AC Joint Osteoarthritis

AC joint arthritis commonly develops from wear and tear with age (degenerative arthritis). It can also result from past injuries like AC joint separations, repetitive use (especially weightlifting or overhead activity), or chronic stress on the joint.

Symptoms include pain on top of the shoulder, tenderness to touch, and discomfort with reaching across the body or lifting overhead. Patients may also notice swelling, a bony bump over the joint, or grinding sensations during movement.

Diagnosis is based on physical exam findings, including tenderness over the AC joint and pain with specific shoulder movements. X-rays often show joint narrowing, bone spurs, or joint irregularities. MRI may help rule out other causes of shoulder pain.

Non-surgical treatment includes rest, anti-inflammatory medications, physical therapy, and corticosteroid injections. These options often provide relief for mild to moderate symptoms. If symptoms persist, surgery may be considered.

Rather than total shoulder replacement (which is used for glenohumeral arthritis), AC joint arthritis is typically treated with a minimally invasive procedure called distal clavicle excision. In this procedure, a small portion of the collarbone is removed to eliminate painful bone-on-bone contact while preserving shoulder function.