They don't really like to do levels that are just bulging and really not having any impact, having said that, yes it is very likely that a bulge above and below your fusion could herniate, but its not a given. The more levels that they do, the more the chance of something going wrong and the less chance of a successful outcome.
I had a fusion back in 2005, I had 2 good size herniations and 1 small one, my surgeon told me only 1 needed to be operated on. 5-6 months after surgery when my recovery basically stalled I went and saw a couple other surgeons, and both of them said I should have at least had one more level done. So in my case, yes do as much as you can at one time so the patient doesn't have to go through it all over again like I do in 2 months. Your MRI doesn't indicate problems at other levels, if you think something's wrong you need to have another MRI, things can change rapidly.
Sorry about your pain, my fingers are still numb after 5 years, sometimes the feeling won't come back and a lot of times these surgeries will not eliminate all your pain. Like I said, if you think something is seriously wrong insist on a MRI.
Take Care
Kalvin,
Yes this was my pre-operative MRI and no I didn't get a post operative one. They keep doing just x-rays. Before surgery my symptoms were tingly/numb hands (including fingers) and arms, pain and muscle spasms in the upper arms and shoulders, neck pain, and right before surgery my legs started having spots of numbness and balance problems. After surgery, constant neck and head ache, sometimes it's worse than other times. My left hand and 2 fingers are still numb with muscle spasms in my upper arms. Loss of strength in my left arm. I had an EMG done and I have issues with my muscles and nerves. And now 6 months later, I feel as if I am going back to the beginning. My shoulders and arms are starting to hurt again.
Plain and simple...surgery helped to ensure things didn't get worse (paralyzed) but I think if more was done with the other discs I wouldn't be going 2 steps back.
I'm going through similar things. This your pre- operative MRI, correct? You haven't had a post- op MRI? What type of pain are you having, what are your symptoms? Did the surgery help at all?