Splint bone fractures are one of the more common types of fractures that occurs in performance horses. A study by Sherlock and Archer in 2008, found that splint bone fractures were the most common type of fracture presented to 6 veterinary referral hospitals in the United Kingdom.

Splint bone fractures can occur anywhere along the length of the splint bone, and often occur in conjunction with suspensory desmitis. Fractures of the splint bone can occur spontaneously during exercise or as a result of direct external trauma, such as a kick from another horse, a blow from a polo mallet, or other traumatic incident.

Clinical Presentation

Clinical signs observed in horses with splint bone fractures typically include:

• Mild to moderate lameness - The degree of lameness depends on the location of the fracture along the bone. It may have an acute or more insidious onset.
• Mild to marked soft tissue swelling and sensitivity in the area of the injury. Sometimes an abrasion or wound may also be present.
• If horses are rested for a short period of time, lameness usually persists.
• When treated as if it were a seemingly superficial wound or abrasion, several weeks to months later, swelling and pus may develop at the same location. Horses may also be mildly lame.

Diagnosis of Splint Bone Fractures

Both open and closed splint bone fractures are determined with radiographs. If horses are diagnosed with a splint bone fracture, since they have been found to occur at the same time as suspensory ligament strains, an ultrasound of the suspensory ligament should be performed, in the same leg as the fracture.

Treatment of Splint Bone Fractures

When fractures occur in the lower two-thirds of the splint bone, in both open and closed type fractures, treatment usually requires surgical removal of the fragment of splint bone. If the fracture occurs in the upper third of the splint bone, horses may or may not require additional stabilization using a bone plate. In many cases of closed fractures, horses can often heal well when confined to stall rest for 6-8 weeks and wear a firm support bandage.

If surgery is needed in cases of open splint bone fractures, additional post-operative care is needed to help reduce risk of infection. These horses require longer stall rest (8 to 12 weeks) with another 2 to 3 months of turnout in a small paddock. Antibiotics, NSAIDs, and bandaging over sututres is also indicated.