The Acromioclavicular Joint (ACJ)


The ACJ is the junction of the clavicle with the shoulder blade. It is a very strong and stiff joint that essentially connects your arm to your body via attachments to the shoulder blade, clavicle and sternum. There are a few conditions that exist in the ACJ, but they usually cause one of two symptoms; pain or instability or both. Pain in the ACJ without proceeding injury tends to due to degenerative or inflammatory change (arthritis). Instability/dislocation is usually secondary to a significant force/injury to the point of the shoulder. 


Shoulder impingement is a clinical diagnosis. The pain is usually felt down the side of the shoulder and can extend towards but not beyond the elbow. Pain comes on when the arm is lifted away from the side of the body (painful arc), over head and behind the back. With time, the shoulder may become increasingly stiff with reduced range of movement due to pain.

X-rays are important in the diagnosis and will be taken. An ultrasound is useful and will be arranged if we suspect other conditions affecting the shoulder such as subacromial impingement, or if we are carrying out a guided injection into the ACJ.

Management without surgery

ACJ arthritis can be treated successfully with activity modification, pain killers and injections. Physiotherapy is of limited value in true mechanical ACJ pain as excessive stretching or strengthening tends to exacerbate the pain. It can however be useful to maintain the shoulder range of movement so that doesn’t become stiff.  Injections with steroid, normally offered under ultrasound guidance work well to control true isolated ACJ pain. If they work well then that is also normally a sign that you would do well with surgery, so that in the future if injections lose their effect, you know surgery is an option for you.

Management with surgery

If the diagnosis is clear and you either fail non-operative treatment or decide that you wish to go along the surgical route, the procedure performed is an ACJ excision. Through small incisions (key-hole surgery), the joint visualised through a small camera. The end of the clavicle is excised so that with full range of movement on table there is no contact between any of the bone that remains in the joint.

The operation is normally performed under general anaesthetic and a nerve block to provide good pain relief after the surgery. It can also be performed with you completely awake just with a nerve block. This means you can watch the surgery taking place on the screen, you won’t feel drowsy or sick afterwards and you’ll be discharged very quickly after the customary tea and toast! Let us know if you would like to consider awake surgery as only certain lists are set up to provide this service.

After Surgery

Your arm will be placed into a collar and cuff sling and the physiotherapists will tell you what you should do with your shoulder. The surgery is performed as a day case procedure, unless it is not safe to do so. It is common to have swelling because of the surgery and the wounds are stitched. At 10 days following surgery, the stitches and dressings are removed at your GP practise. There really are no restrictions on your range of movement postop but pain will be the limiting factor. ACJ surgery can be quite sore and patients should be aware of this soreness which can last up to 3 months following surgery. That said the pain can be worked through and shouldn’t limit your progression with physiotherapy.


Common risks include bleeding, infection, pain and stiffness in the shoulder.

Specific risks with this operation are

  • Failure to get rid of your pain (10-15%)
  • Nerve injury (<0.1%)
  • Further surgery required if fails to work


90% of those undergoing this surgery for ACJ pain will get better by around 3-6 months following surgery.

Mr Sam Vollans

Mr Sam Vollans

Consultant Orthopaedic Surgeon

I graduated from the University of Leeds and completed my specialist training in Yorkshire. Following this, I undertook further training in both elective and trauma shoulder & elbow surgery within the UK and Europe with many renowned surgeons.

Read my story

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