1000 Section - Assessment of Functional Pattern and Pain in Patients with Knee Osteoarthritis Undergoing Viscosupplementation with Hyaluronic Acid in the Physiatry Outpatient Clinic in São Paulo, Brazil

Intra-articular hyaluronic acid (HA) is widely used for symptomatic knee osteoarthritis (OA), but the time-course of response and the role of concurrent physiotherapy in routine care remain unclear. The objective of this study is to evaluate and measure the clinical and functional evolution of participants who underwent intra-articular hyaluronic acid injections for the treatment of knee osteoarthritis.

Design:

This is an Observational, analytical, longitudinal study in a rehabilitation outpatient clinic. Thirteen patients with radiographic knee OA received three weekly intra-articular injections of intermediate–molecular weight HA (RenehaVis). Pain was assessed with the Numeric Pain Rating Scale (NPRS, 0–10) and function with the Lequesne index (0–24) at baseline and at 1, 3, and 6 months. Outcomes were analyzed overall and stratified by concurrent physiotherapy (yes/no). Repeated-measures comparisons used Friedman tests with Wilcoxon post-hoc (p< 0.05).

Results:

Baseline NPRS was 6.9±2.8 and Lequesne 13.7±4.3. NPRS improved at 1 month (p=0.018) and 3 months (p=0.030) versus baseline, with partial rebound by 6 months (mean 6.1). Lequesne improved at 1 month (p=0.002) and 3 months (p=0.001), then worsened from 3 to 6 months (p=0.05). Pain trajectories did not differ by physiotherapy status (p >0.05). Functional benefit was more durable with physiotherapy (baseline vs 6 months p=0.042), whereas the non-physiotherapy group showed no difference from baseline at 6 months (p=0.944) and worsened from 3 to 6 months (p=0.012). Outcomes were not associated with Kellgren–Lawrence grade (p >0.05).

Conclusion: In our research, a three-injection HA regimen produced significant improvements in pain and function through 3 months, with attenuation by 6 months, especially without physiotherapy. Integrating structured physiotherapy may prolong functional gains after viscosupplementation. Furthermore, larger controlled studies with standardized rehabilitation protocols are needed.