What Causes Pain And Swelling In Finger Joint After An Injury?

Hi, I twisted my second knuckle on my ring finger about three months ago. it is still oddly swollen on one side (and the swell is not soft). I did an x-ray and it shows no broken bones.

I can't bend it all the way and it hurts when I bend it to too much.

I would appreciate it if you could give a piece of advice