The intra-operative evaluation of soft tissue balance in knee arthroplasty is executed with trial components of article knee joint. It is needed for excellent long-term result after knee arthroplasty to confirm the proper soft tissue balance. So to assist surgeon, we proposed the robotic instrument for intra-operative evaluation. This paper reports the in vitro experiment with the robotic instrument that consists of tensing robot and 6DOF measurement of the knee joint. We could adjust the soft tissue balance quantitatively by cutting distal femur seeing the robotic data.
