ENDOPROSTHESIS OF HIP JOINT FOR CASES OF DEFECTS OF COTYLOID CAVITY, AFTER REVISION INTERVENTIONS, WHEN THERE IS RISK OF DEVELOPING PERI-IMPLANT INFECTION AND DISLOCATION OF SPHERICAL HEAD Russian patent published in 2024 - IPC A61F2/32 A61F2/34 A61F2/36 

FIELD: medicine.

SUBSTANCE: hip joint endoprosthesis for cases of defects of the cotyloid cavity, after revision interventions, when there is a risk of developing peri-implant infection and dislocation of the spherical head, includes an acetabular component, polyethylene insert, locking ring, spherical head, neck and leg of femoral component, metal cylindrical retainer from ferromagnetic with compression spring, magnet for attracting a metal cylindrical retainer from a ferromagnetic, rods for preventing dislocation of a spherical head with compression springs, each having a projection and a polyethylene coating, tension spring with retainer to turn locking ring, the latter can retain rods to prevent dislocation of spherical head. In the acetabular component there are drug reservoirs connected to the surface of the acetabular component by means of outlet channels closed with plugs from a pH-sensitive polymer, which have the possibility of deformation with reduction of dimensions for opening of outlet channels at reduction of pH of articular fluid to the specified value. At the base of the leg of the femoral component in the opening there is a container with four reservoirs with drugs, from which there are channels with pH-sensitive polymer plugs extending to the surface of the container, having the possibility of deformation with reduction of dimensions for opening of the outlet channels when the pH of the articular fluid is reduced to a given value. Outside the polyethylene insert along the perimeter of the cotyloid component there is a slot of rectangular cross-section for a locking ring. Front wall of the acetabular component and the outer wall of the rectangular slot comprises a first blind hole for a metal cylindrical retainer made of a ferromagnetic with a compression spring, having an axis parallel to the flat part of the acetabular component. Upper wall of the acetabular component and the external wall of the rectangular slot comprises a second blind hole for an extension spring fixed therein, having an axis parallel to the flat part of the acetabular component. Around the polyethylene insert inside the cotyloid component there are equidistant holes for rods to prevent dislocations of the spherical head with compression springs with the possibility of each of these rods extending from the blind holes, wherein axes of said holes pass through slot of rectangular section and intersect at one point above flat surface of cotyloid component. Each of the blind holes has a longitudinal groove inside for the protrusion of the rod to prevent dislocation of the spherical head. Locking ring is made with through holes corresponding to blind holes of the cotyloid component for rods to prevent dislocation of the spherical head. On the front surface of the lock ring there is a retainer of the tension spring for rotation of the lock ring. On the outer surface of the retaining ring there is a slot for a metal cylindrical retainer made of a ferromagnetic material. After bringing the magnet to attract the metal cylindrical retainer from the ferromagnetic, the latter has the possibility of exiting the slot of the retaining ring, wherein under the action of the tension spring with the retainer for the locking ring rotation, the locking ring has the possibility of being rotated in the rectangular groove, wherein the through holes of the retaining ring, corresponding to the blind holes of the cotyloid component for the rods to prevent dislocations of the spherical head from the polyethylene insert, have the possibility of coincidence with these holes, and rods to prevent dislocation of spherical head from polyethylene insert have possibility of extension under action of compression springs from blind holes till contact of protrusions with locking ring.

EFFECT: invention provides an increase in the number of antibacterial agents entering the wound, respectively, preventing the development of paraprosthetic infection, preventing dislocations in the artificial joint.

1 cl, 7 dwg, 1 ex