For future studies, you should try and incorporate a decalcification
endpoint test to know when your decalcification is complete.  This is
important with large bones, even though not a popular thing to do, but
will save knives and shredded sections.  

Chemical determinations are cheap, easy and a bit more time consuming
than radiography, but if you have a Faxitron xray machine available,
large bone specimens can be decalcified intact, and cut down after
decalcification is complete. When you slice through large bones, it is 
now always easy to have the sensitive touch to detect the fine deposits
that you are probably experiencing (lumps of calcium).  It is much nicer
to have ALL the calcium removed BEFORE processing and infiltration with
paraffin.

Gayle Callis