Comparison of Clinical and Imaging Outcomes of Different Doses of Adipose-Derived Stromal Vascular Fraction Cell Treatment for Knee Osteoarthritis

Abstract Background: Favorable clinical outcomes of the intra-articular injection of adipose-derived stromal vascular fraction (SVF) cells for knee osteoarthritis (OA) have been reported. This study aimed to compare the short-term clinical and imaging outcomes of different doses of SVF cells for knee OA treatment.Methods: This study included 60 patients with knee OA who underwent intra-articular injection of SVF cells. The follow-up period was at least 12 months. The envelope method was used to prospectively quasi-randomized the patients to undergo treatment with different doses of SVF cells. Thirty patients received an intra-articular injection of 2.5×107 SVF cells (low-dose group), and the remaining 30 patients received an intra-articular injection of 5.0×107 SVF cells (high-dose group). Clinical evaluations were performed for range of motion, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS) for pain, and the Knee injury and Osteoarthritis Outcome Score (KOOS). Imaging evaluations, which included the hip-knee-ankle angle and magnetic resonance imaging Osteoarthritis Knee Score (MOAKS) features (bone marrow lesions, cartilage defects, osteophytes, Hoffa’s synovitis, and effusion synovitis), were also performed. All clinical and imaging evaluations were performed preoperatively and 12 months postoperatively and compared between the groups.Results: No significant differences in demographic data were found between the two groups. The knee extension angle at 12 months postoperatively was significantly higher than the preoperative angle in both groups. The total WOMAC and VAS scores at 12 months postoperatively were significantly more favorable than preoperative scores in both groups. The bone marrow lesions and Hoffa’s synovitis and effusion synovitis improved approximately 30-40% from baseline to 12 months postoperatively in both groups. However, there were no significant differences in the preoperative and postoperative results of any clinical or imaging evaluation between the two groups.Conclusions: The short-term clinical and imaging outcomes of intra-articular injection of SVF cells for knee OA were excellent, regardless of whether a low- or high-dose was administered. Intra-articular injection of SVF cells for knee OA is an innovative approach.