Perruccio AV, et al. - Through a prospective study with data from 477 (279 women, 198 men) total knee arthroplasty (TKA) osteoarthritis patients, the contributors investigated whether sex altered the influence of pre-surgery traits on post-TKA knee pain. Significantly worse pre-surgery knee pain, joint count, depressive symptoms, and worse post-surgery knee pain were observed in women vs men. With regard to post-surgery pain, the effects of cormorbidities were moderated by sex (worse for women) as was presence of low back pain and depressive symptoms (both worse for men). A need to consider sex differences in understanding TKA outcomes which could have important implications for prognostic tool development in TKA was suggested.