Acromioclavicular joint (AC joint, or ACJ) separation is a very common shoulder joint injury, particularly amongst people who have been involved in a sporting accident. Sports such as cycling, skiing, football and snowboarding have high rates of AC joint shoulder separation, as there is a high risk for falls which can impact the point of the shoulder. The severity of the injury can be classified at three different levels: mild, moderate or severe. Mild separations are usually characterised by the stretching of ligaments, and this can also apply in moderate cases. Severe injuries are characterised by the rupture of ligaments which hold down the collar bone or clavicle, and this makes the collar bone have a more prominent appearance.
A severe acromioclavicular joint injury may be graded as a Grade 3 or 4 injury. These injuries incur a tear of the Coraco Clavicular ligaments, as well as the acromioclavicular capsule. Visually, this results in a bump, or an abnormal looking lump on the top of the shoulder. Initially, loss of movement and mild to severe pain are common. These ligaments never completely heal.
An accurate assessment of the severity of AC joint injuries can be ascertained using x-rays, combined with a clinical examination.
Successful non-operative treatment is possible for mild or moderate AC joint separations (Grade 1,2 or 3), which should be kept in an arm sling for a week or so, subject to pain levels. Surgery is occasionally required, but the bulk of these injuries do not require surgery.
Physiotherapy and gradual mobilisation should then commence for an appropriate period, as recommended by your Specialist, until a normal range of motion is achieved. Most people respond well to this course of treatment and will not require surgery.
Severe injuries (Grade 3 or 4) have two options for treatment: nonoperatively or operatively. These injuries should always be assessed by a shoulder surgeon. This will allow a management plan to be implemented where the reasons to operate or not operate are clearly understood. This then allows you to make an informed decision as to whether you have surgery or not.
AC joint shoulder separation treatment
Patients who opt for non-operative treatment will need to immobilise the joint with a sling, which should remain in use for as long as recommended by your specialist. Physiotherapy should then commence, following the full rehabilitation course recommended by your specialist. The bump at the top of the shoulder will always remain visible, and in some cases the acromioclavicular joint can also develop arthritis – even years after the injury has occurred. Some patients suffering from this injury may experience ongoing pain. If this does occur and pain from this is significant, a small surgical procedure will address the issue. People who regularly engage in heavy overhead work, or throwing, may also experience permanent weakness with activity above shoulder height.
AC joint surgery requires a small incision to be made across the top of the shoulder. Because the end of the collar bone is permanently damaged, it will be removed. An artificial ligament will then replace the torn Coraco Clavicular Ligament. The artificial ligament is made from Dacron, a durable synthetic material.
The rate of successful surgery improves when carried out within 3 weeks of sustaining the AC separation shoulder injury. It is possible to have surgery done at a later stage, but due to the nature of a separated AC joint, and the operation involved, it may not be as successful. People exhibiting signs of chronic injury and those who have been living with it long-term, may require an entirely different operation. This is known as a Coraco Clavicular Fusion, and it will require a bone grafting procedure to be carried out.
It is important that contact/throwing athletes and people who are involved in heavy manual and overhead work, have surgery done as soon as possible after they have been injured.
For most other patients, a non-operative approach may be sufficient. It is important that you realise there is a small element of risk, because not everyone responds favourably to non-operative treatment. Therefore, surgery may be required later, and the success rate may not be as high as it would have been, if the operation were done immediately after the injury occurred.
