Coffin Joint Cartilage Loss on CT: What MRI Missed

In this clinical case review, we follow the complex lameness investigation of a 14‑year‑old Dutch Warmblood four‑star jumper presenting with a chronic left front lameness.

The horse had been treated for a suspected abscess for an extended period, yet lameness persisted. Diagnostic nerve blocks suggested a foot‑level source, but findings remained inconsistent. An initial low‑field MRI identified arthritic changes in the coffin and pastern joints as well as suspensory branch abnormalities—yet these results did not fully explain the severity or progression of the lameness.

When the horse worsened on recheck and responded unusually to an intra‑arterial coffin joint block, advanced imaging with Asto CT and intra‑articular contrast was pursued.

🔍 What We Found with CT + Contrast

-Marked coffin joint changes and synovitis

-Diffuse cartilage thinning

-Widespread medial full‑thickness cartilage erosion

-Clear medial contrast filling defects indicating severe cartilage loss—findings not appreciated on low‑field MRI

-Confirmation of suspected medial joint space narrowing

Unfortunately, despite targeted therapies—including joint injections, suspensory branch treatment, shockwave, laser therapy, and systemic bisphosphonates—the horse’s condition deteriorated. With end‑stage coffin joint disease confirmed, euthanasia was elected.

📌 Key Takeaway

This case highlights the diagnostic power of CT with intra‑articular contrast for accurately assessing distal limb pathology, especially when MRI findings are equivocal or incomplete. CT provided a definitive understanding of the extent of cartilage loss and joint disease, ultimately guiding appropriate case management.