[Intraoperative revision of initially loosened pedicle screws]

Intraoperative revision of initially loosened pedicle screws.Intraoperatively loosened/stripped pedicle screws.None.Removal of the loosened/stripped pedicle screw. Checking the screw channel and re-implantation using a different trajectory, a larger screw diameter or a cement-augmented pedicle screw.Early functional mobilization and initiation of osteoporosis therapy if indicated.A biomechanical study with human vertebral bodies was performed. Augmented and not augmented pedicle screws were tested until loosening using a fatigue testing setup. After loosening occurred a subsequent augmentation of the loosened, not augmented screw was performed, and it was tested using a fatigue test again. Both the initial (p = 0.009) and the augmentation after loosening (p = 0.001) showed a significant increase in failure load compared to the non-augmented pedicle screws. In our own patient collective from April 2016 to August 2018, 11 of 524 patients treated with pedicle screws showed intraoperative screw loosening. This was revised in 6 cases with a subsequent augmentation and in 5 cases with a larger screw diameter. In the postoperative control at 6 weeks, none of these screws showed loosening again.