Fig. 4.

This is an illustration of JIC type. Type A lesions occupy the medial one-third or less of the weightbearing portion, Type B lesions occupy the medial two-thirds or less, Type C1 and Type C2 lesions both occupy more than the medial two-thirds; however, whereas Type C2 lesions extend laterally to the acetabular edge and Type C1 lesions do not. The weightbearing portion (blue dotted lines) is defined as the area lateral to the midvertical line of the line through the acetabular edge and teardrop bottom (yellow dotted lines).