Efficacy of conservative treatment regimes for hip osteoarthritis - Evaluation of the therapeutic exercise regime "Hip School": A protocol for a randomised, controlled trial

217 participants with hip OA, confirmed using the clinical score of the American College of Rheumatology, are recruited from the community and randomly allocated to one of the following groups: (1) exercise regime "Hip School", n = 70; (2) Non-intervention control group, n = 70; (3) "Sham" ultrasound group, n = 70; (4) Ultrasound group, n = 7. The exercise regime combines group exercises (1/week, 60-90') and home-based exercises (2/week, 30-40'). Sham ultrasound and ultrasound are given once a week, 15'. Measures are taken directly prior to (M1) and after (M2) the 12-week intervention period. Two follow-ups are conducted by phone 16 and 40 weeks after the intervention period. The primary outcome measure is the change in the subscale bodily pain of the SF36 from M1 to M2. Secondary outcomes comprise the WOMAC score, SF36, isometric strength of hip muscles, spatial-temporal and discrete measures derived from clinical gait analysis, and the length of the centre of force path in different standing tasks. An intension-to-treat analysis will be performed using multivariate statistics (group × time).Results from this trial will contribute to the evidence regarding the effect of a hip-specific exercise regime on physical function, pain, and health-related quality of life in patients with hip osteoarthritis.German Clinical Trial Register DRKS00000651.Osteoarthritis (OA) is a disease with a major impact on both the national economy and the patients themselves. In Germany, approximately five million people suffer from osteoarthritis [1]. It is the most prevalent musculoskeletal disease and its impact on morbidity and mortality in industrialized countries is almost as large as the impact of respiratory or digestive disorders [2]. The knee and hip joints are the most commonly affected joints of this disease [1,3]. Data from a large cohort-study reveal hip symptoms in 36% of an American population aged 45 and older. 28% of this population had radiographic, and 10% had symptomatic