The published medical research clearly shows that most costochondritis (and Tietze’s Syndrome) is NOT a "mysterious inflammation" which nobody understands. That's why treating it like one doesn't fix it.
There is a sort of mad disconnect between how most costochondritis is understood and fixed in manual physiotherapy in New Zealand, and how it is not understood and not fixed in most other places in the world. Our understanding of costo and how to fix it is based on the actual research. The "mysterious inflammation" idea is not. Yes, this is a crazy situation, and you are probably confused and still in pain because of it. Of course it’s not a mystery and of course it’s usually fixable.
Costochondritis is a scary and confusing (but not life-threatening) condition with pain where your ribs join onto your breastbone. Tietze’s Syndrome is just costochondritis with enough inflammation to cause obvious swelling at the rib joints on your breastbone - it’s not a whole different entity. Slipping ribs are the same sort of thing where the pain and clicking is further out to the sides at the costochondral junctions, where the bony curves of the ribs change to cartilage.
Steve August has a history of costochondritis himself:
"I had costo for seven years myself after a climbing fall onto my rib cage - with all the sharp stabbing chest pain, the breathing difficulties and the fear I was having a heart attack that comes with it. I fixed it after qualifying a a physiotherapist in New Zealand, and haven’t had even a twinge in over 30 years. I can do anything physical - it’s completely fixed. This is the normal response to correct treatment."
Important - any acute chest pain should always be seen first (and urgently) by a doctor or Accident and Emergency Department in case it’s your heart. Cheeringly, more than half of acute chest pain isn’t the heart or anything else risky or dire.