Fingernail Disorders More Condition_symptoms I Have A Friend With An Arm Deformity?

I have a friend with an arm deformity? - fingernail disorders more condition_symptoms

I always wondered what is called his condition, but I dare not ask. In fact, it is not so much a friend. fortiori one aquaintence. Arm looks like a T-Rex ... not the size (they are normal size), but they are always bent at an angle of 45 degrees and can not be extended. He has no knee and fingers a little grief. I am wondering if anyone knew the name of this disease, if at all, and this may be the cause? Thank you.