I have spinal fusions from t4-l4/5 with metal rods. Of course as everyone stated it is purely up to you, but I have ridden quite a few of the rides. My biggest issue is getting back up out of the vehicles. I have done the following: Space Mountain, Thunder Mountain, Splash Mountain, Expedition Everest, Goofy's Barnstormer (new name same ride) and many more. Of all of them Expedition Everest was the smoothest. I say try one that you really want to go on & see how you feel. If your doctor says that you are healed enough to handle it then go for it, just make sure that it is at a time where if you do end up in pain that you won't be disappointed about having to leave the park or take it easy. Because Expedition Everest is the smoothest I would try that one 1st & go from there.