Patent RU-2673980-C1 (RU)
Title: Set for hip replacement
Inventor: Varfolomeev Denis Igorevich
IPC: A61F2/32
Filed: 2018-05-10
Granted: 2018-12-03
Abstract: FIELD: medicine. 
     SUBSTANCE: invention relates to medicine. Hip joint endoprosthesis replacement kit consists of the acetabular component, a spherical head, an intramedullary pin, a neck and a leg of the endoprosthesis. Inside the leg there are through holes located perpendicular to the axis of the legs, on several levels of the legs in different planes relative to each other. At the end of the stem there is an external thread for connection with the intramedullary pin, the upper part of which is designed as a cylinder with an internal thread for connection with the endoprosthesis leg. Lower part of pin is made in form of tube with holes for dynamic and static screws arranged perpendicular to its axis, and inner thread in its upper part. Upper and lower parts of intramedullary pin are connected by means of locking mechanism, including joint and pin located in tube channel and wrapped in thread of lower part of pin. Ball head of joint has a cylindrical projection and is connected to upper part of pin, and joint body has a corresponding slot for cylindrical projection and is connected to lower part of pin. Head of the hinge has a through hole located along the axis of the upper part of the intramedullary pin, and on the lower surface of the hemisphere of the hinge head there are non-through holes that connect with each other and with a through hole of the upper part of the intramedullary pin in the center of the hinge head, so that in any position of the hinge head one of the holes is connected to the canal tube of the lower part of the intramedullary pin. Along the axis of the legs is the central channel with extensions in its upper and lower parts. In the leg there are pairs of parallel through holes, perpendicular to the axis of the leg on both sides of the central channel, on several levels of the leg in different planes relative to each other. In each of the pair of parallel through holes there is a thread starting from the surface of the stem and ending in the middle of the stem and located on opposite sides of the central channel. Inside each of the two parallel through-holes of the leg is a screw, half of which contains a thread screwed into the thread of the hole, and the second half of the screw is made in the form of a hexagon. In the middle of each of the pair of parallel through holes there is a cylindrical expansion, inside which there is a worm wheel with a hole in the center corresponding to the hex of the screw, and in the central channel there is a worm shaft, having at the upper end a head with a screwdriver groove located in the upper expansion of the central channel and at the lower end a head with a screwdriver groove located in the lower expansion of the central channel. In the leg there are two side channels, starting in the lower expansion of the central channel, located along the front and rear walls of the leg, connected to the through holes of the leg, which have no threads. 
     EFFECT: invention provides a reduction in the morbidity in the surgical treatment of periprosthetic fractures, as well as an increase in the stability of the femoral component of the endoprosthesis in the surgical treatment of instability. 
     1 cl, 9 dwg