Patent ID: 7776092
Filing Date: 2010-08-17
Classification: A61F

Abstract:
1. An intervertebral disc prosthesis for implanting between adjacent vertebrae in a spinal motion segment, comprising: an upper rigid prosthesis endplate for fixation to an adjacent upper vertebra, and having a periphery, an antero-posterior dimension, and a transverse dimension, a lower rigid prosthesis endplate for fixation to an adjacent lower vertebra, and having a periphery, an antero-posterior dimension, and a transverse dimension, and an elastomeric core located between said prosthesis endplates and attached to said endplates, said elastomeric core including at least a first elastomeric core member and having a total cross-sectional area in a horizontal plane and durometer hardness sufficient to provide sufficient compressive strength to support physiological axial loads, and said elastomeric core having at least an average antero-posterior dimension, sufficiently less than at least one of said upper prosthesis endplate antero-posterior dimension and said lower prosthesis endplate antero-posterior dimension, such that said elastomeric core does not protrude beyond the periphery of one of said prosthesis endplates during normal flexion and extension of said spinal motion segment, wherein a maximum antero-posterior dimension of said elastomeric core in a central horizontal plane of said prosthesis is less than a maximum transverse dimension of said elastomeric core in said central horizontal plane and each prosthesis endplate has a ratio of a maximum antero-posterior dimension thereof to a maximum transverse dimension there of that is different from a ratio of said maximum antero-posterior dimension of said elastomeric core to said maximum transverse dimension of said elastomeric core in said central horizontal plane.