# Computed tomography identifies the proximodorsomedial subchondral bone of equine central tarsal bones as a predilection site for sclerosis, demineralisation and associated fractures

## TL;DR

Computed tomography reveals that a specific area of horse tarsal bones is prone to bone changes like sclerosis and fractures.

## Contribution

The study identifies the proximodorsomedial subchondral bone as a predilection site for specific bone changes in equine central tarsal bones.

## Key findings

- 90% of cases showed moderate to severe sclerosis in the dorsomedial region of central tarsal bones.
- Most fissures/fractures were in a dorsomedial–plantarolateral direction and associated with demineralisation.
- Cyst-like lesions were predominantly located in the distal subchondral bone, with a notable medial distribution.

## Abstract

The distribution pattern of central tarsal bone (CTB) changes has not been described, except for slab‐ and dorsomedial–plantarolateral fractures.

To describe CTB changes in CT and document their distribution and associations.

Retrospective case series.

Standing and recumbent tarsal CT studies from 94 clinical cases were retrospectively evaluated. General case information, degree of sclerosis (none‐severe), lesions (demineralisation, cystoid, fissure/fracture) and their location were recorded, dividing CTBs into 8 regions.

Eighty five of 94 tarsi showed at least one region of moderate to severe sclerosis, of which 90% affected the dorsomedial region. The prevalence of lesions was significantly associated with higher degrees of sclerosis (p = 0.04) at this site. Of 32 demineralising lesions, 21 were in the proximal subchondral bone dorsomedially. Twenty‐four CTBs showed fissures/fractures; 19/24 were in a dorsomedial–plantarolateral direction, and 17/19 were associated with demineralisation. Of five fissures/fractures with different configurations, none had associated demineralisation. There were 27 cyst‐like lesions, 21/27 in the distal subchondral bone, of which almost half (13/27) located medially.

Retrospective design; heterogeneous, warmblood‐oriented population; no clinical correlation of findings nor histological confirmation of described changes.

Given the links between sclerosis, demineralisation and fissures/fractures, the dorsomedial proximal subchondral bone plate of the CTB must be scrutinised both in CT and radiography.