Thirty-six UKAs were carried out on identical knee models, 12 with the Sculptor, 12 with PSI and 12 conventionally under timed conditions. Implant placement in these knees was then judged against that in a pre-operative plan.
Tibial implant orientations and femoral implant positions and orientations were significantly more accurate in the PSI group with mean errors of 6掳, 2 mm and 4掳 respectively, than the conventional group which had means of 9掳, 4 mm and 10掳. There was no significant difference between the robot and PSI generally except in tibial implant orientation (mean robotic error 3掳) and tibial implant position did not vary significantly across all three groups. It was also found that use of PSI and conventional methods took half the time taken by the robot (p < 0.001).
With further development, PSI can match and possibly surpass the accuracy of the robot, as it does with the conventional method, and achieve planned surgery in less time.
This work sets the foundation for clinical trials involving PSI.