Precision of a Novel Computed Tomographic Method for Quantification of Femoral Varus in Dogs and an Assessment of the Effect of Femoral Malpositioning

Abstract

The reported protocol for the measurement of FVA in dogs is repeatable and reproducible. Small variations in femoral orientation, as might be expected with conventional radiography, lead to clinically significant alterations in measured FVA.

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

“…Computed tomography (CT) and magnetic resonance imaging (MRI) have shown superiority over radiographs in diagnostic evaluation of bone deformities. The inaccuracy due to femoral malposition using CT and MRI has been investigated and statistically quantified . CT and MRI have been used to assess femoral conformational deformities, detect geometry and joint changes mediated by surgical treatment, as well as quantify and monitor joint disease for early diagnosis of hip dysplasia .…”

“…Efforts to develop consistent and standardized imaging protocols have improved the accuracy of assessment and quantification of femoral deformities . Human medical research has focused on developing imaging modalities that generate precise morphometric analyses of bone surfaces through the reconstruction of 3D geometric models.…”

Repeatability and Reproducibility of Measurements of Femoral and Tibial Alignment Using Computed Tomography Multiplanar Reconstructions

“…Radiographic measurement protocols are described for distal femoral varus, known as the anatomic lateral distal femoral angle (aLDFA), angle of anteversion (AA), proximal tibial varus or valgus, which is expressed as the mechanical medial proximal tibial angle (mMPTA)), and tibial torsion . Protocols are also described for measurements using computed tomography (CT) for aLDFA, AA, tibial torsion, and tibial tuberosity displacement (TTD) …”

“…Measurements of alignment made from radiographs of hindlimbs are repeatable and reproducible but are vulnerable to positioning errors that reduce accuracy . Measurements made from CT of distal femoral varus have excellent repeatability and reproducibility …”

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

“…CT has been used to assess pelvic limb conformation in dogs and has been shown to be repeatable and reproducible (Oxley et al ). The ability to perform multi‐planar reconstruction (MPR) allows the elimination of the effect of positioning error on resulting measurements, even in the presence of angular limb deformity (Aper et al ).…”