Posteriorly Offset Femoral Component to Restore Anteroposterior Position of the Distal Femur in Revision Total Knee Arthroplasty

This study is based on a radiographic analysis of 50 cadaveric femurs (26 males, 24 females). The position of a press-fit stemmed revision total knee arthroplasty femoral component was simulated with templates. A diaphyseal engaging stem was templated in 74% of the subjects (23 males, 14 females). Every diaphyseal engaging stem required the use of a posterior offset coupler to achieve engagement in the femoral isthmus. In 26% of femurs (3 males, 10 females), anterior bowing of the distal metaphysis prevented the use of a diaphyseal engaging stem. Our results suggest that males have less flexion of the distal femur than females and can be templated effectively with a diaphyseal engaging posteriorly offset stem, whereas a metaphyseal flexed stemmed component templates better in females.