A Single Intra-articular Injection of Autologous Stromal Vascular Fraction for Moderate-to-Severe Knee Osteoarthritis: Results of a Multicenter Randomized Placebo-Controlled Trial With 12-Month Follow-up

Background: This randomized controlled trial evaluated the 12-month outcomes of a single intra-articular injection of autologous adipose-derived stromal vascular fraction (SVF), prepared and administered during the same clinical encounter, for the treatment of moderate-to-severe knee osteoarthritis (OA). Purpose/Hypothesis: To evaluate the efficacy of a single intra-articular injection of 25 million autologous adipose-derived SVF cells for moderate-to-severe knee OA, compared with placebo, at 12 months. The authors hypothesized that SVF-treated patients would demonstrate a significantly greater responder rate based on prespecified clinically meaningful improvements in pain and function derived from composite outcomes of the index and contralateral knees. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Adults aged 35 to 85 years with symptomatic unilateral or bilateral knee OA were eligible if the index knee demonstrated a Western Ontario and McMaster Universities Osteoarthritis Index pain score of ≥8, an Outerbridge grade of 2 to 4 on magnetic resonance imaging (MRI), and a Kellgren-Lawrence grade of 2 to 4 on radiographs. Autologous adipose-derived SVF was prepared using a point-of-care isolation system during the same clinical encounter, assessed against predefined release criteria, and administered as a single intra-articular injection into the index knee. MRI of the index knee was obtained at baseline and at 12 months. Results: A total of 618 participants were assessed for eligibility, of whom 114 were randomized (SVF, n = 83; placebo, n = 31). At 12 months, a single intra-articular injection of 25 million SVF cells demonstrated statistical superiority over placebo for the primary composite clinical endpoint. The responder rate was 51.8% (43/83) in the SVF group compared with 29% (9/31) in the placebo group (difference, 22.8% [95% CI, 3.5%-42%]; 1-sided P = .0149). No serious investigational device-related adverse events were reported. Conclusion: A single intra-articular injection of 25 million autologous adipose-derived SVF cells resulted in statistically superior and clinically meaningful improvements in pain and function at 12 months compared with placebo, with no serious investigational device-related adverse events reported. Registration: IDE 16734; ClinicalTrials.gov NCT04440189.