骶二椎弓根钉外进钉固定拧紧力与骶骨应变分布规律的研究

Experiment on Fixation Tightening Force of the Second Sacral Outside Pedicle Screw and Sacral Strain Distribution of the Sacrum

研究骶二椎弓根钉固定拧紧力与骶骨应变分布,为临床骶二椎弓根钉固定术提供生物力学参数。取正常国人新鲜尸体骶骨标本,以椎弓根钉内进钉法固定于骶二椎弓根,以小型力传感器与椎弓根钉固定装置连接,测量椎弓根钉的拧紧力,同时以动静态电阻应变仪对预先粘贴在四个椎弓根螺栓固定边缘部位和骶骨不同部位的应变片进行应变电测量。得出了椎弓根钉的最大拧紧力和S1椎体、S2椎体、S3椎体正中线左侧和右侧应变值,还得出了S1左侧、S1右侧上关节突关节面部位及S1、2左侧,S1、2右侧骶后孔连线与骶中间嵴交点处应变值。说明骶二椎弓根钉术式符合生物力学原理。

To study fixation tightening force of sacral Ⅱ pedicle screw and the strain distribution of sacral, and provide biomechanical parameters for chnical fixation method of sacral Ⅱ. We got sacrum specimens from fresh corpses of normal people, and fixed in the second sacral pedicle by the method of outside pedicle screw and connected the small sensors to fixation device of pedicle screw to measure the tightening force of pedicle screw. At the same time, the electric strain measurement was done on the strain gauge of different parts which was resistance to static and dynamic strain gauge pre-pasted on the four fixed-site edge of Pedicle and the different parts of sacrum using the resistance strain gauge. As a result, we got the biggest tightening pulling-out force of the pedicle screw and strain value on the left side and right side of the center line strain of the S1 vertebral body, S2 vertebral body and the S3 vertebral body, and we also got strain value on the left side of S1 , on the right side of the joint of S1, and the strain value on the sacral connection hole and the middle sacral crest point on the left side of S1,2 and the right side of S1,2. It proves that second sacral pedicle screw procedure in line fits for the biomechanics principles.