[Update on navigation in total knee arthroplasty. Where are we today and what lies in the future?].

BACKGROUND: The implantation of an artificial knee is one of the most common operative interventions in German hospitals. Navigation procedures have developed into an integral component of such interventions in the operating theatres of many clinics.
METHODS: For orthopedic surgeons who want to implement an as exact as possible reconstruction of the mechanical leg axis and require intraoperative control of the three dimensional positioning of components and/or the capsular ligament situation, navigation is a well-proven intraoperative tool. The immediate intraoperative control possibility of bone resection and capsular ligament soft tissue balancing means that navigation is a valuable instrument for the biomechanical fundamental understanding in training operations for further education of orthopedic surgeons in training. DEVELOPMENTS: The greater precision obtained by the implementation of the procedure has not yet been conclusively reflected in an improved postoperative knee function or an increased durability of prostheses. New developments in navigated knee prostheses are pinless navigation and navigation kinematics. In pinless navigation the conventional reference marker system fixed in the femur and shin bones is replaced by a non-invasive reference system. With the aid of navigation kinematics it is possible to image the tibiofemoral and patellofemoral movement dynamics, intraoperatively. PERSPECTIVE: The aim of the next generation navigation systems for computer-assisted knee prosthetics is implant positioning aligned to the individual anatomy of patients with high and stable range of movement for optimum patellar guidance and kinematics of the artificial joint.