Hairline Fracture of the Patella in Horses

As a horse extends his back legs to rest, the patella, which is comparable to the knee cap in a human, elevates and locks the stifle (knee) joint. Generally not serious, a hairline fracture of the patella does require treatment.

  1. Causes

    • A hairline fracture of the patella may occur from a kick by another horse or a blow to the knee. Other causes include hitting the stifle on a hard jump rail while jumping or striking a solid vertical object at high speed.

    Symptoms

    • Symptoms include lameness, pain and swelling at the front of the stifle. Other signs include difficulty bearing weight on the leg and standing with the leg flexed. A veterinarian may recommend a radiograph or x-ray of the patella to determine the exact location and severity of the fracture.

    Treatment

    • Due to the constant weight on the patella, hairline fractures heal slowly. Treatment begins with stall rest for at least six weeks. After the fracture has healed, another three months of rest in a small pen is necessary to limit the activity of the horse. A veterinarian also may prescribe anti-inflammatory medication.