Intra-articular Stromal Vascular Fraction and Mesenchymal Stem Cell Injections Show Variable Efficacy and Higher Potential Complications Compared to Corticosteroid and Hyaluronic Acid in Treatment of Knee Osteoarthritis: A Meta-analysis of Randomized Controlled Trials.

[PURPOSE] To evaluate the clinical outcomes of intra-articular stromal vascular fraction (SVF) and adipose-derived mesenchymal stem cell (ASC) injections in patients with knee osteoarthritis through a meta-analysis of randomized clinical trials.

[METHODS] PubMed, Embase, the Cochrane Library, and Google Scholar were systematically searched to identify Level I studies that compared the clinical efficacy of SVF or ASC with that of other nonoperative treatments. Clinical scores measured 3, 6, and 12 months postinjection were standardized to pain and functional scales for meta-analysis based on minimal clinically important differences. Follow-up magnetic resonance imaging findings and safety-related data were also investigated.

[RESULTS] Nine studies involving 671 patients were included. SVF demonstrated superior pain and function score improvements compared to saline or hyaluronic acid (HA) at 3, 6, and 12 months postinjection. However, SVF was inferior to corticosteroid at 3 months, showed no difference at 6 months, and was comparable or slightly superior at 12 months. ASC consistently showed better pain and function score improvements compared to saline and conservative treatment at all time points, with no significant differences observed compared to HA. High heterogeneity was noted in SVF function score results, requiring cautious interpretation. No serious adverse events related to SVF or ASC were reported, although complications associated with liposuction were observed.

[CONCLUSIONS] SVF showed consistent superiority in pain and function scores compared to HA and saline but not corticosteroids, except for the 3-month function score. ASC improved pain and function scores compared to saline and conservative treatment but was not superior to HA. While SVF and ASC significantly improved clinical scores, the potential complications from liposuction limit their ability to replace existing minimally invasive treatments for knee osteoarthritis.

[LEVEL OF EVIDENCE] Level I, meta-analyses of randomized controlled trials.