Femoroacetabular Impingement RandomiSed Controlled Trial

Femoroacetabular impingement (FAI) is a condition of the hip where there is a mismatch of the ball and socket in the hip joint. This mismatch creates abnormal contact in the hip which can cause patients to experience hip pain. This can eventually lead to hip damage and osteoarthritis. Hip arthroscopy, a form of minimally invasive surgery has become a popular treatment option. The investigators are conducting a definitive randomized controlled trial (RCT) to determine whether surgical correction of the impingement morphology via arthroscopic osteochondroplasty (shaving of bone) will provide improved clinical results (decreased pain and improved function) in adult FAI patients compared to arthroscopic lavage (washing out of painful inflammation debris) and treating obvious damage of the hip joint.

Like most RCTs, FIRST is designed to demonstrate efficacy (i.e. that an intervention can work theoretically under optimal conditions). In order to address generalizability and improve external validity of the FIRST trial, we are including an external validation cohort using a "RCT with and Embedded ProspectIve Cohort design" (FIRST-EPIC). This pragmatic cohort will allow us to: 1) safeguard against bias attributable to patients declining to take part in the RCT; 2) corroborate or refute whether our efficacy (RCT) population represents the best case scenario (i.e. those with optimal response to osteochondroplasty); 3) evaluate effectiveness of osteochondroplasty and other standard of care treatments for FAI in patients with potentially distinct prognostic factors; and 4) evaluate the cost-effectiveness of the interventions.

Inclusion criteria

• Adult men or women ages 18 to 50 years
• Hip pain for greater than 6 months with no relief from non-operative means (physiotherapy, non-steroidal anti-inflammatory medication, rest)
• Documentation of failed physiotherapy, including core conditioning of the hip, back, and abdomen
• CAM or Mixed Type FAI as diagnosed on x-rays and magnetic resonance imaging (MRI) or magnetic resonance arthrogram (MRA)
• Temporary relief from an intra-articular hip injection
• Informed consent from participant
• Ability to speak, understand and read in the language of the clinical site

Exclusion criteria

• Previous inclusion in a study involving FAI
• Evidence of hip dysplasia (centre edge angle less than 20)
• Presence of advanced hip osteoarthritis (Tonnis Grade 2 or 3)
• Presence of other hip syndromes (concurrent non-FAI related pathology)
• Previous trauma to the affected hip
• Previous surgery on the affected hip or contralateral hip
• Severe acetabular deformities (e.g. acetabular protrusion, coxa profunda, circumferential labral ossification)
• Immunosuppressive medication use
• Chronic pain syndromes
• Significant medical co-morbidities (requiring daily assistance for ADLs)
• History of paediatric hip disease (Legg-Calve-Perthes; slipped capital femoral epiphysis)
• Ongoing litigation or compensation claims secondary to hip problems
• Any other reasons given to exclude the patient

• If a patient does not meet the eligibility criteria for the FIRST trial, they may be considered eligible for the FIRST-EPIC sub-study.