正中神经返支“握拳三点法”体表定位

The localization of the recurrent branch of the median nerve through "three points clench fist method "

目的:研究正中神经返支简单实用的体表定位方法。方法:对20侧成人新鲜上肢标本的正中神经返支进行解剖,观测返支的走行,测量起点,最高点,入肌点,根据解剖学观测制定体表定位。结果:⑴返支起点变化较大,多起源于腕管外,正中神经返支最高点,距远侧腕横纹距离为(36.80±2.82)mm(33.98～39.62mm),距屈肌支持带远侧缘(5.35±2.25)mm(3.1～7.6mm),返支入肌点在拇短屈肌与拇短展肌肌间隙上距拇指基底桡侧缘(35.5±1.86)mm(33.64～37.36mm);⑵握拳三点定位法:①返支起点A点定位:握拳时中环指间线与拇指近节指骨基底尺侧,豌豆骨连线交点。②返支最高点B点定位法:握拳时中指指尖与拇指近节指骨基底尺侧,钩骨钩连线交点。③返支入肌点C点定位法:握拳时示中指间线与拇指近节基底桡侧,豌豆骨连线(此线为拇短屈肌与拇短展肌肌间隙的体表线)交点。结论:握拳定位法既可以给返支定位,又可以体现返支走行及常见变异。

Objective： To explore a simple and useful projection method for locating the recurrent branch of the median nerve. Methods： 20 specimens of the fresh upper extremity were dissected. The course of the recurrent branch was observed, while the origin, the highest point and the point reaching muscle of it were measured. And then the surface landmarks were defined according to anatomic observations. Results： 1.The origin of the recurrent branch was variable, most of them from the outside of the carpal tunnel. The distance from the highest point of the recurrent branch to the distal carpal transverse striation was （36.80±2.82）mm （33.98-39.62 mm）, to distal margin of transverse carpal ligament （5.35±2.25）mm （3.1-7.6 mm） respectively. The average distance was （35.5±1.86）mm （33.64-37.36 mm） from the insertion point which was between the flexor pollicis brevis and the abductor pollicis brevis to basal radialis margin of the thumb. 2. According to ＂three points clench fist method＂, the origin of the recurrent branch （A point） located at the intersection from the interdigital line between middle and index fingers ulnarly to the base of proximal thumb to pisiform bone at the position of clench fist. The apex of the recurrent branch （B point） located at the intersection of the line from the middle finger tip and the ulnar base of proximal thumb to the hook of hamate bone at the same position. The insertion point of it （C point） located at the intersection of the line from middle interdigital line and the radial base of the proximal thumb to pisiform bone at the same position. Conclusions： ＂three points clench fist method＂ can define the position of the recurrent branch of the median nerve, it is also helpful to show the course and variation of the branch.