9.1 Classification of SC-joint injury according to Allman [1]
This is an injury to the capsule and to the sternoclavicular ligament or costoclavicular ligament, or both.
n A Grade I sprain of the sternoclavicular joint results from a mild medially directed force applied to the lateral aspect of the involved shoulder of from the shoulder being suddenly forced forward. There is no laxity of the joint, and pain is minimum.
n A Grade II sprain of the sternoclavicular joint is characterized by rupture of the sternoclavicular ligaments without rupture of the cost- oclavicular ligament. Pain and swelling usually are localized over the joint, and mild deformity may be present.
n Grade III sprains of this joint are complete ruptures of the sternoclavi- cular and costoclavicular ligaments (Fig. 36). The displacement may be anterior or retrosternal. Usually pain and swelling are more pronounce than in Grade II sprains and the deformity is more prominent.
Sternoclavicular Joint 9
Fig. 36. Anatomic sketch of grade-III sprain of sternoclavicular joint
Retrosternal dislocations of the clavicle must be given special mention because of their serious complications of sudden death, respiratory dis- tress, and damage of the great vessels that may occur.
104 9 Sternoclavicular Joint
