Oztürk Nail Can, Uzmansel Deniz, Oztürk Hakan
Department of Anatomy, Faculty of Medicine, Mersin University, Mersin, Turkey.
Surg Radiol Anat. 2010 Nov;32(9):887-90. doi: 10.1007/s00276-009-0616-6. Epub 2010 Jan 5.
An unreported pattern of communication between musculocutaneous (Mcn) and median nerve (Mn) with multiple variations of biceps brachii (Bb) was observed during the dissection of a male cadaver. The first branch of the Mcn ended in coracobrachialis (Cb). The second was the main Mcn piercing the Cb and giving its motor branches to the muscles of the anterior compartment of the arm. It then continued as the lateral cutaneous nerve of the forearm. The largest third branch also pierced the Cb distal to the main Mcn and communicated with the Mn which was classically formed by relevant roots of the medial and lateral cords. Additionally, a third head of Bb was observed bilaterally. Slips from the pectoralis major were inserted on the tendon of the third head on both sides. The origin of the third head was the greater tubercle to the left and the joint capsule to the right. These extremely rare patterns of both variations which were seen concomitantly in the same subject do not exist in the literature. Lack of awareness of such variations with different patterns of communications between Mcn and Mn might complicate surgical repair of the nerves. Knowing different patterns of Bb variations also have clinical importance as they also may cause compression of neurovascular structures or confuse a surgeon during surgical procedures.
在一具男性尸体解剖过程中，观察到肌皮神经（Mcn）与正中神经（Mn）之间一种未报道过的沟通模式，肱二头肌（Bb）存在多种变异。肌皮神经的第一分支止于喙肱肌（Cb）。第二分支是肌皮神经的主干，穿过喙肱肌并向臂前群肌发出运动分支。然后它继续作为前臂外侧皮神经。最大的第三分支也在肌皮神经主干的远侧穿过喙肱肌，并与正中神经相通，正中神经通常由内侧和外侧索的相关神经根形成。此外，双侧均观察到肱二头肌的第三个头。两侧胸大肌的肌束均止于第三个头的肌腱。第三个头的起点左侧为大结节，右侧为关节囊。在同一受试者中同时出现的这两种变异的极其罕见模式在文献中并不存在。对肌皮神经和正中神经之间不同沟通模式的此类变异缺乏认识可能会使神经的手术修复复杂化。了解肱二头肌变异的不同模式也具有临床重要性，因为它们也可能导致神经血管结构受压或在手术过程中使外科医生感到困惑。
