Acromioclavicular (AC) joint stabilisation is a surgical procedure employed to treat severe cases of AC joint dislocation.

AC joint dislocation is the separation of the collar bone or clavicle from the acromion (the top portion of the shoulder blade or scapula at the outer edge of the shoulder) due to severe trauma. AC joint dislocation usually occurs as a result of a direct fall on to the top of the shoulder which causes the shoulder blade to be forced downwards and the collarbone to pop up. It is most commonly seen in individuals involved in sports such as mountain biking, rugby, football, snowboarding, motocross, and horse riding.

AC joint stabilisation surgery involves repairing the torn tendons and ligaments, or more commonly replacing them with either natural tissue grafts obtained from your own body (autograft) or donor (allograft) from the anterior tibia/hamstring or by using an artificial synthetic graft, which helps to hold the AC joint firmly in its position and prevent recurrent pain and instability.

Anatomy of the AC Joint

The AC joint is located at the highest point of the shoulder. It acts as a junction between the acromion of the shoulder blade and collarbone. The joint is easily identified as a slight bump that you feel when you move your hands over the top of your shoulder. The AC joint is supported and stabilized by the capsule of the joint and two ligaments known as the coracoclavicular ligaments that attach the collarbone with the front portion of the shoulder blade (coracoid process). The joint enables you to lift your arms overhead and functions by passing the intensity from your arm to the skeleton. If the joint is damaged, it can become displaced and unstable. In certain circumstances stabilisation surgery may be required.

Indication for AC Joint Stabilisation

An AC joint dislocation that exhibits persistent symptoms of pain, loss of motion, and weakness in the arm and shoulder for about 3 to 6 months despite undergoing conservative treatment measures is usually an indication for AC joint stabilisation surgery.

Procedure for AC Joint Stabilisation

AC joint stabilisation surgery, in general, involves the following steps:

  • The procedure is performed under general or regional anaesthesia.
  • A diagnostic arthroscopy may be performed to visualize the position of the dislocation and the extent of the damage. It also allows inspection of the remainder of the shoulder joint.
  • An incision is made over the top of the shoulder to expose the AC joint and any damaged tissue is trimmed.
  • Tissue is dissected to expose the coracoid process.
  • A graft is passed from under the coracoid process to a hole or holes drilled into the clavicle and the displaced clavicle is reduced. This graft is also passed across to the acromion process to restore stability to the AC joint.
  • The graft ends are secured to  each other and through the drill holes.
  • The incision is closed with sutures and sterile dressings are applied.

Postoperative Care and Recovery

In general, postoperative care instructions and recovery after AC joint stabilisation will involve the following steps:

  • Post surgery, your arm is placed in a sling and your shoulder will be immobilized for a up to 6 weeks.
  • You may notice some pain, swelling, and discomfort in the shoulder area. Pain and anti-inflammatory medications are provided as needed.
  • Medications will also be prescribed as needed for symptoms associated with anaesthesia, such as vomiting and nausea.
  • It is important to keep the surgical site clean and dry. Instructions on surgical site care and bathing will be provided.
  • Gradual increase in activities over a period of time is recommended. Information regarding this will be provided by the surgeon.
  • An individualized physiotherapy protocol will be designed to help strengthen your shoulder muscles and optimize shoulder function.
  • You will be able to resume sedentary to light weight waist level activities in a couple of months; however, return to sports and more physical tasks may take 4 to 6 months or longer.
  • A periodic follow-up appointment will be scheduled to monitor your progress.