I dont really know... I've had problems with it (locking and giving way etc.) for ages, but after a trip to SA for aholidays 3 months ago it just swelled right up and pain set in after that. I left it for month, hoping it would go away but it didnt. Got it checked and turned out to be a bakers cyst, rheumatoid arthritis and what looks like to be a badly torn miniscus pad... :(

I just spent 8 hrs in a hospital today JUST to get a blood test, an injection and 4 pills... talk about ####ed up