FIRST METATARSAL HEAD ENDOPROSTHESIS (VERSIONS) Russian patent published in 2025 - IPC A61F2/42 

FIELD: medicine.

SUBSTANCE: according to the first version, the endoprosthesis of the head of the first metatarsal bone consists of an articular head and a leg. Articular head is made in the form of a convex hemisphere in the shape close to the anatomical shape of the head of the metatarsal bone. Articular head comprises a plantar surface having two longitudinal recesses in a sagittal plane for sesamoid bones. Inner surface of the articular head has a lower facet, an intermediate facet and an anterior facet arranged at different angles relative to each other. Lower facet is located at angle of 40-50 degrees to the intermediate facet and at angle of 90 degrees to the front facet. Leg is located at the centre of the intermediate face perpendicular to its surface. Endoprosthesis of the head of the first metatarsal bone according to the second version consists of an articular head and a leg. Articular head is made in the form of a convex hemisphere in the shape close to the anatomical shape of the head of the metatarsal bone. Articular head comprises a plantar surface having two longitudinal recesses in a sagittal plane for sesamoid bones. Inner surface of the articular head has a lower facet, an intermediate facet and an anterior facet arranged at different angles relative to each other. Lower facet is located at angle of 40-50 degrees to the intermediate facet and at angle of 90 degrees to the front facet. Leg is located at the centre of the intermediate face perpendicular to its surface. Additionally, the articular head is provided with an upper inner facet, which is located perpendicular to the intermediate facet.

EFFECT: inventions provide a stable clinical effect consisting in reducing the length of postoperative healing and restoring the function of the metatarsophalangeal joint.

8 cl, 3 dwg