I Have A Lot Of Pain In Groin Area, Left

I have a lot of pain in groin area, left hip, which I've been told is arthritis. I also have bursitis in same hip. I just saw a Dr for a 2nd opinion. In October 2017 i was told by the PA that I am a candidate for hip replacement.I saw the orthopedic surgeon in March 2018 and he said since it is not none on none he could not do the surgery. Today, June 2018 I saw a different(and younger) surgeon for another opinion. He is requesting an MRI and then possible surgery. His diagnosis is vascular (spelling ?) necrosis. What does his diagnosis mean? How is it different from the first doctor.
I have done injections with no relief, 3-1/2 months of twice weekly physical Therapy and have tried both heat and ice.
I am highly allergic to aspirin and all Nsaids so I only take Tylenol for the constant pain.
Do you have any other thoughts or recommendations?