19 years ago, a really bizarre accident resulted in a 90% amputation of my right thumb. The cut went right thru the knuckle so all that needed to heal was muscle, tendon and nerve. I had just started a new job with a startup speaker company where my primary responsibility was to get manufacturing started (i.e. I was assembling speakers) Pretty hard to do when your primary thumb was just re-attached.

Full recovery was well over a year, five moths of which I could not use my thumb (had to let the tendons heal properly.) I was allowed (encouraged actually) to move the thumb in one direction, but not the other. The solution involved a removable splint on my had/arm that held a rubber band that attached to a hook on the end of my thumb. The rubber band served in place of the muscles and tendons that were healing. The splint was specifically designed so that I could use my right hand (and even my thumb to some extent) during the first five months. All in all, I was able to build speakers.

Amazingly, I've only lost about 5% use of the thumb... very rarely do I even notice an issue.