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Evaluating Screw Stability After Pedicle Screw Fixation With PEEK Rods
Jie Wu1,2, Lei Shi1, Daohong Liu2
1540274Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shanxi, China.
Global Spine Journal
|March 4, 2021
Summary
Polyetheretherketone (PEEK) rods enhance posterior spinal fixation screw stability by promoting bone growth around the screw. This animal study suggests PEEK rods may reduce screw loosening rates in clinical practice.
Area of Science:
- Spinal surgery
- Biomaterials science
- Orthopedic research
Background:
- Posterior spinal fixation is crucial for spinal fusion.
- Screw loosening is a common complication, potentially leading to revision surgery.
- Polyetheretherketone (PEEK) is a biomaterial increasingly used in spinal implants.
Purpose of the Study:
- To compare the screw stability of polyetheretherketone (PEEK) rods versus titanium alloy rods in posterior spinal fixation.
- To evaluate the effect of PEEK rods on bone integration and screw loosening in a sheep model.
Main Methods:
- Sheep underwent anterior-posterior cervical fusion with either PEEK or titanium alloy rods.
- Screw stability was assessed at 24 weeks using CT, pull-out tests, micro-CT, and histological analysis.
Main Results:
- No screw loosening was observed in either group via CT.
- PEEK rods demonstrated significantly higher pull-out force and energy compared to titanium alloy rods.
- Micro-CT and histological analyses revealed denser and thicker trabecular bone around screws in the PEEK group.
Conclusions:
- PEEK rods improve screw stability by enhancing bone growth around the screw in posterior spinal fixation.
- PEEK rods did not significantly improve bone integration at the bone-screw interface.
- These findings suggest PEEK rods may offer a clinical advantage in reducing screw loosening rates.
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