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.