Is there a characteristic distal tarsal subchondral bone plate thickness pattern in horses with no history of hindlimb lameness?

This research reveals a consistent pattern in the thickness of subchondral bone (SCB) in the distal tarsal bones of horses with no history of hindlimb lameness. The findings provide valuable reference for the identification of osteoarticular pathologies.

Objectives and Methods

• The study aimed to determine whether there is a repeatable pattern of subchondral bone (SCB) thickness across the distal tarsal joints of horses. Specifically, the researchers hypothesized that the thickness would be greater in the dorsal and lateral regions.
• Twenty horse cadaver tarsi were collected for the study. These came from mature horses that had only experienced low-level exercise and had no history of hindlimb lameness.
• The research employed high-resolution sagittal 3-dimensional T1-weighted spoiled gradient echo sequence for the attainment of magnetic resonance images.
• SCB thickness was measured from the images at the dorsal and plantar locations on the proximal and distal aspects of the central tarsal (CT) and third tarsal (T3) bones, as well as the proximal aspect of the third metatarsal bone (Mt3).

Results

• The results showed a significantly greater medial and lateral SCB thickness than midline on the proximal aspect of the central tarsal bone (CT).
• On the distal aspect of the CT and T3 and proximal Mt3, the lateral SCB thickness was significantly greater than the medial and midline sites.
• Additionally, the dorsal SCB thickness was the greatest on the proximal and distal aspects of the CT and proximal Mt3.
• The SCB accounted for a greater proportion of the CT and T3 on the dorsal aspect than the plantar.

Conclusion

• The findings indicate the presence of a repeatable pattern of SCB thickness in the distal tarsal bones of horses which have no history of hindlimb lameness.
• The pattern apparently reflects the pattern of loading across the horse’s joints.
• The research adds robust evidence of a consistent osteochondral pattern present in the equine tarsus, providing a reference for the identification of osteoarticular pathologies.