Assessment of the Conformation of the Radioulnar Joint Comparing Dogs with and without Medial Coronoid Disease

Abstract

Objective

The aim of our study was to assess the conformation of the radioulnar joint using transverse plane computed tomography in dogs with medial coronoid disease (MCD).

Study Design

The study included 101 elbow joints with arthroscopically confirmed MCD and 20 sound control elbow joints. To assess the conformation of the radioulnar joint, we determined the ratio for the radial head centre of supination and pronation toward the ulnar joint surface in the transverse computed tomography plane. In addition, we assessed the opening angle of the radioulnar joint.

Results

The MCD group showed decreased lateral, laterocentral and central radioulnar ratios, with 1.78 (± 0.09) and 1.81 (± 0.07) centrally (p = 0.044), 1.75 (± 0.10) and 1.78 (± 0.09) laterocentrally (p = 0.044) and 1.74 (± 0.09) and 1.77 (± 0.08) laterally (p = 0.044), in the MCD and control groups, respectively, indicating radioulnar joint malformation. The mediocentral and medial sections showed no differences in radioulnar ratios consistent with joint congruity. The opening angle of the radioulnar joint showed no significant differences between the groups.

Conclusion

Dogs with MCD showed lateral, centrolateral and central malformation and incongruity of the radioulnar joint in the transverse computed tomography plane. Medial coronoid disease appears to coincide with radioulnar joint malformation ipsilateral to the medial coronoid process and medial joint compartment. Radioulnar malformation in the lateral and central compartments could be a factor in the development of MCD and limit the success rate in arthroscopic MCD treatment.

Keywords

medial coronoid disease - radioulnar joint - radioulnar malformation - radioulnar opening angle - dog

Contributors' Statement

M.S. and L.F.H.T. contributed to the conception, study design, acquisition of data, data analysis and interpretation. Both the authors drafted, revised, and approved the submitted manuscript and are publicly responsible for the relevant content.

Publication History

Received: 31 December 2024

Accepted: 19 August 2025

Article published online:
01 September 2025

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