Relationship between Radioulnar Incongruity of Elbow Joints and the Type of Fragmented Processus Coronoideus Medialis

Abstract

The aim of the study was to find the difference between actual and anticipated frequencies of individual types of FCP (fragmented coronoid process) in relation to the extent of radioulnar incongruity.We evaluated the radiographs of elbow joints (n = 135) of dogs (n = 77) with arthroscopically (n = 109) or arthrotomically (n = 26) proven fragmented coronoideus medialis ulnae. Radioulnar incongruity was classified as a congruent joint (0-0.5 mm), moderate incongruity (0.6-2 mm) and marked incongruity (> 2.1 mm). In elbow joints without radiologically identifiable radioulnar incongruity (0-0.5 mm) significantly higher occurrence of fissured PCM (processus coronoideus medialis) was found (p < 0.01). In elbow joints with pronounced radioulnar incongruity (> 2.1 mm) we found significantly higher occurrence of FCP with a dislocated fragment (p < 0.001).The results of this study suggest the possibility of using the assessment of radioulnar incongruity from radiographs of elbow joints in mediolateral projection for specifying the X-ray diagnosis of FCP with regard to the type of FCP lesion.

Computed tomographic evaluation of elbow congruity during arthroscopy in a canine cadaveric model

“…Radio-ulnar incongruity has been the predominant focus of arthroscopic investigation of incongruity within the elbow joint due to its association with medial coronoid disease (1,5,16,17). The shift in radio-ulnar congruence seen in this study is small, with a mean change in radio-ulnar congruence of no more than 0.84 mm in any plane, which, in isolation, could be considered within the bounds of normal anatomic variation (11,21,22). In one study, mean radio-ulnar step in normal dogs in the sagittal plane was reported to be 0.21 ± 0.34 mm, with a range of 0 to 0.8 mm (11).…”

Medial coronoid process disease in the course of elbow dysplasia in dogs

“…It should be emphasized that the most frequently diagnosed lesion in medial coronoid process disease is a rupture of the medial coronoid process with complete fragmentation, which may occur even in the first few months of a dog's life. The separated fragments of the medial coronoid process may remain in place or be displaced within the joint cavity (10,33,37,50,41). According to some authors, apart from fragmentation, the frequently diagnosed abnormalities of the medial coronoid process include the presence of a fissure (visible in the CT image in the form of a hypoattenuating line) and chondromalacia (8).…”