MATHEMATIC MODELING OF DESTRUCTIVE AND CYSTIC TUMOR-LIKE PROCESSES IN PROXIMAL FEMORAL PART

Aim. To create the instrument for forming surgical tactics based on predicting the processes of bone destruction in aseptic necrosis and tumor-like cystic processes in the bone tissue of proximal part of the hip using spatial mathematical hip joint model. Materials and methods. For the purpose of studying the pathogenetic mechanism of developing local destructive and tumor-like processes with formation of cystic cavities, a spatial hip joint model developed by the authors was used. By means of the method of finite elements, deformation mode of femoral and caxal bones was calculated taking into account different localizations and sizes of bone tissue destruction foci as a result of bone tissue necrosis and tumor-like processes. Results. The developed model was individualized on the basis of real clinicoroentgenological and anatomic data. Stress fields occurring in normal and “pathologically changed” hip joint, character of these changes corresponded to the posed clinical problem. The created model permitted to study the effect of the form of pathologically changed hip joint on distribution of strain in the whirlbone connective tissue and in case of the other problem posed - in methaphyseal and metadiaphyseal parts of the hip. There is a real possibility to prognosticate the character of pathological fracture, to reveal the areas of critical strain depending on the bone form, foci localization, strength characteristics, forces of different muscular groups and their directions, sizes of formed bone wall defect and other parameters important for a surgeon-orthopedist. Conclusion. The developed model is a good instrument for studying pathogenesis of destructive and cystic foci in the bone tissue, formation of surgical tactics, solving technical problems of defect replacement, determination of risk degree and necessity of using metal pawls or external immobilization in rehabilitation period.