Skie M, Zeiss J, Ebraheim N A, Jackson W T
Department of Orthopaedic Surgery, Medical College of Ohio, Toledo 43699.
J Hand Surg Am. 1990 Nov;15(6):934-9. doi: 10.1016/0363-5023(90)90019-n.
Magnetic resonance imaging was done on the wrists of 14 volunteer subjects with the wrists in the neutral position, then flexed and extended at 45 degrees. Computer enhanced cross-sectional areas were measured on each subject at the level of the hook of the hamate. In the neutral position the distance between confining structures around the median nerve is 2.0 +/- 0.2 mm in the anteroposterior direction, and the mean cross-sectional area of the carpal tunnel is 1.52 cm2. With the wrist in the extended position the distance available for the median nerve measures 2.2 +/- 0.4 mm and the cross-sectional area increases to 1.75 cm2. When the wrist is flexed, the distance available for the median nerve between the flexor tendons and transverse carpal ligament decreases to 1.1 +/- 0.4 mm, and the cross-sectional tunnel area decreases to 1.36 cm2. Flexion of the wrist and/or fingers both produces a palmar rearrangement of the flexor tendons creating potential compression of the median nerve. The nerve responds to these forces by becoming interposed in various positions between the superficial flexor tendons.
对14名志愿者受试者的手腕进行磁共振成像检查，手腕处于中立位，然后分别屈曲和伸展45度。在每个受试者的钩骨钩水平测量计算机增强的横截面积。在中立位时，正中神经周围限制结构在前后方向的距离为2.0±0.2毫米，腕管的平均横截面积为1.52平方厘米。手腕处于伸展位时，正中神经的可用距离为2.2±0.4毫米，横截面积增加到1.75平方厘米。当手腕屈曲时，屈肌腱与腕横韧带之间正中神经的可用距离减少到1.1±0.4毫米，腕管横截面积减少到1.36平方厘米。手腕和/或手指的屈曲都会使屈肌腱在手掌重新排列，从而产生正中神经受压的可能性。神经通过在浅屈肌腱之间的不同位置插入来应对这些力量。
