Version of normal and osteoarthritic knees is evaluated by computed to
mography in this study. Version of the knee is defined as the static r
otation of the tibia with respect to the femur in full knee extension.
It is measured as the difference between the transverse axes of the f
emoral condyles and tibia. The average knee version, or external rotat
ion of the tibia with respect to the femur across the normal knee, was
0 degrees. Version of the osteoarthritic knee was 5 degrees. Rotation
of the tibia with respect to the femur across the extended osteoarthr
itic knee is a relationship that will affect the placement of componen
ts in total knee arthroplasty. This relationship should be addressed i
n alignment instrumentation and technique to avoid component malalignm
ent in total knee arthroplasty.