The Evolution of Lesions on Follow-Up Magnetic Resonance Imaging of the Proximal Metacarpal Region in Non-Racing Sport Horses That Returned to Work (2015-2023).
Authors: van Veggel Elisabeth C S, Vanderperren Katrien, Selberg Kurt T, Bergman Hendrik-Jan, Hoogelander Brenda
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Researchers retrospectively analysed serial MRI scans of 18 sport horse limbs to characterise how proximal metacarpal injuries evolve during rehabilitation and return to work. Using T1-weighted, T2* gradient echo, and STIR sequences, they tracked lesion resolution over a median follow-up period and correlated imaging findings with functional soundness. Whilst hyperintense signals within the dorsal suspensory ligament improved in most horses and third metacarpal (McIII) bone oedema completely resolved in all cases, structural changes such as dorsal ligament margin irregularity and McIII sclerosis persisted unchanged—indicating that complete radiological normalisation is not prerequisite for clinical recovery. McIII bone oedema resolution showed considerable variation (47–202 days; mean 94 days), yet all horses that became sound demonstrated this particular finding, suggesting it may serve as a useful prognostic marker. The authors recommend rescanning at approximately 120 days post-injury to guide rehabilitation decisions, though the proximal suspensory ligament itself did not change in size between initial and follow-up imaging.
Read the full abstract on PubMed
Practical Takeaways
- •Resolution of bone marrow lesions (McIII STIR signal) is a key prognostic indicator for return to work, whereas complete healing of PSL changes is not required
- •Plan for a 120-day recheck MRI interval to assess healing progress in horses with proximal metacarpal lesions
- •Soft tissue (PSL) size does not significantly change during recovery, so increasing size should raise concern for ongoing pathology
Key Findings
- •Hyperintense STIR signal within the dorsal PSL resolved in the majority of cases, and McIII hyperintense STIR signal resolved in all patients
- •McIII hyperintense STIR signal resolution occurred over a mean of 94 days (range 47-202 days)
- •Complete normalization of dorsal PSL is not necessary for return to soundness, but McIII STIR signal resolution is expected for horses returning to soundness
- •A rescan period of 120 days for the proximal metacarpal region is recommended for horses with these lesions