Medial humeral epicondylar lesions and discreet calcified structures in the canine elbow: radiographic description of 183 cases

Arne Magnus Rørvik,Jorunn Grondalen,Cathrine Trangerud

doi:10.1186/s13028-020-00556-w

Abstract

BackgroundIn this 4-year prospective observational study, all elbows in a dysplasia screening program including 14,073 dogs were studied using radiographs in two projections. Elbows were evaluated for the presence of medial humeral epicondylar lesions or discreet calcified structures and were described as they appeared. The age, breed, and sex of affected dogs were recorded. The prevalence for each lesion was calculated exclusively on breeds where the number of radiographed dogs exceeded 500.ResultsMedial humeral epicondylar lesions or medial discreet calcified structures were diagnosed in 183 dogs and 211 elbows. The prevalence of true Flexor enthesopathy (FE) in this Norwegian population of mainly young, large breed dogs was calculated to be approximately 1.4 per 1000 dogs and varied by breed. Also, the prevalence of the other lesions varied considerably by breed. The most common finding was discreet calcified structures, termed medial ossified structures (MOS) (0.7%).In elbows affected with fragmented medial epicondyles (FME) (0.07%) and especially FE (0.14%), the degree of periarticular new bone formation (PNBF) was increased when compared to unaffected elbows. In joints affected with MOSs or medial lucent lesions MLLs (0.25%), there was no difference in the presence or degree of PNBF compared to unaffected joints, even in older dogs.ConclusionsThe prevalence of medial humeral epicondylar lesions and MOSs differs considerably among dog breeds. Elbow joints with FMEs and particularly FE had a highly increased presence and degree of PNBF compared to joints without these lesions. Elbow joints with MOSs or MLLs did not have an increased presence or degree of PNBF compared to joints without these lesions.

Highlights

In this 4-year prospective observational study, all elbows in a dysplasia screening program including 14,073 dogs were studied using radiographs in two projections
Elbow joints with fragmented medial epicondyle (FME) and flexor enthesopathy (FE) had a highly increased presence and degree of periarticular new bone formation (PNBF) compared to joints without these lesions
Elbow joints with medial ossified structures (MOS) or medial lucent lesion (MLL) did not have an increased presence or degree of PNBF compared to joints without these lesions

Summary

Introduction

In this 4-year prospective observational study, all elbows in a dysplasia screening program including 14,073 dogs were studied using radiographs in two projections. While scrutinizing canine elbows in the Norwegian elbow dysplasia (ED) screening program for several years, we came across various forms of lesions of the medial epicondyle or medial discreet calcified structures, Early studies on these lesions were reports of a few lame dogs where a calcified object was surgically removed [1,2,3,4,5,6,7]. Rørvik et al Acta Vet Scand (2020) 62:58 on a radiograph as a ‘partial ununited epicondyle’, but called the lesion ‘ununited medial epicondyle’ (UME) and presented it as a developmental lesion and a new form of ED [5] It was opposed in another report, stating that neither three similar cases presented, nor the one previously presented, were UME [6]. Meyer-Lindenberg et al [8] described the histology of 13 structures that had been surgically removed from the joints when they reported the findings of 23 cases of ‘metaplasia’, and they reported that five structures contained pure bone

Objectives

Methods

Results

Discussion

Conclusion