Separation of the AC joint typically occurs from a direct blow to the shoulder. This common shoulder injury may happen as a result of some type of sports injury, during an accident, or from some other type of impact.
There are four common grades of an AC joint separation. Grade 1 through 3 typically do not involve surgical reconstruction and can be treated conservatively. A recent study found that three out of ten patients with grade 3 and grade 4 AC joint separations had concomitant pathology.
Dr. Paula and colleagues published in the Journal of Shoulder and Elbow Surgery in June 2013 that they found additional shoulder injuries, besides the acromioclavicular joint separation, ranging from rotator cuff damage to labral tears. Tearing of the subscapulars tendon portion of the rotator cuff was the most common finding.
Sometimes an AC joint injury may also involve damage to other parts of your shoulder. If after the AC joint separation has healed and persistent shoulder pain is present, investigation to determine if other structures in the shoulder have been damaged is recommended.