Single-injection viscosupplementation is currently performed with cross-linked hyaluronan (e.g., Durolane®) for treating symptomatic knee osteoarthritis.


This first-in-human study evaluated the safety and performance of single-injection treatment with non-crosslinked KiOmedine®CM-Chitosan.


Patients with painful knee osteoarthritis were randomly assigned to the KiOmedine®CM-Chitosan (n=63) or Durolane® (n=32) group. Patients were blinded to treatment and followed up for 26 weeks. Durolane® was used as scientific control to ensure the validity of the study and reliability of results. No direct comparison was performed between the two groups. The primary objective was defined as an intra-group effect size of 0.8 at 13 weeks post-injection compared to baseline on WOMAC-A (pain). Secondary outcomes included self-reported knee stiffness and knee function, responder rate, quality-of-life questionnaires, and safety.


The primary objective for both the KiOmedine®CM-Chitosan and the Durolane® groups was met: mean pain reduction of 62.5% (effect size 2.08) for the KiOmedine®CM-Chitosan group and 62.4% (effect size 2.28) for the Durolane® group. Secondary performance outcomes showed all clinically relevant treatment effects over 26 weeks for both groups (p<0.05). Treatment-related adverse events were more often reported in the KiOmedine®CM-Chitosan than Durolane® group and were limited to local reactions. No serious treatment-related adverse events were reported.


A single intra-articular injection of non-crosslinked KiOmedine®CM-Chitosan is safe and effective for treating symptomatic knee osteoarthritis with a high responder rate. Pain reduction is maintained for 6 months with a high responder rate.

The clinical trial registration number: NCT03679208.

Keywords: Chitosan, Intra-articular injection, Single-injection, Knee, Osteoarthritis, Viscosupplementation.
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