Nigel, sorry about all that you're going through. Others with RSD will post soon to give you their perspective. I do not have RSD, my wife has had it nearly 10 years so I have experience as an advocate. I am not a doctor but can only advice you on my hunches. You may not have RSD, but you could. Not all your symptoms sound like RSD. What it sounds like to me is nerve damage or aggravated trapped nerves somewhere around the knee. This damaged nerve condition can mimic RSD, rectify the nerve and all symptoms go away, not with RSD, however. I've known one person who showed many RSD symptoms for sometime and found out it was trapped nerves indicated by an EMG test. Doctors released the nerve and she was cured, of trapped nerves no RSD was present after all. Nerve blocks is another technique used to rule in or out RSD. However why take a chance, you are correct in that early treatment is the key regardless. Seek out a doctors who really knows CRPS/RSD. Check these sites out for treatment centers, there should be experts in Europe, specifically Germany. These doctors should be able to rule either in or out RSD.
www.rsdfoundation.org/index.html
www.rsds.org/index2.html
http://rsdhealthcare.org/

I pray you find relief and a diagnosis quickly! Keep us posted

jim