Subchondral Insufficiency Fracture of the Femoral Head Caused by Excessive Lateralization of the Acetabular Rim

Figure 2

Partial collapse of the femoral head and serial MRI images. (a) Coronal computed tomography (CT) image after 4 weeks of therapy shows subchondral collapse (white dotted arrow) at the antipodes of the lateralized rim (white arrow). (b) A subchondral insufficiency fracture (SIF) is evident at the posterolateral aspect of the femoral head in the oblique three-dimensional CT view. STIR images show that the high intensity lesion (c) is smaller after 10 weeks of therapy and (d) has almost disappeared after 4 months of therapy.