Conditions of the Plantar Aspect of the Equine Hock

Injuries of the equine tarsus are frequent causes of hind limb lameness. Osteoarticular problems such as osteochondrosis and distal tarsal osteoarthritis are well known and abundantly considered in the literature.
Although they are quite frequent, soft tissues injuries of the equine hock did not received so much attention. The purpose of this presentation will be limited to describe the variety of soft tissue conditions arising at the plantar aspect of the hock, and to demonstrate the interest of ultrasonography in their diagnosis and documentation.

Material and methods

This presentation is a review of cases presenting deformation or lesions of the soft tissues structures of the plantar aspect of the tarsus. All cases have been examined clinically and evaluated with combination of radiography and ultrasonography. Some of them have also undergone nuclear scintigraphic or magnetic resonance imaging examination.

Radiographic examination

Depending on the physical examination and the suspected condition different radiographic projections were made including: lateromedial, dorsoplantar, dorsolateral- plantaromedial oblique, dorsomedial-plantarolateral oblique, flexed lateromedial and/or flexed proximodistal(sky-line) views. With computed or digital radiography, manipulation of the image helps interpretation of soft tissue as well as bone lesions. When a synovial distension in the area of the point of the hock is present, contrast radiographs are often required to identify the exact bursa involved

Ultrasonographic examination

A 7.5 MHz linear probe coupled with a stand off pad is adequate for imaging of every soft tissue structure of the hock. Sensitivity and specificity of this technique are improved when homologous structures are examined on both hocks of the patient. Being easily used in the field, ultrasonography is an ideal complementary imaging procedure to radiography in a first attempt for diagnosis and documentation of plantar hock conditions. [...]