which completely divides the joint to form two articular compartments. The disc acts to increase the range of movement of the joint.

Ligaments

The joint is reinforced by two intrinsic and two extrinsic ligaments. The costoclavicular ligament is the main limitation to movement, and therefore the main stabilizer of the joint.
* Anterior sternoclavicular ligament (intrinsic)
* Posterior sternoclavicular ligament