Fig. 4.

Three fundamental knee elements; morphology, alignment, and soft-tissue. Each element determines and is determined by the other two elements, creating the best harmony on an individual basis. As a result of this harmony, the individualized kinematics are provided. The mechanical approach tends to change all, while the kinematic approach aims to reproduce all. However, the starting point is different among the respective kinematic alignment (KA) approaches. The calipered approach starts from ‘morphology’, focusing on replicating the original articular surface. The soft-tissue respecting approach starts from the soft-tissue balance, and the restricted approach starts from the control of the alignment. All other elements are expected to be eventually overcome and the patients’ original kinematics will be restored. The functional alignment, inverse KA, and other computer-assisted approaches adjust all elements based on intraoperative measurements.