A significant innovation in TKA has been the introduction of computer navigation and robotic-assisted surgery (3). One such technology is the Navio™ Robotic-assisted Surgical System. This system is a semi-autonomous image-free system. During the surgery, the surgeon maps the condylar landmarks and determines alignment indices to define the volume and orientation of bone to be removed. The tools to remove the bone and place the implants are controlled and manipulated by the surgeon with the guidance of a 3-dimensional digital map of the surgical surface.