A device for positioning a knee joint line for revision total knee arthroplasty. In revision total knee arthroplasty, the position of the joint line of an existing femoral element is measured before the existing femoral element is removed from the femur in revision total knee arthroplasty. A new femoral element is implanted according to the measured position of the joint line. The joint line is formed at the same position as the joint line of the other leg. The position of the surface of the femur to be cut is determined based on the position of the joint line when a loss or the like in the femur must be compensated for by implanting a block between the femur and the femoral element.
