Purpose

To compare the effectiveness of Arthrosamid^® with that of Synvisc-One^® by assessing changes from baseline in transformed WOMAC pain, stiffness and physical function subscale scores (0-100 score where 100 was worst).

Methods and Materials

This was a prospective, double-blind multicentre study (3 sites in Denmark) where 239 subjects were randomised 1:1 to receive a single intra-articular injection of either 6 mL Arthrosamid (n=119) or 6 mL Synvisc-One (n=120). The study was approved by the Capital Region’s Committee on Health Research Ethics. All patients provided informed consent prior to study activities. Injections were given by an experienced investigator, who was not involved further with the patients. Patients could continue analgesics (except 48 hours prior to visits) and non-pharmacologic therapy, but topical (on target knee) and systemic corticosteroids or additional injections were not allowed. This abstract presents data from the 52-week follow-up visit.

The statistical analyses were based on the least squares means for the treatment-by-week interaction effect using a mixed model for repeated measurement with a restricted maximum likelihood-based approach. The estimated mean treatment difference based on this model was reported with two-sided symmetric 95 % CI and the corresponding p-value.

(ClinicalTrials.gov Identifier: NCT04045431)

Results

Demographic and baseline characteristics were similar between groups (Table 1).

There were clinically relevant decreases in the 3 WOMAC subscale scores from baseline to 52 weeks in both groups (Table 2). Treatment differences in favour of Arthrosamid compared to Synvisc-One were measured in the WOMAC pain, stiffness and physical function subscales, but the differences did not reach statistical significance.

Conclusion

At 52 weeks after treatment, the effectiveness of Arthrosamid was numerically superior to Synvisc‑One but not statistically significantly different, as measured by the WOMAC pain, stiffness and physical function subscales.