Injury to the joint on the top of the shoulder, with partial (grade 1 & 2) or complete (grade 3) tearing of the ligaments with dislocation of the AC joint.
Common Causes
Usually caused by a fall onto the shoulder, occasionally by lifting heavy objects.
Symptoms
Pain on the top of the shoulder. May have bruising or swelling at time of injury. There are often complaints of ‘popping’. May develop a ‘bump’ or deformity on top of the shoulder.
Physical Findings
Tenderness at the AC joint. Positive ‘AC joint compression test.’
Workup
Physical examination and x-rays are usually diagnostic. Occasionally, stress x-rays are required.
Non-operative Treatment
Rest, sling, and pain medication for grade 1 & 2 sprains, until symptoms subside. Most grade 3 sprains heal with time, although some physicians advocate early repair in the competitive athlete.
Surgical Treatment
Repair is performed by ‘relocating’ the dislocated joint, and repairing the torn ligaments.
Injury Comment
The majority of these injuries do heal with time, although a bony deformity is common. Surgical repair of the ligaments in grade 3 sprains may lead to faster recovery and better performance in certain athletes.