| Objective:Evaluate the biomechanical stability of the Locking Axial LumbosacralInterbody Fusion to provide experimental data for future clinical usage.Methods:Six fresh human lumbar spines (L5-S1) were tested by applying puremoments of±10Nm. Each specimen was tested for the following order: normalcontrol group(CG);bilateral spondylolysis(EG1);locking AxiaLIF and bilateralspondylolysis(EG2);AxiaLIF and bilateral spondylolysis(EG3);AxiaLIF,bilateralpedicle screws and bilateral spondylolysis(EG4).The L5-S1range of motion (ROM)were obtained by applying pure moments in flexion, extension, lateral bending, axialrotation and axial compression.Results:①EG1significantly increased ROM in flexion-extension and axial rotationcompared with the intact specimen(CG)(p <0.05).These two groups show nosignificant difference in lateral bending(p>0.05).②EG2,EG3and EG4significantlyreduced ROM in flexion-extension and lateral bending compared with the CG.Inflexion-extension,EG2and EG4significantly reduced ROM compared with EG3(p <0.05),and there is no significant difference between EG2and EG4(p>0.05).Inlateral bending,EG2ROM has no significant difference compared with EG3andEG4(p>0.05),but EG4significantly reduced ROM compared with EG3(p <0.05).③EG2and EG4significantly reduced ROM in axial rotation compared withCG(p <0.05),and there is no significant difference between EG3andCG(p>0.05).EG2significantly increased ROM in axial rotation compared withEG4(p <0.05).In EG2,there is no significant difference between left axial rotation andright axial rotation(p>0.05).EG2,EG3and EG4significantly increased in axialcompressive stiffness compared with CG(p <0.05),but there is no significant difference between three groups(p>0.05).Conclusions:The Locking Axial Lumbosacral Interbody Fusion can significantlyenhanced the stability of lumbosacral vertebral instability in all loading modes.Itprovides a effective solution for the question that the AxaiLIF has a poor stability inaxial rotation. |
