Both of my sons have broken fingers, usually while playing basketball. One time, I treated one of the fingers myself by splinting it, but the finger never went back to its original size although that's how the other fingers were treated by their doctor. What might have gone wrong?
Basketball and many other ball sports can cause broken fingers because of the way the balls hit the hand and the speed at which they hit the hand. Some breaks are caused by the finger tips jamming against the ball, other breaks are caused by how the ball is caught.

In many cases, broken fingers are treated by splinting them against the neighboring finger for a few weeks. However, depending on where the break is, other treatment may be necessary. This treatment can range from surgery to traction. Treating a broken finger without an x-ray to confirm where the break is or how severe it is, is rarely a good idea.