Overview
what it is and why it mattersThe acromioclavicular (AC) joint connects the outer end of the clavicle (collarbone) to the acromion process of the scapula (shoulder blade) at the very top of the shoulder. AC joint separations are caused by a direct blow to the top of the shoulder — a fall onto an outstretched hand, or a direct hit in contact sports. The Rockwood classification grades AC separations from I (sprained AC ligament) through VI, with grades IV–VI requiring surgery and grades I–III debated.
Diagnosis
exam first, imaging secondPoint tenderness over the AC joint, visible step deformity (grade III+) where the clavicle is elevated above the acromion. Cross-body adduction test reproduces AC pain. Weighted shoulder X-rays assess the degree of clavicular displacement. CT or MRI helps characterize high-grade injuries.
Treatment Path
how care progresses at OSI1
Sling immobilization
Grade I and II injuries heal with a protected-immobilization phase using a sling, combined with ice and analgesics until acute pain settles.
2
Physical therapy
Shoulder range-of-motion and strengthening once acute pain resolves.
3
NSAIDs
Pain and inflammation management.
AC joint injection
Corticosteroid injection for persistent AC joint pain after low-grade sprains.
Surgical Options at OSI
if non-operative care isn't enoughGrade III separations may be managed either way — current evidence does not clearly favor surgery over non-operative treatment for grade III. Grade IV, V, and VI injuries require surgical stabilization.
Providers Who Treat Ac Joint Separation
sports-medicine team
Further Reading
authoritative sourcesExternal patient-education references and related OSI pages for additional background: