Presence of a Posterior Wall Sign in the Treatment of Femoroacetabular Impingement Syndrome: A Matched Comparative Cohort Analysis at Minimum 2-Year Follow-Up

Abstract

BackgroundAcetabular retroversion may predispose to more severe femoroacetabular impingement syndrome (FAIS) and early labral damage given impaction of the femoral head-neck junction on the retroverted acetabular rim. The cross-over sign (COS), posterior wall sign (PWS), and ischial spine sign (ISS) are markers of acetabular retroversion (AR) on plain radiographs. MethodsPatients who underwent primary hip arthroscopy for FAIS from January 2012 to December 2018 with a positive PWS were matched in a 1:1 ratio by age, gender, and body mass index (BMI) to controls with a negative PWS. Preoperative and postoperative patient-reported outcomes (PROs; HOS-ADL, HOS-SS, mHHS, and iHOT-12) were compared using independent t-tests. Achievement of a Patient Acceptable Symptom State (PASS) or Minimal Clinically Important Difference (MCID) was compared using Fisher’s exact test. ResultsTwo hundred and seventy five patients with a positive PWS and 275 controls were included in the final analysis. Most patients (64%) were female, with average age, and BMI of 37.6 (SD 8.6) and 25.1 (SD 4.4), respectively. PROs improved significantly for both groups from preoperatively to 2 years postoperatively. There were no statistically significant differences (P ≥ .05) in PROs or achievement of MCID or PASS. On a subgroup analysis, patients with all three positive signs had significantly lower postoperative PROs and lower rates of achievement of MCID and PASS. ConclusionPatients with an isolated PWS achieve similar outcomes following hip arthroscopy at 2 years. However, patients with a concomitant PWS, ISS, and COS demonstrate less favorable outcomes, suggesting the need for increased perioperative counseling and potential evaluation for planned concurrent or serial open procedures such as periacetabular osteotomy.