Oh Fio I have trodden that path!
Firstly, my children have a collagen deficiency called Ehlers-Danlos Syndrome. It is hereditary (via me and my mum) and among other things, causes hypermobility of joints, easy bruising, slow healing, keloid scarring. There are a few different types of EDS, and the symptoms depend on which type you have. My oldest has it worst of the 3, she has broken a wrist from over extending, bruises like a peach, and recently we discovered she had suffered a partial dislocation of her knee ( following in my footsteps). The other 2 aren't so bad, but you can feel the muscle laxity around the joints. It's one of those conditions that isn't very common, so doctors get very excited when they chance upon us, ask for students to examine them, try to pretend they know a lot then look stupid when I know more!
As for the hospital denying any wrongdoing, don't even start me there! Tried to sue Hammersmith Hospital years ago for the problems my dd1 was born with (heart defects , hydrocephalus, valproate syndrome) because they failed to inform me of the risks of the anti convulsants I was taking during pregnancy. In fact not only did they not tell me, they positively said there were no associated symptoms or syndromes connected to the drugs I was on. total lie I now know. Anyway it's amazing how the whole medical world suddenly know you when you are trying to sue , and bring it into their conversations, whether relevent or not. Needless to say we got nowhere. Since this there have been many more mums with chidrena ffected by the drug and warnings are now on the leaflets, but not at the time. Am currently in another half hearted attempt to take them to court again but I know it won't go anywhere. Dh basically lost his career because of all the time he had to take off for dd1 in the first couple of years and it still hasn't recovered (he's self employed).
If you can get legal aid to sue them then you might as well try, otherwise it could possibly bankrupt you. I found it a good way to dorect the anger I felt. We got a sort of recognition that it was down to them, but were told my daughter was not affected enough to warrant action. Damned cheek but at least we got it in writing.