Humeruskopf

Humeruskopf, or the head of the humerus, is the proximal, ball-shaped end of the upper arm bone. It forms the head portion of the shoulder joint, articulating with the glenoid cavity of the scapula to create the glenohumeral joint, one of the most mobile joints in the body.

The humeral head is covered with articular cartilage on its contact surface and is directed superiorly, medially, and posteriorly. It is separated from the humeral shaft by the anatomical neck, while the surgical neck lies just below the tubercles and is a common site of fracture. The greater tubercle and lesser tubercle project laterally and anteriorly from the proximal head, providing attachment sites for the rotator cuff muscles and serving as important landmarks for clinical assessment and imaging.

The head forms the ball component of the ball-and-socket shoulder joint, allowing a wide range of motion in multiple planes. The joint is stabilized by the joint capsule, the glenoid labrum, and surrounding rotator cuff tendons, which insert near the tubercles on the proximal humerus.

Clinical significance: fractures of the proximal humerus commonly involve the surgical neck and can risk injury to the axillary nerve and posterior circumflex humeral artery. fractures or dislocations of the shoulder can affect the humeral head, with complications such as avascular necrosis or Hill-Sachs lesions. Imaging typically includes radiographs of the shoulder, with MRI or CT used for detailed assessment when needed.