Acromioclavicular Joint dislocations (ACJ Dislocations)

The Acromioclavicular Joint is usually injured by a direct fall onto the point of the shoulder. The shoulder blade (scapula) is forced downwards and the clavicle (collarbone) appears prominent. Activities like cycling and horse riding are prone to this type of injury in the event of a fall. However MotoX riders without adequate shoulder guard protection or where excessive force occurs during a crash can often suffer these types of injuries.

The degree of damage to the joint is classified by the joint displacement and injury to the ligaments which support the AC joint.:
Grade 1: AC joint sprain
Grade 2: AC joint ligaments torn only
Grade 3: 100% dislocation
Grade 4: clavicle dislocated backwards
Grade 5: >100% dislocation
Grade 6: clavicle under coracoid

For Example:

This cyclist struck a wombat in the early hours of the morning during a endurance cycling event and was found two and half hours later by a passing motorist. EMR was called to the accident scene and the rider was found to be suffering from hypothermia, a noticeably descended shoulder and chest pain.


The photo show how the rider was prepared for transport by EMR prior to the arrival of Ambulance Victoria and our transfer to the AV paramedics for their emergency transport to hospital. The rider had to be warmed, collared, back rolled onto a scoop stretcher and readied for handover. It was later determined that the rider had suffered a Acromioclavicular Joint Grade 3 dislocation, five fractured ribs and a whole lot of rib cartilage damage.


X-rays at hospital to confirm the degree and type of injury. Grade 4, 5 and 6 injuries often require early surgical reduction and fixation.

Most Grade 1,2 and 3 ACJ dislocations do not require surgery and almost all can be managed with:
1. Physiotherapy – to ‘retrain’ the shoulder muscles
2. Painkillers and anti-inflammatories

Most people fully recover without any problems, however overhead athletes and manual workers may have persistent symptoms and require surgery.

Surgery is indicated if the shoulder is still painful and there is some functional loss at about 3-6 months after the injury.

For Grade 1 and 2 injuries removal of the damaged joint is performed. This is done by keyhole surgery (arthroscopically) and is known as an arthroscopic ACJ Excision .
A Subacromial Decompression is usually done at the same time.

For Grade 3,4,5 and 6 injuries the collarbone needs to be reduced to the acromion fixed in place. Numerous surgical options exist and your surgeon will discuss this in more detail with you.


    • admin says

      Craig was such a great sport, despite being very sore from Monday’s adventure he battled on riding only to take on two wombats at the end of a long downhill run early on Wednesday. I did walk up for some distance from the scene, however there was no signs of any of the wombats! So all appears well with the Wombats. From what I understand they are very tough and unless you hit them on the nose, they keep on going.

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