Leonello Domenic T, Galley Ian J, Bain Gregory I, Carter Christopher D
University of Adelaide, Adelaide, Australia.
J Bone Joint Surg Am. 2007 Jun;89(6):1293-7. doi: 10.2106/JBJS.F.00343.
There have been conflicting descriptions of brachialis muscle anatomy in the literature. The purpose of the present study was to clarify brachialis muscle anatomy in order to refine surgical techniques around the elbow.
Eleven cadaveric upper limbs were dissected under loupe magnification. The gross morphological characteristics, relationships, and nerve supply of the brachialis muscle were recorded. The nerve supply was examined histologically to confirm the gross findings.
In all specimens, the brachialis muscle had two heads. The larger, superficial head originated from the anterolateral aspect of the humerus, proximal to the smaller, deep head. The superficial head contained longitudinal fibers, which inserted by means of a thick round tendon onto the ulnar tuberosity. The deep head fibers were fan-shaped and converged to insert by means of an aponeurosis onto the coronoid process. In all specimens, a branch of the radial nerve supplied the inferolateral fibers of the deep head.
Our observations of brachialis muscle anatomy differ considerably from the descriptions in the current literature. The larger, superficial head has the mechanical advantage of a more proximal origin and a more distal insertion, which may enable it to provide the bulk of flexion strength. The smaller, oblique, deep head has a more anterior insertion on the coronoid, which may facilitate the initiation of elbow flexion from full extension. The radial nerve-innervated inferolateral fibers of the deep head run in a direction similar to the anconeus muscle, forming a muscular sling around the elbow. This complex may act to dynamically stabilize the ulnohumeral joint.
This information may enhance surgical techniques about the elbow. The identification of an internervous plane may allow for improvement in the current anterior and anterolateral surgical approaches to the humerus. The tendon of the superficial head is well positioned to allow its transfer to the radial tuberosity, potentially improving supination strength in the absence of a distal biceps tendon. It is possible that the tendon of the superficial head might also be used to reconstruct the anular ligament or the medial collateral ligament of the elbow.
文献中对肱肌解剖结构的描述存在相互矛盾之处。本研究的目的是阐明肱肌的解剖结构，以完善肘部周围的手术技术。
在放大镜放大下解剖11具尸体上肢。记录肱肌的大体形态特征、关系及神经支配。对神经支配进行组织学检查以证实大体观察结果。
在所有标本中，肱肌有两个头。较大的浅头起自肱骨近端的前外侧，位于较小的深头近端。浅头包含纵向纤维，通过一条粗大的圆形肌腱插入尺骨粗隆。深头纤维呈扇形，通过腱膜汇聚并插入冠状突。在所有标本中，桡神经的一个分支支配深头的下外侧纤维。
我们对肱肌解剖结构的观察与当前文献中的描述有很大差异。较大的浅头具有更靠近近端的起点和更靠近远端的止点这一力学优势，这可能使其能够提供大部分的屈曲力量。较小的、倾斜的深头在冠状突上的止点更靠前，这可能有助于从完全伸展位开始肘关节屈曲。深头的由桡神经支配的下外侧纤维走行方向与肘肌相似，在肘部形成一个肌肉吊带。这个复合体可能起到动态稳定尺肱关节的作用。
这些信息可能会改进肘部手术技术。识别神经间平面可能会改善目前肱骨的前侧和前外侧手术入路。浅头肌腱位置良好，可将其转移至桡骨粗隆，在没有肱二头肌远端肌腱的情况下可能会提高旋后力量。浅头肌腱也有可能用于重建肘关节的环状韧带或内侧副韧带。
