RT Journal
A1 Kim, Young-Hoo
A1 Choi, Yoowang
A1 Kim, Jun-Shik
T1 Comparison of a Standard and a Gender-Specific Posterior Cruciate-Substituting High-Flexion Knee Prosthesis. A Prospective, Randomized, Short-Term Outcome Study
JF The Journal of Bone & Joint Surgery
JO The Journal of Bone & Joint Surgery
YR 2011
FD February 16
VO 93
IS 4
SP e12 5
OP 5
DO 
UL http://dx.doi.org/
AB 
We thank Dr. Scuderi and colleagues for their interest in our article. In response to their question concerning how we determined the appropriate size of the femoral component and how many components were upsized, downsized, or a perfect fit, we clearly described in the article our method for determining the appropriate size. After the cut of the distal end of the femur, the size of the femoral component was determined with a sizer. At the end of the implantation of the selected standard or gender-specific femoral component, the aspect ratios of the distal end of the femur (the transepicondylar width divided by the average anteroposterior dimension of the lateral and medial condyles) and of the standard or gender-specific femoral component (the distance from the medial to the lateral margin at the transepicondylar line divided by the average anteroposterior dimension of the lateral and medial condyles of the component) were compared. We defined the component fit as a close fit (perfect fit) when the aspect ratios of the distal end of the femur and the femoral component were equal. We defined the component fit as overhang (upsized) when the aspect ratio of the distal end of the femur was smaller than that of the femoral component. We defined the fit as underhang (downsized) if the aspect ratio of the distal end of the femur was larger than that of the femoral component. As mentioned in Table IV, fifty-one (60%) of eighty-five standard knee implants and fourteen (16%) of eighty-five gender-specific knee implants were close fit (perfect fit). Ten standard knee implants (12%) and no gender-specific knee implant (0%) had an overhang (upsized). Twenty-four standard knee implants (28%) and seventy-one gender-specific knee implants (84%) had an underhang (downsized).