Sixty patients with grade II–III knee osteoarthritis were randomized to receive adipose-derived mesenchymal stem cells (MSCs) (n=30) or triamcinolone (n=30). Primary outcome: pain (VAS). Secondary outcomes: WOMAC subscales (stiffness, pain, physical function), knee ROM, and MRI parameters. Outcomes were assessed at baseline, 2, 4, and 24 weeks. Overall, pain trajectories differed by group with a between-group difference emerging from 4 to 24 weeks favoring MSCs; WOMAC total and subscales and some ROM measures also improved more with MSCs over time. MRI qualitative metrics suggested greater stability and less progression (e.g., synovitis 5% vs 47.5% progressed) with MSCs. These findings suggest a single MSC injection is safe and offers superior medium-term symptomatic benefit versus corticosteroid in grade II–III knee OA.