Concomitant Lumbar Spinal Stenosis Negatively Affects Outcomes After Hip Arthroscopy for Femoroacetabular Impingement

Abstract

Purpose: The purpose of this study was to assess the prognostic effect of lumbar spinal stenosis on clinical outcomes after hip arthroscopy for femoroacetabular impingement syndrome (FAI).

Methods: Patients undergoing hip arthroscopy between September 2009 and December 2015 for FAI with concomitant lumbar spinal stenosis (central/neuroforaminal) and a 2-year follow-up were identified (hip-spine). A 1:1 case-matching query using preoperative modified Harris Hip Score (mHHS) within 3 points, body mass index (BMI) within 3 points, age within 5 years, and sex identified a control cohort without spinal pathology. Follow-up patient-reported outcomes (PROs) and clinical failure rates to revision procedure were compared using analysis of variance (ANOVA) and Kaplan-Meier survival analysis.

Results: Twenty-six patients met criteria of the hip-spine group (age: 45.9 ± 12.2 years; BMI: 27.3 ± 5.0 kg/m², baseline mHHS: 44.17 ± 2.76) vs the control group (age: 46.2 ± 12.4 years, P = .94; BMI: 26.7 ± 4.1 kg/m², P = .61; baseline mHHS: 44.27 ± 2.82, P = .98). ANOVA analysis demonstrated that all PROs improved from baseline to 2-year outcomes (P < .001). The hip-spine vs control group had lower 1-year (mHHS: 65.97 ± 5.64 vs 85.04 ± 3.09, P = .006; nonarthritic hip score (NAHS): 70.26 ± 5.71 vs 87.89 ± 2.65, P = .010) and 2-year (mHHS: 69.72 ± 4.92 vs 84.71 ± 2.56, P = .007; NAHS: 72.23 ± 5.18 vs 87.14 ± 2.23, P = .008) outcomes. While there was no difference in patient acceptable symptomatic state (PASS) and minimal clinically important difference (MCID) rates at 1-year follow-up, the hip-spine group demonstrated lower PASS (42% vs 81%, P = .004) and MCID (58% vs 88%, P = .027) rates at 2 years. Although susceptible to type II error, there was no difference in clinical failure rates to revision procedure (P = .13).

Conclusions: While net PROs from baseline improve after hip arthroscopy for FAI, the presence of concomitant lumbar spinal stenosis negatively affects postoperative PROs. FAI patients with spinal stenosis should be counseled accordingly.

Level of evidence: Level III, case-control study.