Sex-Based Differences in Outcomes,Clinical Benefit,and Survivorship in Patients With Borderline Hip Dysplasia Undergoing Hip Arthroscopy at a Minimum 5-Year Follow-up: A Propensity-Matched Comparison Study

Abstract

Background:

Data on midterm outcomes in patients with borderline hip dysplasia (BHD) based on sex differences after hip arthroscopy are scarce.

Purpose:

To report sex-based differences in patient-reported outcome measures (PROMs), clinical benefit, and survivorship in patients with BHD who underwent hip arthroscopy at a minimum 5-year follow-up.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data were retrospectively reviewed for all patients with BHD who underwent primary hip arthroscopy with a lateral center-edge angle (LCEA) between 18° and 25° from 2008 to 2018. The exclusion criteria were as follows: LCEA <18º or >25º, previous ipsilateral hip surgery or conditions, and Tönnis grade >1. The modified Harris Hip Score (mHHS), Non-arthritic Hip Score (NAHS), and visual analog scale (VAS) for pain and patient satisfaction were reported. Clinical benefit was assessed via minimal clinically important difference (MCID), the patient acceptable symptomatic state (PASS), and the maximum outcome improvement (MOI). Survivorship was defined as nonconversion to total hip arthroplasty. A sex-based propensity-matched comparison was made in a 1-to-1 ratio based on age, body mass index (BMI), and Tönnis grade.

Results:

Propensity-score matching created a cohort of 152 hips, 76 per group. Significant and comparable improvements in all PROMs were observed at a minimum 5-year follow-up, with high achievement rates for the MCID, PASS, and MOI in both groups. However, improvements were significantly higher for women for MCID for the mHHS (86.8% vs 69.7%; P = .0105), MCID for the NAHS (88.2% vs 61.8%; P = .0002), MCID for the VAS for pain (84.2% vs 64.5%; P = .005), PASS for the mHHS (90.8% vs 78.9%; P = .041), and MOI for the NAHS (77.6% vs 55.3%; P = .0057). Survivorship was similar for men (94.74%) and women (89.47%) (P = .229).

Conclusion:

At a minimum 5-year follow-up, a propensity-matched comparison of female and male patients with BHD who underwent primary hip arthroscopy demonstrated significant improvement and comparable PROMs and survivorship. Clinical benefit was significantly higher in women, as evidenced by higher achievement rates on the MCID, PASS, and MOI.