Biomechanics of the deformity of septal l-struts

Objectives/Hypothesis. During septoplasty, an L-shaped septal strut is often preserved or created. The main goal here is to straighten the nasal septum and to provide the required stiffness of the same. Insufficient stiffness of the septum leads to exceeding the maximum permissible value of its deformation and or its excessive deviation, that could result in functional or aesthetic complications. The aim of this work is to study the influence of the geometrical shape of an L-shaped strut on its stiffness. Designed and testing tools. With the use of means of computer simulation, we developed L-strut cartilage models featuring an improved stiffness and resistance to deformation. On this basis, we developed L-strut models of various shapes from a material simulating the mechanical properties of cartilage tissue. All the models were tested under the same conditions using a multipurpose instrument ZWICK Z100 and a special device simulating the septum loading conditions. Methods. At the first stage of the study, a five-sided septum model was created based on computed tomography scans of human subjects. Then, based on this model, we developed a series of models with various combinations of L-struts, with or without the use of arcs of cartilage. It was assumed that the edges of the septum, connected with the bone support, are fixed, whereas the nasal tip is relatively free-supported. L-strut models were tested under the same loading conditions using a multipurpose instrument ZWICK Z100 and a special device simulating the septum loading conditions. The loading of the models was effected by applying a distributed load along the outer contour, that is the same for all the studied models. On the basis of an experimental data analysis, we assessed the stiffness of the modeled septa. Results. We obtained experimental “Force – Travel” dependence for nasal septum models with different geometry. Is shown that a septum with a wider dorsal strut is characterized by the greatest stiffness. Conclusions. It is found that a septum with a wider dorsal strut is characterized by the greatest stiffness and a higher resistance to deformation. The preservation of an arc of cartilage and a wider dorsal strut increase the overall stability of the structure.