Hurt pinky finger as a kid, didn't seek treatment, middle knuckle sticks out side and painfully pops in when bent, what could be done to straighten.

Finger splint. It sounds like you have either a mallet finger, or trigger finger. My orthopedist tried me on these oval 8 finger splints and my trigger fingers on both hands got better after a few weeks of wearing them. You can either see your doctor to confirm the diagnosis, or look for "finger splint" in ebay and try them out.