Skeletal Structure Of The Head Of The Humerus

Description

Humeral head (caput humeri) dominates the proximal end of the arm bone as a smooth, convex articular surface oriented medially, superiorly, and slightly posteriorly toward the glenoid cavity of the scapula. The anatomical neck forms a shallow circumferential groove immediately distal to the cartilage margin, separating the head from the lateral prominences of the greater tubercle and the more anteriorly placed lesser tubercle. Between the tubercles, the intertubercular sulcus (bicipital groove) begins its course inferiorly, marking the transition from the spherical head to the proximal shaft. Spatial cues emphasize how the lateral tubercles sit outside the glenohumeral articulation while the head remains the sole surface intended for contact with the glenoid. Glenohumeral stability depends on this geometry. A small change in head contour can shift contact pressures and compromise cuff function. This illustration supports teaching and preoperative planning for proximal humerus fractures at the anatomical or surgical neck, where displacement can threaten humeral head perfusion via the anterior and posterior circumflex humeral arteries and lead to avascular necrosis. It also helps explain why anterior shoulder dislocation commonly produces a posterolateral humeral head impaction defect (Hill-Sachs lesion) and why osteophytes or cartilage loss on the humeral head drive pain and stiffness in glenohumeral osteoarthritis. Articular surface orientation matters. Use this illustration in upper-limb anatomy labs, orthopedic teaching files, and surgical consent documents covering hemiarthroplasty, total shoulder arthroplasty, or reverse shoulder arthroplasty, where humeral head sizing, version, and the relationship to the tubercles must be communicated precisely. It also suits radiology correlation in AP and axillary shoulder views when discussing head sphericity, fractures, and dislocation patterns. Anatomical accuracy verified by SciePro's Medical Advisory Board.