产瘫后肩关节内旋挛缩发生机制的解剖学研究

An anatomic study on the mechanism of shoulder medial rotation contracture in obstetrical brachial plexus palsy

目的 比较支配肩胛下肌及其拮抗肌的神经在臂丛根 (干 )部的来源 ,观察肩胛下肌营养动脉的来源及其在肌肉内的分布特点 ,为阐明产瘫肩胛下肌挛缩的发生机制提供解剖学基础。方法 对 3 2侧成人尸体的肩胛下肌及其拮抗肌的支配神经作逆行显微解剖分离 ,追踪其神经根 (干 )来源 ,计算来自臂丛各根 (干 )部分的构成比均值 ;观察肩胛下肌的动脉血供以比较肩胛下肌上部和下部血管数量和分布的差异。结果 支配肩胛下肌支配神经的纤维主要来源于臂丛上中干 ,上干占 (81.61± 6.85 ) % ,中干占(18.3 9± 6.85 ) % ;而支配拮抗肌的神经纤维全部来源于上干。自肩胛下肌上部进入的营养动脉在数量和口径上都大于下部 (t1=2 .94,P <0 .0 1;t2 =4.78,P <0 .0 1)。结论 肩胛下肌和其拮抗肌的支配神经在臂丛根 (干 )

Objective To observe the origin of the nerves innervating the subscapularis muscle and its anagonistic muscles at brachial plexus root or trunk level, and the blood supply of the subscapularis muscle in order to clarify the mechanism of subscapularis muscle contracture in obstetric brachial plexus palsy (OBPP). Methods 32 sides of adult human cadavers were used. The innervating nerve of the subscapularis muscle and its antagonistic muscles (the infraspinatus muscle, the teres minor muscle, the deltoid muscle and the supraspinatus muscle) were dissected retrogradely to trace its origin at the root and trunk level of the brachial plexus. The nerve fiber external diameter in the corresponding root and/or trunk was measured and the constituent ratios in the root and/or trunk of the brachial plexus were calculated. The nutrient arteries of the subscapularis muscle were observed to compare the number and distribution of the arteries to the upper parts of the subscapularis muscle and the lower parts. Results The nerve fibers innervating the subscapularis muscle mainly originated from the upper and middle trunk. The percentage in the upper trunk was (81.61 ± 6.85)%, while that in the middle trunk was (18.39 ± 6.85)%. The nerve fibers of its antagonistic muscles only originated from the upper trunk. Not only the number but also the diameter of the arteries entering the upper parts of the muscle was larger than those entering the lower parts. Conclusions The difference in the nerve fiber origin between the subscapularis muscle and its antagonistic muscles and the characteristics of the blood supply of the subscapularis muscle were the major causes of subscapularis muscle contracture in obstetric brachial plexus palsy.