Experimental Study Of A Type Of Vertebral-posterior Wall Sealing Device To Reconstruct Thoracolumbar Vertebrae With Posterior Wall Defect

Objective To explore effects of a type of vertebral-posterior wall sealing device on the change of the temperature of the bone cement reconstruction of the vertebral body with posterior wall defect.Methods(1)The Vertebral-posterior wall sealing device consists of two question mark-shaped pressure gasket,connector,T-type screw,nut,horizontal bar composition.(2)Thirty specimens consisting of three thoracolumbar vertebae were obtained from 30 fresh adult pig spines which were randomly divided into A,B,C three groups with 10 cases each.Then the middle vertebral posterior wall defect model of different degree was made.The depth of the defect was 10 mm,and the percentage of surface area of the defect and the posterior wall in group A was 25%,group B was 50%,group C was 75%.Group A was randomly divided into group A1 and group A2 with 5 cases each.Group B was randomly divided into group B1 and group B2 with 5 cases each.Group C was randomly divided into group C1 and group C2 with 5 cases each.(3)Group A1,group B1 and group C1 were used the device whilerestructuring the vertbrae with posterior wall defect.After the pedicle screws were inserted into the upper and lower vertebral body of the model,the posterior wall of the vertebral body was sealed with the vertebral-posterior wall sealing device.Then bone cement was injected into the vertebral body.Group A2,group B2 and group C2 were directly injected bone cement into the vertebral body.The temperature was measured of the gasket on the area near middle of the posterior wall defect area of group A1,group B1 and group C1,and the surface of the bone cement of group A2,group B2 and group C2 at the time of 0min,1min,2min,3min,4min,5min,6min,7min,8min,9min,10 min,11min after the bone cement was injected.(4)It was statistically analyzed of the maximum temperature.Result The temperature of the 0 min of six groups after the bone cement was injected was no statistically significant different.The maximum temperature of group A1 was 37.4?,group B1 was 37.6?,group C1 was 37.5?,group A2 was 51.3?,group B2 was 51.4?,group C2 was 51.5?.The maximum temperature of group A1,group B1,group C1 and group A2,group B2,group C2 had a statistically significant different.No significant difference of the maximum temperature was found in group A1,group B1 and group C1.Conclusion The device can effectively seal the defect area,to avoid the bone cement leaked into the spinal canal and to avoid the thermal damage of the spine cord while reconstructing the thoracolumbar vertebrae with the posterior wall defect.