Membrane-Free Stem Cell Extract (MF-STEM) Improves Clinical Outcomes and Reduces Recurrence in Canine and Feline Osteoarthritis: A Real-World Controlled Study of 271 Cases

Osteoarthritis (OA) in companion animals is a progressive and debilitating condition for which current treatments primarily provide symptomatic relief without modifying disease progression. Cell-free regenerative approaches have recently emerged as promising alternatives. This study evaluated the clinical effectiveness of membrane-free stem cell extract (MF-STEM) in canine and feline osteoarthritis in comparison with intra-articular hyaluronic acid in a real-world clinical setting. A total of 271 animals were enrolled, including an MF-STEM group (n = 210) and a control group (n = 61), with treatment allocation based on owner preference. Clinical outcomes were assessed using the Joint Evaluation Index (JEI), along with recovery and recurrence rates. MF-STEM treatment resulted in a marked reduction in JEI scores (12.3 → 2.2), compared with a more limited decrease in the control group (11.3 → 7.0). The recovery rate was significantly higher in the MF-STEM group (93.3% vs. 32.8%), while the recurrence rate within one year was substantially lower (2.4% vs. 60.6%). No treatment-related adverse events were observed (0%). Although the non-randomized design limits causal interpretation, key baseline characteristics were generally comparable between groups, and consistent improvements were observed across multiple outcome measures in a relatively large real-world cohort. In conclusion, MF-STEM demonstrated clinically meaningful improvements in canine and feline osteoarthritis and may suggest a potential to influence disease progression with sustained therapeutic benefits. Further randomized controlled and mechanistic studies are required to confirm these findings.