What is the treatment for acromioclavicular (AC) joint narrowing?

Treatment of Acromioclavicular (AC) Joint Narrowing

Conservative management with activity modification, physical therapy, and corticosteroid injections should be the initial treatment for AC joint narrowing (osteoarthritis), with arthroscopic distal clavicle excision reserved for patients who fail 6 months of conservative therapy.

Initial Conservative Management

All patients with AC joint narrowing should begin with non-operative treatment, which has been shown to improve pain by approximately 50% at follow-up 1.

Non-Surgical Treatment Options

• Corticosteroid injections into the AC joint are effective for pain relief and can serve as both a diagnostic and therapeutic intervention 2, 1
• Activity modification is critical, particularly avoiding overhead activities and weight training that exacerbate symptoms 3
• Physical therapy focusing on shoulder strengthening and range of motion exercises should be implemented 2
• A diagnostic injection of local anesthetic (bupivacaine) into the AC joint can confirm the AC joint as the pain source before proceeding with definitive treatment 4

Duration of Conservative Treatment

• A minimum of 6 months of conservative management should be attempted before considering surgical intervention 1
• Most patients with AC joint osteoarthritis respond well to non-operative treatment and do not require surgery 2, 3

Surgical Management for Failed Conservative Treatment

Arthroscopic distal clavicle excision is the preferred surgical approach for patients who fail conservative management, as it provides equivalent or superior outcomes to open procedures with faster recovery 4.

Indications for Surgery

• Persistent pain after 6 months of conservative treatment 1
• Significant functional limitations affecting work or athletic performance 2
• Patients unwilling to modify activities (particularly overhead athletes and manual laborers) who have failed initial conservative treatment 2

Surgical Technique Considerations

• Arthroscopic resection is preferred over open resection due to less soft tissue disruption, shorter rehabilitation, and quicker return to activity 4
• Resection of 4-8 mm of distal clavicle is typically sufficient when performed arthroscopically, compared to larger resections required for open procedures 4
• Studies show patients undergoing 0.5-2 cm of clavicle excision had good outcomes with mean functional scores of 87.8% 1
• The arthroscopic approach preserves the superior AC ligaments, maintaining joint stability 4

Expected Outcomes

• No significant difference exists between open and arthroscopic distal clavicle excision in terms of functional outcomes 1
• Patients with concomitant shoulder pathology requiring additional procedures have similarly good outcomes 1
• Return to full activity is typically faster with arthroscopic techniques 4

Important Clinical Considerations

• Radiographic confirmation of AC joint narrowing should be obtained, though the degree of radiographic changes does not always correlate with symptom severity 2, 1
• Diagnostic injection is highly recommended before surgery to confirm the AC joint as the primary pain generator, as shoulder pain can have multiple sources 4
• Patients may develop mild degenerative changes over time even with successful conservative management, but these often remain asymptomatic 5
• Complications from arthroscopic resection are infrequent but include inadequate bone resection, residual pain, infection, and rarely, post-operative instability or heterotopic bone formation 4