Thibaut Cachon

Prevalence of hip dysplasia according to official radiographic screening, among 31 breeds of dogs in France - A retrospective study

In order to determine the prevalence of hip dysplasia (HD) from radiographs that were submitted for authorative grading, and its changes over the time in 31 breeds of dogs in France, a 14 year-retrospective study was conducted. Significant differences were observed between breeds, with HD prevalence ranging from 59.7% (Cane Corso) to 3.9% (Siberian Husky). When comparing the 1993-1999 with the 2000-2006 period in 15 breeds, a significant decrease in HD prevalence was detected in Berger Picard, Bernese Mountain dog, Briard, Gordon Setter, White Swiss Sheepdog and Rottweiler. Modifications observed in the other breeds were not statistically significant.

Transiliac Approach for Exposure of Lumbosacral Intervertebral Disk and Foramen: Technique Description

OBJECTIVE To describe and evaluate a transiliac approach to the L7-S1 disk and intervertebral foramen in dogs. STUDY DESIGN Cadaver study. ANIMALS Fresh canine cadavers (n=10). METHODS A craniolateral approach was made to each iliac wing of 10 fresh canine mixed breed cadavers. An 18 mm hole was drilled in a standardized position through the iliac wing. The musculature connected to the cranial aspects of the sacral wing was dissected and retracted cranially through this iliac window. Endoscopic exploration of the area was performed. RESULTS The foramen and intervertebral disk were clearly observed in all specimens without iatrogenic injury of the L7 nerve branch. Access to the foramen was possible in 16 of 20 specimens without excision of the sacral wing; however, it was always partially excised to observe the intervertebral disk which lies more caudally and ventrally. CONCLUSION Transiliac approach to the lumbosacral joint allows direct exposure of the intervertebral disk and foramen through an iliac window. Endoscopic exploration provided good observation of the intervertebral disk and/or foramen. CLINICAL RELEVANCE Transiliac approach could be used for lateral corpectomy and foraminotomy in dogs with degenerative lumbosacral stenosis caused by ventral or ventrolateral disk protrusion, foramen stenosis, or OCD of the L7-S1 joint. Clinical study will be necessary to evaluate the efficacy of this approach.

Canine hip dysplasia radiographic screening. Prevalence of rotation of the pelvis along its length axis in 7,012 conventional hip extended radiographs

The prevalence of rotation of the pelvis along its length axis was noted, as was the number of rotations towards the right or left hand side of the dog, on 7,012 conventional hip extended radiographs, which were sent for official screening. 29.8% of the radiographs showed a rotation the pelvis. The rotation was statistically more frequent towards the left hand side of the dog. The number of rejected radiographs for too important pelvis rotation was only 5.2%. The consequences of the pelvis rotation on the Norberg-Olsson angle, on the dorsal femoral head coverage, and in the aspect of cranial acetabular edge have to be taken into account when scoring the dog for hip dysplasia.

Risk of simultaneous phenotypic expression of hip and elbow dysplasia in dogs: a study of 1,411 radiographic examinations sent for official scoring.

In order to look for phenotypic correlation between hip (HD) and elbow (ED) dysplasia, we used radiographic scoring obtained from 1,411 dogs of different breeds, which were evaluated for authoritative grading of both conditions. In this population, we found that the risk ratio for an animal to be simultaneously affected by HD and ED is 1.67. For a dog with ED, the risk ratio to be affected by HD increases as the ED grade increases. Similarly, for a dog affected by HD, the risk ratio to be affected by ED increases as the HD grade increases. In a dog affected by HD or ED, the clinician should look for the second condition in the same animal. Due to the low, yet positive correlation, selection against one trait will not affect the other trait sufficiently. Therefore selection has to be conducted at reduction of HD as well as reduction of ED.

