have they ever actually done an MRI on that shoulder/rotator cuff area? you could have alot of different issues that could casue this,even after doing all recommended PT courses if there is an actual tearing of one of the tendons that just allow all ROMS. i actually tore the supraspinatus,the very top tendon that runs from the base of the neck to the top of that shoulder? this IS the most commonly torn one since it gets the most wear and taer too. you could have even actually had a small tear in one and when you injured it, and it may have actually torn all the way or is kind of much much more enough to impact the ROMS.
if you have never actually had the MRI done when it happened or somewhere in between, you REALLY just do need one now in order to actually fully see the level of impact. "something' is most definitely not right in there or you would be able to just do all ROMS, ya know what i mean? espescially if you already did PT with no real improvement? that kind of stabbing pain is just a 'warning' that something is injured in most cases, or at the very least very inflammed.
have you actually seen an ortho for a full eval done or only just like your primary doc? given the circumstances, at this point that doc who sent you for the PT just owes you that MRI referral now to really see inside and find the main problem or problems. there can be alot of different things that can impact movement within that joint and rotator cuff area that is the main structure that kind of 'runs' that whole shoulder area? you just need this properly evaluated and looked into more in depth before that shoulder really starts to freeze up on you. once that happens it can really get ugly,trust me. just get that MRI done. "something' just is not working right in there. hopefully the damage is not too overly bad at this point. please let me know what you find out. FB