In vitro mechanical testing and finite element analysis of a novel β-Titanium alloy pedicle screw-rod fixation system
LI Jie
LIU Yinan
WANG Dong
LI Haopeng
HE Xijing
LU Teng
Abstract：Objective To compare the biomechanical properties of a novel Ti-3Zr-2Sn-3Mo-25Nb β-titanium alloy and a traditional Ti-6Al-4V titanium alloy pedicle screw-rod fixation system in posterior lumbar interbody fusion(PLIF).Methods In vitro mechanical tests were conducted to evaluate the bending,tensile,compressive,and torsional performance of the β-titanium alloy screws,connecting rods,and the assembled screw-rod fixation system.Two PLIF finite element models were constructed to compare the effects of Ti-6Al-4V versus β-titanium screw-rod systems on range of motion(ROM)and stresses in the endplate and implants.Results In vitro tests showed that the β-titanium alloy screw exhibited good resistance to bending(455.95±18.66 N)and torsion(9.03±0.20 N·m).The maximum tensile load of the β-titanium rod was 17 647.06±101.89 N,and the β-titanium screw-rod system showed a maximum compressive load of 417.65±5.09 N and a maximum torque of 25.00±0.70 N·m.Compared with Ti-6Al-4V,the β-titanium model showed a 2.6%-8.3%increase in ROM,and the peak stresses in the interbody bone graft,cage,and endplate increased by 1.4%-8.5%,2.2%-9.4%,and 2.2%-10.1%,respectively,whereas the peak stresses at the bone-screw interface and within the screw-rod system decreased by 8.8%-23.7%and 19.0%-33.1%,respectively.Conclusion The β-titanium pedicle screw-rod fixation system exhibits good in vitro mechanical performance to provide stability comparable to the conventional Ti-6Al-4V system while markedly reducing stress concentration within the screw-rod construct,suggesting its great potential for clinical application.
Keywords：β-titanium alloypedicle screw-rod fixation systemfinite element analysisposterior lumbar interbody fusion
Publication Date：2026-03-20
Online Publishing Date：2026-04-01(First online date of this platform, not the publication date of the document)
Pages：8( 638-645 )