I understand. It's maybe not related at all. Of course it would be possible to have trapped nerves somewhere for a long time, but why I don't know.

This is old but it explains some more about cubital tunnel syndrome. I'm not saying that's what's going on, but it can cause wasting in hands.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2599973/
Postgrad Med J. Jan 2007; 83(975): 28–31.
doi: 10.1136/pgmj.2006.047456

If I was in your position I'd be wondering about autoimmune diseases.