Inconclusive and Contradictory Evidence for Outcomes After Hip Arthroscopy in Patients With Femoroacetabular Impingement and Osteoarthritis of Tonnis Grade 2 or Greater: A Systematic Review

Purpose: To investigate whether hip arthroscopy (HA) is effective in patients with femoroacetabular impingement and concomitant hip osteoarthritis (OA) of Tonnis grade 2 or greater. Methods: This review was registered in the International Prospective Register for Systematic Reviews and Meta-analysis (PROSPERO, CRD42020210936). It followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines and included multiple databases: MEDLINE, Embase, Web of Science Core Collection, and Cochrane Library. All studies in English or German from database inception to December 1, 2020, that investigated outcomes of HA in patients with OA of Tonnis grade 2 or greater were considered eligible. The risk of bias was assessed using the MINORS (Methodological Index for Non-randomized Studies) tool. Data heterogeneity was explored using the I-2 test in a random-effects model. Results: Eleven studies met the eligibility criteria. The MINORS (Methodological Index for Non-randomized Studies) score averaged 68% (range, 46%-81%). A total of 616 hips, consisting of 247 hips of interest (Tonnis grade 2 or greater) and 369 controls, were included. The weighted estimated follow-up averaged 29.1 months (range, 12-84 months). Data on patient-reported outcome measures (PROMS) could be extracted for 6 of 11 studies, and date on conversion to total hip arthroplasty were available for 8 of 11. Four studies reported an overall improvement in PROMS after HA, and 2 highlighted a failure of improvement in PROMS. Failure of HA with conversion to total hip arthroplasty was observed at a rate of 0% to 9% in 4 studies, as opposed to proportions as high as 35% to 70% in the other 4 studies. There was a high level of heterogeneity, with a calculated / 2 value of 89%. Conclusions: There is currently contradictory and insufficient evidence regarding the efficacy of HA for hips with femoroacetabular impingement and concomitant OA of Tonnis grade 2 or greater. This is in the context of data with low levels of evidence, mainly consisting of retrospective case series (Level IV) with a high risk of bias and high heterogeneity (I-2 of approximately 90%).