An unusual variation of Pectoralis minor muscle and its clinical significance

Abstract

The anatomical knowledge of variations of origin and insertion of Pectoralis minor muscle is of great significance to minimise complications during surgical procedures. An unusual variation of Pectoralis minor muscle was encountered in an adult male cadaver on right side, during routine dissection. Higher origin of Pectoralis minor was noticed (from 2 ^nd to 5 ^th ribs). It can lead to restriction of movements of shoulder joint, especially during abduction and lateral rotation. It can also give rise to neurological and vascular symptoms in arm. The Pectoralis minor was found to be inserted mainly on the Coracoid process and few fibres were found blending with Coracobrachialis and short head of Biceps brachii. Precise knowledge of the anatomy of Pectoralis minor muscle and its possible anatomical variations is important for Orthopaedicians to understand restricted movements of shoulder joint and their management. Variations of Pectoralis minor muscle are also of prominent interest to Plastic surgeons, owing to its use as a free flap. All Surgeons advancing to the surgical exposure of chest wall, as well as Radiologists should be aware of such variations with respect to the precise anatomy of shoulder girdle region.