A spinal interbody or intravertebral device is provided for fusion and
non-fusion spinal applications. The spinal interbody device allows for
limited motion between adjacent vertebrae to help preserve normal motion
between adjacent vertebrae (superior/inferior vertebrae) relative to the
implanted spinal interbody device and limited rotational motion of the
spinal interbody device, once implanted. Limitation of motion is achieved
through one or more protrusions incorporated into the spinal interbody
device. The protrusions preferably, but not necessarily, extend radially
from a hub or ball-shaped body of the interbody device. In one form, a
single protrusion extends radially about the hub of the interbody device
to form a continuous band, ring or base about the hub. In this form,
portions of the band may extend radially further from the hub than other
portions of the band. Preferably, but not necessarily, in this form the
band extends radially a greater distance from the hub in the posterior
and anterior directions. In another form, a first protrusion extends
radially from one side of the hub while a second protrusion extends
radially from another side of the hub. Anchoring means may also be
provided for attachment to upper and lower vertebrae.