The glenoid labrum surrounds the glenoid bone effectively enlarging and deepening the socket. It is made of fibrous cartilage and provides static stability to the shoulder joint. The glenoid labrum is often detached from the bone when the shoulder dislocates.
The capsule of the shoulder joint encloses the joint and is supported by ligaments within the capsule. These ligaments also contribute to static stability. There are three main ligaments, the superior, middle and inferior glenohumeral ligaments. The coraco-acromial ligament originates from the anterior aspect of the acromion and inserts into the coracoid. When this ligament is stressed it can thicken and cause impingement pain. However when removed it can contribute to instability allowing the humeral head to escape to the front. The transverse humeral ligament connects the greater and lesser tuberosities spanning over a groove in which the long head of the biceps tenon passes from the humerus into the shoulder joint. The coracoclavicular ligament consists of two parts (conoid and trapezoid ligaments). As the name suggests it runs from the coravoid to the clavicle and keeps the clavicle in place. When these ligaments are ruptured the clavicle moves more superior resulting in a dislocation of the AC joint.
