Mesenchymal Stem Cell Injections for the Treatment of Osteoarthritis: A Systematic Review of Clinical Trials

Objectives: Osteoarthritis is a prevalent degenerative disease that affects many people worldwide. The use of mesenchymal stem cells (MSCs) in the setting of osteoarthritis has been explored by many clinical trials in the literature. Exploring these clinical trials is important for assessing the benefit of this modality in the setting of osteoarthritis. Methods: On November 9, 2022, a search was conducted on PubMed/MEDLINE databases to explore clinical trials involving MSC injections for osteoarthritis. Only articles that were clinical trials, explored the use of MSC injections in osteoarthritis, involved human subjects, and written in English language, were included. Relevant data was extracted from the included trials. Results: A total of 43 trials were included (N=43). The knee was most the commonly explored joint (95.4%), and adipose tissue was the most commonly utilized MSC source (49%). All but one trial (97.7%) reported clinical improvement in the MSC group on follow up, and 33 trials (76.7%) reported better clinical outcomes in the MSC groups when compared to control groups. Twenty-three trials (53.5%) used imaging to evaluate outcomes following MSC injections, out of which twenty (46.5%) reported improvements in the affected joint. Similarly, four trials (9.3%) used second look arthroscopy, out of which three (7%) reported better outcomes on follow up. Conclusion: While published trials show good therapeutic potential for MSC injections in the setting of osteoarthritis, several discrepancies render the efficiency and reliability of this modality equivocal. The adoption of standardized protocols, employment of comprehensive evaluation tools, and reporting negative results is essential in order to appropriately assess the utility of MSC injections for the treatment of osteoarthritis.