My doctor showed me the little titanium cage that will be inserted when my disc is taken out. There were at least three different sizes and shapes of cages. One was tall and thin. The other was short and more like a ring. Why are they so different?

Fusion of the spine has been around for many, many years now. For a long time, bone graft was used along with plates and screws. More recently, the development of titanium cages has changed this feature.

Now, after the surgeon removes the disc, a device called a cage (often made of titanium) is inserted in place of the disc. The cages usually come in different heights. This is to make it possible to match each patient’s anatomy as closely as possible.

The titanium mesh cages are usually cylindrical in shape. They provide support for the spine while the bone graft fills in and the spine fuses at that level. There are also different sizes and shapes depending on whether the implant is going in the cervical (neck) or lumbar (low back) spine.