RESUMO
BACKGROUND: Exact positioning of implants and accuracy of alignment are important parameters to provide an long survivorship of endoprostheses after total knee arthroplasty. It was suggested that an alignment within 3∘ from centerline provides the best long-term survivorship of TKA. Therefore, computer-assisted navigation became more important in TKAs. Another tool to improve the accuracy in TKA is the preoperative planning software. OBJECTIVE: Main goal was to determine if advantages of an intraoperative navigation system during TKA can be reached by an exact implementation of a preoperative computer-aided planning. METHODS: Based on all patients (n= 100) underwent primarily TKA in 2015 and 2016 two groups were declared: (1) conventionally operated TKA without navigation system and (2) operation with an optical navigation system. Data on age, sex, date, operative time, severe complications and preoperative vs. postoperative alignment were collected retrospectively. RESULTS: The two groups do not differ in postoperative alignment and frequency of outliers. Furthermore, there was no difference referring to complications and the length of stay in hospital, but operative time was prolonged in the navigation-assisted group. CONCLUSIONS: It can be stated that conventional surgical techniques in TKA are as accurate as navigated ones if an exact preoperative computer aided planning is implemented during surgery.