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

摘要

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.