Related Experiment Video
Updated: Jan 23, 2026

A Spine Robotic-Assisted Navigation System for Pedicle Screw Placement
Published on: May 11, 2020
[Intraoperative revision of initially loosened pedicle screws]
Lukas Weiser1, Stephan Sehmisch2, Lennart Viezens2
1Klinik für Unfallchirurgie, Orthopädie und Plastische Chirurgie, Universitätsmedizin Göttingen, Robert-Koch-Straße 40, 37099, Göttingen, Deutschland. Lukas.Weiser@med.uni-goettingen.de.
Objective:
Intraoperative revision of initially loosened pedicle screws.
Indications:
Intraoperatively loosened/stripped pedicle screws.
Contraindications:
None.
Surgical Technique:
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.
Postoperative Management:
Early functional mobilization and initiation of osteoporosis therapy if indicated.
Results:
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.
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