Have Pain And Swelling In Joint (knuckle) Of Pointing Finger.

Have pain and swelling in joint (knuckle) of pointing finger. Pain radiates into elbow. Have hard knot next to joint. Have had carpal tunnel surgery on this hand and carpal surgery and elbow surgery on the other hand. Have also had ganglion cyst removed from other hand. What could the pain and swelling and "knot" be from?