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Acromion or AC Joint injury – to operate or not?

By November 9, 2012April 17th, 2024Uncategorised

Acromion or AC Joint injury – to operate or not?

On the outer top of the shoulder the collar bone is held down by several strong ligaments to a bone called the Acromion. This small yet important joint is known as the AC joint. The AC joint is usually injured by falling onto the outer point of the shoulder or a direct hit such as a rugby side on hit.

The medical world tends to grade AC joint injuries into Grades 1-3. 1 being a “strain” of the ligaments and joint capsule, and 3 being a fairly significant tear of the ligaments holding the collar bone down.

Grade I and II AC joint injuries usually heal with correct exercises

Grade I and II AC joint injuries, although quite painful and debilitating for some 4-6 weeks, usually heal and get back to full movement and strength if the correct exercises are followed.

Grade III AC joint injuries generally need a specialist opinion

Generally speaking for a grade III,  if both AC joint ligaments have been injured then an opinion with an orthopaedic shoulder specialist would be strongly advised, especially if the injury is to your dominant side. In these instances, a clear ‘step’ deformity is visible just above the deltoid muscle on the outside of the shoulder.

Surgery can be performed to hold the collar bone down, but most specialists will do this predominantly to reduce the deformity or lump, not so much for function. They can take some 6-12 mths to recover yet most patients report a full recovery from an A/C joint injury.

In more rare incidences, there can be damage to the bone or underlying nerves and blood vessels, these do often need Orthopaedic consultation and possible surgery.

Your Physiotherapist can help identify the Grade

of an A/C  joint injury and help map out a

suitable management plan to assist recovery.


Written by Brian Payne
MGS Physiotherapy


The author of this article, Brian Payne, is one of our most experienced Physiotherapists. He has extensive knowledge of all injury types and mechanisms presenting to our rooms.  From back strains and headaches through to ankle and knee injuries, Brian welcomes and enjoys the diverse challenges of them all.

Brian proudly boasts of his involvement with the St Augustines College in Brookvale whose 1st XV rugby team has been very successful over the past few years. Over this time, Brian has put in a lot of time and effort into their injury management.