Apophyseal avulsion fracture of the greater trochanter of the femur in a Thoroughbred filly.

This research details a case report about a 14-month-old Thoroughbred filly or female horse that experienced severe lameness in its right hindlimb due to a rare type of fracture called apophyseal avulsion fracture of the greater trochanter of the femur, brought about by an overdose of lidocaine after colic surgery.

Overview of the Study

• The case under review was about a 14-month-old Thoroughbred filly that suddenly developed severe lameness in its right hind leg.
• The condition was triggered by an unfortunate side effect of an overdose of lidocaine, which was administered after the horse underwent a colic surgery.
• The overdose caused a severe and unexpected abduction, or movement away from the midline of the body, of the horse’s hindlimbs.

Diagnosis of the Condition

• The researchers utilized transcutaneous ultrasonography and standing radiography of the horse’s pelvis for diagnosis.
• The diagnostic tests revealed a proximal and cranial displacement of the greater trochanter, a bony protrusion found at the top of the femur or thigh bone, accompanied with free bone fragments.
• Such findings were consistent with an apophyseal avulsion fracture of the greater trochanter, a type of fracture where a tendon or ligament pulls off a piece of bone.
• The condition was fully diagnosed with the horse in a standing position.

Outcome and Significance of the Study

• Due to health deterioration from both the colic condition and the poor prognosis of the avulsion fracture, the decision was made to euthanize the filly.
• A postmortem evaluation confirmed the initial diagnosis of the apophyseal avulsion fracture of the right greater trochanter.
• The authors highlighted that to their knowledge, this case presents unique ultrasonographic and radiographic findings of this type of fracture in a standing horse.
• The diagnosis technique used in this case was found to be relatively straightforward with the horse in a standing position, given the distinctive radiographic and ultrasonographic findings associated with this fracture.