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This website is under development - The information contained on this site is for guidance only and is not intended for self diagnosis or self treatment. This will not replace professional medical advice or consultation. Always seek the professional advice of a qualified health care provider like your doctor or specialist before embarking on  any treatment. If you have a problem please consult your doctor or specialist.
AC Joint Arthritis
What is it?
Clavicle servers as the only ‘bony’ connection between the upper limb to the main body and has two joints at either end. The joint between the acromion (part of shoulder blade) and the clavicle is called the acromio-clavicular joint (AC Joint). Arthritis of AC joint is not a uncommon in young and middle aged population. Thankfully it usually does not serve as a marker for arthritis in other major joints. AC joint arthritis is common in people who do lot of overhead activities, heavy lifting or those who load the joint excessively.The joint consists of a small cartilage disc similar to what is seen in the knee joint and a robust cartilage lining the ends of the bone . In early stages, the damage in the cartilage disc can give raise to ‘clicks’ and pain. When the joint wears out, it can get inflamed and produce excessive fluid or even form ostephytes (bone spurs) or fluid inside the joint which can present as joint swelling. This can give raise to impingement syndrome with a high pain full arc.
Symptoms - High “painful arc syndrome”
The clavicle rotates along its axis during lifting the arm and the rate of rotation increases when the arm is elevated above 90 deg. Therefore, where there is predominant AC joint arthritis, the pain occurs during elevation of arm above the shoulder
height in contrast to classic painful arc of impingement which occurs at a lower level. Pain is typically felt around the shoulder  and one would ‘finger point’ to the AC joint as the epicenter of the pain. Compressing the joint like lying down on the side to sleep or carrying a heavy rug sac can given rise to pain. In addition, many of the symptoms that are present with classic impingement can also be present.
In majority of cases, simple measures will ease the pain. These include activity modification (see self-help leaflet for addressing the pain in the shoulder), avoiding overhead activities, rest and a course of anti-inflammatory tablets. A well-directed physiotherapy may give good pain relief. In some instances, one may need injection of cortisone (steroid) and local anaesthetic mixture into this tight joint space to settle the inflammation and swelling. This may be occasionally repeated or additional injection in the subacromial space may be needed. Improvement is usually gradual and may take place over many weeks or even months.
Overall, a little over 50% get better with activity modification, tablets and physiotherapy and targeted injection. Those who do not get better may require surgical intervention especially when the quality of life is affected.