Supervised Exercise versus Usual Care for Patellofemoral Pain Syndrome

Abstract

To compare the effectiveness of supervised exercise therapy with usual care on self-reported recovery, pain, and function in persons with patellofemoral pain syndrome. Randomized, controlled, unblinded, multicenter trial of 3 month's duration. Sample size was calculated with 80% power to show a minimum clinically important difference of 22% in recovery after 1 year, at P <or= 0.05. Patients were stratified for type of physician and age (14-17y or >or=18y). Sport and general medicine practices in the Netherlands. Inclusion criteria were: age, 14 to 40 years; presence of symptoms for between 2 months and 2 years; >or=3 of: pain when ascending or descending stairs, squatting, running, cycling, or sitting with flexed knees; grinding of the patella; and a positive clinical patellar test. Exclusion criteria were knee osteoarthritis, patellar tendinopathy, or other pathological conditions of the knee, previous knee injuries or surgery or treatment with supervised exercise. Patients were recruited by general practitioners or sport physicians (n randomized = 131; mean age, 24y; 70% 18y or older; 64% women; bilateral knee symptoms, 60%; participation in sport, 76%). The standardized 25-minute exercise protocol was tailored to individual achievement and supervised by a physical therapist. It comprised warm-up, followed by static and dynamic exercises for the quadriceps, adductor, and gluteal muscles, and included balance and thigh-muscle flexibility components. The load was increased progressively by increasing repetitions or intensity of the exercises. Patients attended 9 sessions, and were asked to practice the exercises daily for 3 months. The intervention and control patients received a pamphlet from their physicians about patellofemoral pain syndrome, advice to refrain from sports activities that provoked pain, and instructions for daily isometric quadriceps contractions. Analgesics were recommended for severe pain. Additional interventions, other than referrals to a physical therapist, were permitted. Patients reported the primary outcomes at 3 and 12 months on questionnaires. End points included perceived recovery since baseline (7-point scale from "completely recovered" to "worse than ever"), functional disability measured on the Kujala Patellofemoral Scale (0 = complete disability to 100 = fully functional) and pain severity at rest and on activity (0 = no pain to 10 = unbearable pain). Recovery was defined as "fully recovered" or "strongly recovered". Approximately 90% of patients were followed for 12 months. After 3 months, in intention-to-treat analysis, the groups did not differ in proportions recovered; however, when the category "slightly recovered" was included, a greater proportion of the exercise group had improved (81% vs 53%; adjusted odds ratio, 4.07; 95% confidence interval [CI], 1.86 to 8.90). After 12 months, recovery did not differ for the intervention and control groups. Pain scores decreased progressively for both groups, but more for the exercise group than the control group (adjusted difference [AD] at 3 mo for pain at rest, -1.07; 95% CI, -1.92 to -0.22 and at 12 mo, -1.29; 95% CI, -2.16 to -0.42; and at 3 mo for pain on activity, -1.00; 95% CI, -1.91 to -0.08 and at 12 mo, -1.19; 95% CI, -2.22 to -0.16). Function scores also improved for both groups. At 3 months the increase in function score was greater for the exercise group (AD, 4.92; 95% CI, 0.14 to 9.72) but by 12 months the difference was no longer significant. Supervised exercise therapy improved patients' pain at rest and during activity, and self-reported function improved faster than with no supervised intervention. The patients' perception of recovery from patellofemoral pain syndrome was not greater among the supervised exercise group.