The distal sesamoidean impar ligament: Comparison between its appearance on magnetic resonance imaging and histology of the axial third of the ligament

Abstract

The presence of a cystic structure in the distal third of the navicular bone detected using MRI, a distal border fragment or increased signal intensity at the insertion of the DSIL are suggestive of significant alterations in the infrastructure of the DSIL.

Comparisons of computed tomography, contrast enhanced computed tomography and standing low‐field magnetic resonance imaging in horses with lameness localised to the foot. Part 1: Anatomic visualisation scores

“…It is recognised that high‐field magnets have a better signal‐to‐noise ratio and should produce images with better resolution, lower slice thickness and interslice spacing, than low‐field magnets, thus improving visualisation and lesion detection (Murray et al . 2009; Dyson et al . 2010).…”

Comparison between radiological and magnetic resonance imaging lesions in the distal border of the navicular bone with particular reference to distal border fragments and osseous cyst‐like lesions

“…However, some OCLLs observed on MRI images were not detected on radiographs. A radiolucency at the junction between the horizontal and sloping borders of the navicular bones has been related to a fragment observed on radiographs (Dyson 2008) and also to fragments detected on MR images. Such radiolucent areas usually corresponded to grade 5 fragments, which were often associated with OCLLs on MR images.…”

“…An osseous cyst‐like lesion (OCLL) was defined as a fluid‐filled lesion that extended from the dorsal to palmar cortices of the navicular bone, which was separate from synovial invaginations and surrounded, in all sequences, by a hypointense (i.e. mineralised) band (Dyson et al . 2010; Biggi and Dyson 2010).…”

Relationship between histopathological lesions and magnetic resonance imaging (MRI) in diseases of the foot of the horse

“…In other horses with 'abnormal medullary fluid signal', intertrabecular edema and perivascular mononuclear cellular infiltration have been identified (Blunden et al 2006 a In some other horses, fluid-filled osseous cyst-like lesions have been seen in the distal aspect of the bone, apparently separate from synovial invaginations, and not associated with any detectable abnormality of the flexor aspect of the bone. Such lesions have not yet been characterised histologically and their etiology remains speculative, but recent evidence suggest that their presence is associated with degenerative changes in the impar ligament (Dyson et al 2010). In recent postmortem studies, osseous fragments associated with a defect in the distal margin of the navicular bone were more common in horses with navicular disease than in age-matched controls (figures 3a and 3b) (Busoni et al 2005;Schramme et al 2005;Blunden et al 2006;Wright et al 1998).…”

“…Histologically, distal border fragments have variously been described as avulsion fractures, separate centers of ossification, osseous metaplasia of the impar ligament or synovial osteoma but pathological evidence elucidating their pathogenesis remains elusive. More recently it was shown that the presence of these fragments was associated with varying degrees of histopathological damage of collagen fibers and fibroblasts in the axial third of the impar ligament (Dyson et al 2010).…”