something pops out of place behind knee-painful

[Tinkster54]

Whenever I sit and put my right ankle on my left knee it feels like something pops out of place behind the right knee.  I grab it, and even though it is very painful, I straighten my right leg out.  When I do, it pops back into place.  It still hurts a little for about 3 minutes and then goes away.
Recently I was sitting on a chair with both feet on the floor.  I put my right foot back under the chair and it happened again.  I barely even bent it!
I saw my primary care doctor today and he said it’s probably bakers cyst and I need to keep losing weight.
I looked up bakers cyst online and it doesn’t sound like that at all.  Please someone give me an idea of what it could be.
Though I am still obese, I lost 107 pounds in the last 3 years.  This year plan to lose the last hundred.  

[Tinkster54]

Thank you.  I will get it checked out.

[S. Kaul, MD]

Hi there!

Well, without a detailed clinical evaluation it would be difficult to determine the cause of your symptoms. Possibilities that may need to be considered include dislocations/ subluxation, injuries to tendons/ ligaments, degeneration, loose bodies etc. I would suggest getting this evaluated by an orthopedician for an accurate diagnosis and appropriate management.
Hope this is helpful.

Take care!