A model for easy location of the center of the femoral head during total knee arthroplasty.

Demographic data and radiographs of 115 patients (230 hips) were evaluated to determine factors significantly related to the location of the center of the femoral head, the point critical in determining proper knee alignment during total knee arthroplasty. Separate regression analysis for men and women showed the distance between the anterior iliac spines to be the only clinically significant factor related to the position of the femoral head center (P less than .0001). A model for each sex was then developed, which allowed easy location of the center point from this readily available distance.