Evaluation of the effect of pelvic tilt in the coronal plane on the Norberg angle measured in ventrodorsal radiographic views of a canine hip joint bone model

Abstract

Model-derived results indicated that pelvic tilt during acquisition of ventrodorsal radiographic views of the hip joints of a dog should not affect measurement of the NA.

Comparison of Reliability of Norberg Angle and Distraction Index as Measurements for Hip Laxity in Dogs

“…The slight differences in repeated radiographs may derive from a combination of various factors such as the forces applied, pelvic tilting, muscle relaxation, central beam position or other unknown random effects. 20,24,25 The ICC showed minimally better results for the intra-and interobserver-reliability of the DI compared with the NA. This complies with a recent study where variability of the NA was higher than of the DI.…”

Analysis of pelvic rotation on the standard hip ventrodorsal extended radiographic view

“…In veterinary literature, we can find reports that highlight the importance of positioning during radiographic evaluations of skeletal morphology and implant positioning (26). It has been reported that the degree of pelvic tilt (malposition along the short axis of the pelvis) that occurs during the positioning of dogs to obtain a standard radiograph in the ventrodorsal hip extended view can range from zero degrees to -33° (26). However, any greater rotations would be clear and would probably lead to the patient being repositioned and the examination repeated.…”

Effects of pelvis rotation on the projected radiographic position of the femoral head in relationship to the acetabulum

“…Factors such as age, sedation or anaesthesia, osteoarthritis (Vandekerckhove et al 2003;Gold et al 2009) and pelvic rotation may influence NA scores (Genevois et al 2007;Skurkova et al 2010). In a previous study, using a canine-bone model with changes of between 0° and 30° of pelvic rotation along the short body axis, the NA in VDHE views did not change (Bausman and Wendelburg 2010).…”

“…Radiographic assessment and measurements on the standard VDHE view are the basis of the main international HD scor- Veterinarni Medicina, 62, 2017 (07): 377-385 doi: 10.17221/127/2016-VETMED ing systems: FCI, OFA and BVA/KC (Genevois et al 2007;Skurkova et al 2010;Chalmers et al 2013). Therefore, proper positioning and optimal exposure technique are essential prerequisites for radiographs of sufficient diagnostic quality to allow accurate HD assessment (Genevois et al 2007;Thompson et al 2007;Bausman and Wendelburg 2010). Pelvic rotation over the longitudinal axis changes hip radiographic morphology (Genevois et al 2007;Volta et al 2013;Martins et al 2016).…”

“…First, in the normal hip extended view pelvis symmetry was evaluated; the iliac horizontal diameter (IHD) was measured by drawing a straight line between the dorsal and ventral iliac spines at the level of the cranial aspect of the sacroiliac joint (Martins et al 2016); then, in two independent sessions measurements of NA, PT, SI, SC and FAD in the left and right sides were performed to evaluate repeatability; finally, in six more sessions these variables were measured for each degree of rotation (series of 2°, 4° and 6° of rotation for right and left side). The NA was determined in degrees as the angle formed by a line joining the centre of the femoral heads and a line joining the centre of the femoral head and the craniolateral aspect of the ipsilateral acetabular rim ( Figure 2) (Vandekerckhove et al 2003;Ginja et al 2008;Comhaire et al 2009;Bausman and Wendelburg 2010). The centre of the femoral head was obtained using a circular calliper to delimitate the circular components of the femo- (Fluckiger et al 1999).…”