A Strain-Energy Model of Passive Knee Kinematics for the Study of Surgical Implantation Strategies

Abstract. A mathematical model for studying the passive kinematics of condylartype total knee prostheses can be useful in planning and performing total joint replacement. If the insertion location and neutral length of knee ligaments is known, the passive kinematics of the knee can be calculated by minimizing the strain energy stored in the ligaments in any angular configuration of the knee. The model considered here takes into consideration the geometry of the prosthesis, patient-specific information, and operation-specific placement of the prosthesis. Based on an energy-minimization principle, this model can be used to study the kinematics of the knee joint of a patient after total joint replacement. The effect of various articular geometries, alternative surgical placements of prosthetic devices, and intraoperative ligamentous release can be simulated. The model may be useful in preoperative planning, intraoperative guidance, and the design of new prosthetic joints.