Feasibility study on posterior laminar screw fixation techniques in the axis.
OBJECTIVE
To get morphologic parameters of Chinese adults through observation and measurement on axial laminas, to evaluate the feasibility of placing axial laminar screws and to introduce the technique.


METHODS
Relative parameters of 28 sets of fresh Chinese adults'axial specimens, including distance from the superior and inferior entry points of axial laminar screws to the superior margins of axial laminas, superior, middle, inferior thickness and height of the axial laminas, length and angle of the axial laminar screw trajectories, distance from the entry points of axial laminar screws to the transverse foramen and central points of the inferior articular process, were measured with a digital caliper and a goniometer. Data were statistically analyzed.


RESULTS
Averagely, distance from the superior and inferior entry points of axial laminar screws to the superior margins of axial laminas was 5 mm and 9 mm, superior, middle, inferior thickness and the height of the axial laminas were 3.2 mm, 6.7 mm, 5.5 mm and 12.8 mm respectively, and the length of the superior and inferior axial laminar screw trajectories was 26.2 mm and 25.5 mm, respectively.


CONCLUSIONS
It is feasible and reliable to apply posterior laminar screw fixation techniques to the axes of Chinese adults. Also the C2 laminar screw fixation technique can be taken as a supplementary to conventional posterior screw fixations of C2.
Hu
Yong
Y
Department of Orthopaedics, Ningbo 6th Hospital, Ningbo, China. huyong610@163.com
He
Xian-feng
XF
Gu
Yong-jie
YJ
Xu
Rong-ming
RM
Ma
Wei-hu
WH
Ruan
Yong-ping
YP
Lin
Rong
R
D000328:Adult; D000368:Aged; D001368:Axis, Cervical Vertebra / Q000601:surgery*; D001863:Bone Screws; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013123:Spinal Fusion / Q000379:methods*