Technique and first clinical results of robot-assisted total knee replacement.

Total knee replacement (TKR) is a common procedure for treatment of severe gonarthrosis, but the outcome may be unsatisfactory due to primary malalignment of the prosthetic components. In order to improve precision and accuracy of this surgical procedure, a commercial robotic surgical system (CASPAR) has been adapted to assist the surgeon in the preoperative planning and intraoperative execution of TKR. So far, 70 patients with idiopathic gonarthrosis were successfully treated with a robot-assisted technique in our institution. No major adverse events related to the use of the robotic system have been observed. The mean difference between preoperatively planned and postoperatively achieved tibiofemoral alignment was 0.8 degrees (0-4.1 degrees ) in the robotic group vs. 2.6 degrees (0-7 degrees ) in a manually operated historical control group of 50 patients. A clear advantage of robot-assisted TKR seems to be the ability to execute a highly precise preoperative plan based on computed tomography (CT) scans. Due to better alignment of the prosthetic components and improved bone-implant fit, implant loosening is anticipated to be diminished which may be most evident in non-cemented prostheses. Current disadvantages such as the need for placement of fiducial markers, increased operating times and higher overall costs have to be resolved in the future.