Intra-articular mesenchymal stem cells for cartilage repair in osteoarthritis of the knee

Abstract

Background & Aim Increasing numbers of clinical studies have addressed the use of mesenchymal stem cells (MSCs) for the treatment of osteoarthritis. However, the clinical benefit of MSCs for cartilage repair in osteoarthritis remains unclear. Although some recent studies reported the clinical benefits of intra-articular MSCs in the treatment of osteoarthritis, the clinical efficacy of MSCs in cartilage repair or cartilage protection in osteoarthritis has not been established. In addition, there is little consensus as which cell source, type of cell population, or delivery method should be used. Hence, this study aimed to provide a systematic review of the clinical literature supporting the efficacy of MSCs in terms of clinical outcomes and cartilage repair in patients with osteoarthritis and to strictly differentiate the various cell sources, types of cell populations, and delivery methods that have been used. Methods, Results & Conclusion Methods We systematically reviewed any studies investigating the clinical application of cell populations containing MSCs in human subjects with knee osteoarthritis through MEDLINE, EMBASE, the Cochrane Library, CINAHL, Web of Science, and Scopus. Studies with a level of evidence of IV or V were excluded. Methodological quality was assessed using the Modified Coleman Methodology Score. Clinical outcomes were assessed using clinical scores, and cartilage repair was assessed using MRI and second-look arthroscopy findings. Results A total of 17 studies that met the criteria were included in this review, with 6 randomized controlled trials, 8 prospective cohort studies, and 3 retrospective case-control studies. Among 17 studies, 8 studies used bone marrow-derived MSCs, 6 used adipose tissue-derived stromal vascular fraction, 2 used adipose tissue-derived MSCs, and 1 used umbilical cord blood-derived MSCs. All studies except 2 reported improvements in clinical outcomes. In terms of cartilage repair, 9 of 11 studies reported improvement of the cartilage state on MRI, and 6 of 7 studies reported repaired tissue on second-look arthroscopy. The mean Modified Coleman Methodology Score was 55.5±15.5 (range, 28-74). Conclusion Intra-articular MSCs seem to provide improvements in pain and function in knee osteoarthritis at short-term follow-up. However, the improvement was modest overall, and the effects of adjuvant treatment need to be clarified. Overall, evidence of the efficacy of MSCs for cartilage repair in osteoarthritis remains limited.