CT Imaging Study Of Healthy Adult Translaminar Screw Fixation In The Thoracic Spine

Objective:To measure the thoracic vertebral lamina thickness,lamina nail length and laminar camber angle by CT,and guide the clinical application of T1 ~ T12 segmental translaminar screw diameter,length and nailing direction.Methods:The results of CT scan of thoracic vertebrae in healthy adults were randomly selected,except for the history of thoracic surgery,no obvious abnormalities in imaging examination,and no bone-destructive diseases such as fractures,deformities,tumors and obvious degeneration in the lamina area.including 65 males and 35 females,aged 18-74 years(average of 47.5 years).The length of the thoracic vertebral plate screw,the thickness of the lamina on both sides,and the lacunar camber were measured to determine the placement direction.Result:The data of TI ~ T12 laminar thickness,lamina nail length and camber angle imaging of 100 healthy adults were compared.P>0.05 difference was not statistically significant;T1~T12 lamina thickness was 4.1~6.76 mm,T1 to T12 segment P <0.05 difference was statistically significant,the overall trend change gradually decreased;T1~T12 lamina nail length is 25.15~34.46 mm,T1 to T12 segment P <0.05 difference was statistically significant.The trend of T1 to T6 gradually decreased,and the trend of T7 to T12 gradually increased.The T1 to T12 lamina camber angle was 49.90° ~ 58.41°,and the T1 to T12 segment was P<0.05 difference was statistically significant,and the overall trend gradually increased;in male and female,the length of lamina nail and the thickness of lamina were both P<0.05,difference was statistically significant,and the camber angle was P>0.05,difference was not statistically significant;comparison between different age groups P>0.05 differences were not statistically significant.Conclusion:CT imaging data showed that the diameter of the thoracic spine suitable for placement of the lamina screw was T1~T6 4.0 ~4.5mm,T7~T12 3.0~3.5mm;length T1~T6 25~35mm,T7~T12 25 ~ 30mm;implanted screw direction T1 ~ T650 ~ 57 °,T7 ~ T12 58 °.The laminar screw can be used as an alternative or remedy for the failure of pedicle screw fixation.The measurement results of this study can be used for clinical application.