May "dubel" be a solution for pullout problem of the pedicle screws at osteoporotic spine?

Abstract

Aim: To improve the strength of stabilization systems currently used in osteoporotic spinal fractures, essentially by increasing the fixation force of pedicle screws. Mater Ial and Meth ods: Six human cadaveric vertebrae were used. Bone mineral densities of the specimens were measured with Dual Energy X-ray Absorptiometry in order to assess the osteoporosis. All vertebrae were found to be severely osteoporotic. Standard pedicle screws were applied to left pedicles of vertebrae. Pedicle screws reinforced by fixing plugs "Dubel" were applied to right pedicles of vertebrae. Afterwards the vertebrae were embedded in acrylic casts to prevent possible fracture of the osteoporotic vertebrae and to obtain a correct vertical pull-out vector. The biomechanical pullout tests were performed with biomechanical testing machine. Pullout forces in each group were recorded and compared with Mann-Whitney U test. Result s: The pedicle screws strengthened by "Dubel" were found to be four times stronger than the standard pedicle screws, in the osteoporotic human cadaveric vertebrae. Conclusion: "Dubel"-augmented pedicle screws may contribute to developing better stabilization systems for osteoporotic thoracolumbar fractures needing surgery and in the revision of the previous fusion surgeries of the spine.