Stress Radiography for the Diagnosis of Medial Glenohumeral Ligament Rupture in Canine Shoulders.

Abstract

This study aimed to describe a stress radiography to detect medial glenohumeral ligament rupture and to investigate the repeatability and reproducibility of this test. Six adult Beagle cadavers were used. Both shoulders of each dog were randomly assigned into two groups: a normal shoulder group (NS group) and an affected shoulder group (AS group) where the medial glenohumeral ligament was arthroscopically transected. Goniometry, image analysis and radiography (normal and stress views) were performed before and after arthroscopic procedures. An abduction angle was determined for each stress view and an evaluation of the repeatability and the reproducibility was performed. Abduction angles were significantly larger in the AS group as measured by goniometer (p < 0.001), image analysis (p < 0.001) and radiographic stress view (p < 0.001) than in the NS group. The abduction angle difference varied from 12° to 29.3° (median difference of 19.4°) between NS and AS groups. There were good intra-observer and very good inter-observer agreements. A very good (r = 0.74; r = 0.72, respectively) significant (p < 0.001) positive correlation between goniometric and radiographic techniques and between image analysis and radiographic techniques was observed. Shoulder abduction angles measured with a stress radiograph-specific view provide objective data that may contribute to diagnosis of medial shoulder instability in dogs.