中通过对肩骨韧带进行切片来模拟肩cap骨的损伤）与5个具有慢性肩cap骨游离的手臂进行了比较。研究结果两组中舟骨的行为相同，但慢性舟骨月长解离腕关节的移位幅度较大，尽管在统计学上不显着。尺侧腕腕肌是唯一引起舟骨旋前的肌肉。其他所有肌肉都会诱发其旋后。解释在患有慢性肩cap骨分离的手腕中观察到的舟骨旋转量中，不同的因素可能起作用。在实验装置中，单独的韧带切片只能部分复制真正的肩cap骨离解的行为。尺腕腕骨在使肩cap骨高级塌陷腕关节不稳定方面起主要作用。因此，在保守治疗中应避免该肌肉等距收缩。