A novel device and method for fusions inside a forward widely tapering
human disc space. A stabilizing/guiding system is driven into and against
the disc space. The device is further stabilized by spreading and
gripping means inside both vertebral end plates. Rod retaining members
hold calibrated rod units whose adapted tips perform reaming and
threading of the disc space. Subsequently, the tapered cage or implant
can be inserted by a free-hand method under direct vision into the
prepared and tapered bed. Rod unit divergent angulation is preferably set
to match that of the disc space as well as the implants so they obtain
optimal distributed purchase of vertebral bone. In one embodiment,
inserts are confluent with parallel medial walls rather than their long
axes, increasing torsional or lateral translational stability and
simplifying placement of additional bone chips. No tubular guide means
are required.
