Antiversion of the femoral neck is overcome by what degree of internal rotation of the toes during an AP projection of the pelvis?

In an AP projection of the pelvis, internal rotation of the toes is performed to compensate for the normal anatomical alignment of the femoral neck. Antiversion refers to the angle of the femoral neck relative to the femoral condyles, and typically it is about 15 to 20 degrees of antiversion in a normal adult.

When positioning the patient for the AP pelvis view, the toes are internally rotated to align the femoral neck properly with the image receptor, thereby preventing distortion of the image due to the orientation of the femurs. A rotation of 15 to 20 degrees is generally considered adequate to overcome the typical femoral antiversion. This internal rotation allows the femoral neck to fall into a more appropriate alignment, ensuring accurate imaging of the hip joint and the acetabulum.

Using less internal rotation might not compensate enough for the antiversion, potentially leading to a distorted or misrepresented image, while too much internal rotation could also introduce errors in the evaluation of the pelvic and hip structures. Thus, internal rotation in the range of 15 to 20 degrees provides a balance that supports optimal visualization of the relevant anatomy in the pelvis.