Runners Knee ?

I came across this article today on Google +

http://www.bodyheal.com.au/blog/what-is-runners-knee-patellofemoral-pain-syndrome-symptoms-causes-treatment-options

               I had a similar injury that was more of a mystery. It started out in my left knee, on the outside of the joint area. the pain would start after about an hour of running with a dull pain in the area. the pain would increase to a sharp stabbing pain and I would have to stop running. I could not walk up or down stairs or over uneven ground. I had an MRI, loads of X rays , went to physio and all that jazz. No one could find a problem.
                   Two years later i started running again and the pain came back. This time in my right knee! Exactly the same. I went to the Dr and explained my symptoms etc and she said " your knee hurts when you run? Then stop running".

my pain is more to the outside of the knee

Its now got to the stage where i cant walk for any distance without getting pain.  It cant be as simple as this? Can it? I'm just wondering if anyone has anything similar happen to them ?