Related Experiment Video
Updated: Aug 7, 2026
06:11
Anterior Cervical Discectomy and Fusion in the Ovine Model
Published on: October 5, 2009
Cervical Total Disc Replacement and Anterior Cervical Discectomy and Fusion Responses Under Aircraft Ejection
Balaji Harinathan1, Hoon Choi2, Tyler F Rooks1
1Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI 53226, United States.
Military Medicine
|August 6, 2026
Summary
Cervical total disc replacement (CTDR) shows promise for military aviators undergoing ejection, preserving motion and reducing stress compared to anterior cervical discectomy and fusion (ACDF). Further evaluation is needed for tactical flight safety.
Area of Science:
- Biomechanical analysis
- Spine surgery outcomes
- Aerospace medicine
Background:
- Military aviators face accelerated spine degeneration and neck pain.
- Anterior cervical discectomy and fusion (ACDF) is permitted for return to flight but restricts motion and accelerates degeneration.
- Cervical total disc replacement (CTDR) may mitigate ACDF's adverse effects, but its performance under dynamic loading is unknown.
Purpose of the Study:
- To evaluate the biomechanical responses of ACDF and CTDR under simulated hyperdynamic vertical loading conditions.
- To compare the effects of CTDR and ACDF on spinal motion, facet forces, and intradiscal pressure in a finite element model.
Main Methods:
- A human body finite element model was subjected to ejection-type vertical loading (Gz).
- Simulations included C5-C6 level CTDR (Mobi-C) and ACDF (conventional plating).
- Segmental motion, facet force, and intradiscal pressure were measured and normalized to the native spine.
Main Results:
- CTDR decreased index level motion by 30% and ACDF by 81% compared to the native spine.
- Adjacent level motion increased for both, but less with CTDR.
- Intradiscal pressure increased at adjacent levels, with higher increases for ACDF.
- Facet forces at the index level increased more with CTDR, but adjacent level forces were minimally affected.
Conclusions:
- CTDR preserved index level motion and reduced motion transmission to adjacent segments under dynamic loading.
- CTDR increased posterior column load sharing at the index level.
- Neither ACDF nor CTDR resulted in spine failure under simulated ejection conditions, supporting CTDR evaluation for aviators.
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