Surgical management of an atypical chronic fracture of the third trochanter of the femur

Abstract

Fractures of the third trochanter of the femur are an uncommon cause of hindlimb lameness in the horse. The diagnosis is easily made with ultrasonography. Reported prognosis is good after a period of rest and a progressive return to exercise. This case report describes a third trochanter fracture in a 5-year-old trotter mare, which is atypical in terms of both its clinical presentation and management. At the dynamic examination, a left hind lameness was only observed when harnessed at the track. Nuclear scintigraphic examination revealed a marked increase in radiopharmaceutical uptake on the third trochanter of the left femur. Radiographic and ultrasonographic findings confirmed an old complete fracture of the third trochanter of the left femur, with a displaced fragment. The mare was referred for surgical treatment in order to remove the fractured third trochanter. At the follow-up examination, the mare was sound in hand and imaging revealed successful resection of the main fractured fragment. After a period of stall rest, the mare progressively resumed training and then racing 7.5 months after the surgery, performing at its expected level. Surgical treatment may be an option for chronic fractures of the third trochanter.