Provided is a device and method for replacing a diseased or damaged
intervertebral disc in the spine of a patient. The device provided having
at least two units, each of the units having an articulation surface and
a bone contacting surface, the articulation surfaces of each of the at
least two being in articulating opposition one to the other, one of which
having a convex articulation surface and the other having a complementary
concave articulation surface. The bone contacting surfaces being provided
with bone implantation securing elements such as keel type or spike type
protrusions. Also provided is a method of implanting the device into an
intervertebral space from a posterior approach.