DEVICE FOR VERTEBRAL SEGMENTS FIXATION Russian patent published in 2020 - IPC A61B17/70 A61B17/80 A61B17/86 

FIELD: medicine.

SUBSTANCE: invention relates to medicine. Device for vertebral segments fixation includes plate (1) and screws (7). Plate is made in form of rectangle with concave sides and rounded corners and with four holes (2) at corners. Screws are made in the form of a head and a rod with a threaded part and smooth undercut. Plate is made in the form of a section of a toroidal surface with a radius of curvature in width of 39.7–40.3 mm and along length of 170.5–171.5 mm. Holes are made in the form of cylindrical part and spherical seat for screw head, wherein axis of cylindrical part of each hole is perpendicular to chord of lower surface of plate with large radius of curvature. Axis of each hole is directed at convergence angle 5° to plate axis of symmetry in transverse direction. Diameter of cylindrical part of holes is equal to diameter of screw. Outer diameter of threaded part of screw is equal to diameter of smooth undercut. Screw head is made in form of parallelepiped in upper part and spherical surface in lower part, wherein profile of spherical surface of screw head is mapped to profile of spherical surface of seat of plate hole. Height of screw head is equal to height of seat of plate hole. Threaded part of the screw is made in the form of a stop thread, at that the inner diameter of the thread is tapered with conicity angle less than self-braking angle. Length of smooth undercut is 0.25–0.34 of the total length of the rod of the screw.

EFFECT: invention provides eliminating a high risk of damaging an adjacent intervertebral disc.

1 cl, 10 dwg