OBJECTIVES: Patients with knee osteoarthritis (OA) may experience severe pain, aching, and functional loss with an end stage treatment of total-knee-replacement (TKR). Treatment with hyaluronic acid (HA) injections has been shown to alleviate pain, improve physical function, and delay disease progression. The objective of this study was to examine the time-to-TKR of patients who were injected with a high-concentration non-avian high molecular-weight hyaluronan (HMW-HA) prior to TKR compared with those who did not receive HMW-HA injections.

METHODS: A retrospective analysis of the Truven Marketscan Commercial Claims & Encounters database was performed. All patients aged between 18 and 64 years who had a TKR surgery between January 1, 2008 and June 30, 2016 were identified. There were two cohorts (1) patients receiving ORTHOVISC® high molecular weight hyaluronan, a HMW-HA, injections and (2) patients who did not receive any formulation of HA (non-HA cohort). Time-to-TKR was defined as the total days from the date of diagnosis of knee OA on the patient’s first visit to an orthopedic surgeon to the date of TKR surgery.

RESULTS: A total of 94,692 patients who received TKR surgery were included in the analysis. Majority of patients were female (58%) and in the 55-64 age group (70%). The number of patients in the HMW-HA cohort and non-HA cohort were 4,376 and 90,316, respectively. The median time-to-TKR surgery was 469 days in the HMW-HA cohort and 128 days in the non-HA cohort (p<0.001), a difference of 341 days (or about 11.4 months).

CONCLUSIONS: This retrospective analysis of an administrative database in the United States demonstrates that the time from the initial diagnosis of knee OA by an orthopedic surgeon to TKR surgery is 11.4 months longer in patients who received treatment with a set of HMW-HA injections in comparison to patients who did not receive any HA injections.