The concept of sex-related differences in knee morphology that has led to sex specificity in total knee replacement has generated a great deal of interest in both the popular press and the orthopaedic literature. Some clinicians and implant designers purport that there are sex-based anatomical differences in the size and shape of the female knee. Because of these differences, they add, women need an implant that is "just for them." Sex-specific knees have been touted as "the next level of sophistication."1 There is, however, legitimate skepticism about the scientific evidence supporting this view; thus, the need for these implants is a matter of debate.