手部A_2滑车的解剖学及Ⅱc亚区内肌腱的滑动

Anatomy of the A_2 pulley and tendon gliding in zone Ⅱc

目的 :研究手部指屈肌腱功能最为重要的A2 滑车的解剖学及其所在区域 (Ⅱc亚区 )内肌腱的滑动。方法 :本研究采用 1 0只成人尸体手共 40个手指 ,观察A2 滑车的位置 ,并测定其长度、管径的垂直高度和横径 ;测定指深、浅屈肌腱由Ⅱb亚区向A2 滑车区域以及A2 滑车向Ⅱd亚区的滑动幅度。切开 1 0个中指测定A2 滑车近侧半或远侧半时手指屈曲度总和。结果 :A2 滑车位于的节指骨中部和近侧A2 滑车长度为近节指骨长度的 2 / 3。A2 滑车的中部口径是为细小 ,在手指完全屈曲时 ,几乎整个长度的Ⅱc亚区内指深屈腱滑动至Ⅱd亚区 ,切开A2 滑车近侧或远侧半对手指屈曲功能影响很小。结论 :A2 滑车的解剖学位置和形态特殊 ,A2 滑车中远部份最为细缩 ,部分切开A2 滑车对肌腱功能影响不明显。

Objective: To study the anatomy of the A 2 pulley and tendon gliding in the area of zone Ⅱc. Methods: The location,length and morphological feature of the A 2 pulley were studied on 40 fingers from 10 adult cadaveric hand specimens.Gliding excursions of the flexor digitorum superficalis (FDS) and profundus(FDP) tendons into or out of the A 2 pulley area were measured when the fingers were passively flexed.On 10 middle fingers,the total flexion of the finger joints was measured after incision of either distal or proximal half of the A 2 pulley. Results:The A 2 pulley located in the middle and proximal parts of the proximal phalanx,which had a length of approximately 2/3 of the proximal phalanx.The gliding tunnel was the most narrow at the middle of the A 2 pulley.When the fingers were completely flexed,almost entire segment of the tendons from zone Ⅱc glided into zoneⅡd.The incision of either proximal or distal half of the A 2 pulley did not produce obvious changes in the total flexion of the fingers. Conclusions: The A 2 pulley locating at the proximal 2/3 of the proximal phalanx is morphologically different from other pulleys.Incision of proximal or distal parts of the A 2 pulley does not obviously influence functions of the flexor tendons.The results of this study also indicate that the sheath in zone Ⅱd may affect function of the tendons in zone Ⅱc.