Acromioclavicular disorders
See also separate article Acromioclavicular Joint Problems.
They are usually caused by trauma or osteoarthritis.
Dislocation of the joint may occur after injury. Pain and tenderness are localised to the acromioclavicular joint and there is a restriction of passive, horizontal movement of the arm across the body when the elbow is extended.
Acromioclavicular osteoarthritis may cause subacromial impingement.