Alignment Philosophies in Total Knee Arthroplasty: A Comprehensive Narrative Review

For many years, providing patients with a total knee arthroplasty (TKA) prosthesis which is stable with a neutrally aligned lower limb using a mechanical alignment philosophy has represented the primary technical goal of TKA. However, it has previously been reported that only 50% of patients have neutral mechanical axis. Furthermore, despite continuous engineering developments with respect to implants used in TKA, contemporary philosophies, computer-assisted navigation and robotic-assisted TKA, registry data suggest that 1 in 5 patients undergoing TKA report overall dissatisfaction with their procedure in the medium to long term. Therefore, the purpose of this review was to first describe and compare outcomes of current alignment philosophies in TKA. Additionally, the authors sought to review the outcomes of computer-assisted navigation and robotic-assisted TKA procedures, while also evaluating the role of sensors and tensioners with respect to TKA alignment. Finally, the authors aimed to review potential future developments within this ever-developing space in the literature.