AC joint osteoarthritis
The ACJ is the joint at the end of the clavicle (collar bone) as it meets the acromion (tip of the shoulder blade). The joint is stabilised by ligaments that cross the joint (from clavicle to acromion) as well as ligaments from the coracoid to the clavicle.
ACJ osteoarthritis is the term for degenerative changes that occur in the joint. This condition most commonly occurs as a result of wear and tear which happens with age or with excessive use of the joint, particularly sports involving throwing or lifting. ACJ osteoarthritis can also stem from a previous injury, such as dislocation of the AC joint or previous fracture.
The symptoms include localised pain over the AC joint. The pain may be worse with over-head movement and also at night. There may be weakness and stiffness in the arm.
Xrays are often sufficient to make the diagnosis.
ACJ Osteoarthritis can be treated with painkillers and anti-inflammatorys. It is also advisable to maintain a healthy weight, keep up muscle strength with exercise and minimise repetitive overhead lifting. Injections into the painful joint can provide temporary relief. When pain cannot be controlled with these measures, surgery may be required.