In Vivo Studies of Mesenchymal Stem Cells in the Treatment of Meniscus Injury

This review summarizes the literature of preclinical studies and clinical trials on the use of mesenchymal stem cells (MSCs) to treat meniscus injury and promote its repair and regeneration and provide guidance for future clinical research. Due to the special anatomical features of the meniscus, conservative or surgical treatment can hardly achieve complete physiological and histological repair. As a new method, stem cells promote meniscus regeneration in preclinical research and human preliminary research. We expect that, in the near future, in vivo injection of stem cells to promote meniscus repair can be used as a new treatment model in clinical treatment. The treatment of animal meniscus injury, and the clinical trial of human meniscus injury has begun preliminary exploration. As for the animal experiments, most models of meniscus injury are too simple, which can hardly simulate the complexity of actual meniscal tears, and since the follow‐up often lasts for only 4–12 weeks, long‐term results could not be observed. Lastly, animal models failed to simulate the actual stress environment faced by the meniscus, so it needs to be further studied if regenerated meniscus has similar anti‐stress or anti‐twist features. Despite these limitations, repair of the meniscus by MSCs has great potential in clinics. MSCs can differentiate into fibrous chondrocytes, which can possibly repair the meniscus and provide a new strategy for repairing meniscus injury.