5 1/2 months Post Meniscus Repair - Still in pain

I had a medial meniscus tear treated arthoscopically back in Apirl - left knee.  I'm 42 female and have always been very active.  Doc said 6 wks max and I would be back to 100%.  5 1/2 months later, the knee is still causing me pain, different but still cannot do any exercising and pain wakes me up at night.  I have been back to see the surgeon several times, and have had follow-up MRIs.  He cannot say for sure what is causing the pain.  He has said perhaps patella tendonitis, perhaps a deeper tear within the meniscus.  He wants to do a follow-up surgery to "figure out what's going on".  The latest MRI shows a shadow that could be another tear, or it could just be a shadow from the previous surgery.

My symptoms now include a weak knee that buckles/gives out at times, radiating pain around the top of the knee and down both sides of the knee cap.  There is a "nobby" on my knee that was never there before.  

I REALLY do not want to have another surgery "just to see if we can figure out what's going on".  Clearly, my knee did not react well from the first and I don't like the odds.  I know typically this kind of surgery is very straight-forward with few complications.  Could the pain be from a tendonitis caused by the surgery?  I feel like the whole leg is getting weaker from improper use.  I just want to be back to where I was before the surgery.  I can do little exercising, walking, biking all cause increased pain.

Any ideas?? Anything at all.  I have recently seen an acupunturist to see if I can find some relief there, but I really just want to know why it's still hurting and what I need to do to help it heal.

thanks so much,
M