Patent ID: 7537611
Filing Date: 2009-05-26
Classification: A61B,A61F

Abstract:
1. A prosthetic implant for replacing a facet joint in a spinal motion segment of a human spinal column comprising: a superior component adapted to be implanted at a surgically prepared site on an inferior articular process of a cephalad vertebra of said spinal motion segment, said superior component comprising a generally conical prosthesis having a smooth generally conical external surface and a tapered internal cavity adapted to be implanted on a tapered resected portion of said inferior articular process of said cephalad vertebra, and an inferior component adapted to be implanted at a surgically prepared site on a superior articular process of a caudad vertebra of the spinal motion segment, said inferior component comprising a cup having a sidewall and a hollow interior, and a base adapted to be implanted at said surgically prepared site on said superior articular process with said cup being oriented cephalad to receive said external surface of said superior component within said hollow interior, said sidewall of said cup having an inner surface with an angular flare greater than an angular flare of said external surface of said generally conical prosthesis, said hollow interior of said cup and said angular flare of said inner surface being configured such that upon full extension of said spinal motion segment said generally conical prosthesis fits tightly within said sidewall of said cup and upon flexion of said spinal motion segment, said generally conical prosthesis fits loosely within said sidewall of said cup.