Try searching on google. This link tells you something about it.
http://www.findarticles.com/p/articles/mi_qa3794/is_200206/ai_n9100318
My disc was removed and the surgeon put a tiny 'cage' in it's place. As you read, it is a carbon fibre filled with bone. This is placed where the problem disc is taken out to keep the spine stable. Eventually, in time the spine is supposed to grow around the disc, stabilising the spine even more.
As you may imagine as I only had this done 6 weeks ago and have been off work ever since, it is not a small operation. I have been left with a scar near the front of my neck (the surgeon goes through the front, hence anterior) and sometime pain in my right shoulder from where the surgeon worked on the nerves in my right arm. Other than that some of the problems are that my neck aches quite badly especially as the day goes on and I have to put my soft collar back on, and I can't as yet lie on my side to sleep, can't drive, have to wear the collar in a car, can't lift any heavy objects and have to be careful not to strain my neck.
I can't tell you if it has worked as I am due to see the consultant tomorrow, but it has given me feeling back in my left hand and some if not all feeling back in my right hand.