Finite element analysis of unilateral and bilateral pedicle screw fixation before and after segment fusion in transforaminal lumbar interbody fusion / 重庆医学

ABSTRACT

Objective To explore the difference between before and afteintervertebral fusion in transforaminal lumbainter-body fusion (TLIF) by unilateral obilateral pedicle screw (PS) fixation .MethodThe L3 -5 Cdatbased on the normal people were used to rebuild the L3 -5 three-dimensional finite elemenmodel(INT) and TLIF operative model .On thibasi,the unilateral Pfixation (M1) and bilateral Pfixation (M2) modelbefore the intervertebral fusion and the unilateral Pfixation (M3) and bi-lateral Pfixation (M4) modelafteintervertebral fusion were buil.Aftesetting the boundary and loading the burden ,the ante-flexion ,retroversion ,lateral bending and rotation of lumbavertebrwere simulated and the L 4 -5 segmenanguladisplacemenand the stresdistribution of implanwere recorded .ResultThe unilateral and bilateral Pfixation model before fusion reduced the range of motion(ROM ) of segmencompared with the Inmodel ,the bilateral fixation wareduced greatethan the unilateral fixa-tion ,buthe difference aftefusion wasignificantly decreased .The peak Von Misestressebefore fusion in the unilateral Pfixa-tion wasignificantly highethan thain the bilateral fixation ,while theipeak Von Misestresseaftefusion trended to be con-sisten.Conclusion The unilateral Pfixation aftefusion can provide the consistensegmenstability same to the bilateral Pfixa-tion .The long-term effecof TLIF with unilateral Pfixation isimilato thawith the bilateral Pfixation .