The acromioclavicular (AC) joint is located at the top of the shoulder where the collarbone (clavicle) meets the acromion, the highest point of the shoulder blade. This small but important joint plays a key role in shoulder movement and stability, particularly when lifting the arm overhead or across the body.
AC joint injuries are common among athletes and active individuals. They often occur from a fall directly onto the shoulder, a collision in contact sports, or other high-impact trauma. Injuries can range from mild sprains to complete separations, where the ligaments holding the joint together are torn.
Types of AC Joint Injuries
AC joint injuries are graded based on severity:
Grade I – Mild sprain of the AC ligaments with no significant displacement
Grade II – Partial tear of the AC ligaments with slight displacement
Grade III – Complete tear of the AC and coracoclavicular (CC) ligaments with visible displacement
Grades IV–VI – Severe separations involving major displacement or injury to surrounding tissues (less common)
Symptoms
Pain at the top of the shoulder, especially with lifting or reaching
Swelling and tenderness over the AC joint
Visible bump or deformity at the top of the shoulder
Limited shoulder range of motion
Weakness during overhead activities
Non-Surgical Treatment
Most AC joint injuries, especially lower-grade sprains, can be treated without surgery. Non-surgical care may include:
Rest and activity modification
Ice to reduce swelling
Anti-inflammatory medications
A sling for comfort during initial healing
Physical therapy to restore motion and strength
Surgical Treatment
Surgery may be recommended for severe AC joint separations, persistent pain, or instability that does not improve with conservative care. Surgical options include:
AC Joint Reconstruction – Rebuilding torn ligaments to restore stability
Distal Clavicle Resection – Removing a small portion of the collarbone to relieve pain from arthritis or chronic injury
Combined Reconstruction and Bone Work – For advanced separations or recurrent injuries
Recovery
Recovery time depends on the severity of the injury and the treatment performed. Non-surgical cases often improve in a matter of weeks, while surgical recovery may take several months with guided rehabilitation. Our team develops individualized recovery plans to help patients return to their normal activities safely and efficiently.
If you have shoulder pain, swelling, or a visible bump after an injury, contact Towson Orthopaedic Associates to schedule an evaluation and discuss your treatment options.
