Tendon and ligament injuries can range form subtle to severe. Most injuries involve the superficial flexor tendon (bowed tendon), the suspensory ligament or its branches. If other tendons or ligaments are injured the principles of diagnosis and and therapy are similar.

Diagnosis: Many tendon injuries are superficial enough to cause swelling and an obvious diagnosis. Mild tendon or ligament injuries can remain hidden. The swelling is minimal and it is necessary to use diagnostic ultra sound and local anesthetic blocks to confirm the the diagnosis. Lameness can be quite variable.

Ultrasound scanning is used to assess any swelling or pain involving these structures, providing answers to the following pivotal questions needed to establish therapy and prognosis.

• Do we have a tear or not ?
• What areas are damaged ?
• What percent of cross sectional area and length of tendon is damaged ?
• What is the degree of damage?

 

Various Treatments

Tendon and ligaments heal at a fixed rate. Assuming optimal circumstances 6 months is a general figure with another 6 months to a year to allow for maturity and strength.

Many different treatments are recommended! Any time there are multiple treatments for a single problem we have to realize that no one has the definitive answer and what works for one horse or injury may not work for another. When choosing a treatment one must consider the logic behind it, the cost involved and most important the ability to follow through on a controlled rehabilitation program.

The trick to any tendon injury is getting it to heal with minimal scar tissue formation and with as much realignment of tendon fibers as possible. Scar tissue is not elastic, so any scarring (thickening) of the tendon is detrimental to its elasticity. For this reason it is logical for horses that bow to have a surgical release on the superior check ligament. This procedure compensates for a certain amount of residual scarring by indirectly lengthening the tendon (see superficial flexor tendon injuries). Elasticity of the structure is promoted by initial therapy and rest. This is followed by a rehabilitation program that includes stall rest simultaneously with a controlled exercise program that is monitored by ultrasound examinations.

Initial therapy should always include icing and anti-inflammatory medication. This should continue until there is minimal heat left in the limb since inflammation persists in tendon lesions causing them to increase in size if left untreated.

Most tendon or ligament tears are within the tendon structure (core lesions) where they can neither drain or receive a good blood supply. Surgical tendon splitting has been used successfully for decompression and as a means to allow for revascularization of the deeper areas of the tendon or ligament. The problem with tendon splitting is that a certain amount of healthy tissue is damaged by nature of the surgery and healing is therefore affected.

A technique published in the "Equine Veterinary Journal" caught our interest in that the same decompression was achieved but through the use of needles instead of a knife. Over the decades we have injected various therapeutic agents into tendon lesions including "Adequan", "Bapten", or "HA . We are now injecting stem cells in the form of bone marrow and commonly combine this with shock wave therapy.

At present this is our treatment of choice for high suspensory and other ligament or tendon tears. The bone marrow is taken from the horse's chest (sternum) and injected into the damaged area. The theory is that bone marrow has growth factors and stem cells that can form tissue that can duplicate the original. This technique is especially useful for more difficult cases such as injuries at ligament -bone junctions(high suspensories).

We were initially quite sceptical about this technology but it has proven to be the most effective non-invasive approach to tendon/ligament healing that we have come across! Data to its efficacy in healing tendons was presented at the AAEP and the annual surgery conference and we continue to use shock wave therapy on more and more horses.

We have had the opportunity to work with hundreds of tendon and ligament injuries. Many horses have returned to peak performance levels but we have had our share of failures as well. In retrospect most of the failures were because of inappropriate activity and inadequate monitoring during rehabilitation. As a result we have developed a very strict controlled rehab program (patent pending) which is initiated soon after injury. Other important issues to address during and after rehab are foot care, footing, and adequate fitness. Nutrition is an important consideration. One must ensure that the feed is cut back so the horse doesn't jump out of his stall or get laminitis. At the same time sufficient protein must be maintained to provide for proper healing. Nutriceuticals such as Equine Power, collagen and oral glycosaminologycans seem to be beneficial in the healing process but controlled studies on tendon/ligament healing are lacking.

Even with optimum healing there is less elasticity in an injured superficial flexor (SFT) resulting in a higher chance of re-injury. Dr. Larry Bramlage's technique of cutting the superior check ligament under general anesthetic allows an extra centimetre or so of give that compensates for the loss of elasticity. Statistics have shown that a thoroughbred racehorse treated conservatively for an SFT injury still has an 80 % chance of re-injury within the first three races after recovery. Cutting the check ligament reduces the re-injury rate to 20 %. Horses that need to pursue athletic careers will greatly benefit from this surgery.

This surgery is routinely done using a minimally invasive approach (tenoscopically) at Kleider Vet Services. Our experience and those of others does not show that on operated horses there is any greater increase in suspensory injuries than in the normal racing population. This was previously a concern which had to be addressed since a paper that published this comment did not take into account the suspensory injuries in the non treated population.