Low back pain is one of the most common health problems worldwide. It affects quality of life, limits work and daily activities, and creates a significant economic burden. In many adults, especially those over age 50, a key driver of this pain is lumbar intervertebral disc degeneration. When the disc between the vertebrae begins to break down, it can become a source of chronic, deep “discogenic” pain that is often difficult to treat.
Traditional treatment options include physical therapy, medications, injections, and, in some cases, surgery. These treatments can help manage symptoms but do not always address the underlying disc damage, and surgery is not suitable or desirable for everyone. This is why researchers have been exploring regenerative approaches, including mesenchymal stem cell (MSC) therapy, to repair or stabilize the disc and reduce pain at its source.
A recent review and meta-analysis by Zhang et al. examined the effectiveness of MSC injections into the disc for patients with lumbar discogenic pain and whether this approach is safe. The results are promising and add to the growing body of evidence supporting MSC-based therapies for spine-related conditions.
Why Disc Degeneration Causes Low Back Pain
The intervertebral discs act as shock absorbers between the vertebrae in the spine. Each disc has a soft, gel-like center (the nucleus pulposus) surrounded by a tougher outer ring (the annulus fibrosus). Over time, age, genetics, mechanical stress, and lifestyle factors can lead to degeneration of these discs. The disc can lose water content, become thinner, and develop small tears.
When this happens in the lumbar spine, it can trigger discogenic low back pain. This type of pain often feels deep, aching, and persistent. It may worsen with sitting or bending and improve when lying down.
Initial treatment typically involves non-surgical approaches such as exercise therapy, manual therapy, nonsteroidal anti-inflammatory drugs, and other pain-modulating medications. While many patients improve, others continue to have significant pain and disability even after trying conservative treatments for months or years.
How Mesenchymal Stem Cells May Help Degenerative Discs
Mesenchymal stem cells are a type of adult stem cell that can be obtained from bone marrow, adipose tissue, cartilage, and other sources. They are known for several beneficial properties. Under the right conditions, MSCs differentiate into bone, cartilage, and other mesenchymal tissues under the right conditions. They secrete a variety of growth factors and signaling molecules that support tissue repair and modulate inflammation. They also communicate directly with nearby cells to influence the local environment.
In the context of disc degeneration, the idea is to inject MSCs directly into the damaged disc. Once there, they may help repopulate the disc with healthier cells, support the remaining disc cells, and alter the inflammatory and degenerative microenvironment.
According to the authors, animal studies and early human trials have suggested that MSC injections into degenerated discs can improve disc hydration, reduce pain, and enhance function. However, these individual clinical studies tend to be small and vary in design, making it hard to draw firm conclusions from any single trial. This is where a meta-analysis, which pools data from multiple studies, becomes particularly valuable.
How the Meta-Analysis Was Conducted
For this meta-analysis, researchers reviewed several major medical databases, including PubMed, Web of Science, Embase, and the Cochrane Library, through September 18, 2022. They focused on clinical studies that examined MSC treatment for lumbar disc degeneration and disc-related low back pain.
Of the 2,392 studies initially identified, 9 met the inclusion criteria. These studies included 245 patients, most of whom received injections of bone marrow–derived MSCs directly into damaged discs. Study quality was evaluated using the Newcastle–Ottawa Scale, and standard meta-analysis methods were used to analyze the data.
The primary outcomes measured were changes in pain levels and changes in the Oswestry Disability Index (ODI), which assesses how back pain affects daily activities. Researchers also reviewed reoperation rates and side effects to evaluate safety.
Pain Relief: Improvements on the Visual Analogue Scale
Pain was measured using the Visual Analogue Scale (VAS), where patients rated their pain on a simple numerical scale. Across the studies, patients who received MSC injections showed clear reductions in pain from the start of treatment to the final follow-up.
When the data were combined, average pain scores improved by more than 40 points on a 0–100 scale. This represents a significant and meaningful decrease in pain for many patients. Although results varied between studies, nearly all showed pain improvement with MSC treatment.
Other meta-analyses have reported similar findings, showing that MSC therapy can significantly reduce pain in people with disc degeneration. This analysis supports those results and suggests that MSC injections provide meaningful pain relief for appropriately selected patients.
Improved Function and Reduced Disability: Oswestry Disability Index Results
Pain is only part of the issue. For many people with chronic lumbar discogenic pain, the most important question is whether they can get back to their everyday lives. This is where the Oswestry Disability Index (ODI) was especially helpful.
In the meta-analysis, ODI scores improved significantly after MSC injection. The pooled data showed an average improvement of more than 20 points from baseline to the final follow-up, indicating better function and less disability. This means that patients were not only reporting less pain, but they were also better able to sit, stand, walk, work, and perform self-care.
