Three-dimensional ultrasonographic in vitro imaging of lesions of the meniscus and femoral trochlea in the equine stifle.

Abstract

The purpose of this in vitro study was to evaluate the value of three-dimensional (3D) ultrasonography for the diagnosis of equine meniscal and trochlear ridge lesions under in vitro conditions. Lesions were created in the isolated meniscus and femoral trochlea of 25 cadaver stifle joints. Cylindric, conic, and cuboid lesions were created on the trochlear ridge. Five different meniscal tear configurations were created. A total of 107 lesions of the trochlear ridge and 103 lesions of the meniscus were created. 3D ultrasonography was performed in a waterbath, using a 7.5 MHz 3D scanner. Trochlear ridge lesions were seen as either hypoechoic or anechoic breaks in continuity or as irregular notches. One-hundred and one out of the 107 trochlear lesions were visible using 2D ultrasonography whereas 104 out of the 107 lesions could be seen using the 3D Cine mode. Three lesions could not be detected by either technique. Eighty-five out of the 103 meniscal lesions were seen with 2D ultrasonography and 90 with 3D Cine mode. Radial tears and horizontal tears were the least commonly visualized 3D. The 3D Cine mode led to a small improvement in lesion detection. 3D ultrasound could be considered as an extension and refinement of the ultrasound techniques already in use and can increase the diagnostic capabilities. However, technical improvements have to be achieved before 3D ultrasound can be used in the daily practice for diagnosis of equine stifle joint disorders.