MOVABLE TYPE PYRAMID SPACER

摘要

PURPOSE:To make a pyramid movable after implantation and to enhance bio- compatibility without imparting a feeling of physical disorder, by forming an artificial intervertebral disk by grasping a medical grade synthetic polymer having rubbery elasticity between a pair of end part bodies each having an apatite layer on the outside surface thereof through a bonding member. CONSTITUTION:In an artificial intervertebral disc, a medical grade synthetic polymer 3 having rubbery elasticity is grasped between a pair of end part bodies 1 by a bonding member 2 and an apatite layer 4 is provided to the outer surface of each of the end part bodies 1. Each of the end part bodies 1 made of titanium forms a flat rectangular parallelepiped shape and has an inverted cone-shape projection 1a turning outwardly at the center thereof. This projection 1a is embedded in the hole formed by opposing adjacent pyramids to each other by operation and has effect for preventing the detachment of each end part body from the pyramid. The bonding member 2 made of titanium or stainless steel has a flat rectangular parallelepiped-shape embedding part 2a slightly smaller than each end part body 1, the columnar projection 2b provided to the center part of the embedding body 2a and brought into contact with the end part body 1 and the screw 2c provided to the columnar projection 2b and screwed in the end part body 1.