Radiographic landmarks for measurement of cranial tibial subluxation in the canine cruciate ligament deficient stifle

Objectives: The primary objective was to develop a repeatable radiographic technique for assessment of cranial tibial subluxation (CTS) and test the intra-observer and inter-observer repeatability of the chosen landmarks. A secondary objective was to determine the effects of digital radiographic magnification on CTS measurement repeatability.

Methods: Twenty-three normal canine pelvic limbs were used to determine the magnitude of CTS before and after transection of the cranial cruciate ligament. Mediolateral radiographs were taken with and without fiduciary markers in place. Three investigators measured the CTS using radiographically visible anatomic landmarks at two different magnifications. The total observed variabilities were assessed by inter-observer and intra-observer differences. Paired t-tests were used to determine the effect of magnification and marker presence on CTS measures.

R. Plesman¹; A. Sharma²; P. Gilbert1; J. Campbell³; J. D. Johnston⁴; C. Shmon¹; K. Linn^1
1Western College of Veterinary Medicine, Department of Small Animal Clinical Sciences, Saskatoon, Saskatchewan, Canada; ²College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA; ³Western College of Veterinary Medicine, Department of Large Animal Clinical Sciences, Saskatoon, Saskatchewan, Canada; ⁴Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada