Tendon disorders are often some of the most difficulty presentations to treat when it comes to musculoskeletal complaints. This is evident from the various modalities that are proposed to help in the healing process of tendinopathies, including physiotherapy, dry needling, active release therapy (ART), extracorporeal shockwave therapy (ESWT), platelet-rich plasma (PRP), and nitroglycerin patches. Stem cells are often touted as the next frontier in medical therapy given their potency to become multiple cell types in the right environment, so it is no surprise that stem cell therapy research has begun for tendinopathies.
Chronic tendon disorders have histological findings of necrotic and apoptotic tenocytes, neovascularisation and collagen disarray. The proposed mechanisms of repair through stem cells involve the cells’ differentiating capabilities into new tenocytes to generate new tendon tissue and their modulation of the local immune response and stimulation of repair in the surrounding cells by the production of growth factors and cytokines.
This systematic review focused on the efficacy of stem cell therapy for pain and functional outcomes in the treatment of tendon disorders in humans. Seven articles were selected for inclusion in the study, but data was only available for four. Three of the studies were case series and one was a matched non-randomized study. Conditions studies included lateral epicondyle, patellar, and rotator cuff tendinopathies. 3 out of 4 studies used bone marrow cells (from anterior iliac crest) and one used adipose tissue derived cells. The 2 studies on the rotator cuff evaluated post-surgical response to bone marrow-derived stem cells. While the studies generally found improvements in pain scores and lower re-tear rates of the rotator cuff, all of the studies were level 4 evidence, so a conclusion about stem cell efficacy cannot be confidently drawn. Furthermore, only 1 study reported adverse events, none of which were serious.
In summary, there is a lack of any evidence for stem cell therapy for tendon disorders and the safety of these procedures cannot be determined. Patients should be made aware of these facts if they are seeking therapy for their tendinopathies.
- H Pas, MH Moen, HJ Haisma, M Winters. No evidence for the use of stem cell therapy for tendon disorders: a systematic review. Br J Sports Meddoi:10.1136/bjsports-2016-096794
Dr. Ryan Shields (PGY3 Sport Medicine, University of Ottawa)
Advisor: Dr. Taryn Taylor BKin, MSc, MD, CCFP(SEM), Dip Sport Med