Proximal phalanx injury in Warmbloods

The take-home message is, that chronically lame horses referrable to the fetlock joint should consider MRI for a complete diagnosis particularly if the radiographs are not diagnostic.
DrO

Diagnostic imaging findings in lame Warmblood horses with bone injuries of the medial proximal phalanx glenoid cavity

Vet Radiol Ultrasound. 2024 Oct 8. doi: 10.1111/vru.13449. Online ahead of print.
Authors
Maxime Vandersmissen 1 , Laurence Evrard 1 , Alexandre Charles 1 , Fabrice Audigié 2 , Valeria Busoni 1
Affiliations

1 Faculty of Veterinary Medicine, Diagnostic Imaging Unit, University of Liège, Liège, Belgium.
2 CIRALE-EnvA, USC INRAE 957 BPLC, Goustranville, France.

PMID: 39377553
DOI: 10.1111/vru.13449

Abstract

This retrospective study aims to describe baseline and follow-up imaging findings in subchondral and trabecular bone damage occurring outside of the sagittal groove in the proximal phalanx (P1) glenoid in a case series of lame Warmblood horses. Thirteen lame horses (16 forelimbs) with standing magnetic resonance imaging (sMRI) evidence of nonsagittal groove glenoid subchondral and trabecular bone injury of P1 as the main lesion were included. All injuries were located at the medial aspect of the P1 glenoid. At sMRI, changes included subchondral bone plate thickening and trabecular sclerosis, bone marrow edema-like signal, subchondral bone resorption (11/16), and new bone production (8/16). Subchondral bone resorption in the transverse plane was linear (8/11), round (2/11), or ill-defined (1/11). Sclerosis, bone resorption, and new bone production were seen radiographically in 10, 4, and 5 limbs, respectively. All limbs had concurrent metacarpal condyle sMRI imaging abnormalities, osteophytosis, and joint effusion. Follow-up sMRIs were obtained in 8 of 16 limbs, five of which showing progression of the resorptive lesion. One horse encountered a comminuted fracture of the affected P1 18 months after the follow-up sMRI examination. The imaging appearance of the medial glenoid bone injuries of P1 in this case series is consistent with chronic bone overload. The linear configuration of bone resorption seen in eight lesions suggests short, incomplete stress fractures, which is supported by the ultimate catastrophic fracture occurring in one case.

Keywords: bone stress; fetlock; magnetic resonance imaging; stress fracture.

© 2024 American College of Veterinary Radiology.