Finite Element Analysis of Bilateral Double Rod Constructs in Thoracolumbar Fractures

To evaluate bilateral double rod contructs in thoracolumbar fractures in a Finite Element model MATERIAL and METHODS: A computed tomography of a 35-year old male have been chosen to create a vertebra model and 1/3 of the T12 was removed to create the burst fracture model. In model A, transpedicular polyaxial screws were inserted two levels above and two levels below the burst fracture. On each side the screws were connected with a single rod. In model B, the screws were connected with two rods on each side attached to two lateral connectors. A uniform 150 N axial load and 10 N/m torque was applied on the superior T10.

ROM and von Mises stress nephrograms revealed that the bilateral double-rod construct is being the most rigid and that the force on the pedicle screws were significantly lower compared to model A.

We believe that bilateral double-rod constructs for the stabilization of thoracolumbar fractures have a decreased load on pedicle screws and rods compared to the classic bilateral single rod stabilization system and can lower the risk of implant failure and the risk for secondary complications and revision surgery.