Clinical Nailing Research Of Lumbar Pedicle Screw Located By The Facet Joint And The Spinous Process

Objective:The transpedicle internal fixation is the most common method of posterior spinal internal fixation treatment,the key of internal fixation is screw whether the screw accurate reach the vertebral body through pedicle.Based on the research of anatomy of facet joint,spinous process and pedicle,placing pedicle screw by reference to facet joint and spinous process,research the feasibility and accuracy of the method of pedicle screw placement located by the facet joint and the spinous process applied to clinical screwing.Methods:1.Rapid prototyping model to measure the relevant data:The 26 cases models(the model is 1:1 physical model and the error is within 0.03 mm)were selected in the research,including a total of 55 cases of vertebral section,from L1-L5 the cases is 7、13、11、14、10.(1):Measure the horizontal distance from the trailing margin of zygapophyseal joint facet to the pedicle axis(D).(2):Measure the vertical distance from the horizontal line of the lower margin of the inferior facet’s to the pedicle axis(K).(3):Measure the angel between the pedicle axis’ tilt and the superior margin of the spinous process(α angel).2.Statistical analysis.All the data were analyzed to compare the statistical difference.3.Clinical screwing.The 56 cases of patients were enrolled in the research,by the same high qualification surgeon using the method of facet joint and spinous process located pedicle set screw.Postoperative CT scans evaluated the screw position to analysis the method of pedicle screw accuracy.Results:The average values are as follows:From L1-L5 the corresponding D value is 5.37±1.13mm、5.48±1.23mm、7.24±2.13mm、7.77±2.14mm、9.87±2.55mm;the corresponding K value is 1.00±1.23mm,0.89±1.34mm,1.17±1.44mm,0.80±1.19mm,0.99±1.54mm;the corresponding a angel value is 7.14±2.270、7.69±2.430°、8.73±3.61°、10.43±4.09°、15.00±5.19°.We set pedicle screw placement 223 with 11 perforation of the cortex.The success rate is 95.07%;the relative risk rate is 4.93%;the absolute risk rate is 0.90%.All cases have no neurological complications or vascular injury,screw breaking and loosing during hospitalization and follow-up.Conclusion:Lumbar pedicle located by the facet joint and the spinous process is accurate,safe,reliable,easy to operate and can overcome part of the variation when individualized screwing,for lumbar pedicle screw placement with a new method.