Evaluating treatment choices for tendon, ligament injury and joint disease in the horse

Evaluating treatment choices for tendon, ligament injury and joint disease in the horse

Apr 01, 2009

Photo 1: Horses with trauma to the splint bones often have reactive thickened bones that may not be fractured or damaged structurally. These thickened metacarpal or metatarsal bones may cause irritation and possible trauma to associated tendons and ligaments, however, and produce a problem for the performance horse. Extracorporeal shock-wave therapy (ESWT) has been shown to be effective in these cases. (PHOTOS: DR. KENNETH L. MARCELLA.)
In the first of these articles we looked at the wide array of different treatment modalities and therapies available for use in horses suffering from varying types of tendon and ligament injuries, and forms of joint disease. Multiple treatment options are available, from stem cells to platelet-rich plasma to shock-wave therapy to Tildren.

This multitude of choices has produced some confusion, and many equine veterinarians have been looking for some research or clinical evidence that will help clarify the issue.

But there is a lack of comparative studies with head-to-head testing, making correct and efficacious choices from among the many options difficult. Similar cases referred to different veterinary schools or to different clinical centers often are treated with differing modalities, furthering the confusion. Published research tends to evaluate an individual therapy itself without comparison or contrast to other methods of healing.

Dr. Rodger Smith of the Department of Veterinary Clinical Sciences at the Royal Veterinary College, University of London, makes this point in an article in the British Journal of Sports Medicine.

Photo 2a: Damage to tendons and ligaments is common in equine athletes. Newer treatment options include platelet-rich plasma, bone marrow- or fat-derived stem cells and A-cell tissue. Clinical experience, treatment familiarity and bias are still the most common reasons for specific choices and recommendations by veterinarians.
In his article on harnessing stem cells for the treatment of tendon and ligament injuries, Smith states, "a multitude of treatments have been advocated for the management of tendon over-strain injuries, but there is little evidence in any species that any is more effective than a prolonged period of rehabilitation with carefully controlled exercise."

Studies comparing different treatment options for tendon injuries with good rest/rehabilitation programs are not available, and it is questionable if they will even be done.

There is little commercial benefit in proving that "rest works best," and the practical issues of doing tendon injury and healing studies may make such clinical trials realistically impossible.

Photo 2b: This ultrasound shows a core lesion to the deep digital flexor tendon (DDF) and superficial digital flexor tendon (SDF). These types of injuries are well suited to stem-cell injection and stem-cell use. This, along with injection of platelet-rich plasma, seems to provide the best healing.
"Equine superficial digital flexor tendon injuries (and generally all equine tendon and ligament damages) are highly variable, and controlled studies are almost impossible to perform in an environment in which treatment is essentially private and dominated by owner/trainer preference," Smith explains.

Clients have heard the claims of faster, stronger healing with various treatments, so getting "control" horses in a study that do not receive these treatments or comparative horses treated conservatively is very difficult.

Without comparative research to guide the decision-making process for the average practitioner, it may be beneficial to look at current treatments used for various cases and problems from the standpoint of clinicians, researchers and practitioners who are more familiar with these therapy options and have found some "comfort zone" through their application to numerous cases.

While this cannot be an exhaustive review and there certainly is room for other opinions, this is the current state of knowledge for use of these treatments in the athletic horse.