Western performance horses with fetlock lameness demonstrate radiographic evidence of chronic exercise remodelling.
Authors: Solum, Acutt, Johnson, Zhou, Contino, Donnell, Donnell, Frisbie
Journal: Equine veterinary journal
Summary
# Fetlock Lameness in Western Performance Horses: Radiographic Patterns and Clinical Correlation Western performance horses with fetlock lameness consistently present radiographic evidence of chronic exercise-induced remodelling, with lesions identified in 96.7% of a retrospective case series spanning 2012–2022. Among 90 horses with lameness definitively isolated to the fetlock joint via diagnostic intra-articular analgesia, distal cannon bone sclerosis, periarticular osteophytes, increased soft tissue opacity, proximal phalanx (P1) sclerosis, and subchondral bone defects emerged as the predominant findings. Notably, whilst overall radiographic severity scores showed no meaningful correlation with lameness grade (r = 0.16), specific lesions demonstrated clinical significance: horses presenting with subchondral bone cysts, P1 fissures, or proximal P1 sclerosis exhibited significantly higher median lameness grades (median 3, 3, and 2 respectively; p < 0.05). This distinction between generalised degenerative changes and clinically relevant pathology has important implications for practitioners—comprehensive radiographic assessment should identify and weight particular lesion types when prognosticating outcome and informing treatment decisions, rather than relying solely on cumulative radiographic scoring systems. The retrospective design and inherent limitations of diagnostic analgesia interpretation warrant cautious application of these findings to individual cases, yet the pattern emerging here provides valuable context for understanding which radiographic findings in fetlock-lame western performance horses are most likely to correlate with clinical severity.
Read the full abstract on PubMed
Practical Takeaways
- •Specific radiographic lesions (P1 sclerosis, SCB cysts, P1 fissures) are better predictors of lameness severity than overall radiographic burden in western performance horses
- •Expect chronic remodelling changes on radiographs in nearly all western horses presenting with fetlock lameness; absence of radiographic findings should prompt re-evaluation of the lameness source
- •Clinical lameness grade alone does not reliably predict radiographic change severity, so radiographic evaluation remains essential for prognostic discussions and treatment planning
Key Findings
- •Radiographic lesions were identified in 96.7% of 90 western performance horses with isolated fetlock lameness (2012-2022)
- •Horses with subchondral bone cysts, proximal phalanx fissures, or proximal phalanx sclerosis demonstrated significantly higher median lameness grades (all p<0.05)
- •Overall radiographic severity score did not correlate with lameness grade (r=0.16, p>0.05), indicating heterogeneous clinical presentations
- •Distal cannon bone sclerosis, periarticular osteophytes, and increased soft tissue opacity were the most common radiographic findings