Regenerative Potential of Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis and Chondral Defects: A Systematic Review and Meta-analysis

Editorial Commentary: Stem Cell Therapy for the Knee: Heterogeneity in Cell Sources, Delivery Methods, and Concomitant Surgery Needs to Be Considered

“…The present article by Maheshwer et al 2 revealed that the therapeutic potential of MSCs for the treatment of osteoarthritis of the knee is still inconclusive based on the currently available data from clinical studies. Sufficient high-quality data do not exist even to perform a meta-analysis; moreover, the existing data are riddled with confounders, such as the source of the stem cells used (e.g., culture-expanded MSCs vs "cell concentrates," i.e., minimally manipulated cells) and the most effective delivery method (intra-articular injection vs surgical implantation), as well as whether concomitant surgery was performed.…”

“…Because there is no treatment option for delaying or modifying this progression, stem cell therapy using mesenchymal stem cells (MSCs) has been gaining significant attention as an option in the field of regenerative medicine for the treatment of osteoarthritis of the knee. 1,2 Thus, the article by Maheshwer, Polce, Paul, Williams, Wolfson, Yanke, Verma, Cole, and Chahla 2 entitled "Regenerative Potential of Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis and Chondral Defects: A Systematic Review and Meta-analysis" is of particular interest.…”

“…4 In my opinion, when evaluating the efficacy of stem cell therapy, clinicians must consider whether the source of cells for implantation is culture-expanded MSCs or cell concentrates. Maheshwer et al 2 described the exclusion of studies investigating the effects of stem cell therapy without adequate numbers of stem cells (i.e., bone marrow aspirate concentrate [BMAC]). As we know, unlike cultureexpanded bone marrowederived MSCs, BMAC has very low numbers of MSCs (0.001%-0.01%).…”

“…I think the answer is yes. I applaud Maheshwer et al 2 for their subgroup analysis stratifying studies based on the administration of MSCs via injection only versus via surgical adjuncts. One recent meta-analysis reported a limited efficacy of the intra-articular injection of culture-expanded MSCs in the treatment of knee osteoarthritis.…”

Mesenchymal stromal cell products for intra-articular knee injections for conservative management of osteoarthritis

“…Currently, other cellular products with chondrogenic capacity, including stromal vascular fraction of adipose tissue (SVF), bone marrow concentrates (BMCs), or expanded mesenchymal stromal cells (MSCs) loaded in specific biomaterials are implanted/grafted through arthroscopy in focal cartilage defects. 9 …”