Purpose of Review: Previous studies involving various mesenchymal stem cell (MSC) sources have reported osteoarthritis (OA) attenuation benefits. In particular, umbilical cord-MSC (UC-MSC) exhibit advantageous characteristics such as a non-invasive collecting process, lower infection and risk of teratoma, and high immunosuppressive capacity. Thus, our purpose is to determine the efficacy of intra-articular injection of specifically UC-MSC without any surgical adjuvant procedure in knee OA cases. Methods: After registering on PROSPERO, we searched PubMed, ScienceDirect, and EBSCO databases using Medical Subject Headings (MeSH) terms and simple Boolean operation keywords. After being included, we measured the clinical and microscopic outcomes improvement. We also measured the radiological outcome and safety profile of UC-MSC injection. We reported this systematic review according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Recent Findings: A total of five articles that specifically used UC-MSC in knee osteoarthritis were included in this study. Two studies are pre-clinical trials, while three of them are human clinical trials. In both pre-clinical trials, microscopic results measured with the Mankin score or Osteoarthritis Research Society International (OARSI) score measurements showed contradictory results. In contrast, three clinical trials showed improved clinical outcomes with functional scores, such as the International Knee Documentation Committee (IKDC) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), with minor radiological improvement. There was not any serious adverse event reported. Summary: Current research has shown that intra-articular UC-MSC effectively improves clinical and microscopic results in knee osteoarthritis while maintaining a safety profile. More clinical trials, however, are required to validate the advantages.
- Mesenchymal stem cell
- Umbilical-cord mesenchymal stem cell