Acetabular labrum in hip dysplasia evaluated by radial magnetic resonance imaging

Objective. To numerically express morphologic conditions and signal intensity in the acetabular labrum of the weight-bearing portion of hip joints in patients with hip dysplasia. Methods. Using a radial magnetic resonance imaging (MRI) technique, where the planes are set radially centered on the midpoint of acetabulum, and which depicts the entire acetabular rim and acetabular labrum, we investigated 60 hip joints of 35 patients with hip dysplasia. Results. The acetabular labrum was larger in dysplastic hips than in normal hips, and the size increased in the posterosuperior portion. All patients had portions with signal intensity changes within the labrum and had impairment on the labrum, When osteoarthrosis due to hip dysplasia was observed, signal intensity changes increased. The changes of intensity varied among the portions observed, and were stronger in the anterosuperior portions than in the superior and posterosuperior portions. Conclusion. Radial MRI numerically depicts morphologic conditions of acetabular labrum; the data were usable To evaluate the size difference in acetabular labrum due to hip dysplasia and the degree of impairment.