Patellofemoral pain: One year results of a randomized trial comparing hip exercise, knee exercise or free activity.

OBJECTIVE: Extended follow-up of a randomized trial comparing hip-focused exercise, knee-focused exercise, and free physical activity in patellofemoral pain (PFP). METHODS: A single-blind randomized controlled trial included 112 patients aged 16-40 years (mean 27.6 years) with a clinical diagnosis of PFP >/=3 months (mean 39 months) and pain >/=3/10 on a Visual Analog Scale. Patients were randomized to a 6-week exercise-based intervention consisting of either isolated hip-focused exercises (n = 39), traditional knee-focused exercise (n = 37), or free physical activity (n = 36). All patients received the same patient education. The primary outcome measure was the Anterior Knee Pain Scale (AKPS, 0-100). Secondary outcomes were usual and worst pain, Tampa Scale of Kinesiophobia, Knee Self-Efficacy Score, Euro-Qol (EQ-5D-5L), step-down test, and isometric strength. Blinded observers assessed outcomes at baseline, 3, and 12 months. The study was designed to detect a difference in AKPS >10 at 12 months. RESULTS: After 1 year, there were no significant between-group differences in any primary or secondary outcomes. Between-group differences for AKPS were as follows: knee versus free physical activity -4.3 (95% CI -12.3 to 3.7); hip versus free physical activity -1.1 (95% CI -8.9 to 6.7); and hip versus Knee 3.2 (95% CI -4.6 to 11.0). The cohort as a whole improved significantly at 3 and 12 months compared to baseline for all measures except for knee extension strength. CONCLUSION: After 1 year, there was no difference in effectiveness of knee exercise, hip exercise, or free physical activity, when combined with patient education in PFP.