Issue release date: 12.11.2024
2The 306 Hospital of PLA, Department of Neurosurgery, Chaoyang District, Beijing 100101, China DOI : 10.5137/1019-5149.JTN.10551-14.5 AIM: To investigate whether C1-occipital condyle complex (CC complex) screws can be safely and rapidly placed without guidance in basilar invagination patients with atlas assimilation.
MATERIAL and METHODS: The occipital-cervical (OC) junction was fixed posteriorly in 8 basilar invagination patients with atlas assimilation using polyaxial titanium screws inserted unicortically into the CC complex and C2 pedicles and subsequent fixation to a 3-mm rod. Anatomic landmarks were used during the drilling. The screw angles and lengths of the CC complex were analyzed.
RESULTS: The width, length, and height values of the left-side CC complex were 7.96?2.23, 16.064±2.73, and 13.764±2.06 mm; those of the right-side CC complex were 7.844±1.38, 16.664±2.58, and 12.814±2.62 mm. The CC complex entry point was at the central point of posterior surface of the CC complex. The angle used for medialization was 10-15°, which was also the maximal superior screw angulation in the sagittal plane. The screw length required for unicortical purchase was 16-22 mm. The screw was not misplaced or poorly positioned, and no neurovascular complications associated with screw insertion were detected.
CONCLUSION: In patients with atlas assimilation, CC complex screws can be placed safely. The CC complex screws can be safely inserted assisted by microscope without image guidance.
Keywords : Occipital condyle, Occipital-cervical junction, Occipital-cervical fusion, Occipital condyle screws, Occipital-cervical instability