Cervical intervertebral prosthesis

摘要

A cervical intervertebral prosthesis includes two connection plates adapted for connection to adjacent vertebral bodies and a hinge core. The hinge core and one connection plate together form a hinge with a concave hinge surface on the hinge core and with a complementary convex hinge surface on the connection plate. The hinge core bears on the other connection plate via a slide surface which extends substantially parallel to the direction of the connection plate and which permits a relative movement in this direction and is surrounded by an edge limiting this relative movement. The concave hinge surface encloses the convex hinge surface within a solid angle of at least 90°. The part of the concave hinge surface lying within this solid angle lies inside the recess surrounded by the edge. The stability of the prosthesis with respect to laterally incident forces is thereby increased.