A bone block for insertion into a patient's intervertebral space. A method
for inserting a bone block into a patient's intervertebral space,
comprising: supporting the bone block in an inserter; advancing the
inserter into the intervertebral space; rotating the inserter, thereby
separating adjacent vertebrae; separating the bone block and the inserter
with a push rod; and removing the inserter from the intervertebral space.