What is the treatment for Acromioclavicular (AC) joint separation?

Treatment of Acromioclavicular (AC) Joint Separation

For AC joint separations, treatment should be stratified by injury grade: grades I-II require conservative management with sling immobilization and early rehabilitation, grade III injuries can be managed conservatively in most patients (with surgery reserved for those with persistent pain >7 days or high functional demands), and grades IV-VI require surgical reconstruction.

Initial Assessment and Imaging

• Obtain standard shoulder radiographs first: anteroposterior (AP) views in internal and external rotation plus an axillary or scapula-Y view to confirm diagnosis and grade the injury 1
• Radiographs should be performed upright, as malalignment can be underrepresented on supine imaging 1
• The Rockwood classification system guides treatment decisions, though be aware that inter-rater reliability is poor (kappa=0.08-0.35), so clinical judgment remains paramount 2

Treatment Algorithm by Grade

Grades I-II (Low-Grade Separations)

Conservative management is the standard of care and yields favorable outcomes 3:

• Sling immobilization for comfort (typically 1-2 weeks)
• Early range of motion exercises as pain allows
• Progressive strengthening program
• These injuries respond well to non-operative treatment with minimal long-term sequelae 3

Grade III (Controversial - Most Common Clinical Dilemma)

Initial conservative management is recommended for most patients, with surgery reserved for specific indications 2, 4:

Conservative approach should include:

• Sling support for 1-2 weeks
• Early mobilization and rehabilitation 3
• Pain control with oral analgesics and/or ultrasound-guided AC joint injection with local anesthetic 5

Surgical indications for grade III:

• Persistent severe pain (VAS >7) at 7 days post-injury with no functional improvement 2
• Young, high-demand athletes requiring rapid return to overhead sports 3, 4
• Manual laborers with heavy overhead work demands 4

Critical evidence: A 2023 study demonstrated no significant difference in functional outcomes (Constant score: surgery=91 vs. non-operative=83, p=0.09) between operative and non-operative treatment at minimum 1-year follow-up 2. However, return to work and sports was significantly faster with conservative treatment, and surgical patients experienced complications in 24% of cases (9/38 patients) while non-operative patients had zero complications 2.

Grades IV, V, and VI (High-Grade Separations)

Surgical reconstruction is typically required 3, 6:

• These represent severe injuries with significant displacement
• Conservative management rarely provides adequate stability
• Multiple surgical techniques exist, though no single gold standard procedure has been established 6
• Early surgical intervention (within 2-3 weeks) is generally preferred to prevent chronic instability 6, 4

Pain Management Strategies

For acute pain control in the emergency or clinic setting:

• Oral analgesics as first-line therapy
• Ultrasound-guided AC joint injection with local anesthetic (bupivacaine) provides rapid, near-complete pain relief and is far superior to landmark-guided injection 5
• The AC joint's superficial location makes it ideal for US-guided injection 5
• Avoid relying solely on pain medication to mask symptoms that might indicate need for surgical intervention 3

Rehabilitation Principles (Operative and Non-Operative)

Conservative management rehabilitation:

• Phase 1 (0-2 weeks): Sling for comfort, gentle pendulum exercises, pain control 3
• Phase 2 (2-6 weeks): Progressive range of motion, isometric strengthening 3
• Phase 3 (6-12 weeks): Dynamic strengthening, sport-specific training 3

Post-operative rehabilitation:

• Typically more prolonged than conservative treatment 2
• Sling immobilization for 4-6 weeks depending on surgical technique 3
• Delayed strengthening to protect reconstruction 3
• Return to sports generally 4-6 months post-operatively 3

Common Pitfalls to Avoid

• Do not rush to surgery for grade III injuries - the evidence shows equivalent long-term outcomes with conservative management and faster return to function 2
• Do not rely on the Rockwood classification alone - it has poor inter-rater reliability; use clinical judgment and patient factors 2
• Do not ignore persistent severe pain beyond 7 days - this is the key indicator for surgical consideration in grade III injuries 2
• Do not use landmark-guided injections - ultrasound guidance is far more accurate and effective for AC joint injections 5
• Do not promise faster recovery with surgery - conservative treatment actually allows quicker return to work and sports 2

Special Considerations

For young athletes or manual laborers, have an honest discussion about the trade-offs: surgery may provide slightly better cosmetic appearance and potentially better stability for overhead activities, but comes with longer recovery time, higher complication rates, and no proven functional superiority at 1 year 2, 4. Conservative management that fails can still be addressed with delayed surgical reconstruction if needed 2.