Assessment of normal radial joint orientation angles in nonchondrodystrophic small-breed dogs

To establish reference intervals for radial joint orientation angles in the frontal and sagittal planes in small-breed dogs and to compare them to those previously reported for medium- and large-breed dogs.

Antebrachii of 30 skeletally mature, nonchondrodystrophic small-breed dogs were evaluated radiographically.

Orthogonal radiographs were retrospectively assessed to determine the anatomic medial proximal radial angle, anatomic lateral distal radial angle, anatomic cranial proximal radial angle (aCrPRA), and anatomic caudal distal radial angle (aCdDRA). The frontal plane angle, θ angle, and procurvatum were also calculated. The radial joint orientation angles determined were compared to those previously reported for medium- and large-breed dogs via a 1-sample t test.

Mean and SD values for anatomic medial proximal radial angle, anatomic lateral distal radial angle, aCrPRA, and aCdDRA were 80.86 ± 2.86°, 85.60 ± 1.74°, 87.99 ± 2.79°, and 83.08 ± 3.14°, respectively. The mean and SDs for frontal plane angle, θ angle, and procurvatum were 4.75 ± 2.46°, 11.88 ± 1.76°, and 16.79 ± 4.13°, respectively. aCrPRA and aCdDRA were significantly different when compared to previously reported radial joint angles for medium- and large-breed dogs.

Reference intervals for small-breed dog radial joint orientation angles were reported. Significant differences were identified for some joint orientation angles when compared to medium- and large-breed dogs. This small-breed reference interval reported can be utilized in planning of radial angular limb deformity corrective surgery, particularly when dogs are bilaterally affected.