Have Knee Pain. Done Deep Tissue Massage For Torn Calf Muscle. Taken Steroid Shots. Diagnosis?

I am a 43 year old female who has had pain on the side of the right knee for 2 years. I am 5'7" and weigh 150 lbs. I exercise a couple of times a week. There was no apparent traumatic event, although I did have deep tissue massage to heal a torn calf muscle just prior to onset of the knee pain and during the course of that, the physical therapist also did a fibular head joint manipulation. About a month later, I started having knee pain. A series of steroid shots worked for the first year, but eventually quit working. The pain has been present off an on for the last year, with only a few weeks of relief and the pain returns. Two MRI's show no problems. I did physical therapy January-March, 2013 and have been doing it again for the last 2 months. Two orthopedic surgeons could not provide a diagnosis. One referred me to a rheumatologist and he diagnosed IT band syndrome and prescribed 15mg/day of Mobic. Therapy has stretched the IT band and strengthened my muscles. Pain had receded during therapy, but is now back and is just as severe as it was at the beginning. My PT is at a loss as to how to help me. The pain is present when I am exercising and when I am not, and often occurs while driving. The PT mentioned a possible meniscus tear that may have been missed on the MRI's. Any suggestions?