Sacroiliac joint (SIJ) dysfunction is an underrecognized yet significant source of chronic low back and pelvic pain, accounting for up to 15–30% of cases of axial low back pain. Despite its prevalence, SIJ-related pain is frequently misdiagnosed or inadequately treated due to its complex biomechanics and overlapping symptom presentation.
Traditional treatment options—such as physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroid injections, radiofrequency ablation, or surgical fusion—often provide temporary relief without addressing the underlying inflammatory and degenerative processes within the joint. In this context, regenerative medicine has emerged as a promising therapeutic approach. In particular, umbilical cord–derived mesenchymal stem cells (UC-MSCs) offer a biologically targeted strategy for managing sacroiliac joint dysfunction.
Pathophysiology of Sacroiliac Joint Dysfunction
The sacroiliac joint is a complex synovial-amphiarthrodial structure that transfers load between the spine and lower extremities. SIJ dysfunction may result from trauma, repetitive stress, pregnancy-related ligamentous laxity, or age-related degeneration.
Biological and pathological contributors include:
- Chronic synovial and periarticular inflammation
- Degenerative changes of the articular cartilage
- Ligamentous microinstability
- Altered joint biomechanics
- Sensitization of nociceptive nerve endings
According to Vleeming et al. (2012), sacroiliac joint pain is driven not only by mechanical instability but also by inflammatory and degenerative changes affecting both intra-articular and periarticular structures.
Why Umbilical Cord–Derived Mesenchymal Stem Cells?
Umbilical cord–derived mesenchymal stem cells, isolated primarily from Wharton’s jelly, possess unique regenerative and immunomodulatory characteristics that make them particularly suitable for treating inflammatory joint disorders such as SIJ dysfunction.
UC-MSCs are characterized by:
- Potent anti-inflammatory effects
- Low immunogenicity, enabling allogeneic use
- High proliferative and paracrine activity
- Secretion of growth factors and cytokines that support tissue repair
- Ability to modulate both synovial and ligamentous inflammation
El Omar et al. (2014) highlight that perinatal MSCs exhibit superior immunomodulatory capacity compared to adult-derived MSCs, making them especially effective in chronic inflammatory conditions.
Mechanisms of Action in the Sacroiliac Joint
The therapeutic benefit of UC-MSCs in SIJ dysfunction is primarily mediated through paracrine signaling rather than direct tissue engraftment. These mechanisms include:
- Downregulation of pro-inflammatory cytokines (e.g., IL-6, TNF-α)
- Upregulation of anti-inflammatory mediators (e.g., IL-10)
- Modulation of synovial macrophage activity
- Support of cartilage and fibrocartilage homeostasis
- Improvement of the periarticular ligament microenvironment
Caplan and Correa (2011) describe MSCs as a “biologic drugstore,” emphasizing their ability to orchestrate repair through the release of bioactive molecules.
Clinical Applications of UC-MSCs in SIJ Dysfunction
UC-MSC therapy is typically delivered via image-guided intra-articular or periarticular injection to ensure precise placement within the sacroiliac joint complex.
Intra-Articular UC-MSC Injection
In patients with degenerative or inflammatory SIJ pain, intra-articular injection of UC-MSCs aims to reduce synovitis, improve cartilage health, and modulate nociceptive signaling. Early clinical experiences suggest reductions in pain intensity and improvements in functional mobility.
Navani et al. (2019) reported that biologic injections targeting the sacroiliac joint produced sustained pain relief in patients with chronic SIJ dysfunction.
Periarticular and Ligamentous Applications
Given the significant contribution of ligamentous structures to SIJ stability, UC-MSCs may also be applied to surrounding ligaments to address microinstability and chronic inflammation. This approach is particularly relevant in postpartum patients or individuals with connective tissue laxity.
Evidence from Regenerative Medicine Literature
Although SIJ-specific clinical trials involving UC-MSCs remain limited, broader regenerative medicine literature supports their safety and therapeutic potential in joint-related disorders.
Safety
“Umbilical cord–derived mesenchymal stem cells demonstrate excellent safety profiles in musculoskeletal applications, with no serious immunologic or procedure-related adverse events.”
— Wang et al., 2021
Anti-Inflammatory Effects
“Perinatal MSCs exhibit strong immunosuppressive and anti-inflammatory properties, making them suitable for chronic joint pain conditions.”
— El Omar et al., 2014
Joint Regeneration Potential
“MSC-based therapies improve the joint microenvironment by regulating inflammation and supporting cartilage and fibrocartilage repair.”
— Barry & Murphy, 2013
Conclusion
Sacroiliac joint dysfunction is a complex and often persistent cause of low back pain, driven by inflammatory, degenerative, and biomechanical factors. Umbilical cord–derived mesenchymal stem cells offer a biologically driven, minimally invasive therapeutic option that targets these underlying processes rather than providing only symptomatic relief.
Current evidence suggests that UC-MSC therapy offers:
- A strong safety and tolerability profile
- Significant anti-inflammatory and immunomodulatory effects
- Potential improvement in joint and ligament health
As regenerative medicine continues to evolve, UC-MSC–based therapies represent a promising frontier for patients seeking non-surgical, biologically focused treatment options for sacroiliac joint dysfunction.
References
- Barry, F., & Murphy, M. (2013). Mesenchymal stem cells in joint disease and repair. Nature Reviews Rheumatology, 9(10), 584–594. https://doi.org/10.1038/nrrheum.2013.109
- Caplan, A. I., & Correa, D. (2011). The MSC: An injury drugstore. Cell Stem Cell, 9(1), 11–15. https://doi.org/10.1016/j.stem.2011.06.008
- El Omar, R., Beroud, J., Stoltz, J. F., Menu, P., & Velot, E. (2014). Umbilical cord mesenchymal stem cells: The new gold standard for mesenchymal stem cell-based therapies? Tissue Engineering Part B: Reviews, 20(5), 523–544. https://doi.org/10.1089/ten.TEB.2013.0664
- Vleeming, A., Schuenke, M. D., Masi, A. T., Carreiro, J. E., Danneels, L., & Willard, F. H. (2012). The sacroiliac joint: An overview of its anatomy, function, and potential clinical implications. Journal of Anatomy, 221(6), 537–567. https://doi.org/10.1111/j.1469-7580.2012.01564.x