肱三头肌的解剖特点及其在臂后中部桡神经显露中的意义

Anatomic features of triceps brachii muscle and its significance on the exposure of radial nerve at the postmedian arm

目的观察肱三头肌与桡神经的位置关系,改进臂中后部桡神经的显露方法。方法尸体标本31具(62侧),在臂中部将肱三头肌外侧头自臂外侧肌间隔上钝性剥离达肱骨,继续向内侧钝性分离肱三头肌外侧头,显露桡神经,观察肱三头肌外侧头和内侧头融合的位置、融合前二者分界是否清晰,观察肱三头肌内侧头起点和外侧头起点与桡神经的位置关系。结果肱三头肌内、外侧头融合近端与桡神经穿过臂外侧肌间隔处距离(6.7±2.6)cm,约在鹰嘴窝上缘水平,融合前肱三头肌内、外侧头分界清晰。肱三头肌外侧头全部起自桡神经沟近端肱骨骨面的为79%(49侧),部分起自桡神经沟以远肱骨骨面的为21%(13侧),其中腱性的9例,肌性的4例。结论利用臂中部肱三头肌内、外侧头的解剖特点,可使臂后中部桡神经的显露更安全、合理。

Objective To investigate anatomic features of the triceps brachii muscle and its relationships to the radial nerve for improving the exposure of the radial nerve at the postmedian arm.Methods 31 adult cadavers（62 sides）were dissected.The lateral heads of the triceps brachii muscles were separated bluntly from lateral brachial intermuscular septum to humerus for exposing the radial nerve.The site where the medial and lateral heads of the triceps brachii muscle merged,the state of two heads before the merge,and the relationship of radial nerve with lateral and medial heads of triceps brachii,were observed and analyzed respectively.Results The distance between the site where the radial nerve pierced the lateral brachial intermuscular septum and the proximal merge point of the medial and lateral heads of the triceps brachii muscle was approximately（6.7±2.6）cm,at the level of olecranon fossa.Two heads of the triceps brachii muscle separated from each other distinctly.79%（49 sides）lateral heads wholly arised from the bone surface of humerus proximately to the radial nerve groove,and 21%（13 sides）partly arised from the bone surface of humerus distally to the radial nerve groove,9 of which were of tendous and 4 muscular types.Conclusions To ulitize anatomic features of the triceps brachii muscle,the exposure of radial nerve at the postmedian arm can be more reasonable and secure.