ROBOTIC SIMULATION OF THE EFFECTS OF SURGICAL PLACEMENT OF THE PRODISC-L ON MOTION SEGMENT MECHANICS: AN IN VITRO HUMAN CADAVERICLUMBAR MODEL

摘要

A variety of lumbar total disc replacement (TDR) designs exist for the treatment of disc pathologies and several of which have undergone clinical trials. A key design parameter for a constrained ball and socket type device is a fixed center of rotation (CoR). A previous study [1] demonstrated that the lumbar motion segment unit (MSU) was highly sensitive to the anatomical location of the sagittal plane rotational axis. Malalignment between the implant CoR and the inherent rotational axis of the MSU may lead to an overloaded or over-constrained condition.rnTwo paradigms exist for the surgical placement of TDR devices relative to MSU anatomy: positioning the implant midline or posterior to midline with respect to the vertebral body. Conventional in vitro testing methodologies lack the sensitivity to discern the effects of implant placement on load mechanics and range of motion of a MSU.