Demographics

• teenage to 30 years

Aetiology

• trauma → joint dislocation → dysfunction
• OA → dysfunction

RFs

• builders, rowers, elderly → OA
• trauma

Clinical features

• Pain, tenderness, and swelling localised to AC joint
• OA: full ROM with painful movements esp overhead
• restriction of passive, horizontal flexion of the shoulder, with the elbow extended, across the body
• Acromioclavicular osteoarthritis may also cause subacromial impingement