Patent RU-2715439-C2 (RU)
Title: Hip joint prosthesis
Inventor: Varfolomeev Denis Igorevich
IPC: A61F2/36
Filed: 2018-07-16
Granted: 2020-02-28
Abstract: FIELD: medicine. 
     SUBSTANCE: invention relates to medicine. Hip joint prosthesis comprises a cotyloid component, a spherical head, a neck and an endoprosthesis leg, an intramedullary nail. Also, the endoprosthesis includes a second intramedullary nail. Endoprosthesis leg has a cylindrical channel located along the pedicle axis. Through the entire length of the canal, apart from its lower part, there is a groove parallel to it in the endoprosthesis leg; also in the upper and lower parts of the channel perpendicular to its axis in one plane there are upper and lower non-through holes. First intramedullary pin is located in a cylindrical channel and is made in the form of a tube with an external protrusion entering a groove of the endoprosthesis leg and located along an axis of the tube in its upper part, also inside the first intramedullary pin along its axis throughout the entire length, except for its lower part, with an internal side there is a slot, and in upper and lower parts of first intramedullary pin perpendicular to its axis in one plane there are first upper, second upper and lower through holes. In the first upper through hole of the first intramedullary pin along its axis there is a first cylindrical retainer made of ferromagnet for interaction with the magnet brought to the body surface during operation, having T-shaped section, and a spring in free state of which protruding part of the first cylindrical retainer is located in the upper non-through hole of the leg. Inside the first intramedullary nail there is a second intramedullary pin made in the form of a tube with an external protrusion entering the groove of the first intramedullary nail, and located along the axis of the tube in its upper part. In the upper part of the second intramedullary pin perpendicular to its axis there is a through hole located in the plane of the second upper and lower through holes of the first intramedullary pin. In the upper through hole of the second intramedullary pin along its axis there is a second cylindrical retainer from the ferromagnet for interaction with the magnet applied to the body surface during surgery, having a T-shaped section, and a spring, in free state of which protruding part of the second cylindrical retainer is in the second upper through hole of the first intramedullary pin. In lower part of second intramedullary pin there are through holes for dynamic and static screws located perpendicular to its axis. All the elements of the endoprosthesis, except the first and second cylindrical retainers, are made of paramagnetics. It is possible to extend the first intramedullary nail along the axis of the leg and fix it with the help of the first cylindrical retainer in the bottom non-through hole of the pedicle, and possibility of extension of the second intramedullary pin along the axis of the leg and fixation with the second cylindrical retainer in the lower through hole of the first intramedullary nail. 
     EFFECT: invention provides reducing traumatism in surgical treatment of instability of femoral component of endoprosthesis and periprosthetic fractures. 
     1 cl, 6 dwg