Is there any advantage of using stand-alone cages? A numerical approach

BioMedical Engineering OnLine

Andrea Calvo-Echenique¹  José Cegoñino¹  Amaya Perez del Palomar¹ 

[1] 0000 0001 2152 8769, grid.11205.37, Group of Biomaterials, Aragón Institute of Engineering Research (I3A), Mechanical Engineering Department, University of Zaragoza, C/Maria de Luna s/n. Betancourt Building, 50018, Saragossa, Spain;

关键词: Finite element method;    Intervertebral disc;    Lumbar spine;    Stand-alone cages;    Posterior screw fixation;    Posterior lumbar interbody fusion;   

DOI  :  10.1186/s12938-019-0684-8

来源: publisher

【 摘 要 】

BackgroundSegment fusion using interbody cages supplemented with pedicle screw fixation is the most common surgery for the treatment of low back pain. However, there is still much controversy regarding the use of cages in a stand-alone fashion. The goal of this work is to numerically compare the influence that each surgery has on lumbar biomechanics.MethodsA non-linear FE model of the whole lumbar spine was developed to compare between two types of cages (OLYS and NEOLIF) with and without supplementary fixation. The motion of the whole spine was analysed and the biomechanical environment of the adjacent segments to the operated one was studied. Moreover, the risk of subsidence of the cages was qualitatively evaluated.ResultsA great ROM reduction occurred when supplementary fixation was used. This stiffening increased the stresses at the adjacent levels. It might be hypothesised that the overloading of these segments could be related with the clinically observed adjacent disc degeneration. Meanwhile, the stand-alone cages allowed for a wider movement, and therefore, the influence of the surgery on adjacent discs was much lower. Regarding the risk of subsidence, the contact pressure magnitude was similar for both intervertebral cage designs and near the value of the maximum tolerable pressure of the endplates.ConclusionsA minimally invasive posterior insertion of an intervertebral cage (OLYS or NEOLIF) was compared using a stand-alone design or adding supplementary fixation. The outcomes of these two techniques were compared, and although stand-alone cage may diminish the risk of disease progression to the adjacent discs, the spinal movement in this case could compromise the vertebral fusion and might present a higher risk of cage subsidence.

【 授权许可】

CC BY