## Introduction
When the cervical spine is unstable due to trauma, tumor, or severe degeneration, **Posterior Fixation** is often necessary to prevent paralysis. Modern posterior cervical systems use a combination of screws and rods to provide rock-solid stability in the most mobile part of the spine.
## Anatomy of the Construct
The posterior cervical spine presents unique challenges due to the small size of the vertebrae and the proximity of the vertebral artery.
* **Lateral Mass Screws:** The most common point of attachment in the mid-cervical spine (C3-C6).
* **Pedicle Screws:** Used primarily at C2 (Axis) and C7 for maximum pull-out strength.
* **3.5mm Rods:** High-strength titanium rods connect the segments, allowing for decompression and stabilization.
## Engineering Challenges: Size vs. Strength
A posterior cervical system must be small enough to avoid muscle irritation but strong enough to handle constant neck movement.
1. **Top-Loading Heads:** Allow for easy rod insertion even in “tight” anatomical spaces.
2. **Variable Angle Flexibility:** Ortholyx cervical screws offer up to 40掳 of angulation to accommodate the complex curvature of the neck.
3. **Transition Rods:** Ortholyx provides 3.5mm to 5.5mm transition rods to connect the cervical spine to the larger thoracic constructs.
## Clinical Indications
* **Cervical Stenosis:** Following multi-level laminectomy.
* **Complex Fractures:** Such as Jefferson or Hangman鈥檚 fractures.
* **Spinal Oncology:** Post-tumor resection stabilization.
## Conclusion
Posterior cervical fixation is a high-stakes surgery that requires the most precise hardware. Ortholyx systems provide the modularity and reliability needed to safeguard the spinal cord and restore quality of life.