
I asked that question after Spends had his op for his disc and was told it was unlikely to make much difference to the discs themselves as they were made of different material than cartilage.
However, my understanding is that the annulus fibrosus, the outer part of the disc consists of fibrocartilage which is a mixture of fibrous, cartilaginous tissue and cartilage cells. The inner part is the nucleus pulposus which is a jelly like material which some say consists in some part of the amino sugar Glucosamine.
A slipped disc is when this jelly substance leaks out and puts pressure on the surrounding nerves. Sometimes with rest and pain relief this jelly can go back into the annulus fibrosus again.
So in theory it would be reasonable to think that Glu and Chron would help in some way by nourishing the discs. Should help with the repair of the cartilage between the facet joints and the vertebrae in the spine anyhow.