Hand Reconstruction Surgery?

So, to add to the crappy week everyone connected with me is having (2 car accidents, chemo, cortisone shots, missed work, shift changes), my future father in law pretty much demolished his left hand at work yesterday. Of course, he’s left handed.
Anyway, he has to have surgery next week. Apparently, the surgeon said he’d “try” to get use of the hand back but it’s not a definite thing (many pulverized bones and possibly tendon damage). Then, he asked an odd question. He asked if fFIL wanted to use his own bones or (jar?) bones. What the heck are jar bones? Could he have misunderstood the doctor?
I did Google the term but I couldn’t find anything.