Raymo this sounds like what I went through in the beginning. A knife sharp tight band feeling across front of my knee, totally unable to walk and a doctor who kept saying nothing was wrong. Out of desperation I had some of my saphenous nerve cut which did take away the sharp pain across my knee but to this day , over 2yrs , I still am in severe pain below knee. Can’t put any weight without terrible pain. This Wednesday I am trying a nerve stimulator in leg to see if it can stop pain signal.