Experiences with robotic systems for knee surgery

Abstract

Robots have the potential to assist in orthopædic surgery and improve the outcome of prosthetic implants. Robots have high positional accuracy, and so can achieve the geometrical precision necessary for implanting prostheses into the tibia and femur but poor tactile response, so are not good at assessing the forces required to apply to a cutter while resecting bone; while surgeons have a good tactile sense, and are able to sense changes in bone density, and adjust cutting forces to match. A system is described here that exploits the synergy between robot and surgeon. A force controlled pobot is used, guided from the end-effector by the surgeon. The robot exploits a software based motion constraint system to ensure that the surgeon cannot move a cutting device connected to the robot outside of a safe region, or resect more bone than is required. Thus, the surgeon retains his tactile sense of the bone, while the precision of the robot allows the bones to be cut accurately. Preliminary results are presented in this paper. More complete details of the robot and system performance will be presented at the symposium.