Page 290 - The Veterinary Care of the Horse

Fractures of the pedal bone (distal phalanx) are a relatively common injury. They are

classified according to the location of the fracture and whether or not it extends into the
VetBooks.ir coffin joint. They occur most commonly in the forelimb.

Causes

• Trauma, e.g. landing on a hard, uneven surface (forelimb) or kicking a solid object (hind

limb).

• Foreign body penetration, e.g. standing on a nail or metal spike.
• A fracture may occur secondary to chronic inflammation, a bone cyst or infection of the

pedal bone.

• Fractures of the extensor process of the pedal bone are associated with over-extension of
the coffin joint.

Clinical signs

• In most cases there is sudden onset, moderate to severe lameness.

• Some horses show an increase in lameness over the first 24 hours due to inflammation
and swelling causing a build up of pressure within the foot.

• Increased heat in the foot.

• Increased digital pulse on the affected side.
• If the fracture extends into the coffin joint there may be distension of the joint capsule

just above the coronary band at the front of the limb.

• Flexion of the lower limb is painful if the joint is involved.
• The lameness is often worse when the horse turns.

Diagnosis

The diagnosis is made on the clinical signs and the results of radiography.
• In most cases the horse is sensitive to hoof testers applied close to the fracture site.

However, horses with thick, hard soles may not show any reaction.
• Nerve blocks of the foot temporarily abolish the lameness.

• Many fractures are immediately obvious on X-rays (Figure 6.57). In other cases, multiple

views from different angles are necessary to see the fracture line. Some fractures do not
show up on the X-rays immediately after the injury occurs. These need to be re-examined

after 10–14 days, by which time sufficient bone resorption will have taken place for the