I had a spinal fusion with a titanium cage between the bones from the front and two screws in the back. The surgeon says the operation was a 100 percent success. How come I don't feel any better? I still have pain, and I can't walk very far.

Despite the increase in medical knowledge these days, chronic back pain is still a mystery. What causes it and how to get rid of it are the focus of many studies.

Spinal fusion has been shown to be a better option for some people than conservative (nonsurgical) care. Surgeons have worked hard to make a better fusion. Their goal is to stabilize the spine so that it doesn't move. For the most part, they've been able to do this with cages and screws.

But the results aren't always what were expected. The spine may be stable but the patient still has pain. Clearly the added stability and increased surgery needed to get it isn't needed. The next step is to make a fusion device that works without the extra screws.

If that doesn't work then doctors are back to the drawing board.