INDIVIDUAL RETRACTABLE FEMORAL COMPONENT WITH REMOTE DISTRACTION Russian patent published in 2024 - IPC A61F2/36 

FIELD: medicine.

SUBSTANCE: individual retractable femoral component with remote distraction comprises a body, a prosthetic rod, a reducer, a drive screw, a sleeve, a radially polarized permanent neodymium magnet with a drive and an expander with a rod for the remaining bone. Expander is made with flats for plates located in the body with the possibility to prevent rotation. Driving screw is connected to the gear wheel of the output shaft through a hexagon made on the axis of the gear wheel of the output shaft. Reducer is located in the sleeve. Radially polarized permanent neodymium magnet is glued into the cartridge and closed with a cover. Drive of the radially polarized permanent neodymium magnet is made in the form of a permanent magnet rotating at a distance. Stop is pressed into the central hole of the cartridge, and on the other side of the cartridge there are teeth, forming the first gear wheel, which engages with the gear wheel, into the hole of which one of the small gear wheels enters, which engages with one of the gear wheels mounted on the gear wheel. one of the small gear wheels, forming the reduction gear section. Reducer consists of sections. In the penultimate section, three gear wheels and three small gear wheels are installed, installed with a gap on each axle and engaged with a gear wheel located on a gear wheel engaging with three pairs of gear wheels, which are located on each small gear wheel, which in turn engage with gear wheel of output shaft, providing possibility of torque transmission through reducer. All small gear wheels are installed with a gap on axes passing through the reduction gear, and their axial movement is limited by boards. In the holes in the boards, as well as in the holes in the spacers, pins are pressed for rigidity of the reduction gear. Ends of pins and axes enter blind holes made in the body; thus, holding the gearbox against cranking. Tightness of the cavity formed by the sleeve, the body, the prosthetic rod and the axis is ensured by the O-rings. Central axle is fitted in central holes of said boards to loose fit accommodate central gear wheels and output shaft gear wheel. Reducer is pressed to the ledge made in the sleeve by a spring washer. Rotation of the drive screw causes axial movement of the expander.

EFFECT: invention provides improved functional properties of endoprosthesis, including considerable reduction of diameter and length of universal drive mechanism of retractable endoprosthesis and possibility of elongation of bones of smaller diameter in surgical treatment of defects of short and long bones.

1 cl, 3 dwg, 1 ex