Design Concept for a Total Knee Replacement with Condylar Guiding Features

Better performance of total knee replacement requires normal kinematics and higher range of motion. A potential solution can be a surface-guided knee with asymmetric configuration including a ball-and-socket articulation in the medial compartment and guiding bearing surfaces on the lateral compartment. An innovative design concept with constant bearing spacing and variable radii for the medial and lateral aspects of the lateral condyle as the guiding features is introduced as a potential design solution. This design allows for normal articulation of the patella and preservation of one or both of the cruciates. In this study, the viability of such surface-guided TKR was tested experimentally. A prototype was built and tested on the joint simulator. The results of the preliminary tests demonstrated that the reference bearing surfaces built based on the novel design concept could successfully generate motion patterns similar to the kinematics of a normal knee joint under compressive forces. The developed concept and methodologies can serve as a basis for development of a TKR with normal kinematics.