Analysis of biomechanical parameters of the first metatarsal bone osteotomy

The main objective of the research was to study the stress-strain state in biotechnical systems formed in the performance of corrective osteotomies of the first metatarsal bone. The hallux valgus is a common pathology in humans. The incidence of this pathology in females is up to 64 % and 25 % - in males. Surgical reconstructive treatment remains an urgent problem in modern orthopedics. The situation is caused by unsatisfactory results of treatment. In addition, there is a question about the admissibility of the load in the early postoperative period in patients with quantitative individual assessment. This assessment can be performed using biomechanics. The paper presents methodology for assessing the bone - screw system when performing corrective osteotomies of the first metatarsal bone. The technique allows us to perform a comparative analysis of various methods of osteotomy for a particular patient. In this study, chevron and scarf osteotomy with displacement of bone fragments by 1/3 and 2/3 with different variants of their fixation were examined. To solve this problem, personalized geometric models of the first metatarsal bone were built on the basis of computed tomography data using 3D Slicer and SolidWorks systems. Also models of implants were built. The finite element analysis was carried out in the Ansys Workbench software. The focus was on analyzing the stresses that occur on the plantar surface of the first metatarsal bone head during walking. An assessment of the maximum allowable shear of bone fragments for the normalization of deformities of the forefoot was carried out. The developed technique allows us the choice of an osteotomy variant with the justification of the possibility of simultaneous surgery on both feet for a particular patient.