title: Influence of different fusion techniques in lumbar spine over the adjacent segments: A 3D finite element study.
abstract: The most conventional technique to treat the intervertebral disc degeneration consists on fusing the affected segment with a posterior screw fixation and sometimes with the insertion of a cage in the intersomatic space. However, this kind of surgeries had controversial results in the adjacent discs. The aim of this work was to prove the stabilization of the spine and the decompression of the disc and to analyze the influence over the adjacent segments. With this purpose, four different models were built and simulated under different loading conditions. The stabilization of the spine was ensured by the screw fixation which reduced dramatically the relative motion in the affected segment. On the other hand, the pore pressure showed a high fall in the operated models proving the decompression of the neural structures. In the adjacent segments, the ROM increased up to 50% in the upper disc and 70% in the lower one. The pore pressure and principal stresses also increased after both surgeries. The observed results suggested that the fusion procedure could trigger a cascade degeneration effect over the adjacent discs, while it is also seen that cage insertion helps to maintain disc height in a better way than screw fixation only.
authors: Group of Biomaterials, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain.
authors: José
authors: J
authors: Cegoñino
authors: Group of Biomaterials, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain.
authors: Andrea
authors: A
authors: Calvo-Echenique
authors: Group of Biomaterials, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain.
authors: Amaya
authors: A
authors: Pérez-del Palomar
mesh_terms: D001863:Bone Screws; D020342:Finite Element Analysis; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000502:physiology*; D008954:Models, Biological; D016059:Range of Motion, Articular; D013123:Spinal Fusion / Q000379:methods*
keywords: arthrodesis; cage; finite element method; fusion; intervertebral disc; lumbar spine