Curvature Radius Measurements From the Ulnar Trochlear Notch in Large Dogs

Abstract

Assessing the ulnar trochlear notch (UTN) radiographic anatomy has been considered important, but difficult, in the diagnosis of elbow dysplasia. The purpose of this study was to evaluate UTN curvature of natural elbows in radiographs, using a methodology applied to disarticulated joints. The methodology was implemented and validated using dedicated software created by the authors. Mediolateral extended (MLE) and mediolateral flexed (MLF) elbow views were used from 20 joints from canine cadavers that were over 20 kg. After arranging the bones to avoid radiographic overlapping of the bones, an additional mediolateral radioulnar (MLRU) view was made. Curvature radius measurements from the central ridge of the UTN of each elbow were acquired in the MLRU view, using the software. The measurements were repeated in a second session, to determine repeatability. Then similar UTN measurements were taken from the MLE and MLF views, to determine reproducibility. Intraclass correlation coefficient (ICC) for repeatability and reproducibility of measurements were above 0.98 (95% confidence interval limits >0.75). The 95% limits of agreement (LA) for repeatability were 22.98 to 3.19 mm. The 95% LA for reproducibility between MLRU and MLE views were 24.32 to 3.75 mm. The 95% LA for reproducibility between MLRU and MLF views were 25.02 to 4.07 mm. The methodology and software are determined to be both precise and suitable to evaluate the UTN in MLE and MLF elbow views of large breed dogs, for anatomical and clinical purposes. In the future it would be useful to characterize normal and dysplasAbbreviations used: CI 5 confidence interval; ICC 5 intraclass correlation coefficient; LA 5 limits of agreement; MLE 5 mediolateral extended elbow view; MLF 5 mediolateral flexed elbow view; MLRU 5 additional mediolateral radioulnar view; MLRU 1 5 second session of measurements in the MLRU view; SD 5 standard deviation; SEM 5 standard error of the mean; UTN 5 ulnar trochlear notch; d 5 mean difference; f 0 5 first derivative of the polynomial fit to the points; q 5 Radii of curvature; r 2 5 correlation coefficient; s* 5 normalized natural coordinate; f 00 5 second derivative of the polynomial fit to the points.

Curvature Radius Measurements From the Humeral Trochlea in Large Dogs

“…In the previous similar study using the ulnar trochlear notch, the curvature radius showed identical main characteristics, greater at beginning and with two intermediate peaks at similar anatomical level. However, ulnar curvature radius showed higher values (Collins et al, 2001;Alves-Pimenta et al, 2015).…”

“…An article recently published in the Anatomical Record described a methodology and dedicated software to study curvature radius from the ulnar trochlear notch curvature in large dogs (Alves-Pimenta et al, 2015). The humeroulnar incongruity has been identified in the literature as one of the etiological factors of elbow dysplasia, however its diagnosis and quantification remains subjective and uncertain (Wolschrijn et al, 2003;Samoy et al, 2013;Skinner et al, 2015).…”

“…The purpose of this letter is to complement the recent article from Alves-Pimenta et al (2015), by describing the curvature radius from the humeral trochlea (HT) in contact with the ulnar trochlear notch studied before, applying the same methodology and software.…”

“…An additional mediolateral humeral view (MLH) was obtained from each humeral bone prepared as described in the previous work (Alves-Pimenta et al, 2015).…”

“…To implement the methodology to the HT, 20 mediolateral extended (MLE) and 20 mediolateral 45 degree flexed (MLF) radiographic elbow views from cadavers over 20 kg were included in this study (Alves-Pimenta et al, 2015). An additional mediolateral humeral view (MLH) was obtained from each humeral bone prepared as described in the previous work (Alves-Pimenta et al, 2015).…”