Desmopathy of the front proximal suspensory ligament in conjunction with a metacarpal cortical fracture in a horse: A multi-modality imaging study

Abstract

Summary: A Warmblood gelding with a grade 3/5 intermitted lameness was presented for nuclear scintigraphic examination, which revealed focal increased uptake at the left proximal metacarpal region ( Figure 1A). Radiographs of this region showed a radiolucent area surrounded by a thin, sclerotic rim. The horse died for reasons unrelated to the lameness. Following, the left forelimb was disarticulated at the elbow joint to further examine the proximal metacarpal region. Ultrasonography showed an enlargement and loss of fibre pattern of the medial lobe of the proximal suspensory ligament (PSL) as well as a focal irregularity of the proximal palmar metacarpal cortex. On transverse T2-weighted magnetic resonance (MR) images the enlargement of the medial lobe could also be detected. Additionally, extensive loss of connective tissue between the PSL and the third metacarpal bone and thickening of the palmar cortex of the metacarpus at this region were seen on MR images. These pathological abnormalities were also detectable with computed tomographic (CT) examination using the soft tissue window. However, CT also demonstrated the presence of a small radiolucent fracture line in the metacarpus. After summarizing all findings the imaging diagnosis of a unilateral, chronic proximal suspensory ligament desmopathy in conjunction with a cortical third metacarpal lesion of the PSL insertion was made. A pathohistological examination confirmed the described imaging findings at the medial lobe of the PSL. Focal areas of granulation tissue and small areas of ossification were detected. The small fracture line at the palmar cortex of the metacarpus was also confirmed by necropsy. Because of its ability to visualize osseous and soft tissue structures, CT-examinations are considered as useful supplementary tool to be included in ambiguous cases of PSL desmopathy.Keywords: horse / suspensory ligament / cortical fracture / computed tomography / magnetic resonance imaging Citation: Berner D., Gerlach K., Brehm W., Mülling C., Schöniger S., Lempe-Troillet A. (2015) Desmopathy of the front proximal suspensory ligament in conjunction with a metacarpal cortical fracture in a horse: A multi-modality imaging study. Pferdeheilkunde 31,[352][353][354][355][356]

Computed tomographic diagnosis of incomplete palmar cortical (fatigue) fracture of the third metacarpal bone in two young adult endurance horses

“…In that case, MRI failed to identify the fracture line and only CT was able to demonstrate the osseous lesion (Berner et al . ).…”

“…; Morgan and Dyson ), although they have been described in older horses (Pinchbeck and Kritz ; Morgan and Dyson ; Berner et al . ). In the majority of reports, horses do not yield any pathognomonic physical findings, and although focal tenderness and/or swelling in the proximal metacarpal area are described (Ross et al .…”

Incomplete metacarpal fracture with exostosis or ‘blind splint’?

“…In contrast, in a separate case report on proximal metacarpal stress fractures, the authors opine that a CT examination should only be included in ambiguous or therapy‐resistant cases of proximal suspensory ligament lesions (Berner et al . ).…”

“…While the images are very detailed and the diagnosis without question, the issue remains whether the risk of general anaesthesia under these clinical circumstances outweighs the value of standing nuclear scintigraphy (Beccati et al 2019). In contrast, in a separate case report on proximal metacarpal stress fractures, the authors opine that a CT examination should only be included in ambiguous or therapy-resistant cases of proximal suspensory ligament lesions (Berner et al 2015).…”