STEM CELL BREAKTHROUGH IN EQUINE MEDICINE
Traditionally, stem cells have been used to treat tendon injuries, particularly in racehorses. These cells were usually harvested from the sternum of the injured horse and were expanded in a laboratory over 30 days for reimplantation into the site of the injury. This was used with variable success, largely as the number of stem cells harvested was inconsistent between individuals.
COMMERCIAL STEM CELLS
The brilliant news is that we now have commercial stem cells available which we can buy in for appropriate cases. This avoids the need for horses to undergo the painful harvesting procedure and, as the new stem cells are licensed, we can be sure that the vials contain the correct number of pure, mesenchymal stem cells for treatment to be as effective as possible. These cells can be used within joints for cases of osteoarthritis and can also be used in soft tissue injuries such as tendons and ligaments.
The stem cells are harvested from umbilical cord vessels of a particular donor herd. This herd undergoes many tests to ensure there is no risk of disease transmission through the cells harvested, hence why the cost of their production remains high (around £1000 per treatment dose for those interested).
The cells are collected in a completely ethical manner which involves no harm whatsoever to either the foal or the mare. The cells collected are termed ‘pluripotent’, meaning that they can convert into whatever cell is in the environment which they are placed within. It is becoming clearer that they promote gene modulation in the injured environment having both anti-inflammatory effects and impacts on the surrounding cells to improve the speed and quality of healing and repair.
SUCCESS STORY: MAX
If you follow us on social media (@OakhillEquineVets) you may have seen our posts about Max, the eventer who sadly suffered severe injuries to the superficial digital flexor tendon and suspensory branch of the forelimb following a 2* event. We implanted stem cells into both of these structures in 2022, and he’s just stepped back up to Intermediate level eventing as we speak which is incredible!
Image 1: an ultrasound image of Max’s tendon injury 2 weeks following the event. You can see the dark area representing significant tendon fibre disruption affecting approximately 50% of the tendon area (green arrow).
Image 2: an ultrasound scan just 4 weeks following stem cell implantation into the tendon! You can see that the cells have filled the defect very well, but there was still a long way to go to get to full healing.
THE IMPORTANCE OF REHABILITION
Some veterinary surgeons claim that if you use stem cells in these injuries, you can bypass a lot of the progressive rehabilitation work, however, we remain firmly of the belief that the horse should undergo gradual rehabilitation in the same way whether or not stem cells are used, as it takes time for the tissues to adapt, remodel and heal.
For us there is never a miracle quick fix with orthopaedic injuries in the horse: it’s always about the team approach using the best science we have available to improve the quality of repair with the long-term aim being to reduce the likelihood of reinjury and further time out of action for you and your horse.