@benjamin8161 I am a spine surgery patient and I was asking this same question 4 years ago, and at that time I was told that stem cell research was not advanced enough yet to heal spinal discs in humans. There is research with some success in animals to regenerate spinal disc tissues that I found back then. If a disc is ruptured and collapsed with the jelly like nucleus extruded, it may be too far gone to be able to heal. That was how my cervical disc was, collapsed to 50% of the normal height and bone spurs growing right next to it and I had a fusion. At this stage, the inflammation from the nucleus tends to cause growth of bone spurs in an attempt to stabilize the spine. Uneven pressure on the end plates causes bone spurs (osteophytes) to grow. If there was a spine procedure to fix a disc with stem cells at this time, I think we would be hearing about that in the new feeds. Mayo has recently had stories of stem cell success with a patient with spinal cord damage that was able to walk again.

Here is a link about research at Mayo with spinal disc regeneration.
https://journals.lww.com/ajpmr/Abstract/2014/11001/Stem_Cell_Therapy_for_Intervertebral_Disk.6.aspx