Key Points • High-purity intra-articular sodium hyaluronate was well tolerated, with only mild, self-resolving adverse events. • Significant and sustained reduction in knee pain was observed through 28 weeks of follow-up. • Radiographic Kellgren–Lawrence grades remained stable at both short-term and mid-term safety evaluations. • Most patients reported high satisfaction, supporting the formulation as a safe and effective real-world option for symptomatic knee osteoarthritis.