Ferramenta computacional para planejamento cirúrgico tridimensional otimizado da osteotomia periacetabular de Ganz via algoritmos genéticos e método dos elementos finitos

Abstract

Developmental dysplasia of the hip (DDH) is a condition characterized by an abnormal relationship between the femoral head and the acetabulum. Periacetabular osteotomy (PAO) is a hip-preserving surgery that aims to increase acetabular coverage of the femoral head, reducing contact pressures by repositioning the hip joint. In this context, the present thesis aims to develop a computational tool applied to three patients with hip joint deformities. These cases were essential for testing and evaluating the developed tool, with the objective of implementing a clinical-surgical application of a three-dimensional surgical planning method optimized by biomechanical parameters, such as contact pressure, contact area, and contact force. The goal is to assess the safety, accuracy, and reproducibility of the proposed methodology. The planning is obtained through the digital processing of computerized tomography images of patients diagnosed with hip deformities and indications for acetabular and/or femoral osteotomies, performed by a qualified surgeon with extensive experience in digital techniques. The optimization of correction positioning (using two distinct strategies) is derived from computerized analysis of simulated interactions between hip joint surfaces using finite element analysis via Abaqus®, and selection of optimized angles for repositioning the acetabular fragment based on a genetic algorithm. The accuracy of the correction achieved through optimized planning is compared with the pre-operative models and those virtually planned by the surgeon, and it was identified that the latter showed better performance in relation to the pathological model in all case studies. The adjustments in correction proposed by the evolutionary technique (AG) were validated through the analysis of clinical-radiographic parameters in all tested case studies, taking into consideration their normal limits.