Is there an association between ossification of the cartilages of the foot and collateral desmopathy of the distal interphalangeal joint or distal phalanx injury?
Authors: Dyson S, Brown V, Collins S, Murray R
Journal: Equine veterinary journal
Summary
# Editorial Summary: Ossification of Foot Cartilages and Distal Foot Injuries Extensive ossification of the foot's lateral and medial cartilages—a process that normally occurs with maturation—has long been suspected of predisposing horses to collateral ligament injuries at the distal interphalangeal joint and distal phalanx fractures, yet large-scale evidence has been lacking until now. Dyson and colleagues examined radiographs from 462 lame horses using a standardised grading scale and found that 12.8% showed possibly significant ossification (grade >3), with notable left-right symmetry between feet but consistent lateral-to-medial dominance in ossification patterns. Horses with advanced ossification of the maximally ossified cartilage demonstrated statistically significant associations with both collateral ligament injury and distal phalanx trauma, whereas marked mediolateral asymmetry in ossification grades did not increase distal phalanx injury risk. For practitioners, these findings suggest that substantial cartilage ossification warrants careful clinical monitoring and appropriate exercise management, though asymmetric patterns alone should not be considered a contraindication at prepurchase examination. The results support a biomechanical link between rigid cartilage structures and soft tissue loading at the DIP joint, informing both diagnostic interpretation and client counselling regarding foot conformation.
Read the full abstract on PubMed
Practical Takeaways
- •Extensive ossification of foot cartilages on radiographs should alert practitioners to increased risk of collateral ligament or distal phalanx injury in lame horses
- •Asymmetric ossification alone is not a reliable predictor of distal phalanx injury and should not be over-interpreted at prepurchase examinations
- •Normal left-right symmetry of ossification patterns can be expected, so significant deviation warrants closer investigation
Key Findings
- •Possibly significant ossification (grade >3) occurred in 12.8% of feet and was significantly associated with collateral ligament and distal phalanx injuries
- •Left-right symmetry of ossification was observed between feet, with lateral cartilages more ossified than medial cartilages
- •Distal phalanx injury was associated with mediolateral asymmetry in ossification grade of ≥2
- •Marked asymmetry of ossified cartilages did not increase likelihood of distal phalanx injury