Robotic clinical trials of uni-condylar arthroplasty

A randomised clinical trial has been completed for uni-condylar arthroplasty. The trial, under the auspices of the UK MHRA, comprised 15 knees of patients undergoing conventional surgery, and 13 knees of patients who had robotic surgery using the Acrobot hands-on robotic system. The results of the trial were checked by comparing post-op CT scans with pre-op CT-based plans, and show a significant improvement in accuracy using the robot. The technical concept of the Acrobot approach is also described. Details of the complete system are outlined, including the pre-operative planner. The plan incorporates 3D CT models of the leg, together with CAD models of prostheses that can be used to plan the leg alignment, position the prostheses, plan the shape of the cuts required and generate the regions within which cuts must be constrained. The robotic system is also described, together with the methods for locating, clamping, cutting and monitoring the patient. An outline is given of the means by which the preoperative model is registered or aligned to the intra-operative position of the patient and of the robot, without the need for fiducial markers. Results of the randomised clinical trial are also discussed.