ePoster #723 - ISHA Annual Scientific Meeting 2016

Predictors of Failure Following Primary Hip Arthroscopy for Femoroacetabular Impingement: A Matched Cohort Analysis

Alexander Weber, MD, Chicago, IL UNITED STATES
Benjamin Kuhns, MD, Chicago, IL UNITED STATES
Gregory Cvetanovich
Jennifer Alter, BS, Chicago, IL UNITED STATES
Richard C. Mather, MD, MBA, Durham, NC UNITED STATES
Joshua David Harris, MD, Houston, TX UNITED STATES
Shane J. Nho, MD, MS, Chicago, IL UNITED STATES
Gift C. Ukwuani, MD, Chicago, IL UNITED STATES

Rush University Medical Center, Chicago, Illinois, UNITED STATES

FDA Status Not Applicable

Summary: We present data identifying patient-related and FAI-related factors that necessitated a revision hip arthroscopy or conversion to total hip arthroplasty.

Abstract:
Introduction: Despite the ability of hip arthroscopy to relieve pain and improve function following treatment of femoroacetabular impingement (FAI), clinical failures still occur. Identification of risk factors for failure will aid in refining surgical indications and ultimately improve patient outcomes. The purpose of this study was to identify patient-related and FAI-related factors that necessitated a revision hip arthroscopy or conversion to total hip arthroplasty (THA). Methods: Clinical data was prospectively collected in an institutional hip repository on all patients undergoing hip arthroscopy for FAI between 1/1/2012-1/1/2014. The repository was queried for patients undergoing primary hip arthroscopy for a diagnosis of FAI with a minimum two-year follow-up that resulted in revision arthroscopy or conversion to THA. Revision hip arthroscopy or conversion THA patients were matched in a 1:3 fashion to patients not requiring an additional operation. The cohorts were matched based on gender, age, and body mass index (BMI). Demographic, preoperative, and postoperative clinical data including patient reported outcomes (PROs) (Hip Outcome Score Activities of Daily Living (HOS-ADL), Hip Outcome Score Sports Subscale (HOS-SS) and modified Harris Hip Score (MHHS)) were compared between these groups to identify predictors for revision arthroscopy and conversion to THA. Results: The repository contained 400 patients treated with primary hip arthroscopy for a diagnosis of FAI with greater than two-year follow-up. Twelve of the 400 were deemed failures. Five patients (1.3%) required a revision hip arthroscopy at an average 1.2 ± 0.2 years and 7 patients (1.8%) required a conversion to THA at an average of 1.56 ± 0.65 years. Of the revision arthroscopies, two were due to instability, two were due to residual FAI, and one was an arthroscopic excision of heterotopic ossification. All 7 patients requiring conversion to THA did so for degenerative arthritis. In the 1:3 matched analysis of revision surgery versus non-revisions there were no differences in FAI-related factors, such as preoperative or postoperative alpha angle or lateral center edge angle, Tonnis grade or joint space width. Additionally, there were no differences in patient-related factors such as preoperative or postoperative PROs, nor the magnitude of change. In the 1:3 matched analysis of conversion to THA versus non-conversions, conversions to THA had significantly less preoperative joint space width (3.41 ± 0.76 mm vs. 4.41 ± 0.74 mm, p=0.001) as well as a greater percentage of patients with preoperative Tönnis grade 1 or higher changes (71% vs. 16%, p=0.01). There were no differences in preoperative or postoperative alpha angle or lateral center edge angle, or rates of labral repair or capsular closure between the THA cohort and control group. Conclusion: There is a cohort of patients that fails primary hip arthroscopy for FAI and requires arthroscopic revision or conversion to THA. A thorough evaluation of patient-related and FAI-related factors may fail to completely identify patients at risk for revision surgery. In contrast, decreased joint space and Tönnis grades greater than one are risk factors for early conversion to THA. This information should aid in guiding preoperative decisions and postoperative expectations.