Radiography and Computed Tomography for the Diagnosis of Distal Limb Fractures in Equines: A Comparative Study

Computed tomography offers added value in diagnosing distal limb fractures in horses. Relative to radiography, the detection of a fracture, defining the fracture orientation, and the other fracture characteristics can more appropriately be determined using computed tomography.

1. Introduction

Distal limb fractures constitute a relatively common problem in equines. Radiography is a firstline investigation; several projections are needed, and superimposition is a problem. Computed tomography (CT) is a cross-sectional modality, with a higher contrast resolution and no superimposition.

2. Materials and Methods

A retrospective study of 27 horses with suspected distal limb fracture and 3 negative controls that underwent radiographic and CT evaluation was conducted. The level of agreement between four observers for a predefined set of radiological characteristics, for radiography and CT separately, and between the two imaging modalities was documented, using Cohen kappa.

3. Results

The detection of a fracture and the anatomic localization showed very good intermodality (IM) and interobserver (IO) agreement levels (0.8 < κ < 1).

Fracture displacement showed good IM and IO agreement levels (0.6 < κ <  0.8). For visualization of articular involvement, fracture comminution, and the number of fracture fragments, all agreement levels bordered on the lower limit of good agreement. Documentation of fracture orientation, fracture width, and coalescing cracks showed poor (0 < κ < 0.2) to fair (0.2 < κ < 0.4) IM agreement levels; for each of these three parameters, IO agreement levels were higher for CT than for radiography.

4. Discussion

Being able to visualize a presumed fracture or fissure is important, and accurately describing the fracture characteristics is necessary for a proper diagnosis and treatment.