The aim of this study was to investigate the relationship between abnormal acetabular labrum depicted by radial magnetic resonance and progressive joint space narrowing (JSN) of hip dysplasia.
Subjects were 23 joints [21 patients; mean age: 35.1 years (16-53 years)] that had acetabular dysplasia with lateral center-edge angle of Wiberg (CE angle) greater than 5 degrees and smaller than 25 degrees (mean, 16.4 degrees ), which did not show any arthrotic changes on plain radiograms and were followed up for 3 years or longer. Radial images of acetabular labrum were classified into three stages.
Progression of JSN was not significantly related to CE angle but to progression of MRI stage (P=.006). In multivariate analysis, one rank progression of MRI stage was significantly associated with progression of JSN (adjusted OR=11.41, 95% CI: 1.51-86.24, P=.018).
Our findings showed that in patients whose acetabular dysplasia has 5-25 degrees CE angle, MRI staging based on radial MRI is a better factor for prediction of progression of JSN than CE angle.