Biomechanical comparison of plates and rods in the unstable thoracic spine

Thoracic spine stabilization after trauma or in tumor reconstruction cases frequently is performed with hook and rod internal fixation systems, the use of which is not always possible. Pelvic reconstruction plates with pedicle screw fixation offer an alternative to hooks and rods. In this study, we biomechanically compared a plate construct with a hook and rod system in an acute postoperative, unstable thoracic spine model. We found that the hook and rod system offered more resistance to flexion and extension bending than the plate construct; the opposite was true for lateral bending and axial torsion. We further determined that the addition of pars interarticularis screws to the plate construct provided increased resistance to all loading modes. Our study indicates that plate constructs can effectively stabilize the thoracic spine.