Study On The Nailing Path Of S₃ Ala-iliac Screw In Adult Spinal Pelvis Fixation

Background:With the development of internal fixation devices and surgical techniques in spinal surgery,iliac screw technique has been widely used in the pelvic internal fixation.Third sacral vertebral sacroiliac screw internal fixation(third sacral ala-iliac screw.S3 AI screw)technology for this study put forward a new type of spinal internal fixation technology pelvis,the technology by S3 lateral placement of iliac screws on both sides,at the same time have improved the traditional spinal internal fixation technology pelvis,allow at least two pieces of iliac screw placement.At present,countries of S3 AI technology in adult spinal fixation of pelvic area path parameters and clinical application of nailing study is less,the through 3d printing model and CT image 3d reconstruction technology of can of nailing ilium planar imaging and 3d model research,explore suitable S3 AI screw placement.Objective:The screw insertion and parameters of S? ala-iliac screw fixation were introduced by3 D printing spinal pelvis model and computer software-assisted navigation.Methods:Determine the nailing space of the S 3 segment by 3D printing model and computer software related data,and select the position of the iliac screw into the needle point.Twenty of the male and female adult patients who had undergone three-dimensional pelvic CT reconstruction scans were randomly selected.The screw point O was selected,the horizontal section X was the coronal or sacral horizontal cross-section.Spherical probe into the minimum angle of the needle angle range A,the maximum angle range B and the optimal range of nailing angle Z was measured,and the needle point screwed into the screw pin length and width.The accuracy and safety of this new method of nailing were confirmed in the corresponding adult 3D printing model.Results:The needle angle is within the range of the minimum angle OA to the maximum angle OB.If the narrowest diameter is more than 7mm,the fixation can be safely done with a universal Iliac screw(average length 80-90mm).The range of needle angle was 47.1 ±1.9-56.7 ± 1.4 ° for the male X-OA-OB plane and 52.3 ± 1.1 ° for the optimal angle.TheX-OA-OB plane for women was 49.6 ± 0.8-59.9 ± 1.1)°,the best angle X-OZ range(53.7 ±0.8)°.The range of nail path length was 91.4 ± 2.3 mm for OA,89.5 ± 4.6 mm for OB and94.2 ± 2.1 mm for OZ.The OA level of female was 90.4 ± 1.9 mm,(85.6 ± 2.3)mm,OZ plane range(96.4 ± 1.7)mm.The statistical results showed that in the best setting angle OZ,nail angle differences(F=4.276,P=0.001)and nail length were statistically significant(F=3.647,P =0.001)in men and women in comparison;OA,men and women,nail angle The difference was statistically significant(F=5.268,P =0.001),nail length lost statistical significance(F=1.513,P=0.139).OB,male and female,nail angle differences(F=8.153,P=0.001)and nail length were statistically significant(F=3.341,P =0.002).There was no significant difference in the values of trailing declination angles between adult men and women of the same sex on the same nail plane(P> 0.05).Conclusion:The iliac bone screw can be safely and effectively inserted into the iliac bone via the S3 block.In theory,the iliac bone screw is safe and stable through the O-Z needle entry point.The O-Z angle is also the best in Spinal pelvis fixation.