Efficacy of Platelet-Rich Plasma and Plasma for Symptomatic Treatment of Knee Osteoarthritis: A Double-Blinded Placebo-Controlled Randomized Clinical Trial
Dório M · BMC Musculoskeletal Disorders (2021)
DOI: 10.1186/s12891-021-04706-7This double-blind RCT compared PRP versus platelet-poor plasma (PPP) versus saline in 62 patients with knee OA. All three groups improved significantly from baseline, but there were no significant differences between groups at any timepoint. The study suggests that the injection procedure itself (needle, volume, placebo effect) may account for much of the observed benefit in PRP trials.
Clinical Relevance
A cautionary study for clinicians: intra-articular injection of any fluid may produce improvement, and PRP's specific benefit above placebo requires adequate dosing and proper preparation to be detected. Highlights the need for placebo-controlled rather than HA-controlled trials.
Key Takeaways
- No significant difference between PRP, PPP, or saline
- All groups improved significantly from baseline
- Suggests a strong placebo or needling effect
- Small sample (n=62) may be underpowered
- PRP concentration details not well characterized, raising the possibility of inadequate dosing
Key Findings
No significant difference in VAS pain scores was found between PRP, non-enriched plasma, and saline at 24 weeks.
Clinical Context
Study Design
Randomized Controlled Trial (Double-Blind)
Condition
Knee Osteoarthritis
Sample Size
62 patients
Follow-up
6 months
Control Group
Saline and Non-enriched Plasma
Primary Outcome
VAS (0-10 cm)
PRP Protocol & Intervention
Injection Frequency
2 injection(s)
Injection Interval
2-week interval
Guidance Method
Ultrasound