A fixation device for a knee replacement. The fixation device includes a stem configured to be fixedly attached to one of a tibial component of the knee replacement and a femoral component of the knee replacement. The stem has a continuously tapered outer surface and has a distal end that is distal to said one of the tibial component and the femoral component. A tapered projection is positioned on the continuously tapered outer surface and is tapered in the same direction as the continuously tapered outer surface. The stem and the tapered projection are configured so that the continuously tapered outer surface and the tapered projection engage a patient's bone when the stem is inserted into a bone canal within the patient's bone. In addition, the continuously tapered outer surface of the stem at the distal end of the stem and the tapered projection are configured to mechanically fix the knee replacement to the patient's bone by being wedged within the bone canal.