Bone Density of the Humeral Condyle in Labrador Retrievers with Medial Coronoid Process Disease

Abstract

Objectives To estimate, using CT imaging, differences in the regional bone density of the humeral condyle in Labrador Retriever elbows with and without medial coronoid process disease (MCPD). Materials and Methods The elbows of Labrador Retrievers that had undergone CT were reviewed. Scans were divided into three groups; Group N - elbows without MCPD; Group R - elbows with MCPD involving fragmentation of the radial incisure; Group A - elbows with MCPD involving fragmentation of the medial coronoid apex. A templating technique was employed to define the weightbearing regions of the medial and lateral portion of the humeral condyle, and estimates of volumetric bone density (defined by Hounsfield unit measurement, HUM) were compared across the three groups. Results CT evaluation was performed on 122 elbows in 81 dogs. There was a higher mean HUM in the medial and lateral portions of the humeral condyles in Group A compared with Group R. Clinical Significance Dogs with apical fragmentation of the medial coronoid process exhibited significantly higher estimated bone mineral density within the medial portion of the humeral condyle when compared to dogs with radial incisure fragmentation. The medial portion of the humeral condyle may be associated with the pathogenesis of apical but not radial incisure medial coronoid process fragmentation in Labrador Retrievers.