Mesenchymal Stem Cells for Degenerative Disc Disease

Degenerative disc disease (DDD) is one of the most common causes of chronic low back pain. It happens when the spinal discs, which act like cushions between the bones of the spine, begin to wear down over time. This process is often part of normal aging, but it can also be influenced by genetics, lifestyle, injuries, and overall health.

As the discs degenerate, they lose their ability to absorb shock. This can lead to pain, stiffness, and in some cases, additional spinal conditions such as herniated discs, spinal stenosis, or instability between vertebrae. People living with DDD often experience pain that limits daily activities, disrupts sleep, and decreases overall quality of life.

Conventional treatments for DDD usually begin with conservative approaches, such as physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), chiropractic care, or acupuncture. For patients whose pain does not improve, surgery may be considered. Surgical options include procedures like spinal fusion or disc replacement. While these approaches can offer short-term relief, they often do not stop the progression of degeneration, and some patients continue to experience pain in the long run.

Because of these challenges, researchers have been looking into new ways to slow or even reverse the disc degeneration process. One of the most promising areas of research involves the use of stem cells—specifically mesenchymal stem cells (MSCs).

As part of this study, Xie et al. evaluate the clinical efficacy and safety of MSC transplantation in patients with DDD.

Why Stem Cells Are Being Studied for DDD

Stem cells are special cells that can develop into many different cell types in the body. Mesenchymal stem cells, or MSCs, are found in bone marrow, adipose tissue, and other areas. They have unique properties that make them attractive for treating degenerative conditions.

MSCs can reduce inflammation, support tissue repair, and even help create new structural material for damaged tissues. In the case of DDD, researchers believe that MSCs could help regenerate spinal discs by:

• Reducing inflammation inside the disc
• Stimulating the production of new, healthy disc tissue
• Improving hydration of the disc, which helps maintain its cushioning ability
  

Animal studies have shown encouraging results, suggesting that MSC therapy could help preserve disc structure and function. Some early human studies have also suggested potential benefits. However, until recently, clinical evidence was limited and sometimes inconsistent.

To better understand whether MSCs are effective for DDD, the authors of this study performed a meta-analysis—an analysis that combines results from multiple studies to look at the bigger picture.

What the Meta-Analysis Looked At

This study by Xie et al. reviewed randomized controlled trials (RCTs), which are considered one of the most reliable types of clinical research. The researchers looked at trials that compared MSC treatment to standard care or control groups in patients with degenerative disc disease.

They evaluated two main outcomes:

• Pain reduction, measured with the Visual Analog Scale (VAS). This tool asks patients to rate their pain on a scale from 0 (no pain) to 10 (worst possible pain).
• Functional improvement, measured with the Oswestry Disability Index (ODI). This questionnaire looks at how back pain affects everyday activities like sitting, walking, sleeping, lifting, and social life.

They also reviewed safety outcomes, including whether MSC treatments led to more adverse events compared to control groups.

By combining results from multiple studies, the meta-analysis aimed to answer two important questions:

1. Does MSC therapy improve pain and function for patients with DDD?
2. Is MSC therapy safe?
   

How MSC Therapy Affects Pain

The results of the pooled analysis showed that MSC therapy was associated with significant reductions in pain scores. Patients who received MSC treatment reported lower VAS scores compared to those who did not.

When the authors looked at different time points, they found that MSC therapy reduced pain at 3 months, 6 months, 12 months, and even beyond 24 months. This suggests that the benefits are not just short-term but may continue over time.

Another way the authors measured results was by looking at how many patients achieved “clinically meaningful” pain relief. This means the improvement was large enough to make a real difference in daily life, not just a small statistical change. They found that a higher percentage of MSC-treated patients reached these meaningful improvements compared to control patients.

According to Xie et al., this demonstrates that MSC therapy doesn’t just lower average pain scores on paper—it helps more patients experience relief they can feel.

How MSC Therapy Affects Function

Pain relief is important, but for people with DDD, regaining function is just as critical. The meta-analysis showed that MSC therapy also improved ODI scores, meaning patients could perform daily activities with less difficulty.

The improvements were especially noticeable in longer-term follow-up, at 24 months or more. While shorter-term results (3, 6, and 12 months) showed trends toward improvement, the most significant functional gains appeared over time. This suggests that MSC therapy may take time to have its full effect, as the cells work to repair and stabilize the damaged disc environment.

Like with pain, more patients in the MSC groups achieved meaningful improvements in function compared to those receiving other treatments.

Safety of MSC Therapy

Safety is always a concern with new therapies. MSCs are generally considered low-risk because they do not trigger strong immune responses. In the studies included in this analysis, most patients tolerated MSC therapy well.

The most commonly reported side effects were back pain, joint pain, or muscle spasms—symptoms that were not significantly different between MSC and control groups. However, there was a small but statistically significant increase in treatment-related side effects in the MSC groups. Importantly, serious adverse events were rare and not significantly different between groups.

This means that while MSC therapy appears relatively safe, careful monitoring is still important, and more research is needed to fully understand potential risks.

Clinical Implications for Patients

The results of this meta-analysis suggest that mesenchymal stem cell therapy could offer meaningful benefits for people living with degenerative disc disease. Patients who received MSCs reported:

• Reduced back pain over both short- and long-term follow-up
• Improved ability to perform daily activities
• Relief that was more likely to reach clinically important levels

At the same time, the therapy appeared generally safe, with no major differences in serious adverse events compared to standard treatments.

According to the authors, this makes MSC therapy a promising option for patients who have not found relief through conservative measures and want to avoid or delay surgery. However, it is important to remember that MSC treatment for DDD is still being studied. More large, high-quality clinical trials are needed to answer key questions, such as:

• What is the best source of MSCs (bone marrow, fat tissue, or others)?
• How many cells are needed for optimal results?
• How often should treatments be repeated?
• Which patients are most likely to benefit?

Until these questions are answered, MSC therapy should be considered experimental, though the evidence so far is encouraging.

Limitations of the Research

While the meta-analysis strengthens the case for MSC therapy, there are some limitations to keep in mind. The number of studies and patients included was relatively small. Some studies showed inconsistent results, and not all measured outcomes the same way.

In addition, the quality of MSC preparations can vary depending on how cells are collected, processed, and stored. Differences in patient age, health status, and stage of disc degeneration may also affect results.

These factors mean that while the findings are promising, they should be interpreted cautiously until more research is available.

The Future of MSC Therapy for DDD

Research on stem cells and regenerative medicine is moving quickly. MSC therapy represents one of the most exciting frontiers in treating degenerative disc disease because it targets the underlying cause of the condition rather than just managing symptoms.

If ongoing studies continue to show positive results, MSC therapy could become a standard treatment option in the future. It has the potential to provide long-lasting pain relief, restore function, and possibly even slow or reverse the disc degeneration process.

For now, patients interested in stem cell therapy should consult with a qualified healthcare provider to learn whether they may be a candidate for clinical trials or specialized regenerative medicine programs.

As research continues, the authors believe that MSC therapy may become an important option for patients with chronic back pain caused by disc degeneration, helping them move beyond symptom management toward true disc repair and long-term relief.

Source: Xie B, Chen S, Xu Y, Han W, Hu R, Chen M, He R, Ding S. Clinical Efficacy and Safety of Human Mesenchymal Stem Cell Therapy for Degenerative Disc Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Stem Cells Int. 2021 Sep 13;2021:9149315. doi: 10.1155/2021/9149315. PMID: 34557231; PMCID: PMC8455197.