Radiographic Research Of Sacrococcyx Arch In AxiaLIF

Objective: Through statistical measurement and data analysis of the sacrococcyx spine CT imaging,to investigate the curve index of sacrococcyx arch effect on axial channel,to provide reference for the selection of surgery operation indication.Methods: Randomly colleting Two hundred patients data of sacrococcyx 64-slice spiral CT slice,they are maked 64 slice spiral check for outpatient clinic, they are aged ranging from 18 to 80 years,100 patients at each gender.rule out any major anatomical abnormality(congenital variation, lateral curvature deformity, tuberculosis, tumors, trauma, surgical history, etc).Mensurement of the straight length and the curved length of the sacrococcyx arch,and calculate the curve index of sacrococcyx by the formula(Ci=straight length/curved length×100);set Axial channel(line AD),mensurement the distance between S3/4 and line AD(d value);point O is labeled the entrance point of axial screw in the leading edge of sacral vertebra,point B and point C are respectively the top and bottom of S1,mensurement BO/BC percentage;parameters are statistical analysis by SPSS 21.0 software.Results: There were no obvious differences in different gender in Ci、d value、BO/BC,and its parameters follow gaussian distribution.According to the value of the sagittal security zones to grouping(19.7mm~26.1mm).12% of the sample is located in the range of 12.82mm~19.66mm;65% of the sample is located in the range of 19.91mm~26.01mm;23% of the sample is located in the range of 26.15mm~33.75 mm.77% of the sample is located in the saggital security zones range;and 23% of the sample is beyond the saggital security zones range,the sample can be divided into two groups:d<26.1 and d>26.1,95% group reference range of Ci and BO/BC are respectively(82.83~84.29)、(80.50~88.64)%;(77.91~80.27)、(61.58~71.98)%.Ci and the value of d was negative correlation(R=-0.608 P=0.000),and its regression eguation:Y=74.65-0.63X(independent variable is Ci);Ci and BO/BC was positive correlation(R=0.431 P=0.000),and its regression eguation:Y=-99.44+2.18X(independent variable is Ci)Conclusion: With the the change of the curve index of sacrococcyx arch,the distance between S3/4 and axial channel and the location of the entrance point of axial screw in the leading edge of sacral vertebra are changed.When the value of the curve index of sacrococcyx less than 77.06,the axial channel of Axia LIF can be obscured more easily,the axial channel can be beyond the saggital security zones,and the operation may get more difficulty and risk.