Magnetic resonance imaging diagnosis and arthroscopic treatment of medial meniscal injury in a dog with a palpably stable stifle.

A dog with lameness, stifle effusion, and osteophytes, but in which the stifle retained stability for 10 months after the onset of lameness, was evaluated with 3T magnetic resonance imaging (MRI). Imaging revealed a tear in the caudal meniscotibial ligament of the medial meniscus. Arthroscopy findings correlated well with MRI and a partial meniscectomy was subsequently carried out, without any surgery to stabilize the stifle, and lameness resolved.

Diagnostic par imagerie à résonance magnétique et traitement arthroscopique d'une blessure du ménisque médial chez un chien ayant un grasset stable à la palpation. Un chien présentant de la boiterie, de l'effusion du grasset et des ostéophytes, mais pour lequel le grasset a conservé de la stabilité pendant 10 mois après l'apparition de la boiterie, a été évalué à l'aide de l'imagerie à résonance magnétique (IRM) 3T. L'IRM a révélé une déchirure dans le ligament méniscotibial caudal du ménisque médial. Les résultats de l'arthroscopie présentaient une bonne corrélation avec l'IRM et une méniscectomie partielle a ensuite été réalisée sans chirurgie pour stabiliser le grasset et la boiterie a été résolue.(Traduit par Isabelle Vallières).

The effect of valgus and varus femoral osteotomies on measures of anteversion in the dog.

OBJECTIVE: To determine whether femoral osteotomies that change frontal plane alignment without affecting torsion influence anteversion and inclination. METHODS: Femurs without deformity were scanned to create three-dimensional reconstructions. The femoral head-neck axis was identified by placement of a virtual intramedullary pin. A proximal osteotomy was simulated to create three conditions while keeping torsion constant: Normal, Coxa Valga (neck-shaft angle increased by 12°), and Coxa Vara (neck-shaft angle decreased by 12°). Femoral anteversion was measured from an axial image in all three conditions. Femoral inclination was calculated for all conditions using the neck-shaft and anteversion angles. Changes in anteversion and inclination were calculated and compared using a one-way repeated measures analysis of variance. Distal femoral osteotomies were then simulated with the native femurs, inducing 18° of distal varus with no change to torsion. Changes in anteversion and inclination for the Normal and Distal Varus conditions were calculated and compared by a paired t-test. RESULTS: Version changed by a mean of 13.9° (± 1.5; p <0.0001) from the Coxa Valga to Coxa Vara conditions while inclination changed by a mean of 1.3° (± 0.39; p <0.01). Version changed by a mean of 6.6° (± 0.7; p <0.0001) between the Distal Varus and Normal conditions while inclination changed by a mean of -3.8° (± 0.75; p <0.001). CLINICAL SIGNIFICANCE: Femoral version changes with changing frontal plane alignment even when torsion is constant. This should be considered when correcting femoral deformities.