Comparison of Radiographic and Anatomic Femoral Varus Angle Measurements in Normal Dogs

Abstract

R-FVA may not be an accurate method of femoral varus measurement in dogs with A-FVA<10 degrees. Using Slocum's criteria for distal femoral osteotomy (R-FVA>10 degrees), the procedure would not have been erroneously performed in any of the normal dogs of this study.

Computation of Femoral Canine Morphometric Parameters in Three‐Dimensional Geometrical Models

“…These skeletal malformations are related to recurrent causes of canine hind limb lameness, including hip dysplasia, cranial cruciate ligament rupture, and medial patellar luxation . Femoral angular deformities such as varus, valgus, and torsional anomalies have been associated with these orthopedic pathologies …”

“…Standard radiography can be technically challenging and time consuming and is operator dependent . Therefore, specific criteria to precisely assess the femoral orientation have been proposed to overcome potential biases of radiographic evaluation . However, the guidelines for correct positioning of the dog for radiographic assessment have been recently questioned …”

“…Although malpositioning can be effectively reduced using CT and MRI, these techniques allow improvement of femoral orientation and visualization of specific anatomic landmarks since the measurement of femoral angles and axes is still achieved with 2‐dimensional (2D) imaging. Thus, the preferred assessment of femoral morphometric parameters is still unclear …”

Are the fabellae bisected by the femoral cortices in a true craniocaudal pelvic limb radiograph?

“…A MPR of each limb was created and re‐orientated such that the frontal plane intersected the most caudal point of each femoral condyle and the most caudal point of the proximal femur (Swiderski et al ) designated frontal plane A (Fig ). The investigator scrolled through images in frontal plane A to obtain the image showing the lateral fabella at its widest.…”

<b>Mensuração do eixo mecânico e determinação do alinhamento do membro pélvico em cães com luxação de patela:</b> estudo radiográfico no plano frontal e correlação com a fisiopatologia da doença

“…Estão descritos estudos que verificam a acurácia dos resultados obtidos por meio da mensuração dos valores diretamente em ossos de cadáveres e nenhuma modalidade de imagem mostrou precisão absoluta quando da comparação com os meios de diagnóstico por imagem descritos (APELT; KOWALESKI; DYCE, 2005;DUDLEY et al, 2006;DISMUKES et al, 2007;TOMLINSON, 2008;SWIDERSKI et al, 2008). Estudo de Meggiolaro (2012), comparando os valores dos ângulos femorais e tibiais obtidos pela mensuração direta em modelos tridimensionais com aqueles obtidos pela radiografia convencional, mostrou que os métodos de mensuração utilizando radiografias para a quantificação e o diagnóstico de deformidades do membro pélvico apresentam boa acurácia, com um erro médio menor do que 5%.…”