Acromioclavicular Joint Separations eMedicine Orthopedics

Description: The acromioclavicular (AC) joint is a diarthrodial articulation with an interposed fibrocartilaginous meniscal disk that links the hyaline cartilage articular surfaces of the acromial process and the clavicle. The joint is stabilized by a combination of dynamic muscular and static ligamentous structures, which allow a normal anatomic range of motion. Because of the transverse orientation of the articulation, direct downward forces may result in shear stresses that cause disruption of these stabilizing structures and create displacement beyond the normal limits. This is evidenced by abnormal positioning of the clavicle relative to the acromion, usually in the superior direction.
Synonyms and related keywords: AC separations, shoulder separation, acromioclavicular joint dislocation, AC dislocation, dislocated shoulder, shoulder pain
Prybyla, Owens & Goss 2005 Updated: Sep 22, 2009