Level I to IV studies in which labral tear and/or femoro-acetabular impingement was the major diagnosis and in which the labrum and/or femoro-acetabular impingement received an intervention were eligible for inclusion. Studies of patients with concomitant severe pre-existing hip osteoarthritis and severe acetabular dysplasia were excluded.
Patients in the included studies had a mean age ranging from 22 to 41 years. Most studies were level IV design (case series) with a mean follow up ranging from 10 to 60 months. Open surgical procedures included surgical dislocation, osteoplasty, labral debridement and arthroscopic surgical procedures included arthroscopy, labral debridement and/or repair, loose body removal and osteoplasty. A variety of outcome measures were included (such as Merle d'Aubigne outcomes instrument, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Harris Hip Score, return-to-play outcomes and subjective questionnaires).
One reviewer performed the initial search, which was independently checked by several other reviewers.