Incomplete humeral condylar fracture in two English Pointer dogs

Abstract

Incomplete humeral condylar fracture was diagnosed by means of radiology, CT, scintigraphy, arthroscopy and bone biopsy in two English Pointer dogs. In both cases an acute thoracic limb lameness, unrelated to a known episode of major trauma, was observed. Incomplete humeral condylar fracture, mainly described in the Spaniel breeds, has been recently diagnosed in Labrador retrievers, Rottweiler, German Wachtel and other breeds. The pathogenesis of the condition is still unknown, but incomplete ossification of the humeral condyle and mechanical stress, alone or associated, have to be considered. However, our clinical and histopathological data lead us to believe that in Pointers, high performance dogs, the mechanical stress can assume a critical ethiopathogenetic role.

Humeral intracondylar fissures and intracondylar sclerosis are common CT findings in the limb contralateral to a humeral condylar fracture in French bulldogs and spaniel breeds

“…Sclerosis adjacent to the intracondylar fracture site was a common finding in both breed groups. Sclerosis has been suggested to be an adaptive remodeling change to abnormal or excessive bone loading 14 . It is possible that abnormal loading is occurring through the humeral condyle in these dogs, but the aetiopathogenesis remains unclear.…”

“…The descriptive term HIF has been adopted and will be used for the remainder of this report. Humeral intracondylar fissures have been reported in several other breeds, more recently including the FBD 14–17 . A case series of 9 FBD presenting with HCF, found that six of nine dogs had a HIF identified on the limb contralateral to an HCF, suggesting that HIF could be a predisposing factor for HCF in this breed 18 .…”

“…Humeral intracondylar fissures have been reported in several other breeds, more recently including the FBD. [14][15][16][17] A case series of 9 FBD presenting with HCF, found that six of nine dogs had a HIF identified on the limb contralateral to an HCF, suggesting that HIF could be a predisposing factor for HCF in this breed. 18 Previous studies have identified HIF in the limb contralateral to an HCF in 50% to 86% of spaniel-breed dogs.…”

Computed Tomography Topographical Analysis of Incomplete Humeral Intracondylar Fissures in English Springer Spaniel Dogs

“…5,25,26 Histopathological and clinical evidence has suggested HIF is a stress fracture rather than incomplete ossification of the humeral condyle. 1,18 Increased weight and activity have been suggested as predisposing factors for mechanical overload leading to stress fracture of the humeral condyle and may, in part, explain the higher proportion of male dogs affected. If humeroanconeal incongruency is occurring, increased muscle mass in male dogs may increase the force on contact between the humerus and anconeus and distracting force across the condyles.…”

“…[15][16][17] This is supported by histopathological findings on biopsy of the fracture line, which were more supportive of a fibrous, osteoclastic environment, similar to that of an atrophic non-union which may represent a stress fracture. 1,18 Ongoing biomechanical stress and instability have been hypothesized in patients with HIF following analysis of broken transcondylar screws by electron microscopy, and elbow incongruence has been suspected as a contributing factor to this stress. 13,19 More recently, humeroanconeal incongruency has been proposed as a possible contributing factor to HIF and ongoing intracondylar instability, following arthroscopic documentation of focal caudal humeral condylar cartilage lesions, adjacent to the apex of the anconeal process.…”