Concomitant Variations of the Scapular Region Musculature With an Aberrant Neurovascular Pattern

The shoulder complex exhibits a distinctive amalgamation of muscular power, integration, and an extensive range of motion. The shoulder joint allows for a wide range of upper limb movements because the four small muscles that make up the musculotendinous rotator cuff work together to keep the joint stable. The four muscles that come from the scapula and form the rotator cuff are the subscapularis, supraspinatus, infraspinatus, and teres minor. Accurate diagnosis and proper management of shoulder-related injuries are essential, particularly for sportspersons and individuals engaged in heavy weightlifting activities. The findings mentioned in this paper were observed during standard cadaveric dissection conducted for undergraduate medical students. Upon the methodical excision of skin and fascia in the scapular region, the findings detailed below were noticed and documented. The infraspinatus muscle was observed to arise from the medial two-thirds of the infraspinous fossa, splitting into two parts, each inserting separately onto the greater tubercle of the humerus. The terminal tendon of the teres major was noticed to attach directly into the posterior and superior parts of the latissimus dorsi tendon. Simultaneously, an atypical vascular configuration was observed in the arm, in which the posterior circumflex humeral artery (PCHA) and the profunda brachii originated together from the brachial artery in the arm. The PCHA then travelled between the long and lateral heads of the triceps, situated within the lower triangular space. The artery ascended to go with the axillary nerve as it emerged through the quadrangular space. Finally, the PCHA supplied the deltoid muscle, marking its termination. Variations in shoulder girdle musculature, combined with an atypical vasculature, may aggravate shoulder injuries, particularly rotator cuff repairs, and enhance the technical complexity of surgical interventions.