In recent years, robots have become commonplace in surgical procedures due to their high accuracy and repeatability. The Acrobot Sculptor is an example of such a robot that can assist with unicompartmental knee replacement. In this study, we aim to evaluate the accuracy of the robot (software and hardware) in a clinical setting. We looked at (1) segmentation by comparing the segmented data from Sculptor software to other commercial software, (2) registration by checking the inter- and intraobserver repeatability of selecting set points, and finally (3) sculpting ( cases) by evaluating the achieved implant position and orientation relative to that planned. The results from segmentation and registration were found to be accurate. The highest error was observed in flexion extension orientation of femoral implant ( °). Mean compound rotational and translational errors for both components were ？mm and ° for tibia and ？mm and ° for the femur. The results from all processes used in Acrobot were small. Validation of robot in clinical settings is highly vital to ensure a good outcome for patients. It is therefore recommended to follow the protocol used here on other available similar products. 1. Introduction In recent years, robots have become commonplace in industry due to their high accuracy and repeatability especially during procedures that require movement that is beyond the human control [1, 2]. As imaging and robotic technology has advanced, there is real potential to use these capabilities in the field of surgery, from planning to performing the procedure. This is especially useful in operations such as unicompartmental knee arthroplasty (UKA) where previous studies have shown the substantial effect of implant position inaccuracy [3–5]. The robotic procedures can be fully controlled (active) , can be shared as control or semiactive, where the robot monitors surgeon performance and provides stability and support through active constraint , they can be tele-surgical where the surgeon performs the operation from a console distant to operating table . The input to the robot can vary from the actual imaging data of the patient to statistical shape models (SSM)  or active shape models (ASM) [10, 11] that are based on a few point estimates of the patient’s morphology. The main problem with the latter is that these models are often created based on a normal anatomy dataset, and using them for pathological subjects can be problematic . Audenaert et al. described the estimated accuracy of imageless surgery as poor because of the significant
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