You probably have some hereditary factors going on there.
Did your father and uncles all have very similar problems that caused the need for their surgeries?

here are some images of wedging {you can click them to get to the page it's on for more info}
http://images.google.com/images?hl=e...-8&sa=N&tab=wi

some images on loss of disk hydration-
http://images.google.com/images?svnu...=Search+Images