METHOD FOR REPLACEMENT OF DEFECTS OF PROXIMAL TIBIA WHEN PERFORMING KNEE JOINT ENDOPROSTHESIS REPLACEMENT AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2020 - IPC A61B17/56 A61F2/38 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to traumatology and orthopedics, and can be used for replacement of defects of proximal tibia when performing knee joint replacement. At the stage of preoperative planning performing, through multispiral computed tomography data, constructing a three-dimensional model of a proximal tibia with a defect and a defect-substituting augment by additive techniques, as well as taking into account the shape of the tibial component of the endoprosthesis and the planned augment with their mutual positioning. Individual shape of the augmentation body is determined taking into account the bone defect configuration. Plane and porous zones of its surface are planned and planned on 3D-models of augment. Thickness of its walls is planned by means of virtual reconstruction necessary axes relative to bone reference points. Final version of the augment completely compensating for the existing bone defect and a congruent adherent surface of the tibial component of the endoprosthesis is created. At next stage 3D-printing of plastic prototype of augment and plastic model of proximal tibia with bone defect is carried out. After fitting and fitting by smoothing the bone defect edges to facilitate the augmentation taking into account the tibial component of the endoprosthesis. After its fitting using the tibial component of the endoprosthesis, 3D printing of the augmentation of powdered titanium is performed in full compliance with created 3D-model. At the stage of the reconstructive surgery, an initially planned augmentation to the defect of the proximal shin of the shinbone is first established. After achieving the required congruence, the standard tibial component of the endoprosthesis is installed using the bone cement under the required angle of inclination and taking into account the planned axes and anatomical landmarks. If necessary, CT images of the contralateral tibia are used, by means of virtual reconstruction the sites of future attachment of soft tissue periarticular structures are planned, in which ligatures are planned, the edges of the bone defect are smoothed and the scar tissue is excised. Device for method implementation includes hollow body with porosity consisting of diaphyseal and metaphyseal parts. Body in strictly personified form, preferable for each specific patient, is made using additive technologies based on three-dimensional modeling at the stage of surgical intervention planning. Body is made on individual relief of proximal shin bone in accordance with existing defect. Inner surface of the body is congruent with the mating surface of the endoprosthesis component. Outer surface is made with individually selected smooth and porous zones depending on diligence of surrounding soft-tissue structures. Thickness of walls is selected taking into account features of individual anatomy of patient and value of bone defect at preoperative planning stage. On the anterior surface of the body in the projection of tuberosity of the shin bone perpendicular to the longitudinal axis of the endoprosthesis leg there are at least three channels for ligatures, and the inlet and outlet openings of the canals are arranged outside.

EFFECT: method provides support ability and recovery of lower extremity function, as well as a full support for the tibial component of the knee joint endoprosthesis and its strong primary fixation and accurate replacement of bone tissue defect with reconstruction of anatomical shape of injured tibia, improvement of osteointegration of an augment into a receiving bone bed and preservation of the maximum possible volume of an affected tibia due to preoperative planning and individual manufacture of an endoprosthesis.

4 cl, 8 dwg, 2 ex