CT and gross pathology are comparable methods for detecting some degenerative sacroiliac joint lesions in dogs

The prevalence of sacroiliac joint CT and MRI findings is high in large breed dogs

Sacroiliac joint (SIJ) disease has been described as one of the possible causes of lumbosacral (LS) region pain in dogs. However, published information is currently lacking for the computed tomographic (CT) and magnetic resonance imaging (MRI) characteristics of canine SIJ disease. The objectives of this retrospective, observational study were to describe and quantify CT and MRI SIJ findings in a sample of large breed dogs and test associations between the numbers of SIJ findings and other variables. Data archives for a veterinary teaching hospital were searched for large breed dogs (≥ 22.7 kg) that had CT or MRI scans of the LS and pelvic regions in 2015-2019. Dogs with a history of acute trauma or scans with incomplete SIJs were excluded. A veterinary student recorded medical record findings. A veterinary radiologist and graduate student recorded CT and MRI findings based on previously published criteria in dogs and humans. Fifty-three dogs were sampled (20 CT, 33 MRI). Categories of findings with the highest prevalence were subchondral erosion (100% CT, 100% MRI) and subchondral sclerosis (95% CT, 97% MRI). The total numbers of SIJ findings per dog were not associated with dog age, sex, weight, or concurrent findings in the LS or pelvic regions. The total number of MRI SIJ findings per dog differed between German Shepherds and Labrador Retrievers (P = 0.0237) as well as between Labrador Retrievers and other breeds (P = 0.0414). These results indicated that CT and MRI findings reported in humans with SIJ disease are common in large breed dogs.

Moving Beyond the Limits of Detection: The Past, the Present, and the Future of Diagnostic Imaging in Canine Osteoarthritis

Osteoarthritis (OA) is the most common orthopedic condition in dogs, characterized as the chronic, painful end-point of a synovial joint with limited therapeutic options other than palliative pain control or surgical salvage. Since the 1970s, radiography has been the standard-of-care for the imaging diagnosis of OA, despite its known limitations. As newer technologies have been developed, the limits of detection have lowered, allowing for the identification of earlier stages of OA. Identification of OA at a stage where it is potentially reversible still remains elusive, however, yet there is hope that newer technologies may be able to close this gap. In this article, we review the changes in the imaging of canine OA over the past 50 years and give a speculative view on future innovations which may provide for earlier identification, with the ultimate goal of repositioning the limit of detection to cross the threshold of this potentially reversible disease.

Computed Tomographic Evaluation of the Sacroiliac Joints of Young Working Labrador Retrievers of Various Work Status Groups: Detected Lesions Vary Among the Different Groups and Finite Element Analyses of the Static Pelvis Yields Repeatable Measures of Sacroiliac Ligament Joint Strain

Musculoskeletal injuries can lead to a working dog being withdrawn from service prior to retirement. During training exercises, young working dogs are often required to perform repetitive tasks, including adoption of an upright posture (or “hupp” task). Non-invasive, quantitative methods would be helpful for supporting research on effects of these repetitive tasks on sacroiliac joints (SIJ). Furthering our understanding of lesions in and biomechanical stresses on the SIJ could provide insight into possible training modifications for minimizing risks of SIJ injury. Aims of this retrospective, secondary analysis, exploratory study were to test hypotheses that (1) mean numbers of SIJ computed tomographic (CT) lesions/dog would differ among work status groups in young working Labrador Retrievers; (2) a methodology for using CT data and finite element analysis (FEA) to quantify SIJ ligament strain in the static canine pelvis would be feasible; and (3) this FEA methodology would yield repeatable measures of SIJ ligament strain. Clinical and CT data for 22 Labrador retriever working dogs, aged 11–48 months, were retrospectively reviewed. Dogs were categorized into three work status groups (Breeder, Detection, Other). A veterinary radiologist who was unaware of dog group status recorded numbers of CT lesions for each SIJ, based on previously published criteria. Mean numbers of SIJ CT lesions/dog were compared among dog work status groups. An a priori FEA model was created from the CT images of one of the dogs using image analysis software packages. Using tissue properties previously published for the human pelvis, various directional loads (n = 8) and forces (48 ligament strain values) were placed on the canine model in five trials. Repeatability was tested using regression analysis. There was a significantly greater mean number of subchondral sclerosis lesions in left SIJ of Breeder vs. Detection dogs, a significantly greater mean number of subchondral cysts in right SIJ for Detection vs. Breeder dogs, and a significantly greater mean number of subchondral cysts in right SIJ of Other vs. Breeder dogs (p < 0.05). Finite element modeling and analysis using CT data was feasible and yielded repeatable results in 47/48 (98%) of tests at each combination of strain, ligament, and side.