Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland.
Department of Orthopaedics Surgery, Hospital Santa Cristina, Madrid, Spain.
Folia Morphol (Warsz). 2023;82(2):439-444. doi: 10.5603/FM.a2022.0021. Epub 2022 Mar 3.
The coracobrachialis muscle belongs to the anterior group of the brachial region. Its main functions are flexion and adduction at the glenohumeral joint. It is highly morphologically variable, especially in the number of bellies, place of origin or insertion, and its relationship to the musculocutaneous nerve. Accessory structures associated with the coracobrachialis muscle include the coracobrachialis brevis or coracobrachialis longus muscle. The present case describes a three-headed coracobrachialis muscle with two such additional structures. One of these has a tendinous origin connected to the periosteum and located on the surgical neck of the humerus. Its insertion is fused with the third head of the coracobrachialis muscle. The other has a proximal attachment fused with the capsule of the shoulder joint, and its distal attachment is fused with the third head of the coracobrachialis muscle in place of its connection with the short head of the biceps brachii. This could result in better stabilisation of the glenohumeral joint; on the other hand, it could limit operational access during treatment of subscapularis tears.
喙肱肌属于臂前区肌群。它的主要功能是使盂肱关节屈和内收。喙肱肌在形态上变化多样，尤其是肌腹的数量、起点或止点以及与肌皮神经的关系。与喙肱肌相关的辅助结构包括短喙肱肌或喙肱肌长头。本病例描述了一个具有三头的喙肱肌和两个这样的附加结构。其中一个具有腱性起点，与骨膜相连，位于肱骨头的外科颈。其止点与喙肱肌的第三头融合。另一个起点附着于肩关节囊，止点与喙肱肌的第三头融合，代替与肱二头肌短头的连接。这可能会更好地稳定盂肱关节；另一方面，在治疗肩胛下肌撕裂时，可能会限制手术入路。
