Establish Implant Accuracy With X-PSI Knee System

The goal of this study is to establish the accuracy of the new X-PSI Knee System guides by analyzing early postoperative (4-6 weeks) imaging data with regards to the mechanical alignment and compare them with preoperative planning imaging data. Mechanical alignment in the hip-knee-ankle (HKA) frontal plane with X-PSI Knee System will be measured and compared with results reported in the literature using a conventional (non-guided) approach. Hypothesis: The use of the new X-PSI Knee System achieves the same accuracy with respect to mechanical alignment as with conventional instrumentation.