Clinical Study Of Needle Point And Needle Track On X-ray Film Of Lumbar Cortical Bone Screw

Objective:To study the position of the projection point and the depth of the needle insertion point and depth on the standard or lateral lumbar spine when the lumbar cortical bone screw is implanted,and to provide a theoretical basis for correct nail placement.Methods:A single vertebral body was dissected using 10 L1-L5 spine specimens.The point of insertion of the cortical bone channel screw was the intersection of the vertical midline of the upper articular process of the corresponding vertebrae and the horizontal line of 1cm below the ipsilateral transverse process.,The open cone is open,the angle of the eversion is controlled at 10 °,the head inclination is 25-30 °,and the depth of needle penetration is below the upper end plate.Tap the screw channel,and probe the four walls of the pedicle for damage.Then measure and analyze the following data:when the guide needle is below the upper end plate,measure the ratio of the distance between the projection point of the guide needle on the lateral film and the posterior edge of the vertebral body to the entire vertebral body length,and record it as b / a(a indicates the guide needle The distance from the posterior edge of the vertebral body,b represents the length of the vertebral body);at the junction of the vertebral body and the pedicle,measure the standard orthophoto,the distance between the projection point of the guide needle tip and the medial edge of the pedicle and the width of the pedicle The ratio of the guide pin is c / d(c is the distance between the guide pin and the pedicle,and d is the width of the pedicle).The distance between the projection point of the guide pin and the upper wall of the pedicle and the projection height of the pedicle Ratio,recorded as e / f(e is the distance of the guide needle from the upper wall of the pedicle,and f is the height of the pedicle);at the middle position of the pedicle,measure the standard orthophoto,and the projection point of the guide needle point from the vertebra The ratio of the distance between the medial edge of the pedicle and the width of the pedicle is written as n / m(n is the distance between the tip of the guide needle and the medial edge of the pedicle,and m is the width of the pedicle).The ratio of the distance between the upper wall of the arch and the height of the pedicle is recorded as x / y(x is the guide pin Distance from the upper wall of the pedicle,where f is the height of the pedicle).At the same time,the clock position of the entry point and exit point on the pedicle projection is recorded.Results:1.The needle entry point is at 5 o'clock on the left side of the pedicle,and the right side is at 7 o'clock.The needle exit point is on the left side at 11 o'clock and the right side is at 1 o'clock.In the middle part of the pedicle,the tip of the guide needle is close to the inner side of the pedicle in the middle and lower part of the pedicle projection;3.At the junction of the vertebra and the pedicle,the guide needle is located at the upper pole of the pedicleConclusion:The position of the guide needle on the standard lumbar anterior and lateral radiographs can better judge the actual position of the guide needle,and the clock method can help clinically correct nail placement.