RE: Deadlift > Finger
As suggested goto the doc and get it checked out. If your feeling the bone stick out you need to investigate.
If grips a problem in the future. SLDL helps allot. You can also do plate pinchs. Maybe even move on to grippers. You will be amaized how fast grip will improve. While adjusting to heavier weights you can also use a staggered grip. One hand over and one hand under. this will prevent the bar from rolling and unwrapping your grip...
This may not be good advice, but i personally dont use my thumb for many lifts. When benching heavy i will add my thumb but for deadlifts and just about everything else my thumb is around front with my other fingers. I havent any difficulty holding 400lbs using this grip. You could say my grips greater than my overall strength. Once these babys close its a done deal. At any rate, if your hands hurting and its not muscle pain, goto the doctor.