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06:24
A Spine Robotic-Assisted Navigation System for Pedicle Screw Placement
Published on: May 11, 2020
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Biomechanical Stability of a Cross-Rod Connection with a Pedicle Screw System
Tetsutaro Mizuno1, Toshihiko Sakakibara1, Takamasa Yoshikawa2
1Department of Spinal Surgery and Medical Engineering, Mie University Graduate School of Medicine, Tsu, Mie, Japan.
Medical Science Monitor Basic Research
|January 27, 2018
Summary
Pedicle screw spinal fixation lacks torsional stability, risking implant failure. Cross-rod constructs offer comparable stability during bending and near-intact stability during rotation, improving spinal fusion outcomes.
Area of Science:
- Spinal Surgery
- Biomechanical Engineering
- Orthopedic Research
Background:
- Pedicle screw instrumentation in spinal surgery has limitations in providing adequate torsional stability.
- This instability can lead to complications such as pseudoarthrosis, pedicle screw loosening, and eventual implant failure.
Purpose of the Study:
- To evaluate the biomechanical stability of different spinal fixation methods.
- To compare the torsional stability of cross-rod constructs against traditional pedicle screw systems and intact spines.
Main Methods:
- Functional spinal units from 18 deer were tested using a 6-axis material testing machine.
- Specimen models included intact, damaged, cross-rod, and cross-link configurations.
- Range of motion (ROM) was measured during bending and rotation tests.
Main Results:
- Cross-rod constructs demonstrated comparable range of motion to cross-link constructs during bending.
- During rotation, cross-rod models exhibited significantly less motion than cross-link models.
- No significant difference in rotational motion was found between intact and cross-rod models, while both were significantly more stable than cross-link models.
Conclusions:
- Cross-rod spinal fixation provides stability comparable to pedicle screw systems during bending.
- Cross-rod constructs achieve stability during rotation that is similar to that of an intact spine.
- These findings suggest cross-rod constructs may offer an improved alternative for spinal fixation, enhancing stability and potentially reducing implant failure.
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