Could a pinched nerve in knee cause pain and numbness is thigh. fell a week ago, sore/ no fracture. doc has no other explanation for the numbness.

No: Numbness in the thigh can be from nerve compression in the lower back or upper thigh but not from the knee.

Doubtful: If you pinch the infrapatellar branch of the saphenous nerve, you can have numbness along the outer side of the knee, but not the thigh. This is usually from a nerve being affected above the area of numbness. Look up meralgia paresthetica and see if this fits with your situation.