Development of an Image-Free Navigation Tool for High Tibial Osteotomy

High tibial osteotomy (HTO) is a common therapy for medial gonarthrosis. Intraoperative planning and control of the correction is difficult. Therefore a workflow for a navigation with an image-free navigation system was developed for direct control of the correction of varus/valgus, internal/external rotation, and increase/decrease of the tibial slope. After registration of the lower limb, two k-wires define the osteotomy plane or planes for open- or closed-wedge osteotomy, respectively. The correction is accomplished under navigation system control in real-time. A rigid plate fixation is used for the fixation of the HTO. The reliability and accuracy of the system was approved with an aluminium phantom model.