Imaging of Sagittal Groove Disease (osteochondrosis) of the Equine Fetlock

Follow-Up Magnetic Resonance Imaging of Sagittal Groove Disease of the Equine Proximal Phalanx Using a Classification System in 29 Non-Racing Sports Horses

Animals (Basel). 2023 Dec 21;14(1):34. doi: 10.3390/ani14010034.
Authors
Josephine E Faulkner 1 , Zoë Joostens 2 , Bart J G Broeckx 3 , Stijn Hauspie 2 , Tom Mariën 2 , Katrien Vanderperren 1
Affiliations

1 Department of Morphology, Imaging, Orthopaedics, Rehabilitation, and Nutrition, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
2 Equitom Equine Clinic, Paalstraat 8, 3560 Lummen, Belgium.
3 Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium.

PMID: 38200766
PMCID: PMC10778323
DOI: 10.3390/ani14010034

Abstract

Evolution of magnetic resonance imaging (MRI) findings in horses with sagittal groove disease (SGD) of the proximal phalanx is relatively sparsely described. This retrospective, descriptive, longitudinal study describes the findings of sequential low-field MRI fetlock examinations in horses with SGD of the proximal phalanx using a classification system. Twenty-nine horses were included, predominantly warmbloods used for show jumping (79%). For 29 limbs re-examined during the initial rehabilitation period, classification remained constant (n = 18), increased (n = 2), decreased (n = 7), and fluctuated (n = 2). Notably, two limbs with initial classification 4b (bone oedema-like signal with subchondral microfissure) and one with 4c (bone oedema-like signal with subchondral demineralisation) progressed to classification 5 (incomplete macrofissure/fracture), highlighting their potential as prodromal or imminent fissure pathology. Following conservative (n = 28) and surgical (n = 1) treatment, 86% of the horses re-entered full training and competition with a mean ± sd recovery time of 9.4 ± 4.4 months. In total, 20% of horses in the study subsequently presented for repeat MRI due to recurrent lameness after resuming full work, with classification that was the same (n = 2), increased (n = 2), or decreased (n = 2) compared with the last scan. This study underscores the variability in progression of SGD MRI findings, emphasising the need for further larger-scale research into patterns of progression.

Keywords: MRI; P1; bone fatigue; bone stress; fissure; horse; subchondral bone.