To put it in a slightly odd way. If I were your doctor and I said to you:
"Your hand is ****, its never going to get better, its only ever going to be 60% useful and its always going to cause you pain for the rest of your life. However we can cut it off, its really going to hurt and continue to hurt for a year or so, but you'll grow another one eventually and that will be better."
Which option would you choose.