Initial Treatment for Acromioclavicular (AC) Joint Arthritis
Begin with conservative management consisting of NSAIDs, activity modification, and consider corticosteroid injection for diagnostic confirmation and therapeutic benefit, reserving surgery only after at least 6 months of failed conservative treatment. 1, 2
First-Line Conservative Management
NSAIDs and Activity Modification
- Scheduled NSAIDs should be the cornerstone of initial therapy, used at the minimum effective dose for the shortest duration necessary after evaluating gastrointestinal, renal, and cardiovascular risks 3, 1, 4
- Acetaminophen (up to 4 grams daily) is an appropriate alternative for mild to moderate pain, particularly in patients at high risk for NSAID complications 3
- Activity modification is essential—patients should avoid movements that exacerbate AC joint pain, particularly overhead activities and cross-body adduction 4, 2
Diagnostic and Therapeutic Injection
- Intra-articular corticosteroid injection serves dual purposes: confirming the diagnosis when local anesthetic provides relief and providing therapeutic benefit 1, 4, 2
- Steroid injections provide significant pain relief, with mean improvement from 61 to 81 points on the Constant score at 6 months, with benefits persisting up to 5 years 5
- The greatest improvement occurs between 6-12 months post-injection, with younger patients and women showing better objective improvement 5
- Pain relief tends to diminish long-term, but significant benefit remains at 5-year follow-up compared to pre-injection baseline 5
Important Caveats About Conservative Treatment
Physical Therapy Limitations
- Physical therapy has a limited role in AC joint arthritis, as therapeutic exercise and range of motion provide only minor benefit compared to other shoulder conditions 2
- This differs substantially from other forms of arthritis where exercise is more beneficial 3
Injection Considerations
- While corticosteroid injections provide short-term pain relief, they do not alter the natural progression of the disease 2
- The judicious use of repeated injections remains controversial among experts 2
- If diagnostic local anesthetic injection provides relief, there is a clear role for therapeutic corticosteroid injection 2
When to Consider Surgical Intervention
Timing and Indications
- Surgery is indicated only after a minimum of 6 months of unsuccessful conservative treatment 2
- Patients who continue to exhibit symptoms after appropriate nonsurgical treatment including anti-inflammatory medications, activity modification, and injections may be candidates for operative intervention 4
- The average duration of conservative management before surgery in published studies is 6 months 6
Surgical Options
- Distal clavicle excision (DCE) is the main surgical treatment, which can be performed via open or arthroscopic techniques 1, 4
- There is no significant difference in outcomes between open versus arthroscopic DCE 6
- Excision of 0.5 to 2 cm of clavicle produces good outcomes 6
- Patients requiring concomitant shoulder procedures have similarly good outcomes 6
Clinical Pitfalls to Avoid
- Do not overlook AC joint pathology when evaluating shoulder pain—the majority of shoulder pain originates from the subacromial region and glenohumeral joint, leading clinicians to neglect the AC joint 2
- Avoid premature surgical intervention before exhausting at least 6 months of conservative management 2
- Do not use NSAIDs at high doses for prolonged periods, particularly in elderly patients who are at high risk for gastrointestinal, platelet, and nephrotoxic effects 3
- Recognize that proper diagnosis requires a thorough physical exam, plain-film radiograph, AND diagnostic local anesthetic injection—not just imaging alone 2
Expected Outcomes
Conservative Management
- Injection therapy shows a mean improvement of 50% in pain levels at mean follow-up of 7.5 months 6
- Benefits from steroid injection continue to improve through 12 months and remain significant at 5 years 5