Morphology of the distal femur is characterized in patients with osteo
arthritis to identify an etiology for the high incidence of patellar t
ilt, subluxation, and failure noted in total knee arthroplasty. This s
tudy demonstrates that the sulcus of the trochlear groove is not locat
ed in the midline as traditionally represented, but is lateral to the
midline in both osteoarthritic and normal knees. The significance of t
his is that the patella will presumably track lateral to the midline u
nless surgically realigned, contributing to the prevalence of patellar
tracking problems associated with symmetric femoral components with c
entralized sulci used in contemporary total knee arthroplasty.