Možnosti fixace zlomenin zubu druhého krčního obratle
Title Alternative:Fixation Options for Dens Fracture of Second Cevical Vertebra
Technická Univerzita v Liberci
Dissertation deals with very current today and still debated issue - the possibility of surgical fixation of fractured odontoid process of second cervical vertebra. Based on the comparison of the advantages and disadvantages of stabilization techniques there seems to be the most physiological method the anterior direct screw fixation of fractures, because the only lets accomplish two major goals imposed on the current reconstruction of spine fractures. That is restoring of full stability while maintaining its unlimited dynamic functionality. Although a direct odontoid osteosynthesis is not a new surgical technique there are still a number of unanswered questions. One of them is controversy if is necessary application of two osteosynthesis screws (lag and anti-rotation) to achieve sufficient primary stability, or whether it is sufficient to introduce only a single (lag screw), which would eliminate the high risks resulting from the difficult and dangerous deployment. Answer to this question and also to propose the optimal way of solving aims in this study. In the first part I present the various types of fractures of the odontoid process C2 and discuss all currently used methods for their therapeutic solutions. Emphasis is placed on the evaluation of the advantages and disadvantages of different surgical approaches and fixation techniques. Followed dens axis stress numerical analysis by FEM models. The experimental part of the thesis I focused first on the simulation of fracture of the dens on human cadaver C2 vertebrae with the determination of fracture strength (bending stiffness) and comparison the data with the literary sources. Subsequently I performed the experimental anterior fixation of fractured dens with using of lag screws with determination of the optimum tightening torque and furthermore I realized a comparison of the stability of this anatomical fixation in bending and torsion after fixation of one and two screws. Based on the results of upper mentioned study I dedicated the final part of the dissertation to experimental design of a new fixation system for more optimal solution of one-screw direct osteosynthesis of odontoid fracture.