Artificial intervertebral disc having limited rotation using a captured ball and socket joint with a compression locking post and a solid ball having a protrusion

摘要

An artificial disc having a pair of opposing baseplates, for seating against opposing vertebral bone surfaces, separated by a ball and socket joint that includes a ball compression locked to a post extending from one of the baseplates. The ball is captured within a curvate socket formed in a peak of a convex structure attached to the other of the baseplates. The socket is formed by opposing curvate surfaces, one on the convex structure and one on the other of the baseplates. While the ball angulates in the socket, its rotation in the socket has a limited range due to interference between a protrusion on the ball that extends into a curvate recess adjacent the curvate socket. The ball and socket joint therefore permits the baseplates to rotate relative to one another through a limited range and also angulate relative to one another.