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Updated: Jan 22, 2026
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A Spine Robotic-Assisted Navigation System for Pedicle Screw Placement
Published on: May 11, 2020
9.3K
Pullout strength of reinserted pedicle screws using the previous entry point and trajectory
Xuanwu Huang1, Zixiang Huang2, Liwei Xu3,2
1Department of Orthopedics, Zhujiang Hospital, Southern Medical University, No. 253, Gongye Road, Haizhu District, Guangzhou, 510282, China.
Journal of Orthopaedic Surgery and Research
|July 6, 2019
Summary
Reinserted pedicle screws showed no significant difference in pullout strength compared to correctly inserted ones. However, reinserted screws exhibited increased stiffness, with fracturing observed in some cases.
Area of Science:
- Spinal surgery
- Orthopedic biomechanics
- Surgical techniques
Background:
- Pedicle screws are crucial for spinal fusion stability.
- Accurate screw placement is vital for surgical success.
- Revision surgeries may necessitate screw removal and reinsertion.
Purpose of the Study:
- To compare the biomechanical properties of reinserted pedicle screws with correctly inserted ones.
- To evaluate the effect of reinsertion using the same entry point and trajectory on screw performance.
- To assess the feasibility of reusing the pedicle screw trajectory in spinal surgery.
Main Methods:
- Utilized 18 calf lumbar vertebrae (L1-6) for pedicle screw insertion.
- Compared correctly inserted control screws with experimental screws reinserted via the original path.
- Tested screws after complete insertion (Group A), 80% insertion (Group B), and 60% insertion (Group C).
Main Results:
- No significant difference in axial pullout strength between reinserted and control screws across all groups.
- Increased stiffness was observed in reinserted pedicle screws compared to controls.
- Fracturing occurred between the vertebral body and pedicle in some reinsertion instances.
Conclusions:
- Pedicle screws can potentially be removed, inspected, and reinserted using the prior entry point and trajectory.
- The biomechanical integrity, specifically pullout strength, is maintained after reinsertion.
- Increased stiffness and potential for fracturing warrant careful consideration during revision procedures.
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