Platelet-Rich Plasma vs. Mesenchymal Stem Cells for Lumbar Disc Degeneration: A Systematic Review and Meta-Analysis.

Platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs) are promising regenerative treatments for lumbar degenerative disc disease (DDD), but their comparative efficacy is unclear. This systematic review and indirect meta-analysis, conducted according to PRISMA guidelines and the PICOS framework, evaluated their effects on pain, function, and safety. PubMed, Scopus, and Web of Science were systematically searched, yielding 1694 records, of which 21 studies (nine randomized controlled trials [RCTs] and 12 prospective studies) were included. Data were analyzed qualitatively and quantitatively, and risk of bias was assessed using RoB 2 and ROBINS-I. Meta-analyses of randomized controlled trials (RCTs) examined pain and disability at 6 and 12 months using a random-effects model. Indirect comparisons were performed using the Bucher method. Qualitative synthesis showed that PRP consistently reduced pain (often > 50%) and improved function, frequently outperforming corticosteroids. MSCs provided sustained benefits, with follow-up extending up to 72 months in some studies. Quantitative meta-analysis of five RCTs demonstrated that PRP significantly reduced pain at 6 months (mean difference [MD] -16.4 mm) and disability (ODI -12.7), with effects persisting at 12 months in one study. In contrast, MSCs showed a modest but significant reduction in pain (MD -4.3 mm) and minimal functional improvement. Indirect comparisons favored PRP over MSCs at 6 months. Both treatments exhibited favorable safety profiles, with mostly mild and transient adverse events. Overall, PRP appears more effective than MSCs in the short to mid-term, although both therapies are safe. Further high-quality head-to-head RCTs are needed to confirm these findings and define optimal clinical indications.