UK FASHIoN: feasibility study of a randomised controlled trial of arthroscopic surgery for hip impingement compared with best conservative care.

Background: Femoroacetabular impingement (FAI) is a syndrome of hip or groin pain associated with shape abnormalities of the hip joint. Treatments include arthroscopic surgery and conservative care. This study explored the feasibility of a randomised controlled trial to compare these treatments.

Objectives: The objectives of this study were to estimate the number of patients available for a full randomised controlled trial (RCT); to explore clinician and patient willingness to participate in such a RCT; to develop consensus on eligibility criteria, surgical and best conservative care protocols; to examine possible outcome measures and estimate the sample size for a full RCT; and to develop trial procedures and estimate recruitment and follow-up rates.

Methods: Pre-pilot work: we surveyed all UK NHS hospital trusts (n = 197) to identify all FAI surgeons and to estimate how much arthroscopic FAI surgery they performed. We interviewed a purposive sample of 18 patients, 36 physiotherapists, 18 surgeons and two sports physicians to explore attitudes towards a RCT and used consensus-building methods among them to develop treatment protocols and patient information. Pilot RCT: we performed a pilot RCT in 10 hospital trusts. Patients were randomised to receive either hip arthroscopy or best conservative care and then followed up at 3, 6 and 12 months using patient-reported questionnaires for hip pain and function, activity level, quality of life, and a resource-use questionnaire. Qualitative recruitment intervention: we performed semistructured interviews with all researchers and clinicians involved in the pilot RCT in eight hospital trusts and recorded and analysed diagnostic and recruitment consultations with eligible patients.

Results: We identified 120 surgeons who reported treating at least 1908 patients with FAI by hip arthroscopy in the NHS in the financial year 2011/12. There were 34 hospital trusts that performed ≥ 20 arthroscopic FAI operations in the year. We found that clinicians were positive about a RCT: only half reported equipoise, but most said that they would be prepared to randomise patients. Patients strongly supported a RCT, but expressed concerns about its design; these were used to develop patient information for the pilot RCT. We developed a surgical protocol and showed that this could be used in a RCT. We developed a physiotherapy-led exercise-based package of best conservative care called 'personalised hip therapy' and showed that this was practicable. In the pilot RCT, we recruited 42 out of 60 eligible patients (70%) across nine sites. The mean duration and recruitment rate across all sites were 4.5 months and one patient per site per month, respectively. The lead site recruited for the longest period (9.3 months) and accrued the largest number of patients (2.1 patients per month). We recorded and analysed 84 diagnostic and recruitment consultations in 60 patients and used these to develop a model for an optimal recruitment consultation. We identified the International Hip Outcome Tool at 12 months as an appropriate outcome measure and estimated the sample size for a full trial as 344 participants: a number that could be recruited in 25 centres over 18 months.

Conclusion: We have demonstrated that it is feasible to perform a RCT to establish the clinical effectiveness of hip arthroscopy compared with best conservative care for FAI. We have designed a full trial and developed and tested procedures for it, including an innovative approach to recruitment. We propose that a full trial be implemented.

Funding: The National Institute for Health Research Health Technology Assessment programme.