Identification of Naturally Occurring Cartilage Damage in the Equine Distal Interphalangeal Joint Using Low-Field Magnetic Resonance Imaging and Magnetic Resonance Arthrography.
Authors: van Zadelhoff Claudia, Schwarz Tobias, Smith Sionagh, Engerand Antoine, Taylor Sarah
Journal: Frontiers in veterinary science
Summary
# Editorial Summary Cartilage damage in the distal interphalangeal (DIP) joint is common in lame horses, yet its detection remains challenging—this study investigated whether low-field MR imaging (0.27T) combined with gadolinium and saline arthrography could reliably identify naturally occurring cartilage lesions compared to gross pathological findings. Using a two-phase approach (initial pilot work on two clinical cases followed by a prospective cross-sectional study of isolated distal limbs), researchers scanned joints before and after contrast injection at 15-minute intervals over two hours, then compared imaging findings against direct cartilage grading at necropsy. Perhaps unsurprisingly, the results were sobering: plain MR and both saline and gadolinium arthrography detected only a fraction of actual cartilage damage, with sensitivity of just 14%, meaning the vast majority of partial-thickness erosions and many full-thickness defects were missed, although specificity was high at 92% (overall accuracy 63%). For equine practitioners, this suggests that whilst a normal-appearing DIP joint cartilage surface on low-field MRI is fairly reliable, the absence of imaging findings should not be interpreted as absence of cartilage pathology—and conversely, any visible cartilage contour abnormality warrants serious consideration as genuine damage is likely present. These findings highlight a significant limitation of readily available MR technology in DIP joint evaluation and should inform clinical decision-making when imaging findings are negative in suspected cases.
Read the full abstract on PubMed
Practical Takeaways
- •Low-field MRI should not be relied upon to rule out cartilage damage in the DIP joint, as it has very poor sensitivity for detecting naturally occurring lesions
- •If MRI shows abnormal cartilage contour, cartilage damage is likely present—but absence of MRI findings does not exclude significant pathology
- •MR arthrography with gadolinium or saline offers no advantage over plain imaging for detecting DIP joint cartilage damage in clinical practice
Key Findings
- •Low-field MRI detected only 1 of 2 clinical cases with confirmed DIP joint osteoarthritis and full-thickness cartilage defects
- •Majority of naturally occurring cartilage damage including extensive partial-thickness erosions were not identified on plain MR or MR arthrography
- •Saline and gadolinium MR arthrography did not improve detection of cartilage damage compared to plain imaging
- •Overall sensitivity for cartilage damage detection was only 0.14 with specificity of 0.92 and accuracy of 0.63