What is acromioclavicular joint osteoarthritis?
Acromioclavicular joint (ACJ) osteoarthritis (OA) results in pain over the ACJ which is situated over the outer border of the clavicle (collarbone).
Osteoarthritis is the name given to age-related arthritis which causes the affected joint to become painful and stiff. The process of osteoarthritis involves wearing or thinning of the smooth cartilage joint surfaces as well as stiffening to the soft tissue surrounding the joint. These aspects combine to produce swelling, inflammation and pain.
Several factors normally combine to cause symptoms of osteoarthritis:
- Previous joint damage
- Age (risk increases with age)
- Repetitive manual overhead work
Most commonly, a focal pain is felt on the top of the shoulder. The main aggravating activities involve movements of the arm above the head, behind the back or across your body as well as pain when sleeping on your side.
If AC joint OA becomes more severe the movements of the shoulder may become increasingly stiff.
The presence of AC joint OA does not always cause pain so it is quite possible to be pain-free despite reasonably advanced arthritis. In addition, the AC joint undergoes a ‘wear and repair cycle’ so pain can improve.
How is AC joint OA diagnosed?
AC joint OA can be reliably diagnosed by your doctor or physiotherapist by taking a history of your condition and by conducting a physical examination.
The main features on examination are often stiffness and pain with movements of the arm across the body (a Scarfe test) as well as focal pain directly over the AC joint. A lump may be visible due to enlargement of the arthritic AC joint.
X-rays are not routinely required but may be requested prior to considering a corticosteroid injection.
How is AC joint OA treated?
Non surgical management
As the condition is often triggered by strenuous or repetitive overhead activities modification and avoidance of aggravating activities is important initially.
AC joint OA can normally be managed effectively by following a regular exercise routine to maintain flexibility to the affected AC joint:
5×30 second holds, 2x per day
3×10 repetitions 3-4x per week
3×15 repetitions, 2x per day
These are suggested exercises only. If you are at all concerned about whether these exercises are suitable for you or if you experience any pain while doing them, please seek appropriate clinical advice from your GP or Physiotherapist.
Using painkillers when needed. Over-the counter-analgesia is available through pharmacies when needed. Paracetamol is most commonly prescribed. Anti-inflammatories, such as Ibuprofen, are also used, but as there is little or no inflammation involved in osteoarthritis these are best avoided without discussing with your GP. Side effects are even more common than with paracetamol so please ensure to take appropriate medical advice. There is a good booklet on the Arthritis Research UK website with information about the various drug options.
Corticosteroid injection therapy. For individuals with AC joint OA who continue to suffer disabling symptoms in spite a course of non-surgical management (outlined above) or for patients who are unable to commence a supervised exercise program due to pain level a corticosteroid injection can be offered. You can read more about local corticosteroid injections here.