Safety and efficacy of autologous adipose-derived stem cells for knee osteoarthritis in the elderly population: A systematic review

Introduction: Osteoarthritis (OA) is a progressive joint disease, and over 240 million people suffer from symptomatic OA, primarily in the knee, and mainly affects the elderly population over 65. A combination of different risk factors leads to biological changes in the microenvironments of the joints, causing cartilage overload and chondrocyte aging. Adipose-derived MSCs (ADSCs) are demonstrated to improve joint environments with an effective therapy for Knee OA. This review focused on patients over 65 years old to evaluate the effectiveness of ADSC therapies in treating KOA in elderly patients and demonstrate that complications are not higher in this cohort of patients.

Materials and methods: We conducted a bibliography search through the PubMed, Scopus, and Cochrane databases for English-language and human clinical trials published until Feb 7, 2024. We extracted the following study characteristics: Authors, year of publication, type of study, number of patients, number of knees, sex, Kellgren-Lawrence classification, culture ADSC, Number of cells injected, mean follow-up, adverse events, significant complications, and clinical outcomes data were extracted recorded and analyzed.

Results: According to inclusion criteria, seven clinical trials on autologous adipose-derived stem cells were considered. Four studies analyzed stem cells as a stromal vascular fraction (SVF), two as ADSC cultured, and 1 study investigated the MAT procedure. All studies reported improved clinical outcomes using autologous adipose-derived stem cells, on 339 knees. Post-treatment increased KOOS, WOMAC, IKS, VAS, and Lysholm knee scores were highlighted. All studies showed an improvement in all outcomes scores, and regarding complications, only 44 knees underwent adverse events, but no significant complications were found in all the studies reported.

Conclusions: The current systematic review demonstrated that using autologous adipose-derived stem cells improved clinical outcomes and is effective and safe in elderly patients. Additionally, this study will encourage orthopedic surgeons not to consider surgery as the only solution in elderly patients who are refractory to treatment and do not show end-stage knee osteoarthritis.

Level of evidence: Level IV, systematic review of level IV studies.