What is the role of hyaluronic acid (HA) injections in treating shoulder osteoarthritis or adhesive capsulitis?

Hyaluronic Acid Injections for Shoulder Conditions

Direct Recommendation

Hyaluronic acid injections may be considered as a treatment option for glenohumeral osteoarthritis, though the evidence is limited, and they should not be used for hip osteoarthritis. For adhesive capsulitis, corticosteroid injections provide faster initial relief, though hyaluronic acid achieves comparable outcomes by 6-12 weeks. 1, 2

Evidence-Based Treatment Algorithm for Shoulder Conditions

For Glenohumeral Osteoarthritis

Initial Treatment Approach:

• The American Academy of Orthopaedic Surgeons provides a Grade C recommendation (Level IV evidence) that injectable viscosupplementation is an option for treating glenohumeral osteoarthritis 1
• This contrasts sharply with hip osteoarthritis, where hyaluronic acid injections are strongly recommended against due to high-quality evidence showing no benefit 1, 3

Clinical Evidence for Shoulder OA:

• A single injection of NASHA hyaluronic acid demonstrated a mean 29.5% reduction in shoulder pain on movement over 6 months, with statistically significant improvements in night pain and patient global assessment 4
• The treatment was well-tolerated with only mild-to-moderate adverse events (41.5% of patients), and only 2 events (shoulder pain) were treatment-related 4

Important Caveat:

• The shoulder osteoarthritis evidence base is substantially weaker than for other joints, with only one industry-supported Level IV study meeting inclusion criteria for the AAOS guideline 1
• This is fundamentally different from knee and hip OA, where meta-analyses of low risk-of-bias trials show effect sizes approaching zero compared to saline 1

For Adhesive Capsulitis (Frozen Shoulder)

Treatment Selection Based on Timeline:

If rapid symptom relief is needed (2-4 weeks):

• Corticosteroid injections are superior for short-term pain reduction and functional improvement compared to hyaluronic acid 2
• Meta-analysis shows CS injections demonstrate better outcomes at 2-4 weeks post-injection 2

If sustained long-term benefit is the goal (6-12 weeks and beyond):

• Hyaluronic acid achieves comparable outcomes to corticosteroids by 6 and 12 weeks 2
• This makes HA a reasonable option for patients requiring repetitive injections or those at risk for corticosteroid side effects 2

Combination Therapy Consideration:

• Simultaneous injection of corticosteroid with hyaluronic acid showed a 58.4% reduction in SPADI scores at one month, significantly better than saline (-7.7%) or HA alone (-14.4%) 5
• The combination showed faster and better pain relief than single injections, though the difference versus CS alone (-43.7%) did not reach statistical significance 5

Critical Evidence Limitation:

• Adding hyaluronic acid to physical therapy provides no additional benefit over physical therapy alone for adhesive capsulitis 6
• A randomized controlled trial found no significant group effect for pain, disability, quality of life, or range of motion when comparing HA plus PT versus PT alone 6

Range of Motion Outcomes

• Neither hyaluronic acid nor corticosteroid injections show significant differences in improving active or passive shoulder range of motion in adhesive capsulitis 2
• Both treatment groups in various studies showed linear improvements in ROM with increasing treatment duration, but the injection type did not differentiate outcomes 6, 2

Clinical Decision Framework

Choose Hyaluronic Acid When:

• Patient has glenohumeral osteoarthritis (not hip or other joints) 1
• Patient requires multiple injections over time 2
• Patient has contraindications to corticosteroids (diabetes, immunosuppression, repeated prior CS injections) 2
• Timeline for improvement can extend to 6-12 weeks 2

Choose Corticosteroid Instead When:

• Rapid symptom relief (within 2-4 weeks) is clinically necessary 2
• Patient has adhesive capsulitis in the acute inflammatory phase 2
• No contraindications to CS exist 2

Avoid Hyaluronic Acid When:

• Patient has hip osteoarthritis (strong recommendation against) 1, 3
• Patient is already receiving adequate physical therapy for adhesive capsulitis (adds no benefit and increases cost) 6

Common Pitfalls to Avoid

• Do not extrapolate knee OA evidence to the shoulder: The ACR/AF strongly recommends against HA for knee OA based on rigorous meta-analyses, but shoulder evidence is separate and more limited 1
• Do not use HA as monotherapy for adhesive capsulitis: Physical therapy remains essential; HA alone without PT has not been shown superior to PT alone 6
• Do not delay definitive treatment: For severe glenohumeral OA, arthroplasty (TSA preferred over hemiarthroplasty) remains the definitive treatment with Grade B evidence 1
• Recognize the heterogeneity problem: Different HA formulations, molecular weights, and injection protocols were used across studies, making direct comparisons difficult 7