What is this?

I’m curious if anyone’s ever seen anything like this.  I know it’s not related to myeloma.  It’s more likely related to an injury I had when I was a teenager.  I just can’t remember anything happening to this finger recently.

What happens is, it’s a little bit sore at the knuckle.  There’s a bump there, on top, which you can’t really see from this view.

These are the distal and middle phalanxes of the left hand’s middle finger.  There should be space between the two bones.  Yes, I asked my doctor about this, and have completely forgotten what she said, except that there’s nothing to be done about it.

Anyway, it’s sort of fun just to see kind of what we look like on the inside.  Except for when blood is involved, I say.

Finger X-Ray