Berdia Sunjay, Short Walter H, Werner Frederick W, Green Jason K, Panjabi Manohar
Department of Surgery, Uniformed Services University of the Health Sciences, Orthopaedic Center, Rockville, MD 20850, USA.
J Hand Surg Am. 2006 Apr;31(4):594-600. doi: 10.1016/j.jhsa.2005.12.028.
Carpal bones show hysteresis that is dependent on the direction of wrist motion during a continuous active loading protocol. We describe an accurate methodology for analyzing the hysteresis effect and we apply this model to analyze the effect of sequential ligament sectioning on scapholunate instability.
In 8 fresh cadaver forearms scaphoid, lunate, and third metacarpal motions were recorded while each wrist was moved in continuous cycles of active motion in flexion-extension and radioulnar deviation. Motions were analyzed for the intact state and after sequential sectioning of the scapholunate interosseous, scaphotrapezium, and radioscaphocapitate ligaments. Carpal motion was curve-fitted with respect to the third metacarpal motion using optimization criteria. The area between the 2 curves that represents opposite directions of wrist motion was measured to give the total hysteresis area. Repeated-measures analysis of variance was used to determine significance.
In the flexion-extension trials the scaphoid and lunate total hysteresis area was significantly greater than the intact state only after all 3 ligaments were sectioned. In the radioulnar deviation trials the scaphoid total hysteresis area was significantly greater than the intact after just scapholunate interosseous ligament sectioning; however, the lunate total hysteresis area decreased with additional sequential sectionings in 4 of the 8 specimens as compared with the intact state. These 4 specimens started with a significantly greater intact total hysteresis area than the other 4 specimens.
The computation of the total hysteresis area from the hysteresis effect was found to be a sensitive technique to determine the subtle onset of abnormal carpal motion. By using this technique in a ligament sectioning study significant increases in the total hysteresis area were seen after just scapholunate interosseous ligament sectioning during wrist radioulnar deviation. This subtle change may signify the onset of dynamic scapholunate instability. The total hysteresis area of the lunate in a subset of lax specimens did not increase after ligament sectioning. This divergent behavior may explain why some patients with scapholunate instability do not develop dorsal intercalated segmental instability.
在连续主动加载方案中，腕骨表现出取决于腕关节运动方向的滞后现象。我们描述了一种分析滞后效应的精确方法，并应用该模型分析连续韧带切断对舟月关节不稳定的影响。
在8个新鲜尸体前臂中，记录舟骨、月骨和第三掌骨的运动，同时每个腕关节在屈伸和桡尺偏斜的连续主动运动周期中移动。分析完整状态以及舟月骨间韧带、舟大多角骨韧带和桡舟头韧带连续切断后的运动情况。使用优化标准将腕骨运动相对于第三掌骨运动进行曲线拟合。测量代表腕关节运动相反方向的两条曲线之间的面积，以得出总滞后面积。采用重复测量方差分析来确定显著性。
在屈伸试验中，仅在所有3条韧带都切断后，舟骨和月骨的总滞后面积才显著大于完整状态。在桡尺偏斜试验中，仅切断舟月骨间韧带后，舟骨的总滞后面积就显著大于完整状态；然而，与完整状态相比，8个标本中有4个在额外连续切断韧带后月骨的总滞后面积减小。这4个标本开始时的完整总滞后面积明显大于其他4个标本。
发现从滞后效应计算总滞后面积是一种确定腕骨异常运动细微起始的敏感技术。通过在韧带切断研究中使用该技术，在腕关节桡尺偏斜过程中仅切断舟月骨间韧带后，总滞后面积就出现了显著增加。这种细微变化可能意味着动态舟月关节不稳定的开始。一部分松弛标本中月骨的总滞后面积在韧带切断后并未增加。这种不同的表现可能解释了为什么一些舟月关节不稳定的患者不会发展为背侧插入节段性不稳定。
