Page 355 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

330 CHAPTER 1

VetBooks.ir 1.642

Fig. 1.642 Acute injury in the medial branch of the SL
(transverse medial approach). A hypoechogenic lesion
is visible in the axial portion of the branch (arrows).
Note the marked periligamentous thickening due to
oedema.

1.644
1.643

Figs. 1.643, 1.644 Transverse (1.643) and longitudinal (1.644) views of a traumatic overreach injury over the
medial SL branch, with subcutaneous tissue contusion and haemorrhage (red arrows), transection of the fascia
(white arrows) and focal, hypoechogenic lesion on the superficial part of the SL (calipers). The yellow arrows
point to the limits of the SL branch.

hypo- to anechogenic lesions and loss of fibre align- (entheseopathy) at the distal insertion on the sesamoid
ment. The lesions are often axially situated (deep on the bone may be present (Figs. 1.645–1.647). These will
image obtained from the abaxial approach) (Fig. 1.642) produce an irregular bone contour and hyperechogenic
and may or may not extend to the distal insertion on areas extending from the PSB interface into the liga-
the sesamoid bone. Abaxial, focal lesions may be asso- ment, sometimes for several millimetres. In chronic or
ciated with overreach injuries (Figs. 1.643, 1.644). recurrent cases there may be marked ectopic miner-
The medial branch is most commonly affected. Both alisation around the edges of, or within, the ligament
branches may be involved, and the lesions can extend (Figs. 1.648, 1.649).
into the body. There is often marked periligamentous Avulsion fractures are characterised by a sharp
soft-tissue thickening, making it difficult to locate the hyperechogenic interface within the branch sev-
actual contours of the thickened ligament branch. This eral millimetres or centimetres from the PSB inter-
often extends for some distance distal to the insertion face (Figs. 1.650, 1.651). Hypoechogenic material
of the SL on the PSB. Irregularity or bone formation is present between the fragment and parent bone.