Computed tomography findings in a cohort of 169 dogs with elbow dysplasia - a retrospective study

Background Canine elbow dysplasia (CED) is a complex developmental skeletal disorder associated with a number of pathological conditions within the cubital joint. Because CED is a heritable disease, it is important to identify and remove the affected animals from breeding. The first objective of this study was to describe the prevalence of medial coronoid process disease (MCPD) without (MCD) or with (FMCP) fragmented medial coronoid process, osteochondrosis (OC) and/or osteochondritis dissecans (OCD), ununited anconeal process (UAP), radio-ulnar incongruence (INC R-U) and humero-ulnar incongruence (INC H-U) in dogs with the use of CT imaging. The second aim was to determine the influence of demographics on the prevalence of investigated pathologies in dogs with clinical evidence of elbow dysplasia. Results In this retrospective study, CT data records of 169 dogs of different breeds presented to the small animal veterinary clinic from 2012 to 2018 were included. 69.23% of dogs diagnosed with CED were young (≤ 2 years old). The mean age of dogs presented with INC R-U was 1.68 ± 1.82 years, while in dogs without INC R-U the mean age was 2.64 ± 2.59 years. The mean age of dogs with INC H-U was 1.94 ± 2.06 years, while without INC H-U 3.29 ± 2.09 years. Labrador Retrievers, German Shepherd and Bernese Mountain dogs were most frequently presented with CED-associated lameness. In 122 dogs OA of varying severity was found. Conclusion INC H-U, FMCP and MCD were among the most frequently found components of CED found in the present study. OCD and UAP were the least frequently diagnosed. Dogs presented with INC R-U and INC H-U were significantly younger than dogs without these CED components. Boxers, Dog de Bordeaux, American Staffordshire terriers and mixed-breed dogs were diagnosed later in life than the other breeds. OA of varying severity was found in 72.18% of dogs. Males accounted for more than 75% of the study population.

Phenotypic status of elbow dysplasia in Boerboel dogs in Nigeria

Elbow dysplasia (ED) is a developmental, multifactorial, polygenic disease of rapidly growing, large breed of dogs. ED can be a significant health concern for affected dogs because treatments are largely ineffective, making selectively breeding of normal dogs the best option for disease control. Despite the relative availability of data on ED prevalence in other breeds, there is dearth of information on ED prevalence in Boerboel dogs. This study evaluated ED prevalence and relative percentages of different ED grades in Boerboel dogs using radiographs of dogs presented for screening between April 2016 and September 2020. Extended latero-medial, flexed latero-medial and cranio-lateral-caudo-medial oblique radiographs from 64 dogs were reviewed. Radiographs were graded using international elbow working group (IEWG) criteria and grades 0-3 assigned to each joint. ED prevalence expressed as percentages were obtained by dividing the number of dogs with grades 1, 2 and 3 by total number of dogs. Age and sex difference in ED prevalence were compared using chi-square test. Differences were considered significant at P ≤ 0.05. Mean age of the dogs was 2.3 ± 0.6 years. Thirty-six (56.3%) dogs were graded as non-dysplastic, while 28(43.7%) were graded as dysplastic, with grade 3 (46.4%) accounting for majority of ED cases. There were no significant (p > 0.05) difference in sex and age prevalence of ED in the breed. In conclusion, ED prevalence in Boerboel dog is high with majority of dogs having severe grade. Widespread phenotypic screening and strict breeding restrictions are recommended| to control the disease in the breed. Keywords: Boerboel, Dog, Elbow dysplasia, Prevalence, Radiographic screening

Digital Analysis of Subtrochlear Sclerosis in Elbows Submitted for Dysplasia Screening

Ulnar trochlear notch (UTN) subchondral bone sclerosis is observed in elbow dysplasia (ED) associated with the medial coronoid disease. However, its evaluation is based on a simple visual examiner assessment of bone radio-opacity level and is considered subjective. The purpose of this study was to objectively characterize the radiographic opacity of the ulnar trochlear notch (UTN) subchondral bone in mediolateral elbow projections classified, using the International Elbow Working Group guidelines. Records and mediolateral flexed elbow images from the Danish Kennel Club database for the ED screening scheme between 2012 and 2018 were available. Of the dogs in the database, those with an ED-negative status in the left limb were identified. From these, 20 dogs each having a status free from ED, or with Grade 1, 2, or 3 in the right limb, were randomly chosen. Joints with primary ununited anconeal process were excluded from the sample. A template was developed using the ImageJ software, for computer UTN sclerosis analysis. It was overlaid onto each image to define five regions of interest (ROIs): ROI-1, distal UTN; ROI-2, middle UTN; ROI-3, caudal UTN; ROI-4, cortical bone; and ROI-5, bone marrow. Mean pixel intensity for each UTN ROI was divided by the mean pixel intensity of ROI-4 to normalize the data. The mean ± standard deviation (SD) of the normalized pixel intensity in the disease joints (ED Grades 1, 2, and 3) was 1.18 ± 0.17, 1.03 ± 0.12, and 0.92 ± 0.09 for ROIs 1, 2, and 3, respectively. The corresponding values for the contralateral normal left joints were 1.16 ± 0.17, 1.01 ± 0.1, and 0.91 ± 0.08. There was a significant difference (P < 0.05) in the normalized mean pixel intensity in dysplastic vs. non-dysplastic elbow joints for ROIs 1 and 2. The raw mean pixel intensity from right and left cortical and marrow bone ROIs sometimes showed relatively large differences. Digital radiography is associated with exposure and post-processing variabilities. Differences in apparent radio-opacity (as indicated by pixel intensity) though statistically significant in dysplastic joints compared with contralateral normal joints are slight and are thus problematic for computer-aided assessments of UTN sclerosis.

Canine developmental elbow disease part 1: aetiopathogenesis and diagnosis

Elbow dysplasia or ‘developmental elbow disease’ as it is now known, is an umbrella term encompassing multiple abnormalities of the elbow joint. These include elbow incongruity, fragmented medial coronoid process, osteochondritis dissecans and ununited anconeal process. These problems may occur individually or in combination with each other and all may cause lameness, pain, reluctance to exercise and restricted movement as the disease progresses. The advanced stage of osteoarthritis associated with medial coronoid disease involving extensive damage to or loss of cartilage is known as medial compartment disease. There are multiple modalities available for imaging the elbow joint: radiography which is widely available in general practice can detect some changes but may miss others; computed tomography in conjunction with arthroscopic examination is considered the ‘gold standard’ in elbow imaging. Part 1 of this two part series of articles introduces the aetiopathogenesis of canine developmental elbow disease, and part 2 will cover the surgical and nonsurgical management.