Well, it is hard to say since PT has called it costochondritis, I have exactly what you have ever since an auto accident 3yrs. ago. Then, I am diagnosed with myofascial pain syndrome at one time and go to PT right now to have the pain worked on and they ultrasound the rib-sternum junction. Said they have had some success with some people, not all.
I am now responding to treatment. It hurts to have this very much, affects breathing when really flaring. I thought maybe I was having heart problems, couldn't breathe right and couldn't bear the pain. The sternum is better now after 2mos. of PT w/ultrasound once a week on it. I also then get deep tissue work on back and mid-back for knife like pain and muscle knots. It is helping finally. I look forward to treatments as it helps. I then follow with chiro immediately afterwards and they are stretching me on a table. It all is helping with this chondritis and myofascial pain. Hope this helps. Please get to treatment as I know every day with it is unbearable and we can't function with it. Soleil