I'm not a chiropractor or back doctor, so I cannot guarantee it will be put back together correctly if you buy it.  This is a vintage piece from West Germany (after WWII to the fall of the Berlin wall).  These are still made by 3B and sold on Amazon (where I got the spine numbers).  Looks to be complete when comparing it to the modern version.  This one is missing a peg on the back which can hold one of the disks (you can see the glue spot in the photos).  Base measures about 4.75" x 4.75".  Neat object for the office, for home schooling decorations, or for anyone who loves anatomy.