osgood schlatter syndrome – bony bumps under knees

hi im new to this forum and to yoga – have been doing bikram classes for about a month now and am feeling a lot better for them so far. My question is just really if anyone else has this knee condition and to see if it affects how they approach any of the poses? particularly fixed firm pose? i’m fairly flexible, and can physically get in to all of the poses but i worry that i haven’t yet built up the strength to do them without doing myself any damage/aggravating this old condition, so consequently i don’t go back in this pose – have done so twice but the pain was fairly bad after about 5 seconds.

im finding it hard to recognise whether the pain in my knees when doing this pose is a warning sign or just my body changing. i was a gymnast when i was younger, but only up until the age of about 13, as this was when i first developed osgood schlatters. at the time its a very painful problem with things like knees getting locked and being unable to move happening frequently. now im 24 all im left with is bony lumps under my knees that dont really hurt in day to day life but ive always found it hard to kneel.

i think a lot of the reason im enjoying yoga so much is down to this enjoyment of being flexible again – some sort of muscle memory. i’m someone who is always having some sort of problem with my joints though, usually in my knees and ankles – my kneecaps are very mobile and have a tendency to dislocate and i’ve currently got tendonitis in my inner ankle, i think from pronating. i’ve been very overweight for the last couple of years which has contributed a lot to these problems i think.

ive seen a lot online about bikram not being good for everyone and i have this horrible sinking feeling that im exactly that “loose” body type that doesn’t suit it, and probably didnt suit gymnastics either. i don’t want to give this up however! all the other benefits at the moment are huge motivating factors for me to continue and i havent had any problems that have directly resulted from my practice as yet.

i think what im basically hoping for is to hear about someone with similar issues? or some advice on how much/if i should try and rein myself in a bit – or is this all just fear?
sorry for the long 1st post!

jennifer