For once I am perfectly qualified to comment on this issue. I too have an artificial left leg made of Titanium and plastic.
As a frequent flyer EGSS-LFRD I am used to surrendering at the metal detector. I simply tell them I have an artificial leg and although it gets a good feel they have never asked to actually look at it. Mind you it is only a metal detector not a scanner as such!!
In this mans situation I too would be absolutely enraged and embarassed and certainly thinking Litigation. If I were to take my leg off to fly, then I would have to carry my crutches on board and they would surely make a brilliant weapon!!
Can you imagine removing the leg and having it sent as checked baggage and then discovering the leg went to the Caribbean instead of Dinard.
Many years ago on a long haul I removed the leg once on board so as to be more comfortable on the flight. On arrival in LHR I had a hell of a job getting it back on as the stump had swollen much like your ankles do on a long flight. So, my leg stays with me and they would have to forcefully remove me as well!!!!