I have been reading about CF related arthritis. My daughter is 3 yrs old and gets knee pain. It is usually at night. Often she will wake from a dead sleep screaming with knee pain. What I have read states that it usually starts after the age of 10 so I am wondering if this is the cause. The cf clinic where she is treated says joint pain is common and they do not know what causes it. I would like her to go for x-rays to ensure that it is not something else since it has been going on for months and months. My theory is that not everything is CF related and it is better to rule out any other causes, but they feel that x-rays are unnecessary. I would like to know what others think? I spoke to her pediatrician and he has agreed to send her, if that is what we want to do, but I was wondering if other parents encountered the same problem with young children.Thanks,AM