if you are in pain then I would suggest seeing your tx drs, and getting their imput....
I was on oxycontin and endone for a lot longer then usual, because my sternum knitted crooked....
I then had a abscess removed and my sternum wire was also removed, which again left me in incredible pain due to my sternum clicking in and out, and cracking...
(all Up i was on hard core pain meds for over 2 years) I since started working out at the gym under the guidance of a PT(personal trainer) and did weight training to strengthen my sternum...(I use to strap my sternum pretty firmly to stop it clicking in and out)
but I wouldnt be taking any pain meds without your drs knowing your in pain, just incase there is something that may be contributing to the pain
I been off all pain meds for over a year now and my sternum only cracks every now and then...and I am no longer in continous pain, which I didnt think Id ever see that day, but I did!