SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
zone, the lesion cross-sectional area in each injury zone, the echogenicity or type of
the lesion, the fiber alignment of the lesion, and the length of the lesion are all
indications of the severity of the tendon or ligament injury. Echogenicity and fiber
alignment of the lesion within the tendon or ligament is graded in each zone using a
scale from 0 – 3 (Table 1). The lesion location of the lesion should be described
(central, medial, lateral, dorsal, palmar or plantar) and the lesion should be described
as discrete or diffuse.
Sonographic examination of the entire tendon or ligament and measurement of the
tendon or ligament cross-sectional area (TCA) and lesion cross-sectional area (LCA)
in each zone is important in assessing tendon or ligament injury severity. Lesion and
tendon or ligament cross-sectional area should be measured with the built-in
electronic calipers at each of the 3 zones in the proximal to mid pastern (P1A, P1B,
and P1C). Cross-sectional area measurements should be summed to calculate
injury severity for the entire tendon or ligament.
Injury Severity (Pastern) = ∑ LCA in zones P1A + P1B (M) + P1B (L) + P1C (M) +
P1C (L)
∑TCA in zones P1A + P1B (M) + P1B (L) + P1C (M) +
P1C (L)
Injuries to the total tendon or ligament are classified as mild if the injury involves
less than or equal to 15% of the total tendon cross-sectional area, moderate if
the tendon damage is greater than 15% but less than or equal to 25% of the total
tendon cross-sectional area, and severe if the injury involves greater than 25% of
the total tendon cross-sectional area. The total tendon or ligament echogenicity
and fiber alignment score should also be calculated by summing all the scores in
each of the zones and dividing by the number of zones. These initial sonographic
findings will be used to characterize the tendon or ligament injury as discrete (core
lesions) or diffuse and quantify its severity. This information is then used to select an
appropriate treatment regimen for the injury sustained to optimize the horse’s
chances of successfully returning to the same level of competition.
Sonographic Findings in Tendon and Ligament Injury
Mild enlargement of the tendon or ligament with a diffuse decrease in tendon or
ligament echogenicity and preservation of fiber alignment is frequently detected in
horses with newly discovered tendinitis or desmitis. This is an early indication of
tendon or ligament inflammation or injury and often precedes the development of a
discrete tear in the tendon or ligament. Fiber damage to the tendon or ligament
appears sonographically as an anechoic or hypoechoic region lacking fibers. The
most common discrete injury to the tendon or ligament is a central core lesion. A
central core lesion appears sonographically as a discrete anechoic or hypoechoic
area surrounded by more normal appearing fibers. Core injuries to the tendon or
ligament can occur in any portion of the tendon or ligament, i.e. medial, lateral,
dorsal or palmar. In the DDFT, longitudinal splits are not uncommon but can be
difficult to detect sonographically.
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