Turkish Neurosurgery 2016 , Vol 26 , Num 5
Occipital Condyle-C1 Complex Screw for Fixation of Basilar Invagination Patients with Atlas Assimilation
Huaiyu TONG1, Lianfeng LI2, Xin-guang YU1, Yuanzheng ZHANG1, Wang PENG1
1Chinese PLA General Hospital, Department of Neurosurgery, Haidian District, Beijing 100853, China
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

Corresponding author : Xin-guang Yu, xinguangyucn@163.com