Stem cells could help knee, stifle injuries

Horses are often subject to injuries that cut short promising show ring or race track careers. In particular, these animals are prone to injuries in the stifle joint, the human equivalent of the knee.

But veterinarians at Colorado State University's Gail Holmes Equine Orthopaedic Research Center use such innovations as stem cells and a syringe of beneficial soup containing the injured horse's blood that is treated to cultivate enhanced levels of its own growth factors and anti-inflammatory substances to heal injuries.

The centre is an international leader in helping performance horses heal joint, tendon, ligament and cartilage damage and continue with successful careers through surgical and medical advancements.

"In the last several years, we've seen several exciting advancements in the field of equine orthopedic medicine," said Dr. Wayne McIlwraith, director of the center, who leads a team of internationally recognized researchers whose work may even benefit humans. "We're able to treat serious injuries in a way that allows these equine athletes to return to their sport as strong as they were before they were injured."

The center has an impressive list of clientele with success stories that include removing a bone chip from a joint in racer Congaree, a horse that placed third in the Kentucky Derby and Preakness Stakes. The center also has operated on some of the nation's premier cutting horses.

The university's center is among the few medical sites pioneering the revolutionary approach to treating equine joint injuries - ligament, tendon or bone fractures - with stem cells. A small sample of cells are gathered from the fat on the hip of an injured horse and then developed into stem cells. The cells are then injected into the site of the injury.

"We know from early research that stem cells are attracted to cartilage damage," McIlwraith said. "They gather at that site to heal the damage. We're seeing this therapy work well on injuries. However, the treatment is new, and while researchers are making advances in its use, this therapy is not yet perfected. For example, the treatment sometimes triggers immune system responses. However, I believe this will be the premier joint treatment therapy in horses within several years."

A stem cell is a naturally occurring cell in an animal that can transform into a type of cell for a specific part of the body, such as a tendon, to heal and regenerate healthy tissue. Laws regulate the use of human embryonic stem cells, but cells used in this procedure are derived from fat and do not contain any embryonic tissues. Unlike embryonic-derived stem cells, these cells have a extremely short "shelf-life," which means that the horse must be treated with its developed cells within a few days of the original fat sample.

While most stem cell information focuses on stem cells derived from embryos, scientists discovered their ability to derive useful stem cells for body tissues, and there is a high level of stem cells in fat that can be purified for use in medical treatments.

In addition to stem cell therapy innovations, the Equine Orthopaedic Center is researching how another successful joint treatment works. IRAP, which stands for Interleukin-1 Receptor Antagonist Protein Procession System, is a substance that blocks the excessive production of synovial fluid in joints affected by osteoarthritis. This fluid carries a protein called interleukin-1, which plays an important role in inflammation and accelerates the deterioration of tissue.

The treatment works by taking a sample of blood from the injured horse and incubating it for 24 hours in a syringe filled with beads coated with substances that encourage healing, such as growth factors and anti-inflammatory aids. The sample is then "spun" to separate these beneficial substances from red blood cells. The beneficial fluid is then injected into the injured joint three to five times, encouraging healing. The treatment also drastically reduces the animal's susceptibility to infection and immune reactions because the fluid is a derivative of its own blood.

The technology sprang from a study by Dr. David Frisbie, a veterinarian at the center. Frisbie's research showed that arthritis could be blocked by the substances that IRAP cultivates, and the Equine Orthopaedic Center continues to research the technology.

"IRAP works well to treat injuries that are too far advanced for other treatment options," McIlwraith said. "It also works well on injuries that don't respond to steroids."

The center also houses one of the only high-field MRI devices devoted to equine medicine in the world. This machine, specially fitted for horses, allows doctors to better illuminate injuries, such as changes in the bone under cartilage.

While these technologies for treating equine injuries are being researched and perfected by McIlwraith and others at the center, the research also has led to advancements in human injuries.