PRP vs Repeat Corticosteroid Injection for Refractory Adhesive Capsulitis
In a patient with adhesive capsulitis who has failed physiotherapy, NSAIDs, and at least one corticosteroid injection, platelet-rich plasma (PRP) injection is the superior choice over repeat corticosteroid injection based on the most recent high-quality evidence showing sustained improvements in pain, function, and range of motion at 3-6 months.
Evidence Supporting PRP in This Clinical Context
The 2024 systematic review and meta-analysis provides the strongest and most recent evidence for this recommendation 1:
PRP demonstrated statistically significant superiority over corticosteroids at 3 months across all outcome measures: VAS pain score (SMD 0.65), DASH functional score (SMD 0.66), SPADI score (SMD 1.50), external rotation (SMD 1.47), and abduction (SMD 1.10) 1
At 6 months, PRP showed even greater superiority with VAS improvement (SMD 3.17) and DASH improvement (SMD 2.10), indicating sustained and progressive benefit rather than the typical decline seen with corticosteroids 1
This meta-analysis included 971 patients across 11 studies (7 RCTs and 4 cohort studies), providing robust evidence specifically for the adhesive capsulitis population 1
Why Repeat Corticosteroid Injection is Less Favorable
The evidence for repeat corticosteroid injections shows important limitations in your clinical scenario:
Corticosteroid benefits are time-limited: A 2017 meta-analysis demonstrated that corticosteroid injections provide pain relief only at 0-8 weeks, with no difference from placebo at 9-24 weeks 2
Multiple injections have diminishing returns: While up to 3 corticosteroid injections show benefit until 16 weeks, there is limited evidence supporting 4-6 injections and no evidence for more than 6 injections 3
Your patient has already received at least one injection, placing them in a category where additional corticosteroid injections offer progressively less benefit 3
Clinical Algorithm for This Decision
Step 1: Confirm the patient has completed adequate conservative therapy
- At least 6 weeks of structured physiotherapy 4
- Trial of NSAIDs 4
- At least one intra-articular corticosteroid injection 5
Step 2: Assess disease duration and severity
- PRP works best in adhesive capsulitis with less than 6 months duration 5
- Ultrasound-guided injection is preferred for accurate intra-articular placement 5, 4
Step 3: Proceed with single PRP injection (4 mL) under ultrasound guidance
- This provides superior outcomes compared to repeat corticosteroid injection 5, 1
- Expect progressive improvement over 3-6 months rather than immediate relief 1
Step 4: Counsel patient on expected timeline
- PRP effects build over time, with maximal benefit at 6 months 1
- Reduced need for analgesic medication compared to physiotherapy alone 4
Important Caveats and Pitfalls
Avoid applying osteoarthritis PRP guidelines to adhesive capsulitis: The American College of Rheumatology strongly recommends against PRP for knee and hip osteoarthritis due to lack of standardization and inconsistent results 6, 7. However, this recommendation does not apply to adhesive capsulitis, which has distinct pathophysiology and separate evidence base 5, 1.
PRP preparation matters: While guidelines criticize PRP for osteoarthritis due to lack of standardization 6, 7, the adhesive capsulitis studies used consistent 4 mL intra-articular preparations with favorable results 5, 1.
Safety profile is excellent: No major complications were observed in the adhesive capsulitis PRP studies 5, contrasting with the known risks of multiple corticosteroid injections including cartilage damage and tendon weakening.
This is not a first-line treatment: PRP should only be considered after failure of conservative management including at least one corticosteroid injection 5, 1. The evidence specifically addresses your clinical scenario of refractory disease.