AC joint is the joint between the Acromion ( a process of the shoulder blade) outer end of Clavicle(collar bone). Like any other joint in the body arthritis may develop in this joint. Most commonly this is an age related process, but sometimes may be related to an old injury.
Symptoms
Most patients complain of pain, which is usually felt over the top of the shoulder localized over the AC joint. This is made worse on overhead activities, and it can be uncomfortable to lie on the affected shoulder.
Treatment
Painkillers and anti-inflammatory medication.
Physiotherapy
Localised injections of steroid and local anaesthetic into the AC joint.
Surgery
This involves excision of bone from the arthritic end of clavicle and acromion. This can be performed arthroscopically or by an open procedure. Arthroscopic excision is preferable as it preserves the top ligaments of the joint and hence reduces the risk of instability.