Shoulder Separation / AC Joint Separation

Anatomy
A shoulder separation is not to be confused with a shoulder dislocation or subluxation. Instead, a shoulder separation is not an injury to the actual shoulder joint. Instead it refers to an injury that actually involves the acromioclavicular joint (AC joint). The AC joint is where the collarbone (clavicle) meets the front of the shoulder blade (acromion).

Cause
An AC separation is usually the result of a fall directly onto the shoulder. This direct fall onto the shoulder results in tearing of the ligaments that surround and stabilize the AC joint. This causes the "separation" of the collarbone (clavicle) from the acromion. The weight of the arm pulls down on the shoulder blade that is now separated from the clavicle, causing a deformity or "bump" above the shoulder.

Symptoms
The severity of a shoulder separation can range from no change in configuration with mild pain, to severe deformity and pain. A mild shoulder separation involves a sprain of the AC ligament that does not move the collarbone and looks normal on X-rays. A more serious injury tears the AC ligament and sprains or slightly tears the coracoclavicular (CC) ligament, putting the collarbone out of alignment to some extent. The most severe shoulder separation completely tears both the AC and CC ligaments and puts the AC joint noticeably out of position.

Conservative Treatment
The majority of shoulder separations tend to heal with conservative treatment and most people regain full function with this injury, even in cases where a significant deformity exists. Nonsurgical treatments include immobilization in a sling, and medication and ice packs to help manage the symptoms.

Depending on the severity of injury to the AC joint, patients who sustain shoulder separations are more prone to develop pain that may be due to the development of arthritis in the AC joint. This is thought to be caused by the abnormal contact between the bone ends when the joint is in motion. However, conservative treatments such as activity modification, medication and steroid injections can be effective in minimizing symptoms.

Surgical Treatment
When conservative treatments have failed to provide relief, or in the case of severe deformity, shoulder separation surgery may be recommended by your orthopedic surgeon. Whether treated conservatively or with shoulder surgery, the shoulder will require rehabilitation to restore and rebuild motion, strength, and flexibility.

When a shoulder separation results in significant deformity, Dr. Samimi may recommend reconstruction of the ligaments that attach to the collarbone (AC reconstruction). In those instances where AC joint arthritis results, Dr. Samimi might also recommend shaving the end of the collarbone (clavicle) to prevent rubbing against the acromion.

For detailed information about this condition and treatments such as Shoulder Arthroscopy please visit: AAOS Online Service Fact Sheet – Shoulder Separation