Disability following injury to the sternoclavicular joint can range from pain, deformity, and discomfort to devastating neurovascular complications . Sternoclavicular pathology can be inflammatory or degenerative but is typically due to a direct blow or indirect force transmitted from the shoulder. The injury pattern is predominantly either an anterior or posterior dislocation with some degree of associated ligamentous, disc, or cartilage damage.

The ligamentous structures that stabilize the sternoclavicular joint are the posterior sternoclavicular ligament, the anterior sternoclavicular ligament, the costoclavicular ligament, the inter-clavicular ligament, and the intra-articular discoligamentous complex . Several authors have proposed that the costoclavicular ligament is the predominant stabilizer of the sternoclavicular joint. However, other biomechanical data suggest that the posterior sternoclavicular ligament is the primary stabilizer.

Although some anterior sternoclavicular joint dislocations can be treated nonoperatively, reduction and stabilization of posterior sternoclavicular joint injuries is necessary as they can cause catastrophic injury to the underlying mediastinal structures. Surgical reconstruction requires posterior dissection of the clavicle and a blind posterior dissection of the manubrium. The mediastinal vasculature is, on average, 6.6 mm deep from the posterior aspect of the sternoclavicular joint. Just anterior to the mediastinal vessels reside the strap muscles, and these muscles could provide some protection during posterior sternoclavicular joint dissection. Other muscles inserting around the sternoclavicular joint include the pectoralis major, sternocleidomastoid, and subclavius muscles. The anatomical locations of the muscle insertions at the medial end of the clavicle and at the manubrium are not well defined.

Currently, a paucity of information exists regarding the quantitative anatomy of the sternoclavicular joint. The purpose of this study was to define the sternoclavicular joint anatomy, to quantify the ligament and muscle-tendon insertions surrounding the sternoclavicular joint, and to define pertinent osseous landmarks, which can serve as reproducible anatomical landmarks during sternoclavicular joint surgery.

Full Article: Surgical Anatomy of the Sternoclavicular Joint