Effectiveness of a structured physical therapist-led intervention compared to usual care in people with longstanding hip and groin pain referred to orthopaedic care in Sweden: protocol for a randomised controlled trial (the HIPSTER trial)

INTRODUCTION: People with longstanding hip and groin pain (LHGP) are often referred to orthopaedic care. Physical therapist-led interventions are recommended in consensus statements as the first line of treatment, but it is unknown if structured interventions are more effective than usual care. The aim of this trial is to evaluate the effectiveness of a structured physical therapist-led treatment model (HIPSTER) compared with usual care on hip-related quality of life at 4 months for people with LHGP referred to orthopaedic care. METHODS AND ANALYSIS: This is a preregistered (clinicaltrials.gov, NCT05853640) study protocol for a double-blinded two-armed pragmatic randomised controlled trial. Patients with LHGP (n=122), referred to the Department of Orthopaedics at a university hospital in Sweden, will be randomised into the HIPSTER model or usual care. The HIPSTER model is a 16-week structured, individualised progressive treatment using exercise therapy and patient education. Usual care consists of a recommendation to contact a physical therapist in primary care. Both groups will undergo standard examinations and a surgical consultation at the Department of Orthopaedics. The primary outcome will be the mean group change in the International Hip Outcome Tool from baseline to 4 months, according to intention-to-treat principles. Secondary outcomes include patient-reported outcomes (such as perceived improvement, psychological factors and physical activity), physical impairment tests and radiographic measures. Additional time points will be 1, 2 and 5 years after baseline. Subgroups of patients will complete semistructured interviews and report additional data on psychosocial variables to provide more information on patient experience as well as determinants of adherence. ETHICS AND DISSEMINATION: The Swedish Ethical Review Authority approved this study (Dnr 202205023-01). The results of this study will be published, regardless of results, in scientific journals and as plain language summaries for participants. TRIAL REGISTRATION NUMBER: NCT05853640.