I'm 19 started popping my right middle finger several years ago on a daily basis and it ended up becoming a very compulsive habit overtime. They say that there's no concrete evidence that knuckle cracking can cause arthritis or joint swelling, though I'd say in my case that's most likely what happened, since over time my fist knuckle and middle joint have swollen. Now my middle finger makes a popping noise very easily (much more so than my other fingers) just by moving it or manipulating it with my other hand slightly, which I'm guessing may be because the cartilage in my finger has worn away leaving the bare bones exposed. I have some pictures here (it took them quickly and the top one's the best):
http://img213.imageshack.us/my.php?image=picture001qs3.gif
http://img381.imageshack.us/img381/6417/picture004ze9.jpg
http://img291.imageshack.us/my.php?image=picture002cu9.jpg
http://img242.imageshack.us/my.php?image=picture003zy5.jpg
On a side note, now that my joints in my middle finger have swollen, popping it has become even more compulsive (I have OCD tendencies I'm starting to think) when I look at it compared to my left hand's finger, because in my mind I'm thinking that I'll be able to "fix" it by forcing it into the right position (though I know that this isn't possible but still pop it compulsively). I'm definitely thinking of seeing a doctor, but if there are any exercises or home remedies available for this type of arthritis, I would definitely look into them Any advice woud be appreciated.
See a dr and they can take blood work and see if there is any inflammation in your body. Does it hurt? If so, try heat or some people prefer ice. See what works for you. ALso, icy hot works well. I can't see your images you posted so I don't know what it looks like. I pop my knuckles all the time and it makes my hands feel better after. Does it make your hands feel better after you pop them? Just curious. I hope you get some answers and soon.