Abstract
Background Instrumentation of C2 vertebra is considered the most difficult for young neurosurgeons
and trainees due to its complex anatomical structures, variety of surgical approaches
and techniques, and proximity to important neurovascular structures. Key points from
a surgical perspective for midline posterior approach is described in the era of neuroradiological
advancements.
Method Computed tomography angiographies (CTAs) of a total of 92 patients were evaluated
with special attention to the key findings for insertion of screws for craniovertebral
junction (CVJ) fixations. All these patients were operated though midline posterior
approach in past 4 years.
Results CTAs included various CVJ disorders, which included traumatic (n = 14), congenital (n = 55), and rheumatoid arthritis (n = 2) patients. Established landmarks for screw insertion sites do not prove safe
for congenital anomalous CVJ conditions. Instead of highlighting screw insertion entry
points, part of the corridor, which is relevant, should be stressed up on.
Conclusion Midpoint of portion of bone segment medial to vertebral artery foramen should be
the focus, which is important for pars interarticularis (and transarticular) and pedicle
screws. A laminar screw should cross the midpoint of the lamina on each side.
Keywords
C2 vertebra - basilar invagination - congenital anomaly - craniovertebral junction
- occipitocervical fixation
