High-concentration nonavian high-molecular weight hyaluronan injections and time-to-total knee replacement surgery.

To examine the time-to-total knee replacement (TKR) surgery among patients with high-concentration nonavian high-molecular-weight hyaluronan injection (HMW-HA) compared with those without HA injections. Using MarketScan Commercial claims all patients aged 18-64 who underwent TKR surgery between 2008 and 2017 were identified. Time-to-TKR surgery was compared between patients receiving Orthovisc (Anika Therapeutics Inc. Bedford MA, USA, referred to as nonavian HMW-HA) injections and patients who did not receive an HA injection. The median time-to-TKR surgery was 893 days in the nonavian HMW-HA cohort and 399 days in the non-HA cohort (p < 0.001), a difference of 494 days (16.2 months). This study demonstrates that the time-to-TKR surgery is 16.2 months longer in patients who received treatment with nonavian HMW-HA injections.