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 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 athletic young patients and results from a fall directly onto the point of the shoulder. A mild shoulder separation is said to have occurred when there is AC ligament sprain that does not displace the collarbone.  In more serious injury, the AC ligament tears and the coracoclavicular (CC) ligament sprains or tears slightly causing misalignment in the collarbone. In the most severe shoulder separation injury, both the AC and CC ligaments get torn and the AC joint is completely out of its position.

Symptoms

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, a physical exam, and an X-ray.

Conservative treatment options

Conservative treatment options include rest, cold packs, medications, and physical therapy.

Surgery

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 used 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 reconstruction of the ligaments. This technique is done through an arthroscopically assisted procedure. A small open incision will be made to place the graft.

This surgery involves replacement of the torn CC ligaments by utilizing 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 use of shoulder sling for 6 weeks followed by which physical therapy exercises should be done for 3 months. This helps restore movements and improve strength. You may return to sports only after 5-6 months after surgery.