Magnetic Resonance Imaging, Computed Tomographic and Radiographic Findings in the Metacarpophalangeal Joints of 31 Warmblood Showjumpers in Full Work and Competing Regularly.
Authors: Nagy Annamaria, Dyson Sue
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Nagy and Dyson's 2024 imaging study examined the fetlock joints of 31 actively competing Warmblood showjumpers using MRI, CT and radiography to characterise what structural changes occur in these high-performance horses when they are clinically sound and working regularly. All 31 horses underwent standardised clinical and gait assessments alongside low-field MRI, fan-beam CT and radiographic examination of both front fetlocks, with images analysed descriptively to document comparative findings. The results revealed that 85.5% of limbs (53 of 62) displayed CT and MRI evidence of densification affecting the sagittal ridge and/or condyles of the third metacarpal bone, which the authors suggest represents an adaptive response to athletic work rather than pathology; additionally, subchondral bone resorption (hypoattenuation on CT) was identified in small numbers of horses in various locations including the metacarpal condyle and proximal phalanx, though notably only the McIII lesions were visible on MRI and none appeared on radiographs. For practitioners, this work is significant because it demonstrates that substantial imaging abnormalities—particularly condylar densification—may be normal findings in sound, competing horses and should not be interpreted as pathological without supporting clinical signs; however, the subchondral resorptive lesions warrant careful monitoring as their clinical trajectory remains undefined and they may represent early degenerative changes. The study underscores the importance of integrating imaging findings with clinical assessment and highlights the superior sensitivity of CT and MRI over radiography in detecting fetlock pathology, though longitudinal follow-up data will be essential to determine which imaging changes carry true prognostic significance for future lameness or performance issues.
Read the full abstract on PubMed
Practical Takeaways
- •MRI and CT abnormalities traditionally associated with lameness can be present in non-lame, working showjumpers, suggesting careful clinical correlation is needed rather than treating imaging findings in isolation
- •Radiography significantly underdetects fetlock joint changes compared to advanced imaging; MRI and CT provide superior diagnostic information for metacarpophalangeal joint assessment
- •Subchondral bone resorption may represent early-stage disease and warrants follow-up monitoring, but densification alone in working horses may reflect normal adaptive responses to athletic demands
Key Findings
- •85.5% (53/62 limbs) of non-lame showjumpers exhibited CT and MRI changes consistent with densification in the sagittal ridge and/or metacarpal condyles
- •Subchondral bone resorption lesions were detected in 6 limbs on CT in various locations (metacarpal condyle, sagittal groove, medial fovea of proximal phalanx)
- •MRI detected metacarpal third bone resorptive lesions but not proximal phalanx lesions; no lesions were visible on radiographs
- •Densification in sagittal ridge and condyles likely represents adaptive change to exercise rather than pathology in non-lame horses