Acromioclavicular joint (AC joint) dislocation

Acromioclavicular joint (AC joint) dislocation or shoulder separation is one of the most common injuries of the upper arm. It involves the separation of the AC joint and injury to the ligaments that support the joint. The AC joint forms where the clavicle (collarbone) meets the shoulder blade (acromion).

Causes

It commonly occurs in young athletes and results from a fall directly onto the shoulder. 

Types

A mild shoulder separation is said to occur in case of an AC ligament sprain that does not displace the collarbone. In more serious injuries, the AC ligament tears and the coracoclavicular (CC) ligament sprains or tears slightly, causing misalignment of the collarbone. In the most severe shoulder separation injury, both the AC and CC ligaments tear and the AC joint is completely out of its position.

Symptoms

The symptoms of a separated shoulder may include shoulder pain, bruising or swelling, and limited shoulder movement.

Diagnosis

The diagnosis of shoulder separation is made through a medical history, physical exam and X-ray.

Treatment

Conservative treatment options include rest, cold packs, medications and physiotherapy.

Surgery may be an option if pain persists or if you have a severe separation.

Anatomic reconstruction

Of late, research has been focused on improving surgical techniques to reconstruct the severely separated AC joint. The novel reconstruction technique that has been designed to reconstruct the AC joint in an anatomic manner is known as anatomic reconstruction. Anatomic reconstruction of the AC joint ensures static and safe fixation and stable joint functions. Nevertheless, a functional reconstruction is attempted through the reconstruction of the ligaments. This technique is performed arthroscopically. A small open incision will be made to place the graft.

This surgery involves replacement of the torn CC ligaments by utilising allograft tissue. The graft tissue is placed at the precise location where the ligaments have torn and fixed using bio-compatible screws. The new ligaments gradually heal and help restore the normal anatomy of the shoulder.

Postoperative rehabilitation includes the use of a shoulder sling for 6 weeks, followed by physiotherapy for 3 months to help restore movements and improve strength. You may return to sports only after 5-6 months after surgery.