METHOD OF TIBIAL DIAPHYSIS DEFECT REPLACEMENT WITH INDIVIDUAL IMPLANT Russian patent published in 2024 - IPC A61B17/56 A61F2/28 

FIELD: medicine.

SUBSTANCE: method of replacing a tibial diaphysis defect with an individual implant is implemented using a bone tissue resection template, an L-shaped impact pad, a trial implant template, a Z-shaped conductor template and an individual implant for the tibial diaphysis defect replacement, wherein the trial implant template is made of proximal and distal components, pins. Distal component has a stem to control the depth of the canal in the distal portion of the bone, with a mark, holes for pins, a toothed portion and a recess for the proximal component. Proximal component has a stem, a mark, holes for pins, a toothed portion, a slot for a toothed portion of the distal component and a slot for a lower portion of the distal component. Individual implant for tibial diaphysis defect replacement is made by 3D printing by direct laser sintering from titanium powder based on results of computed tomography of tibial bone tissue areas and consists of proximal and distal parts, keys, cortical screws, fixing screws and sealing rollers-dampers. Fixing screws are made with transverse holes for sealing rollers-dampers. Proximal part is made in the form of a body with a leg for fixation in the shin bone, with holes for fixation with cortical screws, with a mark, a slot for fixation of the upper part of the distal part, a slot for fixation of the lower part of the distal part, a slot for a key, transverse holes for fixing screws. Distal portion is made in the form of a body with a leg for fixation in the tibia, a mark, toothed projections for the lower portion of the proximal portion, for fixation of L-shaped impact pad, slot for key fixation, slot for lower part of proximal part, for L-shaped impact pad and holes for fixing screws. Proximal and distal parts can be connected by means of fixing screws with rollers-dampers and keys. Z-shaped conductor template is made with holes for a drill for cortical screws, with protrusions for a slot of the proximal part and can be fixed to the proximal part by means of a pin. L-shaped impact pad, the fitting implant template, the resection template and the Z-shaped conductor template are made of biocompatible plastic using 3D printing technology, based on a three-dimensional model of the patient's bone tissue defect. Prior to surgery, localization of proposed defect of tibia is determined, in computer environment resection of bone tissue is planned, designing and simulating a fitting implant template and a bone tissue resection template, determining the shape and size of the bone defect, performing a three-dimensional computer simulation of the resection template and the implant fitting template, individual implant for tibia defect replacement is simulated and 3D printing of the implant is performed by direct laser sintering by 3D printing from titanium powder. Fitting implant template, a resection template, a Z-shaped conductor template and an L-shaped impact pad are made from biocompatible plastic based on a three-dimensional model of the patient's bone tissue defect. Operation involves approaching a tumour-bearing segment of the shin bone, and performing a resection of the diaphysis according to a template for bone tissue resection. After bone resection, fitting is performed with installation of proximal component into treated proximal bone canal with diameter of 16 mm and depth of 65 mm, marking on bone in accordance with mark on proximal component of fitting implant template, processing a canal in a distal portion of the bone with diameter of 11 mm and depth of 95 mm, performing the depth control of the distal component of the fitting implant template, placing a mark on the bone in accordance with the mark on the distal component of the fitting implant template, assembling the fitting implant template and fixing the distal and proximal components of the fitting implant template with pins through the pin holes, tension of soft tissues is controlled and a proximal part of an individual implant is installed for replacement of a defect of a tibial diaphysis with a cement on a bone mark. Z-shaped conductor template is placed in the slots of the proximal part and fixed with a pin. Two holes are created with 2.5 mm drill for cortical screws. Two cortical screws 40 and 45 mm long are installed in accordance with the holes on the Z-shaped conductor template. Distal portion of the individual implant is installed to replace the defect of the tibial diaphysis in accordance with the proximal portion and the mark on the bone. L-shaped impact pad is placed in the toothed projections and the groove of the distal portion, and the leg is driven in for fixation in the tibia of the distal portion into the bone. Sealing rollers-dampers are installed in transverse holes of fixing screws. Distal and proximal parts are connected to each other. Key is installed in the slots, and the fixing screws are installed in the holes for the fixing screws of the proximal and distal parts. Individual implant for tibial diaphysis defect replacement is made by 3D printing by direct laser sintering from titanium powder based on results of computed tomography of tibial bone tissue sections and consists of proximal and distal parts, keys, cortical screws, fixing screws and sealing rollers-dampers. Fixing screws are made with transverse holes for sealing rollers-dampers. Proximal part is made in the form of a body with a leg for fixation in the tibia, with holes for fixation with cortical screws, with a mark, a slot for fixation of the upper part of the distal part, slot for fixation of lower part of distal part, slot for key, transverse holes for fixing screws, slot for fixation of lower part of distal part. Distal portion is made in the form of a body with a leg for fixation in the tibia, a mark, toothed projections for the lower part of the proximal portion, for fixation of the L-shaped impact pad, a slot for the key, a slot for the lower portion of the proximal portion, for the L-shaped impact pad and holes for fixing screws. Proximal and distal parts can be connected by means of fixing screws with rollers-dampers and keys.

EFFECT: inventions provide optimal anatomical compliance with the geometry of the defect, reduced preparation time and total length of the operation, reduced volume of surgical trauma, reduced time for implementing a personalized approach in treating patients with shin bone defects.

2 cl, 15 dwg