Intraosseous stress distribution and bone interaction during load application across the canine elbow joint: A preliminary finite element analysis for determination of condylar fracture pathogenesis in immature and mature dogs

Abstract

Distal humeral fractures are common fractures especially in immature small breed dogs. The pathogenesis is still unknown. For this study, a three-dimensional bone model of the canine elbow was created and finite element analysis performed in order to determine the relationship between fracture type and bone interactions. Fused and non-fused humeral condyles were considered. A failure criterion was implemented to simulate the pathogenesis until fracture. Our study results confirm the clinical observation that lateral condylar fracture is the most common fracture type, implying interaction with the radius. Medial and Y-fractures are less common and occur always in interaction with the ulna whereas the radius causes lateral condylar fracture. Additionally, the fracture type is sensitive to bone positioning during trauma. The pathogenesis of distal humeral fractures is more complex than generally reported in the literature.

A Prevalence Study of Canine Humeral Condylar Fractures Over a Ten-Year Period at an Academic Teaching Hospital

“…While French Bulldogs have been reported as being a breed predisposed to HCF in older literature, 9 recent literature has shown large increases in the prevalence of this condition in this breed 1 19 with the current study showing French Bulldogs being 49.3 times more likely to develop HCF compared with the general population. The median age at presentation for HCF in French Bulldogs was 5 months of age with 75% occurring at 6 months of age or less, consistent with current literature.…”

“…Isolated medial condylar fractures are thought to be less common due to the fact that the shear force required to cause a medial condylar fracture should also cause a lateral condylar fracture, thus leading to a Y/T fracture which is reportedly more common than a medial condylar fracture on its own. 5 Condylar fractures often occur following minimal trauma and several studies have explored the pathogenesis 8 9 however, this largely remains speculative. The canine humeral condyle develops as three separate centres of ossification.…”

“…Prevalence studies highlight French Bulldogs and Spaniel breeds as at-risk breeds with odds ratios (OR) of 5.86 to 8.12 for French Bulldogs 1 9 19 and 5.66 to 15.52 for English Springer Spaniels, respectively, when compared with crossbreed dogs. 1 9 19 Both these study populations were pooled from referral centres in the United Kingdom. In addition, French Bulldogs were at higher risk of developing medial humeral condylar fractures (HCF) compared with the populations of dogs in these studies.…”

Impact of breed on canine humeral condylar fracture configuration, surgical management, and outcome

“…In the current study, French bulldogs had a different predisposition of fracture configuration with a higher rate of medial HCF compared with other dogs. The cause is unclear; however, it has been has determined that medial HCF occur due to the interaction between ulna and humerus, whereas the radial loading is implicated in lateral HCF 2 . The chondrodystrophic conformation of the elbow in French bulldogs may influence loading patterns and hence fracture configuration.…”

“…Humeral condylar fractures (HCF) account for nearly 50% of all humeral fractures in dogs 1 and are classified into lateral, medial, or intercondylar/bicondylar configurations 2 . Lateral HCF predominate, with prior articles reporting the distribution of lateral, medial, and bicondylar fractures as 62.1%, 7.7% and 30.2% respectively 1,3‐7 .…”