Bone Scan Report - What Does It Mean?

Had a hip replaced 18 mos ago and started having pain in my thigh in august, Dr. Did plain x-rays and said things looked fine. Put me on lodine 400mg, I took it for 8 weeks with no improvement, the pain is worse now. Dr. Ordered bone scan which I have the report and a cd with the images, but I really don't understand what it means and my appt. With the Dr. Is not until after the 1st of the year. I was wondering if someone could tell me what the report is saying.Should I be aggresive on following up on this or is it nothing to worry about? (report follows) 1) there is focal mild to moderate increased uptake with a patchy distribution seen in the region of the mid femur. This does not clearly appear to be continuous with the inferior tip of the prothesis and correlation with the length of the prosthesis on plain films is necessary. The femur distal to the neck on 3/18/03 (prior bone scan) was normal. (impression)- focal patchy moderate increased uptake in mid femur. Uncertain if this is contiguous with the inferior tip of the prosthesis, although I believe this is distal to the prothesis. Given that this area was normal on prior bone scan, differential considerations include stress fracture, other posttraumatic cause, or neoplastic cause. Osteomyelitis in the mid femoral region is possible although unlikely since this does not extend along the adjacent femoral prosthetic component. 2) otherwise normal appearance of hip prothesis. 3) mild degenerative changes of left hip, as noted on prior bone scan.