Biomechanical support for the physician's decision when choosing a treatment option based on quantitative success criteria

Preoperative planning for the treatment of the consequences of diseases and injuries of the spino-pelvic complex surgical treatment is a mandatory procedure and should ensure the selection of implants, modes and techniques for their installation, as well as the reconstruction of the optimal biomechanics of the operated segment. For each individual patient, the surgeon chooses a treatment variant based on his qualitative and quantitative individual parameters. Therefore, the task of developing some measurable characteristics (criteria) seems to be urgent, with the help of which it would be possible to choose a successful variant for each specific patient. In surgery of the spino-pelvic complex pathologies, it is customary to use questionnaires of the patient's quality of life to assess the long-term treatment results. During preoperative planning, surgeons also calculate geometric parameters to assess the degree of deformity and select the necessary correction. At the same time, a geometrically and anatomically correctly planned operation may not be successful in terms of assessing the strength of implanted structures and the “bone-implant” system as a whole. This paper presents the results of the development and testing of criteria for assessing the success of surgical reconstructive treatment of the consequences of the spino-pelvic complex diseases and injuries. Three groups of criteria have been identified: geometric, biomechanical, and clinical. Geometric and biomechanical criteria make it possible to obtain short-term postoperative prognosis. The use of clinical success criteria makes it possible to formulate long-term postoperative prognosis. The criteria for assessing success do not offer the surgeon any new treatment variant, but only provide a tool for quantitative comparison of the treatment variants that are considered by him and the choice of successful ones among them. The criteria for evaluating the success of treatment are implemented in the Smart Plan Ortho preoperative planning system developed at Saratov University, which provides a full cycle of preoperative planning in accordance with the planning–modeling–forecast methodology.