What is the appropriate treatment for moderate acromioclavicular osteoarthritis and mild subacromial‑subdeltoid bursitis?

Treatment for Moderate Acromioclavicular Osteoarthritis and Mild Subacromial-Subdeltoid Bursitis

Begin with a structured conservative approach combining exercise, NSAIDs, and consider ultrasound-guided corticosteroid injections into both the AC joint and subacromial bursa if initial measures fail within 4-6 weeks.

Core Treatment Algorithm

First-Line Management (Weeks 0-6)

Start all patients with these foundational interventions 1:

• Exercise therapy: Local muscle strengthening of the rotator cuff and scapular stabilizers, plus general aerobic fitness training
• Activity modification: Avoid repetitive overhead activities and "peaks and troughs" of shoulder use
• Weight loss if overweight or obese (reduces joint loading)
• Paracetamol (acetaminophen): Regular dosing for pain relief as first-line analgesic 1

Second-Line Pharmacologic Options (If inadequate relief after 2 weeks)

Add topical or oral NSAIDs 1:

• Topical NSAIDs first (lower systemic toxicity)
• If insufficient, add oral NSAIDs or COX-2 inhibitors at the lowest effective dose for the shortest duration
• Always co-prescribe a proton pump inhibitor with oral NSAIDs/COX-2 inhibitors 1
• Consider individual risk factors: age, GI/cardiovascular/renal disease, concurrent aspirin use

Adjunctive Non-Pharmacologic Measures

Consider these evidence-based additions 1:

• Local heat or cold applications
• TENS (transcutaneous electrical nerve stimulation)
• Assistive devices if functional limitations exist

Avoid: Glucosamine, chondroitin, electroacupuncture 1

Injection Therapy (If conservative measures fail at 4-6 weeks)

For AC Joint Osteoarthritis

Corticosteroid injection into the AC joint is an option for moderate to severe pain 1, 2:

• Provides short-term pain relief (evidence suggests weeks to months)
• Does not alter disease progression 2
• Ultrasound guidance recommended to ensure accurate placement 3
• Use diagnostic local anesthetic injection first to confirm AC joint as pain source 3, 2

For Subacromial-Subdeltoid Bursitis

Subacromial corticosteroid injection is strongly indicated when bursitis is present 4, 5:

• Most effective when bursal thickening or effusion >2mm on ultrasound 5
• Patients with ultrasonographic bursitis show significantly better outcomes than those with normal bursa 5
• Typical regimen: 20mg triamcinolone acetonide 5
• Ultrasound guidance is superior to blind injection—ensures accurate bursal placement and avoids neurovascular structures 6

Key Clinical Point: The presence of mild bursitis on imaging predicts better response to injection therapy 5. Your patient's documented bursitis makes this intervention particularly appropriate.

When to Consider Surgery

Refer for surgical evaluation if 1, 7:

• Symptoms remain refractory after minimum 6 months of comprehensive conservative treatment 2
• Joint symptoms substantially affect quality of life
• Functional limitation becomes prolonged and established

Surgical options include arthroscopic or open distal clavicle resection for AC joint OA 2. However, current evidence shows no clear superiority of surgery over conservative management for AC joint OA 7.

Critical Pitfalls to Avoid

1. Don't skip the diagnostic injection: Use local anesthetic in the AC joint to differentiate AC joint pain from rotator cuff pathology before committing to treatment 3, 2

2. Don't use corticosteroids without ultrasound confirmation: Blind injections have lower accuracy and efficacy 6

3. Don't rush to surgery: Both conditions respond well to conservative care, and surgery shows no proven superiority 7

4. Don't overlook NSAID gastroprotection: Always prescribe PPIs with oral NSAIDs, especially in elderly patients 1

5. Don't use ineffective modalities: Avoid glucosamine, chondroitin, and electroacupuncture—they lack evidence 1

Practical Treatment Sequence

Weeks 0-2: Exercise + activity modification + paracetamol + topical NSAIDs

Weeks 2-6: Add oral NSAIDs with PPI if needed; continue exercise

Week 6+: If inadequate response, perform ultrasound-guided diagnostic/therapeutic injections:

• AC joint: corticosteroid if AC joint tenderness confirmed
• Subacromial bursa: corticosteroid (especially effective given documented bursitis) 5

Month 6+: Consider surgical referral only if refractory to all above measures

This stepwise approach prioritizes safety, follows guideline recommendations 1, and leverages the specific finding of bursitis to optimize injection therapy outcomes 5.