Artificial expansile total lumbar and thoracic discs for posterior placement without supplemental instrumentation and its adaptation for anterior placement of artificial cervical, thoracic and lumbar discs

摘要

A total artificial expansible disc having at least two pairs of substantially parallel shells, which move in multiple directions defined by at least two axes, is disclosed. Several methods for implanting the total artificial expansile disc are also disclosed. The total artificial expansile disc occupies a space defined by a pair of vertebral endplates. An expansion device, which preferably includes a jackscrew mechanism, moves the pairs of shells in multiple directions. A core is disposed between the pairs of shells, and the core permits the vertebral endplates to move relative to one another.