METHOD FOR SURGICAL TREATMENT OF PLANOVALGUS FOOT DEFORMITY IN OLDER CHILDREN USING OSTEOTOMY OF CALCANEAL BONE BASED ON PREOPERATIVE COMPUTER SIMULATION Russian patent published in 2024 - IPC A61B17/56 A61B17/80 A61B17/68 A61F2/28 

FIELD: medicine; traumatology; orthopedics.

SUBSTANCE: invention can be used for surgical treatment of planovalgus foot deformity in children 12–17 with application of calcaneal bone osteotomy based on preoperative computer simulation. At the stage of preoperative planning, multilayer spiral computed tomography of feet and ankle joints is performed with creation of imitation of vertical load with fixation of foot position at angle of 90° to ankle axis, based on the results of which, using computer software, a virtual three-dimensional model of the patient’s planovalgus foot deformity is created. Obtained virtual three-dimensional model of the ankle joint and foot is used to virtually determine a plane of surgical correction of the deformity by setting it perpendicular to the plane of the calcaneal-cuboid joint. In this projection, the longitudinal axis of the hindfoot is virtually determined as a line virtually drawn from the anterolateral edge of the calcaneal bone to the most protruding lateral contour of the calcaneal bone, and a tangent line to the outer edge of the cuboid bone, at the intersection of which the abduction angle of the cuboid bone is virtually determined, which is normally from 0° to 5°. On the created three-dimensional model, perpendicular to the plane of surgical correction, at distance of 1.5 cm from the plane of the calcaneal-cuboid joint, virtual osteotomy of the calcaneal bone is performed, and diastasis formation is simulated relative to the medial cortical layer of the calcaneal bone to restore the normal value of the abduction angle of the cuboid bone. Obtained parameters of the virtually formed diastasis are used to determine the distance between the external corticals of its fragments and its volume, the size of the individual fixing H-shaped reconstructive plate and the volume of the osteoinductive material required to fill the formed defect are calculated. In the process of surgical treatment, a layer-by-layer approach to the calcaneal bone body is performed along the outer surface of the foot and a Z-shaped lengthening of the tendon of the short peroneal muscle is performed. Osteotomy of the calcaneal bone between the medial and anterior articular facets of the calcaneal bone is performed parallel to the calcaneal-cuboid joint at distance of 1.5 cm from the plane of the calcaneal-cuboid joint. In the osteotomy area, a dilator is installed, using which the calcaneal bone fragments are moved apart with the formation of diastasis taking into account the parameters, obtained at the stage of preoperative computer simulation. Fixing H-shaped reconstructive plate is installed on the formed diastasis between the external corticals of the calcaneal bone and fixed with the help of four fixing screws. Diastasis cavity is filled with an osteoinductive material. Wound is closed in layers. Plaster bandage is applied from the metacarpophalangeal joints to the upper one-third of shin for 8 weeks. Osteoinductive material used is granules of a complex alloplastic preparation based on hydroxyapatite, containing 60 wt.% collagen, or granules of osteoplastic biological material based on bone tissue or auto-bone crumb, and an individual fixing H-shaped reconstructive plate is made of titanium alloy BT6.

EFFECT: method provides restoration of accurate anatomical relationships of bone fragments in foot, reduction of operational time of surgical treatment of planovalgus deformity of foot in older children, providing reduced operational time for modeling an individual fixing plate, enabling early activation of the patient due to the implementation features.

3 cl, 3 ex