Background: Obesity is a negative prognostic factor for various surgical procedures. The purpose of this study was to compare patients with obesity who underwent hip arthroscopy for femoroacetabular impingement and labral tears with a match-controlled group of normal-weight patients.
Methods: Data were prospectively collected and retrospectively reviewed for patients who underwent arthroscopy between February 2008 and December 2011. Inclusion criteria were treatment for femoroacetabular impingement and labral tears and completed preoperative patient-reported outcomes and visual analog scale (VAS) for pain. Exclusion criteria were previous ipsilateral hip conditions or preoperative Tönnis grade of ≥2. Patients with obesity (body mass index [BMI] of ≥30 kg/m) were matched and were compared with normal-weight patients (BMI of 18.5 to 24.99 kg/m) using a 1:1 ratio by age at the time of the surgical procedure within 5 years, sex, acetabular Outerbridge grade (0 or 1 compared with 2, 3, or 4), and capsular treatment.
Results: Of the 96 obesity cases with follow-up, 74 were pair-matched to control cases. The mean BMI was 34.3 kg/m for the obesity group and 22.7 kg/m for the control group (p < 0.0001). The mean follow-up time was 71.6 months for the obesity group and 71.3 months for the control group (p = 0.41). All mean preoperative patient-reported outcomes and VAS scores for patients without conversion to total hip arthroplasty were significantly worse in the obesity group: modified Harris hip score (p = 0.0001), Non-Arthritic Hip Score (p = 0.0001), Hip Outcome Score Sports-Specific Scale (HOS-SSS) (p = 0.015), and VAS (p = 0.01). No significant differences were observed with regard to demographic characteristics, intraoperative findings, procedures, follow-up scores, magnitudes of improvement, or secondary arthroscopy rates (p > 0.05). Both groups demonstrated significant improvements in mean outcome scores at ≥5 years (p < 0.0001). In both groups, no significant differences were detected in mean outcome scores between 2 years and ≥5 years (p > 0.05). The conversion rate to total hip arthroplasty was 29.7% for the obesity group and 14.9% for the control group (relative risk, 2.0 [95% confidence interval, 1.1 to 3.8]; p = 0.04).
Conclusions: Hip arthroscopy for the treatment of femoroacetabular impingement and labral tears in patients with obesity yielded significant improvements at ≥5 years; these results were similar to a matched group of normal-weight patients. However, patients with obesity demonstrated a twofold increased risk of conversion to total hip arthroplasty.
Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.