Osteoarthritis is a degenerative disease of the joints for which pain management is the most common treatment. Researchers are investigating using bone marrow aspirate concentrate (BMAC) as a cellular-based method of regenerating damaged tissue and treating osteoarthritis.
Patients with osteoarthritis (OA) suffer from painful inflammation in their joints and a slow deterioration of articular cartilage. It affects millions of patients and half of all Americans in their lifetimes. Current treatments fail to treat the degenerative loss of cartilage, and are reduced to treating pain and inflammation associated with the disease. New research into the field is centered on the use of stem cells to regenerate lost tissue and treat the source of OA.
Stem cells are human cells that have yet to differentiate into a specialized form. They are useful due to their high proliferative abilities, whereas specialized cells stop replicating much sooner due to cell damage. The exact mechanisms of stem cells are still unknown, but they are becoming increasingly used in the treatment of degenerative diseases such as Alzheimer’s and osteoarthritis. One source of stem cells is bone marrow aspirate concentrate (BMAC), the subject of a recent study.
In a new study published in The American Journal of Sports Medicine, Shapiro et al. investigated the safety and efficacy of BMAC in treating patients with knee OA. 25 patients with bilateral knee pain were entered into the study, with bone marrow extractions from the iliac crest injected in one knee and placebo saline injections in the other. Patients were included if they had longstanding bilateral knee pain despite conventional treatments and excluded if they had other conditions that jeopardized completion of the study. MRIs were conducted at 6 months and 12 months, and patient-reported pain scores and joint examinations were conducted at 1 week, 3 months and 6 months post injection.
While the mechanisms for stem cell action are still unclear, this study showed BMAC injection to be safe and well tolerated by patients. Patients also reported pain relief, improved range of motion and increased activity, but reported similar results for the placebo knee as well. This result could be due to a number of factors, including that: the injections themselves triggered a positive response, regardless of the contents, the stem cells produced a systemic rehabilitating effect, improvements in the active injection knee improved biomechanics and thus relieved pain in the placebo knee, or that a strong placebo effect occurred resulting in pain relief from both knees. There were also concerns about a small sample size and a bias towards normal weight and active participants. It is clear that BMAC injections are not yet viable for clinical use, and further studies must be done to clarify mechanisms of action, ideal frequency and volume of injections, and its effects compared to other regenerative therapies.
Written By: Wesley Tin, BMSc