Osteoarthritis is one of the most debilitating conditions faced by millions of people worldwide, with almost 50% of Americans predicted to experience it within their lifetime. It is characterized by abnormal joint biomechanics, which leads to deterioration and wear of the articular cartilage over time. This results in chronic pain, stiffness, and a decreased range of motion in affected joints.
The conventional approach to treating osteoarthritis has been limited to symptomatic relief such as medications, physical therapy and exercise. When these interventions are no longer effective, a costly knee replacement may be necessary. However, recent advances in cellular-based therapies have provided new options for treatment.
Most notably among these treatments is the use of mesenchymal stem cells (MSCs). MSCs are multipotent cells that can differentiate into multiple cell types including those that form cartilage tissue. They are found throughout the human body, including adipose tissue, umbilical cords, and bone marrow, meaning they can be obtained from easily accessible sources for use in treatment. The regenerative potential of MSCs holds promise for not just pain relief, but also for true structural repair and restoration of joint health as well.
While further studies are needed on both MSCs before they become more widely accepted treatments for osteoarthritis, they offer a potential alternative to knee replacement surgery especially when used in conjunction with traditional therapeutic strategies such as medications or physical therapy. With continued advances in our understanding of these therapies and their efficacy in treating osteoarthritis symptoms, patients may soon have access to less invasive yet more effective treatments than ever before.
A study, A Prospective, Single-Blind, Placebo-Controlled Trial of Bone Marrow Aspirate Concentrate for Knee Osteoarthritis, looked into the potential of stem cell therapy to improve knee osteoarthritis outcomes.
Results of the Study
A total of 25 patients with painful bilateral knee osteoarthritis were seen at the Mayo Clinic in Jacksonville, Florida, between November 2013 and February 2015. Each patient received an intra-articular injection of bone marrow aspirate concentrate (BMAC), rich with stem cells, into one knee and saline placebo into the other knee.
Treatments were assigned to knees within each patient using computer-based randomization, which is a commonly used method for randomized clinical trials. The Osteoarthritis Research Society International (OARSI) Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire was used to assess patient-reported pain, as well as Visual analog scale (VAS) pain score and algometry measures.
Outcomes were measured by a qualified orthopedic research nurse that was independent of the operating physician before the treatment and at 1 week, 3 months, and 6 months after surgery. Adverse events such as effusions, warmth, erythema, or joint line tenderness were recorded during these intervals through clinical examinations documenting any changes in symptoms from those observed prior to surgery.
At baseline, there were no significant differences between the BMAC and placebo-treated knees regarding ICOAP or VAS pain scores. However, after treatment with BMAC, there was a significant improvement in the ICOAP constant pain score, intermittent pain score, and total pain score from baseline to 1 week, 3 months, and 6 months. Comparatively speaking, these same pain scores also improved significantly in placebo-treated knees. When assessing the changes from baseline in all of the pain score measures between BMAC and placebo-treated knees over time, there was no evidence of any differences at any of the follow-up time points.
VAS pain scores were improved from baseline at 1 week for both groups receiving either BMAC or placebo treatments. Fortunately, there were not any serious adverse events reported during this study; however effusions were often seen for several days after treatment but decreased by 6 month follow up period. In one instance warmth occurred on one knee at 3 days after treatment but it eventually resolved without any further issues arising.
One potential explanation for the similar degree of pain relief observed in both BMAC- and placebo-treated knees is that the injection process itself was responsible for improvements in pain, even without a therapeutic component. This could be due to the release of natural endorphins during the injection process, which may be capable of providing some analgesic effect. Additionally, it is possible that there is some systemic action to BMAC treatments, though the exact mechanism has yet to be elucidated.
In light of the cell counts, further questions arise regarding how BMAC dosing can affect theoretical efficacy. It is possible that various dosages may produce different effects on joint homeostasis or that a certain dose must be achieved before any noticeable effects are seen. Further research into this area will shed more light on this relationship and provide insight into determining optimal dosing for BMAC treatments and other cell-based therapies.
Recent studies into BMAC have provided support for theories around MSC paracrine signaling mechanisms being capable of modulating joint homeostasis and thus providing symptomatic pain relief. As such, understanding more about how these signaling pathways interact with the joint environment can potentially lead to better outcomes from these treatments. Furthermore, gaining knowledge about how these pathways interact in both normal and pathological states may also lead to insights into potential disease modifiers or treatments for conditions like osteoarthritis or tendinitis.
