RADIUS HEAD IMPLANT Russian patent published in 2009 - IPC A61F2/38 

FIELD: medicine; traumatology and orthopaedics.

SUBSTANCE: said implant contains a cylindrical head notched at end face, a cone leg equal-length stepped, a crosswise tool to prevent the implant rotation in intramedullary canal, and a cylindrical neck. The cone leg represents "n" of truncated cones with a cone rounded tip. The smaller bases of the previous cones are coaxially connected with the greater bases of the next cones thereby forming protruding edges and subtending a cone angle of the leg not exceeding 2°. Diametres of the greater bases of edges of the leg truncated cones are 1.5 times more than those of the smaller bases of the respective truncated cones to prevent axial mobility of the implant. The latter is solid and comprises the crosswise tool being coaxially fixed between the equal-diametre cylindrical neck and the greater basis close to the crosswise tool of the truncated cone of the cone leg. The cylindrical head from the neck is bevelled that is perpendicular to the leg axes, and fastened to the neck at the inclination of the head axis to the neck axis at least 10°. The crosswise toll presents a cylinder axially truncated with four equal concave segment surfaces to form four elbow flanges, while double distance from the cylinder axis to distant points of the flanges is 1.2 times more than the neck diametre. The implant design is selected concerning optimal parameters providing geometric penetration of angular flanges of the crosswise tool of the implant radially into spongy layers of intramedullary canal with loaded seating fit of the leg in intramedullary canal, reduced recovery time (within 2-3 weeks) of complete recovery of radial joint and complete mobilisation in elbow and radiocarpal joints.

EFFECT: ensured axial and rotational stability.

4 cl, 3 dwg