Regarding “Operative Versus Nonoperative Treatment of Femoroacetabular Impingement Syndrome: A Meta-analysis of Short-Term Outcomes”

Abstract

We recently read with interest the article titled “Operative Versus Nonoperative Treatment of Femoroacetabular Impingement Syndrome: A Meta-analysis of Short-Term Outcomes.”1Dwyer T. Whelan D. Shah P.S. Ajrawat P. Hoit G. Chahal J. Operative versus nonoperative treatment of femoroacetabular impingement syndrome: A meta-analysis of short-term outcomes.Arthroscopy. 2020; 36: 263-273Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar The authors conducted a meta-analysis of patient-reported outcomes of both treatment strategies and concluded that patients with femoroacetabular impingement (FAI) syndrome treated with hip arthroscopy have superior hip-related outcomes in the short term compared with patients receiving physical therapy. We have some queries about the statistical methods and interpretation of those pooled analysis results. The first concern relates to the heterogeneity of input values used in the meta-analysis. Dwyer et al.1Dwyer T. Whelan D. Shah P.S. Ajrawat P. Hoit G. Chahal J. Operative versus nonoperative treatment of femoroacetabular impingement syndrome: A meta-analysis of short-term outcomes.Arthroscopy. 2020; 36: 263-273Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar not only conducted a pooled study indiscriminately using unadjusted and adjusted mean differences in International Hip Outcome Tool 33 (iHOT-33) scores but also pooled the 6- and 12-month follow-up scores even though all 3 included trials reported 6-month follow-up scores.2Griffin D.R. Dickenson E.J. Wall P.D.H. et al.Hip arthroscopy versus best conservative care for the treatment of femoroacetabular impingement syndrome (UK FASHIoN): A multicentre randomised controlled trial.Lancet. 2018; 391: 2225-2235Abstract Full Text Full Text PDF PubMed Scopus (298) Google Scholar, 3Mansell N.S. Rhon D.I. Meyer J. Slevin J.M. Marchant B.G. Arthroscopic surgery or physical therapy for patients with femoroacetabular impingement syndrome: A randomized controlled trial with 2-year follow-up.Am J Sports Med. 2018; 46: 1306-1314Crossref PubMed Scopus (118) Google Scholar, 4Palmer A.J.R. Ayyar Gupta V. Fernquest S. et al.Arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of symptomatic femoroacetabular impingement: Multicentre randomised controlled trial.BMJ. 2019; 364: l185Crossref PubMed Scopus (149) Google Scholar Also, the authors even used a fixed-effects model in their pooled study and considered an I2 statistic of 41% as low heterogeneity, but usually in medicine, there is consensus that a random-effects model is recommended to avoid overestimation of the study results.5Schmidt F.L. Oh I.S. Hayes T.L. Fixed- versus random-effects models in meta-analysis: Model properties and an empirical comparison of differences in results.Br J Math Stat Psychol. 2009; 62: 97-128Crossref PubMed Scopus (478) Google Scholar The study concluded that hip arthroscopy is associated with superior hip-related outcomes in the short term compared with physical therapy for FAI; however, if the meta-analysis were performed using matched data and appropriate statistical methods, one might generate the opposite findings. Our second concern is about the interpretation of the meta-analysis results. Even though the authors showed a superior International Hip Outcome Tool 33 (iHOT-33) score for the hip arthroscopy group compared with the physical therapy group in their pooled results,1Dwyer T. Whelan D. Shah P.S. Ajrawat P. Hoit G. Chahal J. Operative versus nonoperative treatment of femoroacetabular impingement syndrome: A meta-analysis of short-term outcomes.Arthroscopy. 2020; 36: 263-273Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar is it prudent to generalize this to all hip-related outcomes? As the authors mentioned in the “Discussion” section, the number of included studies was relatively small and the trial designs were variable, so we think it would be more sensible to reserve conclusions about the superiority of one treatment strategy over the other until larger-scale robust trials can be performed. With the ongoing debate about which strategy is better for treating FAI syndrome, we worry that this report could unnecessarily mislead people. We hope that the authors address the points presented because the overall discussion of the presented points will only serve to benefit the research community at large. Download .pdf (5.38 MB) Help with pdf files ICMJE author disclosure forms