ABNORMAL IMAGING FINDINGS OF THE FEMORAL THIRD TROCHANTER IN 20 HORSES

Ultrasonographic diagnosis of femoral fractures in large animals

OBJECTIVE

Femoral fractures are often catastrophic in large animals. Radiographic diagnosis is limited by patient size and feasibility, especially in ambulatory settings. Ultrasonography is widely available and may provide an alternative to radiography for definitive diagnosis.

ANIMALS

12 large animals (6 horses, 5 cattle, and 1 elephant).

PROCEDURES

Retrospective analysis of large animal patients diagnosed with femoral fracture by use of femoropelvic ultrasonography (2000 to 2019).

RESULTS

5 of 12 cases were ≤ 1 year of age. The remaining 7 cases were 2 to 33 years of age (median, 13 years). All patients developed severe acute lameness after falling (n = 4), limb entrapment (2), dystocia (1), vehicular collision (1), ipsilateral full limb casting (1), or unknown events (3). All were non-weight-bearing or lame at the walk, including 2 recumbent cattle. Ten cases showed upper limb swelling that was variable in location, and 3 had nonspecific upper limb crepitus. Ultrasonography revealed evidence of diaphyseal (n = 6), greater trochanteric (2), capital physeal (2), and distal femoral (2) fractures. Fracture movement during limb manipulation or weight shifting was sonographically visualized in 5 animals. Radiography confirmed fractures in 3 of 8 animals: 2 bovines with distal femoral fractures detected on standing projections and 1 capital physeal fracture that required ventrodorsal projections under general anesthesia. All animals were euthanized (11) or slaughtered (1 bovine). Postmortem examination confirmed ultrasonographic findings in 10 of 10 necropsied animals.

CLINICAL RELEVANCE

Femoral fractures were not localized nor confirmed in any case prior to ultrasonography. Study findings supported the use of ultrasonography for rapid patient-side diagnosis, prognostication, and decision-making in suspect cases.