Hi, This happened to me 2 years ago and I had surgery to repair the tear. However, the ligament snapped recently and I had swelling on
top of my knuckle
and at the side, whicg sounds similar to you, I have just had surgery again to repair the ligament, have the swelling cut away and I have also had the joint wired for 6 weeks to prevent me from moving it. I would advise that you try to get another opinion. Do not leave it as it will not get better and if anything it will only get worse.