HIP JOINT ENDOPROSTHESIS Russian patent published in 2019 - IPC A61F2/32 A61F2/36 

FIELD: medicine.

SUBSTANCE: invention refers to traumatology and orthopedics. Hip joint endoprosthesis comprises a leg for fixation in the femoral bone, a cup for attachment to the cotyloid cavity, a spherical head. Leg is made of titanium alloy and contains an intraosteal portion intended for implantation into the intramedullary canal of the femoral bone and a neck designed to accommodate the head. Intraosteal portion has a tapering width towards the distal end of the leg and has a proximal and distal portion. Cross-section of the proximal portion intended for placement in the metaphyseal portion of the femoral bone has two flat parallel sides related to the anterior and posterior surfaces of the leg, and two rounded sides related to the medial and lateral surfaces of the leg. Medial surface of leg is bent and in frontal projection is parallel to profile of Adams arc. Lateral surface in frontal projection of rectilinear shape. Distal end of distal portion of the leg has cylindrical shape. Medial surface of the proximal portion smoothly along the radius is conjugated with the medial surface of the distal portion and the neck legs. Lateral surface of the proximal portion and a lateral surface of the distal portion form a straight surface. Cross-section of the distal portion intended for placement in the diaphyseal part of the femoral bone has a circle shape at the distal end. Thickness of the proximal portion corresponds to the diameter of the distal portion of the leg. Distal portion smoothly changes into the proximal portion and has a cross-section of diameter equal to the average diameter of the narrow portion of the medullary canal of the femoral bone. Structure of the material of the intraosteal portion has a predetermined structure in the form of longitudinal through cells with a transverse size in range of 0.8 to 1.6 mm and transverse through pores with a transverse size in range of 300 to 500 mcm. Transverse size of the longitudinal cells varies along the length of the leg cross-section. Direction of longitudinal through cells approximating to the medial surface is parallel to the profile of the medial surface in the frontal plane. Direction of longitudinal through cells approximating to the lateral surface is parallel to the lateral surface profile in the frontal plane. Direction of longitudinal through cells at the medial surface smoothly changes into the direction of longitudinal through cells at the lateral surface. In wall cross-section of longitudinal cells of inner part with thickness of 1.0 mm. External surface of leg has thickness of cell walls of 0.5 mm. Surface of the intraosteal portion of the leg contains a bioactive layer of hydroxyapatite with thickness of 40 mcm and is saturated with a wide-spectrum antibiotic.

EFFECT: invention ensures increased service life of the endoprosthesis.

1 cl, 3 dwg