Three-dimensional analysis of CT-based navigation system for total knee arthroplasty

摘要

Introduction: Optimal postoperative alignment of the lower extremity alignment is fundamental to achieving long-term survival of total knee arthroplasty (TKA). Some studies have evaluated the postoperative alignment and reported improved accuracy of implantation of the prosthesis with CT-based navigation system for TKA. We developed a new three-dimensional analysis system with postoperative CT data and evaluated accuracy of implantation of CT-based navigation system. Methods: Twenty-nine primary TKAs in 27 patients between November 2002 and December 2005 were included in this study. We informed them the risk of additional exposure to radiation and spending time for this study, and informed consent was obtained. All implants were the Nexgen Legacy Posterior Stabilized prosthesis (Zimmer, Warsaw, IN) using CT-based navigation system (Vector Vision Knee Brain LAB Inc., Heimstetten, Germany). Reconstruction of 3-dimentional data from postoperative CT data Postoperative CT was performed in the same manner as the preoperative CT. A 100-mm section of the femoral head, a 200-mm section of the knee joint, and a 100-mm section of the distal tibia were scanned. The hip joint, the ankle joint and the implants in knee joint were extracted with adequate thresholds, respectively.