Hi Tom,
Sorry to see you have not got this sorted out yet! Have you tried at the London Knee Clinic or Droitwich Knee Clinic yet? They led the field in specialist knee clinics.
Another thought is that the pain could be referred, I.e. The source is elsewhere. I had problems with pain which was ignored or I was told it was muscle imbalance or I was too sensitive! Turned out I had a postereo-lateral corner injury that had been completely overseen in the original diagnosis and ignored by all except my current surgeon. He found that the LCL was completely torn off and that a fracture of the fibula head had been missed, it healed badly and trapped the nerves in the process. The inflammation triggered scar tissue that squeezed the nerves causing me to have ever increasing pain. It was a shooting pain that increased in intensity as the time went on. It bought tears to my eyes when it triggered. Luckily for me during my first examination by the current surgeon, something triggered it and he was able to see and feel the effect.
Good luck with your search, I hope you get some answers soon.
Sue
PS where you at the Wies'n again this year? Been fantastic weather this year and a record amount of beer drunk, over 7.5 million Litres!