Fitbit Analysis Shows Enhanced Mobility Of Knee Osteoarthritis Patients Treated With Triamcinolone Acetonide Extended Release

Abstract

PURPOSE: In knee osteoarthritis (OAK), walking >6000 steps/day can prevent functional limitation (White DK. Arthritis Care Res. 2014;66:1328). Intra-articular triamcinolone acetonide extended-release (TA-ER) is approved for OAK pain. This Phase 3b study assessed safety and an exploratory endpoint of mobility (steps/day) in patients treated with TA-ER. METHODS: OAK patients aged ≥40 years, symptomatic ≥6 months, with Western Ontario and McMaster Universities Osteoarthritis Index pain (WOMAC-A) score ≥6, and index-knee pain >15 days during the past month received TA-ER on Day 1. Movements were analyzed with a Fitbit® device (≥7 days prior to Day 1 to end of Week 12). RESULTS: A total of 208 patients were treated with TA-ER; 67.8% had moderate-severe OAK, mean age of 60.8 years, and mean body mass index (BMI) of 31.4 kg/m2. Baseline mean WOMAC pain score was 2.17. Mobility improved as seen by increases in weekly mean steps/day. 73 of 203 patients (36%) with sufficient step data at baseline had <6000 steps. Of these, 42 (57.5%) had ≥1 post-baseline week with average daily steps >6000; 19 (26.0%) had ≥50% of their follow-up with >6000 steps. Patients treated with TA-ER had mean changes from baseline in WOMAC pain scores of −1.4, −1.2, and −0.8 at Weeks 4, 8, and 12, respectively. A significantly greater change in steps from baseline was associated with decreases in WOMAC pain scores, male sex, lower BMI, lower baseline GPAQ average MET, and lower baseline steps/day. For every 1-unit decrease (from baseline) in mean WOMAC pain, mean steps/day increased by 339 (Figure 1). CONCLUSIONS: OAK patients given TA-ER had increased mobility (≥6000 steps/day) as measured by fitness monitor which was associated with a decrease in pain. Limitations were incomplete adherence to monitor usage and a no comparator open-label design. Fitness monitors are a feasible tool to measure patient mobility and understand pain and function.