A tight knot, pulsating pain 6" above each knee in thighs like a fist digging in, stiffness, aches, pain, down legs, difficult to walk giving backache?

Maybe spine: The fact that this is in both legs at the same time, in the front and above your knees clues me in that this is either metabolic (like dehydration) or coming from your spine. If this is new, coming along with weakness in your legs, or changes in your ability to feel or control bowel/bladder, go to the er. Otherwise, call your doctor and be seen in the office. Ibuprofen, gentle stretching can help.

See an orthopedist: This sounds like something that may be going on in your spinal column and needs investigation soon. A doctor specializing in back surgery would be good, but you could start with your pcp and have them refer you if felt necessary. Good luck.