Biomechanical Research on Oblique Lateral Interbody Fusion at L5/S1 under Osteoporotic Conditions and Two Types of Posterior Fixation:A Finite Element Analysis
Objective To evaluate the biomechanical performance of oblique lateral interbody fusion at L5/S1 segment(OLIF51)and its combination with bilateral cortical bone trajectory screw(CBT)and bilateral pedicle screw(BPS)under osteoporotic conditions.Methods One male healthy youth was recruited as a volunteer to obtain 3D CT data of the lumbosacral spine,and the modeling of the L4-S1 3D model,the OLIF51 surgical model with only anterior titanium plate(TP)fixation,the OLIF51+CBT,and the OLIF51+BPS surgical model was completed in finite element analysis software and were named as models A,B,C,and D respectively.The values were assigned,conditions were set,loads were applied,and the biomechanical properties were analyzed under different conditions.Results The construction of four finite element models was completed.The mean range of motion for the four models over all motions tended to be model A＞model B＞model C＞model D;Among which,compared with model A,model B decreased from 84.21%to 94.42%,model C decreased from 88.12%to 96.40%,and model D decreased from 90.07%to 96.49%(P all＜0.05);Compared with model B,model C decreased from 7.41%to 52.38%and model D decreased from 27.78%to 58.33%(P all＜0.05).The trend of the mean maximum stress change of Cage in all motions for the three surgical models was model B＞model C＞model D;Among which,compared with model B,the decrease of model C was 12.89%-57.62%,and the decrease of model D was 36.43%-73.11%;there was a significant difference between model D and model C compared with model B,except for the left lateral bending(P all＜0.05);The decrease of model D was 21.83%-37.67%.The trend of the mean maximum internal fixation stresses in all movements for the three surgical models was model B＞model C＞model D;Compared with model B,the decrease ranged from 3.55%to 65.47%for model C and 18.58%to 84.41%for model D;and the CBT stresses were greater than the BPS stresses(P＜0.05).Conclusion Supplemental posterior internal fixation in the OLIF51 procedure enhances the stability of the fused segment and reduces stress on the TP.OLIF51 surgery alone is not recommended for osteoporosis patients,and BPS-assisted fixation provides optimal biomechanical properties.Patients undergoing CBT-assisted internal fixation need to wear a brace postoperatively and avoid bending and avoid right-sided flexion of the fusion site.
oblique lateral interbody fusion at L5/S1stabilityinternal fixationfinite element analysis
万方数据
维普
