Tamgire Dharmaraj Wamanrao, Sontakke Yogesh Ashok, Rajasekhar Sssn, Aravindhan Karuppusamy
Assistant Professor, Department of Anatomy, JIPMER, Pondicherry, India.
Additional Professor and Head, Department of Anatomy, JIPMER, Pondicherry, India.
J Clin Diagn Res. 2017 May;11(5):AD01-AD03. doi: 10.7860/JCDR/2017/25552.9927. Epub 2017 May 1.
Multiple muscular and neurovascular anomalies in upper limb are reported continuously in medical literature because of their clinical significance. A unique case of the triad of variations was encountered during routine dissection activity. The variations observed were: 1) Accessory third head of biceps brachii; 2) High division of Brachial Artery; 3) Communication between Musculocutaneous Nerve and Median Nerve. Taken independently these variations are common but it is rare in a single cadaver. These abnormalities were found unilaterally on the right arm of the cadaver. The third head of biceps brachii was seen to be originating from the medial border and adjacent area on the anteromedial surface of the humerus at the level of insertion of coracobrachialis fusing with main muscle belly just before it forms the tendon. Additional head of biceps brachii was supplied by a branch from the Median Nerve. This branch after supplying the additional head of biceps was seen to join the Musculocutaneous Nerve. Further, a higher bifurcation of brachial artery was observed at the level of insertion of coracobrachialis. The medial division was traced distally as radial artery and the lateral division was traced as ulnar artery. The knowledge of these variations is of immense importance to correlate abnormal displacement of fractured bone segments, avoiding fatal injuries to vital structures, transradial angiography and diagnostic clinical neurophysiology.
由于其临床意义，上肢多种肌肉和神经血管异常在医学文献中不断被报道。在一次常规解剖活动中遇到了一个独特的三联变异病例。观察到的变异情况如下：1）肱二头肌副三头；2）肱动脉高位分支；3）肌皮神经与正中神经之间存在交通。单独来看，这些变异很常见，但在单个尸体中出现则很罕见。这些异常在尸体的右臂单侧发现。肱二头肌的第三头在喙肱肌附着水平处，起自肱骨内侧缘及肱肌前内侧表面的相邻区域，在形成肌腱之前与主要肌腹融合。肱二头肌的额外头由正中神经的一个分支供血。该分支在供应肱二头肌额外头后，与肌皮神经相连。此外，在喙肱肌附着水平观察到肱动脉有更高位的分叉。内侧分支向远端追踪为桡动脉，外侧分支追踪为尺动脉。了解这些变异对于关联骨折骨段的异常移位、避免对重要结构造成致命损伤、经桡动脉血管造影以及诊断性临床神经生理学具有极其重要的意义。
