I'm going to have two levels of my lumbar spine fused with titanium rods and bone graft. Why are both needed? Wouldn't the rods be enough support?

Despite best efforts at fusion sometimes it doesn't work and the person has movement at the problem level. Studies are being done to find the best method to give the patient immediate stability with long-term fusion.

Researchers have found that using titanium implants along with bone graft gives a stiffer, more stable spine right after surgery. The more rigid the fusion, the more reliable the results. Combining materials and fusing front to back seems to work best.