Many fractures once deemed inoperable can now be surgically repaired successfully, but management approaches during the critical post-fracture window can have a major impact on outcomes. One equine practitioner reported that veterinarians must be prepared with the appropriate knowledge and equipment to help save these patients' lives.
Scott Palmer, VMD, Dipl. ABVP, owner and hospital director of the New Jersey Equine Clinic in Clarksburg, reviewed equine fracture stabilization techniques at the 2012 American Association of Equine Practitioners convention, held Dec. 1-5 in Anaheim, Calif.
"Successful management of unstable fractures in the field involves a combination of clinical assessment, appropriate medical treatment, stabilization of the fracture, and careful and prompt transportation to a facility equipped for fracture repair," Palmer said, noting that the majority of equine limb fractures cannot be treated in the field.
Fracture Locations and Prognoses
Palmer reviewed the variety of fracture classifications and general prognoses for each. In all cases, he said, horses with closed fractures have better prognoses than do open ones (in which bone has penetrated skin), and simple fractures carry better prognoses than do comminuted fractures (having multiple fractures in the same bone). In most cases nondisplaced fractures pose better prognoses than do displaced ones. That said, prognoses are also dependent on fracture location.
Level 1 Fractures—Level 1 fractures are located in or below the fetlock joint. Common Level 1 injuries include fractures of the phalanges (which include the long pastern bone, the short pastern bone, and the coffin bone), proximal sesamoid bones, and lower end of the cannon bone. Palmer said that prognoses for Level 1 fracture cases depend on the severity and nature of the injury, and they range from good to poor.
Level 2 Fractures—Level 2 fractures include mid-shaft cannon bone fractures. Because little soft tissue covers the cannon bone, Palmer said, these fractures are often open, leading to a poor prognosis. Horses that survive generally have a guarded to poor prognosis for return to athletic function.
Level 3 Fractures—Level 3 fractures occur between the horse's knee and elbow on the forelimbs and between the hock and stifle on the hind limbs. Palmer said that while the general prognosis for adult horses with Level 3 fractures is poor, veterinarians can repair some ulna (one bone in the forelimb) fractures. In foals, he noted, some fractures of the radius (another bone in the forelimb) and tibia (a bone in the hind limb) can be repaired successfully.
Level 4 Fractures—Level 4 fractures—those located above the elbow and stifle—generally have a poor prognosis for adult horses, but a better prognosis for foals and yearlings, Palmer said. Simple scapula (shoulder blade) and femur (the long upper bone of the hind leg) fractures can be repaired in some cases he reported. Pelvic fractures are uncommon in horses, he noted; however, affected horses have a 50% to 70% survival rate.
A veterinarian should begin assessing a horse with a fracture by considering the animal's general condition and temperament, Palmer said. Next, he or she should determine the location and severity of the fracture and whether repair is possible. Specific questions to answer in the evaluation include:
- Is the horse able to bear weight on the injured limb?
- Is the fracture open or closed?
- Is the fracture unstable?
After completing the evaluation, the veterinarian should stabilize the fracture and discuss options with the owner. It's crucial to establish what resources (financial and otherwise) are available for the horse's treatment, and what the owner's expectations would be for the horse post-recovery, Palmer said. This is also the time to consider if the nature of the injury and the prognosis warrant euthanasia.
If the owner elects to transport the horse for treatment, stabilization becomes particularly important. In some cases veterinarians administer a sedative and tranquilizer to relieve a horse's pain and encourage relaxation during splinting and transportation. Veterinarians also typically administer a non-steroidal anti-inflammatory drug and, if open fractures are present, antimicrobial medication.
"An effective splint must provide rigid support to neutralize, as much as possible, the forces acting on the fracture site that can damage the fracture surfaces as well as adjacent soft tissues," Palmer said. He detailed splinting options for the different fracture locations on front and hind legs.
Level 1 Fractures—In the forelimb, veterinarians should immobilize these fractures using a splint on the front of the leg that extends from the horse's toe to just below his knee, Palmer said. To achieve this, he recommended using either a Kimzey Leg Saver Splint (a commercially available splint that practitioners apply over a padded bandage) or a Robert Jones bandage (a layered and padded bandage designed to limit limb mobility) in conjunction with rigid splints—often made from 4-inch PVC pipe cut into longitudinal sections.
Splinting Level 1 hind limb fractures involves a similar process, although in the hind limb it’s best for the veterinarian to apply a PVC splint to the back of the limb. Splints should stretch from the horse's toe to the hock, he said, and a Kimzey Leg Saver can be used if available.
Level 2 Fractures—Palmer explained that it’s best to stabilize forelimb fractures using a Robert Jones bandage with rigid splints on the back (caudal aspect) of the leg and the outside (or lateral aspect) of the leg; veterinarians should secure the splints to the bandage by applying duct tape as tightly as possible to prevent splint movement of when the horse applies load to the limb. The finished splint and bandage should extend from the horse's toe to his elbow, and he said it should be roughly three times the diameter of the limb at the fracture site. A Robert Jones bandage and splint combination is also used on Level 2 hind-limb fractures.
Level 3 Fractures—These fractures are difficult to immobilize, Palmer said, and veterinarians often recommend euthanizing affected horses due to the patients’ poor prognoses. Foals with Level 3 fractures have a better prognosis, and veterinarians use a full-leg Robert Jones bandage in these animals, in addition to a splint that extends from the toe, up the leg, and up past the shoulder to provide extra support.
Similar to forelimb fracture outcomes, veterinarians often recommend euthanasia for adult horses with Level 3 hind-limb fractures. Foals with Level 3 hind-limb fractures have a better prognosis, and practitioners can combine a full-leg Robert Jones bandage with an extended splint that stretches from the hoof up along the hindquarters to stabilize these limbs.
Level 4 Fractures—Palmer said veterinarians don’t generally apply splints to Level 4 forelimb fractures. Rather, because horses with Level 4 fractures cannot fix, or lock, their knees (which Palmer said is essential when bearing weight) a full-leg bandage with a support splint should be placed on the back edge of the leg.
Practitioners do not splint Level 4 hind-limb fractures because the large gluteal muscles protect the injury site, Palmer said. He noted it is crucial to keep affected horses as quiet as possible while loading and during transport.
Once a fractured limb has been appropriately splinted, load and transport the patient carefully for further treatment. Palmer recommended having assistants on hand to help stabilize the horse as he enters the trailer.
"Adult horses should be placed in a partitioned or confined space in the trailer, restrained with chest or rump bars, and the head should be tied loosely to allow the horse use of the head and neck for balance," he said.
He noted that a horse with a forelimb fracture should be transported facing the rear of the trailer so he can use his hind end to brace when the trailer slows or stops. Similarly, a horse with a hind-end injury should face forward so he can use his front end to balance.
Ship affected foals with their dams, Palmer said, noting that young affected horses often travel lying down.
Palmer reminded practitioners that fracture repair success depends on the type and quality of emergency care the horse receives in the field.
"Proper splinting and transportation of the fracture patient improves the chances of successful surgical repair," he said. "In some cases, the correct application of these basic principles will literally be a matter of life or death of the patient."
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.