2015 ISAKOS Biennial Congress Paper #0

Minimum 5-Year Follow-Up Survivorship and Outcomes, In and Risk Factors for Total Hip Arthroplasty Conversion in the Obese Patient Population Following Revision Hip Arthroscopy

Benjamin G. Domb, MD, Chicago, IL UNITED STATES
David R. Maldonado, MD, Houston, TX UNITED STATES
Michael Lee, BA, Milwaukee, Wisconsin UNITED STATES
Cynthia Kyin, BA, Des Plaines, Illinois UNITED STATES
Andrew Jimenez, MD, Chicago, Illinois UNITED STATES
Jade S Owens, BS, Chicago, IL UNITED STATES
Paulo Padilla, MD, Des Plaines, IL UNITED STATES
American Hip Institute Research Foundation, Chicago, IL, UNITED STATES

FDA Status Cleared

Summary: The purpose is to report minimum 5-year follow-up survivorship, patient-reported outcome scores (PROs), clinical benefit, and risk factors for conversion to total hip arthroplasty (THA) in the obese patient population following revision hip arthroscopy.

Abstract:

Background

There is a paucity of literature reporting outcomes following revision hip arthroscopy in the obese patients.

Purpose

To report minimum 5-year follow-up survivorship, patient-reported outcome scores (PROs), clinical benefit, and risk factors for conversion to total hip arthroplasty (THA) in the obese patient population following revision hip arthroscopy.

Study Design: Case-series; Level of evidence, 4.

Methods

Data were prospectively collected and retrospectively reviewed for patients who underwent revision hip arthroscopy between April 2010 and August 2016. Inclusion criteria were having a body mass index = 30, baseline and minimum 5-year scores for the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score–Sports Specific Subscale (HOS-SSS), and Visual Analog Scale (VAS) for pain. Exclusion criteria were a Tönnis grade > 1, hip dysplasia, or were unwilling to participate. Survivorship was defined as non-conversion to THA. Clinical benefit was measured with the minimal clinically important difference (MCID). Survivors and non-survivors underwent further bivariate and regression analysis to determine predictors of conversion to THA.

Results

Twenty-four hips (80%) had minimum 5-year follow-up. The average follow-up was 83.9 ± 26.5 months and the average age was 39.3 ± 12.7 years. Survivorship was 75% and patients demonstrated significant improvement in all PROs (P < 0.01). Patients achieved rates of MCID for the mHHS, NAHS, HOS-SSS, and VAS at 70.6%, 94.1%, 86.7%, and 64.7, respectively. Age, ligamentum teres percentile, and acetabuloplasty were significant in the bivariate analysis for THA conversion. Age was identified as a significant variable for THA conversion in the regression analysis (P = 0.018, Odds Ratio: 1.297, 95% Confidence Interval [1.045 – 1.609]).

Conclusion

In this single surgeon case series study, obese patients who underwent revision hip arthroscopy reported a survivorship of 75% with significant improvement in all PROs and achieved MCID rates for the mHHS, NAHS, HOS-SSS, and VAS at 70.6%, 94.1%, 86.7%, and 64.7, respectively, at a minimum 5-year follow-up. Age was identified as a significant predictor in the regression and every additional year before surgery was identified as a 29.7% greater risk of conversion to THA.