HELP!! MY BEARDIE HAS MBD AND IS LIMPING AND SWOLLEN!!!

Hello!

I got 2 baby bearded dragons from my friend 4 months ago. She was feeding them a diet of carrots, and crickets once a week which is terrible and also no calcium powder and even no heat lamp! I knew imediatley i wanted to take them and make them healthy again! One was a little bigger then the other when i first got them, but he has since grown a TON and is thriving! The other one (toothless) is really struggling. It seems that he has not grown much. He hasn't even shed. He definitely had MBD when i first got him and it is even worse now. His front leg drags a little and his back legs are worse. His back legs are also really swollen! I read that the swelling can be from not shedding all the skin and cutting off blood supply, so I have been soaking him in warm water a lot. But I don't think that's it. I have been feeding him crickets coverd in calcium every day since he is so small and doesn't eat more then 5 on a good day. He gets chopped lettuce and bell pepper covered i. Calcium every day too (dont usually eat it). He is under a UVB bulb and 75 W basking light everyday. PLEASE HELP!!!I DON'T KNOW WHAT I AM DOING WRONG!!

What sort of UVB light is it (brand, type, uvb rating)?
Are they housed together? If so, they need to be separated ASAP, as one is most likely stealing the food/basking spots and stressing the other out.
Don't feed him anymore lettuce, too much water and tends to give them diarrhoea. Give him calcium rich greens instead, like endive, escarole, collard/dandelion greens etc. This is a good guide: http://www.beautifuldragons.com/Nutrition.html
What size crickets are you feeding him? It almost sounds like impaction.
I'd also suggest a visit to a herp vet, he sounds like he's just getting worse.
Hopefully a more experienced member can offer more advice.

His legs do look a bit deformed. Hopefully, since he's so young, that can be halted or reversed. I agree that it's important to keep them in their own enclosures as one may be dominating resources such as basking areas and food which could keep the smaller one from thriving.

More information about your lighting would be helpful, as mentioned. It's important to provide an excellent UVB source as well as proper heat gradient and diet, especially in this case. I can help you get that sorted out for him. I'm glad you got them out of the situation they were in. You probably saved them from a lot of suffering by doing so.