PROGNOSIS AND SURGICAL CORRECTION OF LENGTHENING EFFECT OF VALGUS TROCHANTERIC OSTEOTOMY OF THE FEMUR

Background: the article describes the methods for solving the problems of valgus trochanteric osteotomy of the femur. It is noted that the biomechanical aspects of such a surgical operation have not been adequately studied. Aim: to develop and test the calculating methods of evaluating the influence of proximal femur angles of rotation during valgus osteotomy, as well as the femur characteristic dimensions in the osteotomy area on preserving biomechanics of the hip joint. Results: statistical diagrams and analytical dependencies have been obtained to determine changes in the values for vertical, horizontal and full displacement of femoral head center and points of the supporting surface due to valgus osteotomy. The results of calculations on the change in the force and kinematic biomechanical parameters of the femur for a wide range of the valgus osteotomy angles of rotation and the values of characteristic sizes (diameter of the femur, distance from the center of the trochanter to the center of the head) most commonly observed in practice are presented. It has been shown that horizontal displacement of the head center and the supporting surface points creates more favorable biomechanical conditions in the zone of unstable femoral neck fracture. Vertical displacement of the supporting surface, which leads to the elongation of the operated limb, can be decided by rotation of the osteotomised fragment of the femur during the operation for 180 о. Conclusion: the performed mathematical modeling allows planning the parameters of the operation before valgus trochanteric osteotomy of the femur.