Biomechanical evaluation of the ped icle screw system in the treatment of lumbar spondylolisthesis / 中华骨科杂志

ABSTRACT

Objective To evaluate the biomechanical featu res of the HOIST in the treatment of lumbar spondylolisthesis.Methods Seven fresh cadaver specimens from L 2 to sacrum was used in the study.Each specimen was tested in five statesintact state as the control,spon dylolisthesis model by Panjabi meth od without fixation,spondylolisthesis model fixed with HOIST device,fatigued test of the HOIST and fixed with DICK system.During the experiment,the flexion,extension,bilateral bending and axial rotation loading we re applied to the specimens and measure d with three dimensional analysis ap paratus.A fatigue process of HOIST device was carried out with multifunctional test system(MTS 858,American).The ranges of motion(ROM)of spinal segments were determined with two special cameras and t test was used in statistical analysis.Results The ROM in spondylolisthesis state was significantly greater than that o f the others(P0.05).The difference among two HOIST grou ps and DICK group was not significant at the0.05level except the ROM of left axia l rotation(P