Page 366 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.8 Soft-tissue injuries 341

VetBooks.ir the flexor surface of the bone. Radiographs should Magnetic resonance imagine/computed
tomography/scintigraphy
be carefully assessed for associated changes in artic-
MRI and CT provide detailed imaging of the ISL.
ular structures.
Scintigraphy may be useful in occult cases to confirm
Ultrasonography or detect the origin of the lameness as being the ISL.
Ultrasonographic examination should include the
fetlock joint and the digital sheath areas. The diag- Management/prognosis
nosis of ISL injury is made from a palmar/plantar There is some controversy regarding the treatment
approach by visualising alterations of the ISL: echo- of choice for this condition, due in part to the small
genicity is usually decreased and heterogeneous and numbers of cases reported and the variety of aeti-
there may be irregular bone-to-ligament interfaces ologies. In a report of eight cases, arthroscopic and/
representing either fragmentation or entheseophy- or tenoscopic debridement appeared to provide a
tosis (Figs. 1.669, 1.670). The ligament may be fair prognosis for return to function, except in sep-
thickened dorsopalmarly and changes may extend tic cases, although surgery was performed early in
to the fibrocartilage (heterogeneous appearance, these horses. Other reports have shown the prog-
mineralisation) and palmar axial surface of the PSBs nosis to be rather poor with either conservative or
(erosions). The transversely arranged linear pattern more aggressive therapy, especially in chronic cases.
may be partially or totally lost. Rarely, complete rup- The prognosis for the specific condition in Friesians
ture will be visible with penetration of hypoecho- appears to be very guarded. Aggressive surgical
genic fluid in the ligament and widening of the space intervention is recommended in the acute stage. The
between the PSBs. prognosis when the ISL desmopathy is secondary to
chronic tenosynovitis or joint disease is poor.

1.669 1.670

Figs. 1.669, 1.670 Transverse (1.669) and longitudinal (1.670) scans over the palmar aspect of the fetlock.
The axial border of the PSBs is irregular (red arrow) with a bone fragment visible just off the axial border of the
lateral PSB (yellow arrow). The PSB (white arrows) is heterogeneous with loss of transversely arranged fibre
pattern on the transverse image.