Hi, completely random question, sorry! 20 odd years ago my DS (now 30) had a disease that affected his knees, they would suddenly lock and give great pain. He was diagnosed with something, but for the life of me I can't recall the name! It was definitely not Osgood-schlatter, but something similar sounding (I.e double barrel) off the top of anyone's head any ideas? Tried googling but nothing popped up, it's happened again, for the first time in 20 years so a bit concerned. He will contact his GP but I thought SOMEONE will know on MN!