An instrument for setting ligament tension between a distal femur and a proximal tibia has a rod mounted on a femur. The rod has an extension extending along a first axis. A first drive element is mounted on the distal femur and is rotatable about a second axis. A body is rotatably mounted on the rod extension for rotation about the first axis. The body has a second drive element engaging the first drive element and a third drive element extending about a third axis offset from the first and second axes. A ligament tensioning element is mounted on the body and has a foot for engaging a posterior condyle of a femur and has a fourth drive element. A fifth drive element engages both the third and fourth drive elements for moving the ligament balancer with respect to the body along the third axis.
