Hip Arthroscopy Femoroplasty Resection Characteristics as They Relate to Postoperative Clinical Outcomes: A Retrospective Cohort Study.

Abstract

Adequate cam resection during hip arthroscopy for femoroacetabular impingement syndrome (FAIS) is necessary to restore femoral head-neck offset while avoiding under- or over-resection. The relationship between the extent of femoroplasty and postoperative patient-reported outcomes remains unclear. We sought to answer the following questions: What is the association between the extent of cam femoroplasty resection and postoperative improvements? and is a 5% resection threshold associated with improved outcomes? We conducted a retrospective review of patients with adequate acetabular coverage who underwent primary hip arthroscopy with femoroplasty between January 2015 and December 2022 at our institution and had preoperative and 1- and/or 2-year postoperative modified Harris hip score (mHHS) and/or International Hip Outcome Tool (iHOT) scores. We included 400 patients (409 hips; ages 14-50 years). Outcomes included score changes and achievement of minimum clinically important difference (MCID) and substantial clinical benefit (SCB). Postoperative Dunn lateral radiographs quantified femoroplasty by resection depth percentage (resection depth/femoral head diameter), proximal resection angle, and postoperative α angle. Hips were classified as under-resection, neutral (0%-5%), or over-resection (>5%), and differences in outcomes were compared between resection groups. Multivariable regression analyses controlled for demographic, radiographic, and surgical variables. Mean resection depth was 4.8%; mean proximal resection angle was 72.6°. No differences were observed in score improvements or MCID/SCB rates between groups with under-resection versus over-resection at 1 or 2 years. Greater resection depth was associated with larger 1-year mHHS and iHOT improvements and independently predicted 1-year iHOT MCID and SCB. Higher proximal resection angle predicted 2-year iHOT MCID. In this retrospective, single-institution cohort study, we found that in patients with FAIS, greater femoroplasty depth was associated with improved 1-year clinical outcomes. Level III, retrospective cohort study.