Do they still use cotrel dubouset spinal instrumentation to stabilize fracture? Why or why not? What are the long term risks?

Not that I know of. Cd horizon is the name of the system you describe and it was supplied by sofamor danek. Medtronic now owns sofamor danek and cd horizon isn't used anymore to my knowledge due to advances in spinal technologies. It was an excellent system for thoracic deformities as it had a large hook system to use. No long term risk to having it in you- it worked very well.