Taken together, the pain and disability findings suggest that MSC therapy has the potential to provide both symptom relief and functional benefit in patients with disc-related low back pain.
Safety and Reoperation Rates: A Reassuring Profile
Any new therapy needs to be evaluated not just for benefit but also for risk. In this meta-analysis, MSC injection therapy for discogenic low back pain demonstrated a favorable safety profile.
No serious adverse events related to the MSC therapy were reported across the included studies. Treatment-emergent side effects, when they occurred, were generally mild and included symptoms such as back, joint, or muscle pain, which are also common in the underlying condition. Previous meta-analyses in this area have similarly reported no statistically or clinically significant increase in adverse events with MSC injections.
The pooled reoperation rate was low, around 7%. This suggests that most patients did not require further surgical intervention at the treated level during follow-up. While longer-term data are still needed, the findings support the idea that MSC disc injections are both safe and potentially protective against the need for additional procedures in the short- to medium-term.
MSCs Compared With Other Cell-Based Strategies for Disc Repair
MSCs are not the only cell type being studied for disc repair. Disc-derived chondrocytes and nucleus pulposus cells have also been explored. These cells can be harvested from disc tissue, expanded in the lab, and reimplanted. However, this approach has challenges. Disc cells have a limited natural capacity to multiply, and obtaining enough cells may require harvesting from other discs, which can be invasive and may compromise healthy tissue.
According to the authors, MSC-based therapies offer several advantages. MSCs can be isolated from bone marrow, adipose tissue, and other sources and expanded in culture to achieve therapeutic doses. Bone marrow–derived MSCs, used in all nine influential clinical studies in this meta-analysis, can differentiate into nucleus pulposus-like cells and support existing disc cells by secreting beneficial cytokines, such as transforming growth factor-beta 1.
That said, bone marrow harvest is invasive and yields relatively few MSCs. Adipose-derived MSCs, which can be obtained in higher quantities from fat tissue, are an attractive alternative and may have strong anti-inflammatory properties. Adipose tissue, which naturally contains MSCs, has shown promising results in joint applications and is being explored for discogenic pain, although these data were not included in the current analysis. This highlights that most of the evidence so far is for bone marrow–derived MSCs, and more research is needed on other sources.
Limitations of the Current Evidence
As encouraging as the results are, it is essential to interpret them in context. Zhang et al. point out that the meta-analysis has several limitations. The number of clinical studies and the total number of patients remain relatively small. Of the 245 patients included, 193 received bone marrow–derived MSC injections, limiting the ability to generalize the findings to all MSC products.
Not all studies reported pain and disability outcomes in the same way. Only four studies provided complete VAS data suitable for pooled analysis, and only five contributed to the ODI analysis. Differences in how scales were reported and in follow-up timing can introduce variability and make it harder to fully capture the treatment effect.
Additionally, most of the included studies focused on single-level disease and carefully selected patients. Outcomes in broader, more varied patient populations may differ. Longer-term data are also needed to determine how durable the benefits are and whether MSC therapy can truly halt or reverse disc degeneration over many years.
Finally, this analysis focuses on bone marrow–derived MSCs and does not fully address other MSC sources such as adipose tissue, synovium, or perinatal tissues. Future trials will be needed to compare cell sources, doses, and delivery methods more systematically.
What This Means for Patients With Discogenic Low Back Pain
For patients living with chronic, disc-related low back pain that has not improved with standard conservative care, this meta-analysis offers cautious optimism. The pooled data suggest that MSC injections into the degenerated disc can significantly reduce pain and improve function, with a low rate of serious side effects and reoperations.
MSC therapy is not yet a universal, first-line treatment for discogenic pain, and much work remains to refine protocols, identify ideal candidates, and confirm long-term outcomes in larger randomized controlled trials. Still, the evidence to date supports MSC injection therapy as a promising, biologically targeted option that goes beyond symptom control and aims to support disc health at the tissue level.
As research continues to evolve, patients considering regenerative approaches should discuss the latest evidence, risks, and potential benefits with experienced clinicians and seek care in settings that follow rigorous standards for cell processing and clinical monitoring. With ongoing high-quality studies, mesenchymal stem cell therapy may become an important part of the future treatment option for managing discogenic low back pain and improving the quality of life for many individuals.
Source: Zhang, W., Wang, D., Li, H., Xu, G., Zhang, H., Xu, C., & Li, J. (2023). Mesenchymal stem cells can improve discogenic pain in patients with intervertebral disc degeneration: A systematic review and meta-analysis. Frontiers in Bioengineering and Biotechnology, 11, 1155357. https://doi.org/10.3389/fbioe.2023.1155357
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