Acromial-clavicular Joint Arthritis

This is arthritis affecting the joint between the outer end of the clavicle and the acromial part of the shoulder blade (AC Joint arthritis)

Onset is often insidious without trauma. An injury may however result in AC joint arthritis some years later or provoke pain in a previously trouble free but arthritic AC joint.

Symptoms are of pain localized to the apex of the shoulder. There is often a bony swelling at the joint which when symptomatic can be very tender to localized pressure. Pain is often worse when reaching across the body or when lying on this side.

Diagnosis is best made from the history and physical examination. Imaging such as x-rays or an MRI scan helps confirm clinical findings.

It is important to note that arthritis in the AC joint is part of the normal aging process and is very commonly reported as being present on xray or mri examination. In most individuals this is not a source of pain and is only an incidental finding unless it correlates with clinical findings.

AC joint arthritis causing pain often settles down with rest, oral anti-inflammatories and targeted injection. Symptoms will often persist for 12-18 months then resolve.

In individuals with persistent pain and failure of nonsurgical treatment surgery to remove the end of the collarbone (Lateral clavicle excision) either arthroscopic or open may be a good option.