Artikel
Biomechanical comparison of radiolucent peek cervical spine interbody fusion cages
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Autoren
Veröffentlicht: | 13. Juni 2005 |
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Gliederung
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Study Design
Biomechanical study of PEEK cervical spine interbody fusion cages (CSIFC) using an in-vitro method.
Objectives
The purpose of this study was to evaluate the segmental stability provided by two newly developed PEEK CSIFC and to compare it to the native motion segment
Summary and Background Data
Despite the initial favourable results, the long-term effects of metallic cage devices on spinal motion segments are still unknown. Furthermore, short comings of metallic cages like migration, adjacent level degeneration, stenotic myelopathy and artefacts in postoperative radiological assessment have already been reported. Radiolucent cages have been designed to avoid some of these complications.
Material and Methods
8 human cervical spines (C2 to C7) were tested in flexion, extension, axial rotation, and lateral bending with a non-destructive stiffness method using a nonconstrained testing apparatus. First the motion segment C5/C6 was tested intact. After complete discectomy the following groups were evaluated: (1) NEOCIF cervical PEEK cage provided by Biomet Inc. (2) Stryker Solis PEEK Cage. The mean apparent stiffness, ROM (range of motion), NZ (neutral zone) and EZ (elastic zone) were calculated from the corresponding load-displacement curves.
Results
No significant difference in ROM and segmental stiffness between the Stryker Solis cage and the Biomet PEEK cervical cage could be determined. The Stryker significantly (p<0.05) failed to restore ROM and stiffness in extension in comparison to the intact motion segment. It showed significant higher results for neutral Zone in flexion, bending and rotation compared to the native motion segment.
Conclusion
In this study, two types of PEEK cervical interbody fusion cages were compared in regards of biomechanical stability. A statistical significant difference between these two implants could not be found, although the Biomet implant showed better results regarding the ability to restore native stability.