What causes acromioclavicular joint (ACJ) arthritis?

Depending on the severity of the impact, the joint will either be sprained or will actually dislocate. The injury is typically graded into a Type I injury (simple compression of the joint), Type II where the ligaments are stretched and there is slight widening of the joint and Type III where all the ligaments stabilising the joint are damaged and the end of the clavicle displaces. There are also other less common, but more severe, types of injury.

How is acromioclavicular joint (ACJ) instability diagnosed?

Usually Mr Moverley can diagnose ACJ instability with a combination of clinical examination and a careful history of your symptoms. A thorough examination is very important to exclude other injuries to the shoulder. There is often an obvious bump on the top of the shoulder, which is very tender. Movement of the shoulder is usually limited by pain and weakness.

• X-rays can be obtained on the day of your consultation demonstrate the injury to the joint and will exclude a fracture of the end of the clavicle.

• MRI scans of the shoulder can be useful when there is diagnostic uncertainty and to rule out other injuries such as a rotator cuff tear.

Treatment options

All Type I & II and the majority of Type III injuries are managed without surgery initially. 

Types IV & V can be managed initially without surgery but in reality a high percentage of patients with these injuries ultimately require surgery.

Non-operative Management

Non-operative treatment should always be exhausted before considering any form of surgery.  The vast majority of patients will respond well to non-operative treatment. Possible non-operative options include:

• A focused physiotherapy program to stretch the soft tissues around the shoulder and to strengthen the muscles that stabilise the shoulder blade will often be all the treatment that is required. 

• Rest, activity modification, and simple pain relief can provide good benefit, particularly early after the onset of symptoms. 

• Steroid injections are used to provide relief if the joint is stable but pain persists longer than 2-3 months.

Surgical Management

Open Acromioclavicular joint stabilisation

For more severe injuries and type III injuries that have not responded to non-operative treatment a ligament graft is used to reconstruct the torn ligaments. The graft, which maybe artificial or donated tissue, is looped around the coracoid (a protuberance of your shoulder blade), passed behind your collar bone and is fixed in place on the top of your collar bone with a screw once the collar bone has been pulled down into place. Mr Moverley’s most commonly used technique is demonstrated below.

Shoulder arthroscopy

For persistent pain after a Type I or Type II injury key- hole surgery is performed to excise 5mm off the end of the collar bone and clear the scar tissue. You will be able to move you arm straight after surgery but it can take up to three months for the pain to settle.