See your doctor. You could have a host of issues that could cause your knee pain, could be bursitis, tendonitis, arthritis, ligament issues, meniscal injury, sciatica etc. So you may want to see an orthopedic pain specialist that can tell you what is going and help you with the latest treatments and exercise therapies available. Consider Stem Cell therapy to help as well. Regenexx.Com.
I agree. This is essentially the same, depending on your age. If this is causing pain and inhibiting your activities of daily living, you should see an orthopedist for treatment and eval.