I have had this pain in my left ribcage for about 2 months now. I posted about it myself here on this board, and the replies I got diagnosed me correctly, although I was not actually diagnosed by a doctor until today. The neurologist said I have costachrondritis, and gave me a cortisone injection in my ribs. He said that I may need another injection; and if I do, he will do the next one with x-ray imaging so he can tell better how deep to place the needle. He also put me on vioxx for the inflammation. Also my ribs are thinning some adding to the pain.
From being tested for this rib pain, I also was diagnosed with having osteopenia in my hip and bone density in my spine is in the low/normal range. At least we caught it before it has gotten too bad, and am now taking actonel and calcium supplements to hopefully strengthen the bones. I already exercise at a fitness center 5-8 hours per week. Keep us posted, and I hope you get some relief soon.