Liu Kristina J, Thomson J Grant
Section of Plastic Surgery, Yale University School of Medicine, New Haven, Connecticut.
J Hand Surg Am. 2013 Oct;38(10):1933-40. doi: 10.1016/j.jhsa.2013.06.033. Epub 2013 Aug 24.
Although it can be reasonably assumed that trigger digits occur as the result of a size mismatch in the pulley-tendon system, it is unclear whether locking, histological changes, and nodule formation occur owing to an intrinsically too small pulley or an enlarged digital flexor tendon. Our purposes in this feasibility study were to (1) create a model of trigger digit by pulley constriction in nonpreserved human tissue, (2) measure the change in work of flexion as the force of pulley constriction increased, (3) compare the work of flexion between nontriggering and triggering conditions, and (4) determine whether triggering can occur at the A2, A3, and A4 pulleys under similar conditions.
Using a tensiometer, we studied the work of flexion in 4 fingers (thumb, index, middle, and ring) in a human cadaveric hand. The load of flexion was measured as the A1 to A4 pulleys were incrementally constricted in order to induce triggering. Work of flexion was analyzed for differences among trial conditions.
Triggering was successfully induced in all 4 digits through constriction of the A1 pulley. No triggering occurred in any of the A2, A3, or A4 pulley systems in this model.
We successfully created a trigger model in a human cadaveric hand. Our results demonstrate that the A1 pulley can cause triggering from manual constriction of the pulley alone.
A trigger model such as this may allow investigations of pathophysiology, and this may result in novel treatment strategies and modalities.
虽然可以合理推测扳机指是由于滑车 - 肌腱系统尺寸不匹配所致，但尚不清楚锁定、组织学改变和结节形成是由于滑车本身过小还是指屈肌腱增粗引起的。我们进行这项可行性研究的目的是：（1）在未保存的人体组织中通过滑车缩窄创建扳机指模型；（2）测量随着滑车缩窄力增加时屈曲功的变化；（3）比较非扳机状态和扳机状态下的屈曲功；（4）确定在类似条件下A2、A3和A4滑车是否会出现扳机现象。
我们使用张力计研究了一具人体尸体手部4根手指（拇指、示指、中指和环指）的屈曲功。在逐渐缩窄A1至A4滑车以诱发扳机现象的过程中测量屈曲负荷。分析不同试验条件下的屈曲功差异。
通过缩窄A1滑车，成功在所有4根手指中诱发了扳机现象。在该模型的任何A2、A3或A4滑车系统中均未出现扳机现象。
我们成功在人体尸体手部创建了扳机模型。我们的结果表明，仅通过手动缩窄滑车，A1滑车就可导致扳机现象。
这样的扳机模型可能有助于对病理生理学进行研究，这可能会带来新的治疗策略和方法。
