Coffin Bone Fracture

Veterinary advice should be sought before applying any treatment or vaccine.

Coffin Bone Fracture

Pedal Bone Fracture

The coffin bone, also known as the pedal bone, third phalanx, distal phalanx, and os pedis, is located in the horse's foot. It is completely encompassed by the hoof wall, and is where the horse's body weight rests as a pressure-force before it is transferred to the hoof plate. Coffin bone fractures can occur a number of ways, some of the most common being:
  • Stepping on a rock
  • Exercising or getting turned out in areas with very hard or irregular surface, such as dried clay, rocky, or frozen ground
  • Kicking at a stall wall
  • Jumping and coming down very hard, or at an angle
Coffin bone fractures can occur along the wing (side), center (body), extensor process, or solar margin (perimeter) of the coffin bone.

Clinical Presentation of Horses with Coffin Bone Fractures


The degree of lameness in affected horses varies depending on the location of the fracture. Extensor process and solar margin fractures usually result in slight lameness (grade 1-2 of 5), where center and wing fractures tend to cause moderate to severe lameness (grade 4-5 of 5). Since the coffin bone is completely enclosed within the hoof capsule, there will not be any swelling or pain on palpation.

Diagnosis of Coffin Bone Fractures


Coffin bone fractures are often difficult to diagnose. Since there is no obvious signs of a fracture (swelling or pain on palpation), and lameness varies depending on the portion of the bone that's fractures. The only way to diagnose a coffin bone fracture is with radiography. However, since the hoof wall restricts separation of the fracture pieces, the fracture may not show up in radiographs until a couple days following the injury.

Symptoms

Lameness
Reluctance to walk

Diagnosis

  • History
  • Radiographs
  • MRI

Treatment

TherapiesDetails
Extended stall restFor most pedal bone fractures, the typical length of stall rest needed for an adult horse is 3-4 months. Followed by 4-6 months of turnout in a small pasture.
Corrective shoeingMost center, wing, and solar margin fractures in adult horses are managed by fitting the horse with a special shoe that is used to limit hoof wall expansion, while horses recover on stall rest.
SurgerySometimes fractures can be stabilized with a bone screw, however it is usually not recommended due to the high risk of infection and due to the difficulty of placing the screw in the exact right location.

Prevention

  • Walk through horse pastures and remove any loose rocks. Even if your horse is normally very quite and just walks around and grazes most of time---all it takes is one time.
  • Discourage horses from kicking at stall walls, or increase length of turnout outside.

Scientific Research

Risk Factors

  • Horses That Frequently Kick At Stall Walls
  • Turning Horses Out In Or Exercising Them In Areas With Scattered Rocks.
  • Exercising Horses In Areas With Very Hard, Irregular Or Uneven Surface Materials (such As Dried Clay Soil Or Frozen Ground
  • Turning Horses Out In Pastures With Uneven Footing.
  • Standardbred Racehorses Have A Predisposition For Wing Fractures.

Horse Case Stories