Mesenchymal Stem Cell therapy is a relatively new treatment which is becoming increasingly popular. It is primarily used in horses for treatment of injuries to structures which are known to have poor or limited capacity to heal effectively through rest alone, such as tendons and ligaments. Stem cells have the potential to develop into different cell types depending on the environment that they are in.
There are currently two different sources of the stem cells:
Autologous stem cell harvesting – this involves harvesting cells from the horse’s own bone marrow (usually from the sternum). The bone marrow is then cultured in a dedicated laboratory for around 4 weeks until there are about 10 million stem cells. The cells are then injected directly into the injury under ultrasound guidance to ensure accurate positioning where they can contribute to an improved healing response.
Mixed stem cells - direct injection of about 10 million non autologous banked stem cells (i.e. stem cells not derived from the patient). The cells are known to not stimulate an immune or "rejection" response in the patient and so it is possible to use such cells which have been cultured from a different horse.
The stem cells are implanted directly into the injured tissue (usually under local anaesthesia and sedation only) where they have the potential to grow and differentiate into new tendon or ligament cells, as well as being a source of growth factors which also help to stimulate healing. If you are cosidering stem cell therapy the veterinarian will discuss with you the different options and their potential benefits and limitations as well as the important post-implantation care and exercise management.