Acromioclavicular (AC) Separation

Damage to the AC joint generally occurs from direct trauma to the joint, although it may occur from a fall on an outstretched arm. Diagnosis of AC separation can be made through history, physical exam, and xrays. AC separation can be classified as 1st, 2nd, or 3rd degree.

1st degree – tenderness to palpation, incomplete tear, <3mm AC width, treat with rest, ice and a sling and range of motion exercises.

2nd degree – disruption of the AC ligament without disruption of the coracoclavicular (CC) ligament, AC width >3mm, treat the same as 1st degree with direction of no heavy lifting or contact sports for 3 months.

3rd degree – disruption of both AC and CC ligaments with the clavicle displaced superiorly, treatment should begin with rest, ice, and a sling. Orthopedic follow up is indicated as surgery may be required.

All AC separations should follow up with an orthopedist. 1st and 2nd degree injuries generally do not require surgery, but 3rd through 6th degree may require surgical intervention.

There are three additional classes of AC separation (4th, 5th, and 6th degree). However, they will not be discussed here.