Method for correcting varus or valgus deformities of bones that form knee joint, eliminating excess torsion

Abstract

FIELD: pediatric orthopedics.SUBSTANCE: intended for the correction of varus or valgus deformities of the limbs while simultaneously eliminating the torsion component. The method includes the application of the apparatus rings and their mounting on wires so that each ring support is perpendicular to the axis of the bone segment above and below the level of deformation; pairs of hinges are installed in diametrical directions in the sagittal and frontal planes. After osteotomy at the level of the apex of the deformity, distraction is performed with the growth of bone regenerate. Angular deformity is corrected by advanced distraction from the concave side of the deformity. Torsional deformation is eliminated simultaneously with the elimination of angular deformation by moving the rods on two pairs of hinges in the appropriate direction. Before inserting the wires, an X-ray of the proximal tibia bones is performed with “markers” installed at the apex of the deformity on the inner and outer sides in the frontal plane. The first Kirschner wire is inserted into the proximal metaphysis of the tibia from back to front through the fibula and passed through both bones - the fibula and tibia – 0.5–1.0 mm below the growth zone. The second wire is passed from the outside to the inside, from the front surface to the back, parallel to the first, crossing relative to the first wire. The third wire is passed between the first two, parallel to them and at the same level, the angle of passing all three wires should exceed the angle of the existing deformation by 10°. The wires are fixed in the ring support, two ring supports are mounted: the intermediate one - at the level of the middle third of the leg and the distal one - at the level of the lower third of the leg, on wires drawn at an angle of 90° to the axis of the tibia. Moreover, on the distal support, the wires are passed through both bones - the fibula and tibia, on the inner side of the proximal support, two pairs of hinges are installed, placing them in a pair diametrically opposite to each other, with a spacing of 90° along the ring support. In the first pair, the hinges are made of curved plates with slots, in which U-shaped posts are installed with the possibility of movement and fixation, which connect to the intermediate support. In the second pair, hinges in the form of bushings are installed at the ends of the rods with the ability to move and fix along the rods curved in the shape of a ring. In this case, the ends of the rods that are not connected to the hinges are connected to the intermediate support; in both cases, the connection to the intermediate support is made with threaded rods and nuts. In this case, the nuts are not tightened; the distal support is fixed to the intermediate support with threaded rods and nuts. After performing a dissection of the skin and soft tissues at the apex of the deformity on the inner surface of the tibia, a corticotomy is performed along the line of deformity, parallel to it, and an oblique osteotomy of the fibula is performed at the border of the middle - lower third of the leg. Corticotomy of the tibia is performed with a chisel, cutting the outer and inner cortical layer of the bone, holding the proximal and intermediate supports with the hands. Rotational movements are performed between them, thereby achieving a fracture of the posterior cortical layer of the bone, and the position of the fragments of the tibia is manually controlled. The nuts on the rods connecting the proximal and intermediate supports are tightened. The wound is sutured. In the postoperative period, after the pain syndrome has been reduced, distraction is performed with the growth of bone regenerate; advanced distraction from the concave side of the deformity is performed at a distraction rate of 0.75 mm per day, both for eliminating varus and valgus deformities, by turning the nuts that connect the ring supports of the apparatus and the threaded rods on the corresponding side by 90° thrice a day. At the same time, torsional deviation is eliminated at a rate of 0.5 mm per day by turning the nuts that move the bushings along the rods, bent in the shape of a ring, connecting the drawbars with the drawbar posts in hinges in the form of bushings, by 90° twice a day. Walking with a load on the operated limb is allowed simultaneously with the start of distraction, the process of formation of the distraction regenerate is monitored radiographically, increasing the load on the limb, the device is dismantled after the “maturation” of the distraction regenerate, after radiographic control.EFFECT: method ensures a significant reduction in rehabilitation measures due to the gradual simultaneous elimination of angular and torsional deformations of the limb segment and a reduction in the maturation time of the formed distraction regenerate of a given shape and size.1 cl, 8 dwg, 1 ex

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