I have recently begun to getbad stinging like pain in the front of my thigh's, also my left hip is very painful when standing up from a sitting position, I had surgery 18 Month's ago for spinal stenosis L4 to L5, which I still suffer greatly from pain in my back, but it has helped with the numbess in my legs.
I would recommend you get back to the surgeon. It's not good that it's affecting both legs. The front of your thighs could well be associated with the surgery.
Whilst you're there, ask him/ her if you could/ should be doing back exercises. In the circumstances, I wouldn't use the exercise regimen and Chiropractic-Help.com - rather have a skilled person direct you to the correct and appropriate exercises.
You say "hip" pain when standing up. In the groin? Side of the hip? In the sacroiliac joint? Ask him to examine you for hip arthritis if it's in the groin. The right exercises may help with this hip pain too.
Sorry, I feel this hasn't contributed much.