Summary

Objective: The objectives of this study were to determine the frequency of incomplete ossification of the contralateral humeral condyle (IOHC) in mature dogs with unilateral, atraumatic humeral condylar fracture (HCF), and to determine the sensitivity of radiographs as a diagnostic tool for IOHC. Methods: Computed tomography and radiographs were obtained for both elbows of 14 dogs with unilateral HCF. The images were evaluated by two boarded radiologists and the prevalence of IOHC in the limb contralaterla to the HCF was identified. Sensitivity and specificity of the radiographic diagnosis of IOHC were determined. Results: Incomplete ossification of the humeral condyle was present in six of 14 dogs, however IOHC was incomplete in three of the six affected dogs. Plain radiographs had a sensitivity of 0.83 (CI 95%: 0.36 to 0.99) and specificity of 1 (CI 95%: 0.60 to1). The Kappa coefficient between radiologists for radiographic examination was 0.714. Of the Spaniel breeds, four out of eight had IOHC in the limb contralateral to the HCF. Clinical significance: Computed tomo-graphy evaluation is more sensitive than radiographs for diagnosis of IOHC, particularly when assessing partial or incomplete IOHC. However, sensitivity of radiographic diagnosis is good and should be adequate in most cases. Clinical suspicion of IOHC in the contralateral limb to the unilateral HCF should be present; however overall frequency may not be as high as previously reported.