Sternoclavicular joint

• Although the overall stability of the joint is enhanced by the presence of a fibrocartilaginous disc, the SC joint has the poorest bony stability of any of the major joints. Its strong ligamentous structure and protected location, however, makes it one of the least frequently dislocated joints. Surrounded by a synovial membrane, the SC joint is supported by the anterior and posterior SC ligaments, the costoclavicular ligament, and the interclavicular ligament.

• The sternoclavicular disc, which has qualities similar to the menisci found in the knee, functions as a shock absorber. The upper portion of the disc is attached to the clavicle, and its lower portion is attached to the manubrium and first costal cartilage. This disc divides the joint into two articular cavities, one between the disc and the clavicle and a second between the disc and the manubrium.