Mesenchymal Stromal Cells for the Treatment of Discogenic Low Back Pain: A Systematic Review of Clinical Studies

This study aimed to elucidate the efficacy and safety of mesenchymal stromal cell (MSC) therapy for chronic discogenic low back pain (LBP). A systematic literature search was conducted on PubMed/Medline, Scopus, Cochrane, and ClinicalTrials.gov following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines. Eligible studies included published and ongoing clinical trials assessing intradiscal MSC injections in patients with chronic discogenic LBP unresponsive to conservative treatment. Risk-of-bias (RoB) assessment was performed through MINORS (Methodological Index for Non-randomized Studies) and RoB 2 tools. Within- and between-group differences were expressed as means and 95% confidence intervals. Effect sizes were calculated through Cohen d and g. Data from 10 published clinical studies (n=736; 470 in treatment and 266 in control groups) revealed a mean age of 41.5 years and an average follow-up of 21.6 (range, 6-72) months. Various MSC sources were employed, including autologous and allogeneic bone marrow-derived MSCs and adipose-derived MSCs, with doses ranging from 6×10⁶ to over 50×10⁶ cells/disc. Visual analogue scale, Oswestry Disability Index, and quality-of-life questionnaires indicated modest improvements in pain, disability, and functional status. Additionally, magnetic resonance imaging assessments occasionally demonstrated increased disc hydration and stabilization or improvement of Pfirrmann grade. Data from 8 ongoing trials (n=498 participants; 276 treatment, 222 control) with follow-up periods ranging 6-24 months further corroborate the feasibility and safety of MSC-based interventions. MSC therapy is a biologically-driven approach for managing chronic discogenic LBP. While preliminary data support its potential to alleviate pain and improve disc integrity, further high-quality, standardized trials are necessary to optimize treatment protocols and confirm long-term clinical benefits.