C2 Vertebra: An Enigma for Young Spine/Neurosurgeons

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Anatomy

Background:

• C2 vertebra instrumentation is challenging for neurosurgeons due to complex anatomy and proximity to neurovascular structures.
• The midline posterior approach for craniovertebral junction (CVJ) fixation requires precise anatomical understanding.
• Neuroradiological advancements aid in surgical planning for CVJ instrumentation.

Purpose of the Study:

• To describe key surgical insights for the midline posterior approach in C2 vertebra instrumentation.
• To identify safe and effective screw insertion corridors for craniovertebral junction (CVJ) fixations.
• To address challenges in C2 instrumentation, especially in patients with congenital anomalies.

Main Methods:

• Evaluation of 92 computed tomography angiographies (CTAs) from patients undergoing CVJ fixation via midline posterior approach.
• Analysis of anatomical landmarks and screw insertion sites for craniovertebral junction (CVJ) fixation.
• Review of surgical cases over the past four years involving various CVJ disorders.

Main Results:

• CTAs revealed diverse CVJ pathologies including traumatic, congenital, and rheumatoid arthritis cases.
• Standard landmarks for screw insertion were found to be unsafe for congenital anomalous CVJ conditions.
• Optimal screw placement focuses on the corridor medial to the vertebral artery foramen for pars interarticularis and pedicle screws.

Conclusions:

• The midpoint of the bone segment medial to the vertebral artery foramen is crucial for safe pars interarticularis, transarticular, and pedicle screw placement.
• For laminar screws, crossing the midpoint of the lamina on each side ensures proper fixation.
• Refined anatomical targeting enhances safety and efficacy in C2 vertebra instrumentation, particularly for complex cases.