SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
Tarsal Arthrosonography: A Systematic
Approach to a Complex Joint
Virginia B. Reef, DVM, ACVIM (LAIM)
Mark Whittier and Lila Griswold Allam Professor of Medicine
Chief Section of Imaging
New Bolton Center, University of Pennsylvania
382 West Street Rd., Kennett Square, PA 19318
610-925-6403, Fax: 610-925-6831, Email:[email protected]
Introduction
Diagnostic ultrasonography has more recently been applied to the assessment of
other less traditional musculoskeletal problems such as evaluation of bone, cartilage,
joints, muscle and nerves. The soft tissue structures of the hock can be evaluated
ultrasonographically yielding important diagnostic information that cannot be
obtained radiographically.
The Ultrasonographic Examination
Patient Preparation
A thorough knowledge of the anatomy of the structures under investigation
and their relationship to one another is crucial for the accurate interpretation of the
sonogram. Patient preparation is also important in obtaining a quality
ultrasonographic image. The hair over the structures to be scanned should be
surgically clipped with a #40 blade and the skin thoroughly cleaned. In situations
where clipping the hair overlying the joint is not an option, hosing the palmar or
plantar aspect of the leg with water for 10 – 15 minutes or the application of a wet
bandage facilitates obtaining a good quality ultrasound image. After cleaning the skin
a liberal application of ultrasound transmission gel is necessary to provide an air free
interface between the transducer and the skin surface.
A high frequency transducer with a standoff is necessary to obtain optimal
image quality of the structures immediately beneath the skin surface. A 7.5-18.0 MHz
transducer is ideal for obtaining quality images of the tendons or ligaments of the hock
in the horse and allows visualization of the structures up to 4 or 5 cm from the skin
surface. As most of the tendons or ligaments are usually within a few cm of the skin
surface, this choice of transducer selection and the standoff provide optimal image
quality to evaluate these structures. If using a machine with variable focusing, the focal
zone should be centered in the tendon or ligament being examined.
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