Evaluation of the behavior of five intersomatic cervical spacers using the finite element method

Abstract

Introduction: cervical pain is a symptom frequently found in clinical practice. One of the most frequent treatments for this condition, specifically for disc herniations, is discectomy with anterior cervical arthrodesis. The use of iliac crest graft is the habitual practice in Cuba, although it is gathered the antecedent of the use of other materials. Objective: to compare the behavior of grafts of bovine cortical, hydroxyapatite, polymethylmethacrylate, chromium-cobalt-molybdenum and tricortical autograft of iliac crest in the intervertebral space C6-C7 before the usual loads of cervical column. Methods: an experimental study was carried out by means of numerical simulation according to the finite element method, the different grafts were subjected to the axial loads recommended by the ASTM F2423-11e ISO 18192-1.2011 standards by means of the Free CAD 0.18 software in the C6-C7 space of an experimental model of the cervical spine. Results: the highest stresses supported by different grafts were: tricortical: 19190 kPa, xenograft: 13210 kPa, hydroxyapatite without porosity and with 50% porosity: 41500 kPa and 45100 kPa, respectively, polymethylmethacrylate: 4440 kPa and chrome-cobalt-molybdenum: 148470 kPa. Conclusions: all the grafts resisted the applied load except for the hydroxyapatite with 50% porosity. The tricortical graft described an adequate behavior. All caused stress in the adjacent vertebrae, mostly polymethylmethacrylate and chromium-cobalt-molybdenum.

Keywords

• artrodesis cervical
• injertos intersomáticos
• elementos finitos