Acromioclavicular joint injuries

Acromioclavicular (AC) joint injuries are common in athletes, especially in sports like football, wrestling, cycling or skateboarding where there might be a direct blow to the top of the shoulder. The injury can cause a strain or tear of the acromioclavicular ligaments and coracoclavicular ligaments.

It is common for a grade III injury to leave a visible deformity at the top of the shoulder due to the clavicle sitting higher than the acromion. However, most injuries resolve with no long-term issues.

AC joint injuries are graded on level of severity based on which ligaments are torn and how much separation there is at the joint.

Types I and II are managed conservatively, with a sling for immobilization until pain decreases, then physical therapy to regain strength and motion. Return to sports and lifting when movement is pain-free and normal compared to the uninvolved shoulder. Pain can last up to 6 months from the time of injury.

Management of Type III injuries is controversial, with limited quality evidence to guide treatment. These injuries should be assessed by an orthopedist. Conservative management with immobilization and physical therapy often provides excellent results.

Type IV-VI injuries usually require surgical fixation.

Although a visible deformity may remain after this injury, with a bony protrusion at the top of the shoulder, the good news is that the majority of AC joint injuries have good to excellent outcomes, and athletes are able to return to their sports once healing has occurred.

Li X, Ma R, Bedi A, Dines DM, Altchek DW, Dines JS. Management of acromioclavicular joint injuries. J Bone Joint Surg Am. 2014 Jan 1;96(1):73-84. doi: 10.2106/JBJS.L.00734. PMID: 24382728.