🔍 Key Findings

• HIF-affected dogs had significantly greater angle A and B, indicating increased axial articular angulation of the medial and lateral humeral condyle (p < .001).
• Vertical condylar height (lengths a and b) was significantly greater in HIF-affected dogs compared to controls (p = .007 and p < .001 respectively).
• Angle G (dorsal plane medial condyle angle) was also significantly greater in HIF-affected dogs, suggesting altered medial humeral morphology (p < .001).
• The angle between axial surfaces (A–B angle) was significantly more acute in HIF dogs (107.4° vs. 114.2°, p < .001), suggesting potential for increased shear force.
• Springer Spaniels with HIF showed significantly greater angulation and vertical height than unaffected Springer controls (p < .001 to .007 across variables).
• Morphological differences persisted across non-spaniel breeds, reinforcing that altered condylar geometry is not breed-restricted.
• Authors propose that greater condylar angulation contributes to shear stress, orthogonal to the fissure, possibly contributing to HIF pathogenesis.
• These morphologic alterations could inform future screening or preventive strategies, and may explain variable surgical outcomes and implant failure.