Abstract
The study aims to optimize the topology of the complete disc replacement. In this paper, we present a stress-based topology optimization of a complete disc replacement for the lumbar spine using the finite element level set method (LS). The disc was optimized to reduce stress and strain at the level of two segments. The new modified pro disc design was proposed to increase the space for bone ingrowth and increase the stability of fixation. The intact model was tested in six degrees of freedom (compression, extension, flexion, lateral bending, and torsion). The volume of the intact model was reduced by 50% by optimizing the topology, and validation showed more significant results under biomechanical loading conditions. The Von Mises stress remains the same with minor differences. Topology optimization allows to increase bone ingrowth and reduces stress-shield effects in the cortical bone and cancellous bone.