US 5,534,031 AGranted

Prosthesis for spanning a space formed upon removal of an intervertebral disk

AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha

InventorsHiromi Matsuzaki, Satoshi Ojima, Masashi Nakamura

Life of this patent

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Abstract

An artificial vertebra spacer is embedded in and bridges a space between two adjacent vertebrae which are positioned superiorly and inferiorly of a removed intervertebral disk, respectively. The artificial vertebra spacer includes a hollow cylindrical member, and a helical screw thread disposed integrally on and extending helically around the hollow cylindrical member. An annular plate has a tubular member fitted in an axial end of the artificial vertebra spacer and a circular flange extending radially outwardly from the tubular member. The circular flange is fastened to the helical screw thread by screws when the artificial vertebra spacer is embedded in the vertebrae. Each of the artificial vertebra spacer, the annular plate, and the at least one screw is made of a titanium alloy.

Claims10

Dependent claims

An assembly member comprising:

an artificial vertebra spacer comprising a hollow member adapted to be embedded in two adjacent vertebrae which are positioned above and below a removed intervertebral disk, with respective confronting portions of the vertebrae being positioned within said hollow member, said hollow member being made of a material having a predetermined degree of mechanical strength and rigidity;
and
a plate connected to an end of said artificial vertebra spacer which is exposed on the vertebrae when said hollow member is embedded in the vertebrae;
wherein said hollow member is of a cylindrical shape and has a helical screw thread on an outer circumferential surface, said helical screw thread having screw holes defined therein parallel to an axis of said hollow member, said plate being of an annular shape having an outside diameter which is substantially the same as the outside diameter of said helical screw thread, further comprising at least one screw extending through said plate and threaded into said screw holes defined in the helical screw thread, thereby fastening said plate to said artificial vertebra spacer.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 08/306,430Filed 19 Sep 1994 · continuation
Priority: JP 4-3856628 Jan 1992
Granted: 9 Jul 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification27 codes

A61L 31/022
Inorganic materials: metals or alloys
A61F 2/446
For the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages: having a circular or elliptical…
A61L 27/06
Metals or alloys: titanium or titanium alloys
A61B 17/7059
Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant: cortical plates