Watanabe S, Akagi R, Shiko Y, et al. - A retrospective observational study was performed to explore the intra- and inter-observer reliability in the assessment of total knee arthroplasty (TKA) component positioning after surgery using a three-dimensional (3D) computed tomography (CT) image matching system. Researchers enrolled 14 knees from 14 patients who received primary TKA, and images were examined by blinded readers not associated with the surgeries. The data suggested that using 3D-CT image matching, postoperative evaluation of implant position in the coronal and sagittal planes is reliable and has good reproducibility except for the sagittal alignment assessment of the femoral component. According to the findings, the measured implant position according to the traditional mechanical axis and the implant-based axis were slightly but significantly different.