Are injectable regenerative therapies effective in the treatment of degenerative disc disease? A systematic review

INTRODUCTION: Degenerative disc disease is a major health concern in spine surgery. The aim of this systematic review was to summarize the current knowledge about injectable regenerative therapies (mesenchymal stem cells [MSC] or platelet rich plasma [PRP]) in degenerative disc disease. EVIDENCE ACQUISITION: A research and analysis of the literature on Pubmed, Medscape, Medline, Google Scholar and Cochrane databases was performed, in accordance with the Preferential Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) flowchart. Only peer-reviewed randomized controlled trials (RCTs), prospective single-arm trials, case series, and cohort studies were included. EVIDENCE SYNTHESIS: A total of 17 studies were included. All were homogeneous regarding indications to the procedure: discogenic lowback pain for at least 3-6 months, failure of conservative treatment, MRI evidence of disc degeneration. A total of 182 patients were treated with MSC and 198 patients were treated with PRP. Considering the efficacy, the studies were heterogeneous in clinical evaluation systems; however, they all reported significant improvement in clinical and functional scores. Neither major complications nor adverse effects were reported by any author. As for radiographical outcome none of the studies reported a disc height improvement after treatment. CONCLUSIONS: Degenerative disc disease is a major health concern. Regenerative therapies could play a role in the treatment of its symptoms, as they have been proven to be clinically effective, cheap, and safe. Nevertheless, further studies are needed, in order to establish evidence based standardized treatments.