My son has spina bifida, and is also in a chair. He had the surgery several yrs. ago, is 19 yrs. old, and hasn't had a problem. He had his whole spine fused, and had the rods. Well, I have to take one part back about no problems. The rods did break, but aren't creating a problem at all. They broke at the bottom where he bends most of the time. They aren't causing a problem, and he has no pain, so they are leaving them in. Besides, the upper part is still doing what they are in there for. He sits up nice and straight now, and will forever.