I have displaced ribs also. Many doctors told me it was because my floater ribs were lodge where my rib cage ends. I fell down the stairs and had many things displaced. If you stand up straight and life one leg to where your thigh and stomach are a90 degree angle and you feel you spine slightly shift, it's a displace rib. If you feel a cracking and cannot breath while doing this, you have a cracked rib cage. Ask to have an x-ray taken and try not to stretch your arms backwards in any ways to keep from causing more damage.
I really hope this helps.
I feel your pain (literally)
Good Luck