Spring-loaded Dynasplint exerts tension to stretch contracted tendons easily and safely

SPLINTING AND bandaging has been the only way to conservatively treat foals born with contracted tendons, a condition that causes the legs to fold up similar to the position assumed by a horse while lying down. One or more joints in the forelegs or hind legs may be affected.

On a typical farm, those caring for the foal help its legs to straighten by applying splints and bandages that exert tension on the leg to gradually stretch the foal's tendons. Tetracycline is administered by the farm veterinarian to soften the tendons and allow them to stretch.

Three major drawbacks of this treatment are:

• It inhibits the foal's activity (in some cases, even preventing the foal from standing);
• Make-shift splints fashioned from PVC pipe or other material often cause skin sores; and
• Tetracycline may cause serious allergic reactions.

For the past 30 years in human orthopedics, a special apparatus developed by Dynasplint Systems of Severna Park, Maryland, has been in use to aid patients who have lost range of motion due to contracted tendons and ligaments. That technology is now available to treat foals with contracted tendons.

Jana Caldwell, a former nurse, came upon Dynasplint five years ago when researching how she could help a rescued yearling named Ginger whose tendons were badly contracted from a neglected fracture that had healed improperly. Caldwell contacted Dynasplint, which had produced a canine version of its splinting system, about the possibility of adapting the technology for equine use.

Today, Dynasplints are beginning to be accepted into the horse industry as a better alternative for conservatively treating contracted tendons in foals, with other uses on the horizon.

The Dynasplint

Dynasplint is a brace composed of jointed, stainless-steel tubing that allows the patient to move its limb in a biomechanically correct manner. Cuffs fit the Dynasplint to the limb and are secured by Velcro straps.

The key part of the steel framework is an adjustable, spring-loading device that maintains pressure on the limb to gradually stretch the contracted tendons. The tension can be adjusted from zero to 12, with 12 being the highest setting.

Pieces of sponge padding contoured to fit the curves of the limb are attached to the inside of the steel tubes to prevent skin sores. The sponges, placed where the individual needs them to promote a comfortable fit, can be replaced with fresh sponges or removed entirely if they are no longer needed.

"The splint allows the horse to move his joint naturally," said Caldwell, who joined Dynasplint's veterinary division as its first equine territory manager. "When he is at rest, the splint applies a low-load, prolonged stretch to the tissues. This is why it is so much better for the horse, rather than a static splint. It encourages the use of the joint."

"Humans were actually the guinea pigs in this," said Kristen Perzanowski, director of Dynasplint's veterinary division, on the decision to cross over into the veterinary market. "There is no difference in the physiology of the soft tissue. At first, it was just an idea here and there, but it has proven to be a very easy switchover."

Field trials

Charles Haugh III, D.V.M., of Equine Veterinary Associates in Phoenix, Maryland, and Dan Flynn, V.M.D., of Georgetown Equine Hospital in Charlottesville, Virginia, were the first veterinarians to work with Dynasplint to develop an equine splint. Subsequently, formal trials were conducted in Maryland, Virginia, Colorado, and Texas. But not until Nathan Slovis, D.V.M., an internal medicine specialist at Hagyard Equine Medical Institute in Lexington, began experimenting with the apparatus earlier this year did it attract the attention of major horse breeding farms in Kentucky.

At Hagyard, more than 30 successful test cases in a month relating to contracted tendons in foals pleased Slovis enough that he issued a memorandum to the other Hagyard veterinarians, recommending the use of Dynasplint and asking them to refer similar cases to him.

Slovis has applied Dynasplints to sick foals that arrived at the clinic that also had contracted tendons, because the combination of contracted tendons and physical weakness made it difficult for them to get up or stand.

"When these foals aren't able to or have difficulty getting up, it often increases hospital stays and, naturally, the hospital bills," Slovis said. "We see more than 450 foals in a five-month time frame, and 10% are going to have some flexural limb deformities, be it mild or major."

"We [Dynasplint] are, of course, excited that Hagyard sees value in our technology," said Perzanowski. "Everyone here is so excited that there are options for animals that weren't there before. We want to work hand in hand with a top facility like Hagyard, and it's good that we share that interest. Who wouldn't be ecstatic if Hagyard was interested?"

Farm use

A veterinarian must prescribe a Dynasplint and supervise its use. A Dynasplint representative then comes to the farm to perform a custom fitting on the foal and instruct the caretaker how to apply and use the splint.

All cuffs are labeled to minimize confusion when reapplying them. There is virtually no daily care required other than putting on the splints and taking them off.

"The splints are not worn 24 hours a day," said Caldwell. "It [wear time] is case-specific and usually can be adjusted to the caretaker's schedule."

Use of Dynasplint is by rental agreement and currently costs $350 per month, though that fee is subject to change. Most cases require less than one month's application.

Dynasplint estimates typical duration of treatment for contracted tendons, depending on the age of the foal and severity of the contracture, to be:

• Over at the knee (one to six weeks);
• Upright pasterns (less than a week in newborns; two weeks in older foals; more than a month if chronic); and
• Deep digital flexural tendon contractures (less than one week).

The sooner the need for a splint is identified and it is applied, the quicker the results.

"Ideally, we like to get to them [foals] the day they are born or soon thereafter, as the tissues are very pliable at this time and much easier to stretch," said Caldwell, who added that Dynasplints also are effective on older horses with flexural deformities, just with a different time frame.

Out of 53 cases (at Hagyard, in Colorado, and in Texas), only four yielded some problems. According to Caldwell, three owners claimed no improvement, and two of the three stopped using the splints due to rubs on the skin, which Caldwell attributed to untrained application.ÊAnother owner did not follow protocol.

For this reason, Dynasplint emphasized the need for a custom-fitting and proper training in how to apply the apparatus by one of its equine representatives.

"Our focus is that everyone is doing this correctly," Perzanowski said.