Hip MRI: Prevalence of articular cartilage defects and labral tears in asymptomatic volunteers. A comparison with a matched population of patients with femoroacetabular impingement

PurposeTo prospectively compare defects of the articular cartilage and labrum in asymptomatic volunteers and in patients with femoroacetabular impingement (FAI) matched for age and gender. Materials and MethodsThis cross-sectional study was institutional review board approved. A total of 63 asymptomatic volunteers and 63 patients with symptomatic FAI between 20 and 50 years underwent 1.5 Tesla MRI (coronal T1-weighted, coronal intermediate-weighted fat saturated, transverse oblique true fast imaging with steady-state precession [FISP], sagittal dual echo steady state [DESS] sequence). Two radiologists independently assessed defects of the cartilage and labrum at six positions. Statistics included Mann-Whitney U-test and Spearman's rho. ResultsA defect of the articular cartilage and/or labrum was present on average in 57% of asymptomatic volunteers, compared with 80% of symptomatic patients (P0.028). A total of 14% of volunteers had acetabular cartilage defects, and 6% had femoral cartilage defects, compared with 47% and 30% in symptomatic patients (P0.001 and P0.003), respectively. Labrum defects were seen in 44% of volunteers versus 61% of patients (P0.12). Both cartilage and labral defects were more commonly encountered in male volunteers than in female volunteers, with the largest difference seen for the acetabular cartilage (P0.02). In all groups, the majority of cartilage and labrum defects were encountered in the anterosuperior, superior, and posterosuperior position. ConclusionA substantial number of asymptomatic volunteers had labral tears, defects of the acetabular cartilage, and to a lesser degree, defects of the femoral cartilage; our data demonstrate that not all cartilage and labral defects of the hip joint are symptomatic and that a similar predilection for location of defects is found in volunteers and FAI patients. Level of Evidence:2 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2017;46:440-451