10-Year Survival of Navigated Versus Conventional TKAs: A Retrospective Study

The computer-assisted navigation of total knee arthroplasty (TKA) offers a radiologically demonstrated higher precision of implantation than conventional implantation in relation to the axis alignment. The impact on long-term clinical outcomes is currently unknown. In 1999, 217 consecutive TKAs were performed in a total of 213 patients (113 navigated and 104 conventional). After 10 years, it was possible to follow up on 94 patients with 96 TKAs, of which 46 were conventional and 50 were navigated. The radiographs were evaluated using the Knee Society protocol. In addition to the Hospital for Special Surgery Score and Knee Society Score, the current authors also used the patient-focused 36-item Short Form Health Survery. After 10 years, 8 TKAs were revised because of aseptic loosening, 7 in the conventional group and 1 in navigated group. This equates to an 87% survival rate for conventional and 98% for navigated implantation. This difference was statistically significant (P<.05). After conclusion of the follow-up, 17% of the conventional and 9.8% of the navigated TKAs were found to have undergone aseptic loosening. All of the TKAs subject to aseptic loosening presented a mechanical femorotibial angle outside the optimal zone of ±3° around neutral axis. The study indicates a clinically significant advantage of the navigation technique compared with the conventional procedure. [Orthopedics. 2016; 39(3):S72-S76.].