Radiographic measurement of the quadriceps angle in dogs

Abstract

The direction of the force of the quadriceps muscle group is expressed by the value of the quadriceps angle, between the long axis of the muscle rectus femoris and the patellar ligament. This value is often modified in dogs with patellar luxation, a common orthopaedic disease of the stifle joint in both small and large dogs. The aims of the present study were to give a reference value for the quadriceps angle in healthy small and medium-large breed dogs. The medical records of healthy dogs and their pelvic limb radiographs (2014–2016) were reviewed. The radiographs were then divided into two groups: Group A (small dogs <15 kg body weight) and Group B (medium-large dogs >15 kg). The quadriceps angle of each pelvic limb was assessed using a digital software program in order to compare values between the two groups. The radiographs of 160 dogs, 80 per group were studied along with the assessment of the 320 pelvic limbs. The median quadriceps angle values obtained were in contrast with the literature: in Group A, it was 18.3° and, in Group B, it was 8.7°; moreover, the quadriceps angle value for Group A was statistically higher than for Group B (p<0.0001). No significant difference was present between males and females, or between right and left hindlimbs. In Group B, the Labrador Retriever breed influenced the quadriceps angle (p = 0.0005). The outcome of this survey provides an objective parameter, or additional information, to explain the different quadriceps mechanisms of small and medium-large dogs. In future studies the QA range values assessed in the two size groups may be useful in defining the magnitude of the malalignment of the extensor mechanism in both healthy dogs and ones with patellar luxation.

Evaluation of the Femoral and Tibial Alignments in Dogs: A Systematic Review

“…According to the purposes of the study, articles were classified into two main groups. The first group was the articles that focused on reporting standard methods for measurements of femoral and tibial alignments and reporting reference values [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. Eleven articles from a total of 29 articles were included in this group.…”

“…Fourteen studies were performed on medium-to-large-breed dogs [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 27 , 28 , 29 , 37 , 39 , 40 ]. Eight studies evaluated small-breed dogs [ 24 , 30 , 35 , 36 , 38 , 42 , 43 , 44 ], and 14 studies evaluated a combination of small and large breeds [ 25 , 26 , 31 , 32 , 33 , 34 , 41 ]. The number of dogs included in the studies is demonstrated in Figure 2 , categorized according to the dog breeds.…”

“…The dogs in the included studies had different health statuses. Nine studies reported the measured values in healthy dogs [ 16 , 17 , 18 , 22 , 23 , 24 , 25 , 26 , 31 ]; however, 20 studies investigated dogs with and without different orthopedic diseases, such as CrCL rupture [ 19 , 20 , 21 , 29 , 32 , 33 , 34 , 37 , 38 ], different grades of MPL or LPL [ 28 , 30 , 35 , 36 , 39 , 40 , 41 , 42 , 43 , 44 ], and other orthopedic diseases such as hip dysplasia [ 27 ]. The main goal of these studies was to assess the influence of the mentioned orthopedic disease on the hind limb alignments.…”

“…The Q angle is the angle between the long axis of the rectus femoris muscle and the patellar ligament. It represents the force generated by the quadriceps muscle [ 22 , 25 , 48 ]. Łojszczyk-Szczepaniak et al [ 22 ] reported standard values in healthy German shepherd dogs, which was larger than those reported by Kaiser et al [ 48 ], for the sound dogs.…”

Canine cruciate ligament ruptures: Implications for financial costs and human health

“…Coxa vara of the femur and decreased FAA are typically associated with MPL (Pinna & Romagnoli, 2017). There are two proposed theories for this relationship.…”