Does stem cell therapy work for back pain? Only before-and-after data

The research on stem cell therapy for back pain is small and short, and none of it sets treated people against untreated ones. The largest summary pooled 283 people with discogenic low back pain across eight studies, meaning pain traced to a worn spinal disc rather than a pinched nerve or a strained muscle, and found that both pain scores and daily-function scores improved after treatment [4].

The same review reported that treated discs looked less degenerated on scans afterwards [4]. The comparison was the same people before and after, not one group against another, which is the weakness running through all of this work.

An earlier review of 98 patients and 122 injected discs put a size on the improvement. Pain was about 30% lower a year after the injection, and average disability moved from the "severe" band to the "minimal" band on the standard back questionnaire [6]. Everyone in those studies had already tried non-surgical treatment without enough relief before cells were offered [6].

The most detailed single study is also the smallest. Nine people with one worn disc each received 10 million stem cells taken from their own body fat, with an optional second injection six months later [3]. Twelve months on, seven of the nine reported less pain, five reported being able to work more, and three had cut back on painkillers [3]. Scans showed no further wear of the disc over that year [3].

The evidence on how long any of it lasts runs out at twelve months [3][6], and past that there is nothing either way.

On safety, these reviews record few problems, though on small numbers: one herniated disc among the 98 patients and nothing at the sites where cells were taken or injected [6], and no serious adverse events among the nine [3]. With groups this size, a harm that affects one person in a few hundred would simply not appear.

A spinal disc is a tough outer ring around a soft, jelly-like centre called the nucleus pulposus. As the disc wears out it loses the water-holding molecules that keep that centre springy, and the structures around it carry more of the load [2].

The reasoning behind injecting cells is that mesenchymal stem cells, which are cells drawn from bone marrow or body fat that can mature into several different tissue types, can become cells resembling the disc's own and start rebuilding that water-holding material [2].

The obstacle is where those cells are being asked to live. The centre of a disc is the largest enclosed tissue in the body with no blood supply of its own, under high mechanical and osmotic pressure, very low in oxygen and short on nutrients [1]. Injected cells have to survive conditions that are already killing the disc's resident cells.

Reviewers in this field point at that survival problem, plus a limited understanding of what starts disc degeneration in the first place, as the reason results have stayed inconsistent [1][2].

Nobody has yet shown this works better than doing nothing. Back pain improves on its own in a lot of people, and injection procedures of all kinds produce strong placebo responses, so before-and-after improvement [3][4][6] is exactly the pattern an inactive treatment would also produce.

The evidence also does not describe most people with a bad back. It was gathered in people whose pain had been traced to a specific worn disc [4], and the groups it came from were narrow:

• the most detailed study took only people with a single affected disc [3]
• the reviews covered early-stage degeneration, and left out anyone with previous or planned spine surgery [6]
• everyone had already been through non-surgical treatment first [6]
• nine people [3] is too few to detect anything except a common effect

What gets called stem cell therapy also varies between these studies. Cells from fat, cells from bone marrow and concentrated bone marrow aspirate are pooled together [3][4], which hides the question of which preparation, if any, does something.

Injecting cells into a spinal disc is a medical procedure, and whether it makes sense for one particular person is a question for a doctor who can see their scans.

Longevity clinics offer this service. Those in the Longevinsights directory list stem cell therapy alongside platelet injections and other regenerative treatments. Almost all of it sits outside approved medical use.

A first visit is normally a consultation plus imaging, because the studies selected people on scan evidence that one specific disc was the source of the pain [3]. Where a clinic proceeds, cells are taken from the person's own body fat or bone marrow, processed, and injected into the disc under imaging guidance [3][6]. In the study that offered it, a second injection was available after six months [3].

The people in these studies had already tried physiotherapy and other non-surgical treatment without enough relief [6], and their results were only ever measured out to one year.