Figure 6.

The reamer in the acetabulum is shown in the lower left-hand quadrant. The position of the reamer relative to the acetabular peripheral bone and medial wall is shown in the upper two quadrants. The CC is center of rotation (positive number means superior displacement); ML is mediolateral displacement from the center of rotation by the reaming (negative number means medial displacement); AP is the anterior-posterior position of the reamer (negative number means posterior displacement). The numbers on the left give the angular position of the reamer in the acetabulum both by inclination and anteversion, which is also adjusted.