What is the recommended treatment for a patient with shoulder pain and suspected mild degenerative changes in the acromioclavicular (AC) joint, with normal glenohumeral joint and unremarkable soft tissues?

Treatment of Mild AC Joint Degenerative Changes with Shoulder Pain

For a patient with shoulder pain and mild degenerative changes of the AC joint on radiograph, initiate conservative management with NSAIDs (such as naproxen 500 mg twice daily) and activity modification, reserving corticosteroid injections for cases that fail initial therapy. 1, 2, 3

Initial Conservative Management

Start with oral NSAIDs as first-line therapy:

• Naproxen 250-500 mg twice daily is appropriate for mild AC joint osteoarthritis 2, 4, 5
• Use the lowest effective dose for the shortest duration consistent with treatment goals 2
• NSAIDs reduce pain and diminish inflammation in the joint, which is the primary goal of pharmacological treatment 5
• Consider acetaminophen as an alternative if NSAIDs are contraindicated 4

Activity modification is essential:

• Avoid overhead activities and movements that provoke AC joint pain 3
• This is particularly important as physical therapy has limited benefit for isolated AC joint pathology 3

Physical Therapy Considerations

Physical therapy plays a minor role in isolated AC joint osteoarthritis:

• Unlike other shoulder conditions, therapeutic exercise and range of motion have limited effectiveness for AC joint pathology 3
• Focus should be on pain management rather than aggressive rehabilitation 3
• If glenohumeral motion is restricted, address soft tissue limitations, but this is less relevant given your patient's normal glenohumeral joint 5

Second-Line Treatment: Corticosteroid Injections

If NSAIDs and activity modification fail after 4-6 weeks, consider intra-articular corticosteroid injection:

• A diagnostic local anesthetic injection should be performed first to confirm the AC joint as the pain source 3
• If diagnostic injection provides relief, corticosteroid injection may provide short-term pain relief 3
• However, steroid injections do not alter the natural progression of the disease 3
• The American Academy of Orthopaedic Surgeons notes insufficient evidence to formally recommend corticosteroid injections for glenohumeral OA, though they may be considered for other shoulder pathologies 6, 1

Surgical Referral Criteria

Reserve surgery for patients who fail conservative management for at least 6 months:

• Surgical options include open or arthroscopic distal clavicle resection 7, 3
• Direct (superior) arthroscopic resection of the distal clavicle is successful for treating isolated AC joint osteoarthritis 7
• Surgery is indicated only after unsuccessful conservative treatment for a minimum of 6 months 3

Important Clinical Pitfalls

Do not overlook concomitant shoulder pathology:

• AC joint symptoms commonly occur with other shoulder pathology, particularly rotator cuff disease 3
• Your patient's radiograph shows normal glenohumeral joint and unremarkable soft tissues, making isolated AC joint pathology more likely 6
• If symptoms persist despite appropriate AC joint treatment, consider advanced imaging (MRI) to evaluate for rotator cuff pathology 1

Avoid premature surgical intervention:

• The majority of patients with mild AC joint degenerative changes respond to conservative management 8, 3
• Surgical intervention should only be considered after documented failure of at least 6 months of conservative therapy 3