Thoracic bite trauma in dogs and cats: a retrospective study of 65 cases

OBJECTIVES To report a case series of thoracic bite trauma in dogs and cats and to evaluate risk factors for mortality. METHODS A retrospective study concerning thoracic bite wounds in dogs and cats was performed. Lesions were categorized by depth of penetration: no wound, superficial, deep or penetrating. Thoracic radiographic reports were reviewed. Lesion management was classified as non-surgical, wound exploration, or explorative thoracotomy. RESULTS Sixty-five cases were collected. Twenty-two percent of patients with normal respiratory patterns showed thoracic radiographic lesions. Respiratory distress was not correlated with mortality. Twenty-eight patients were presented with superficial wounds and 13 with deep wounds. Eight patients exhibited penetrating wounds. Radiographic lesions were observed in 77% of dogs and 100% of cats. Explorative thoracotomy was performed in 28% of patients, and surgical wound exploration in 17.2%. With the exception of skin wounds, thoracic wall discontinuity was the most frequent lesion. Thoracotomy was associated with increased length of hospitalisation but was not correlated with mortality. The mortality rate was 15.4%. No studied factor correlated with mortality, and the long-term outcomes were excellent. CLINICAL SIGNIFICANCE A penetrating injury, more than three radiographic lesions, or both together seemed to be indicative of the need for a thoracotomy. In the absence of these criteria, systematic bite wound explorative surgery is recommended, with extension to thoracotomy if thoracic body wall disruption is observed.

Comparison of radiographic measurements of the patellar tendon-tibial plateau angle with anatomical measurements in dogs. Validity of the common tangent and tibial plateau methods.

OBJECTIVE To evaluate the validity of the common tangent and conventional tibial plateau angle methods for measuring the patellar tendon angle (PTA) in dogs. METHODS Radiographs of cadaveric stifles (n = 20) placed at 135° in true lateral position were obtained to measure the PTA with both methods. A Kirschner wire was inserted perpendicularly to the patellar tendon at its insertion on the tibia and the stifle was dissected. Two Kirschner wires were then used to identify the anatomical landmarks of the tibial plateau. A digital image was obtained of the proximal tibia in true lateral position. Six blinded observers measured each PTA digitally while the anatomical PTA was determined by an independent blinded observer from the angle between the line representing the tibial plateau and the Kirschner wire representing the perpendicular to the patellar tendon. The agreement between the methods was determined statistically from an intraclass correlation coefficient (ICC). RESULTS The global ICC for the common tangent method (0.44) and for the conventional method (0.4) indicated that their overall validity is poor. The measurements obtained by common tangentmethod and conventional method were respectively below and above the anatomical measurements. The reproducibility of the PTA measurements based on images of the dissected stifles was very good. CLINICAL SIGNIFICANCE Both the common tangent and conventional methods show poor concordance with the anatomical measurement of PTA. Further studies are needed to determine if errors in measurements affect the clinical outcome.

Pedicle Screw Fixation Study in Immature Porcine Spines to Improve Pullout Resistance during Animal Testing

The porcine model is frequently used during development and validation of new spinal devices, because of its likeness to the human spine. These spinal devices are frequently composed of pedicle screws with a reputation for stable fixation but which can suffer pullouts during preclinical implantation on young animals, leading to high morbidity. With a view to identifying the best choices to optimize pedicle screw fixation in the porcine model, this study evaluates ex vivo the impact of weight (age) of the animal, the level of the vertebrae (lumbar or thoracic) and the type of screw anchorage (mono- or bi-cortical) on pedicle screw pullouts. Among the 80 pig vertebrae (90- and 140-day-old) tested in this study, the average screw pullout forces ranged between 419.9N and 1341.2N. In addition, statistical differences were found between test groups, pointing out the influence of the three parameters stated above. We found that the the more caudally the screws are positioned (lumbar level), the greater their pullout resistance is, moreover, screw stability increases with the age, and finally, the screws implanted with a mono-cortical anchorage sustained lower pullout forces than those implanted with a bi-cortical anchorage. We conclude that the best anchorage can be obtained with older animals, using a lumbar fixation and long screws traversing the vertebra and inducing bi-cortical anchorage. In very young animals, pedicle screw fixations need to be bi-cortical and more numerous to prevent pullout.

Computed tomography morphometric analysis of porcine spinal growth for scoliosis model development

Scoliosis is a 3D deformity of the spine resulting in aesthetic and functional discomfort, sometimes leading to respiratory insufficiency due to abnormal thoracic cage development (Canavese and Dimeglio 2013). The pig appears to be a suitable animal model for early-onset scoliosis without chest wall insult (Odent et al. 2011), and for preclinical testing of fusionless scoliosis correction device (Roth et al. 2013). Such a model could be an interesting tool to study the growth process in scoliosis deformity. However, limited data are available for the size and the growth potential in the reported models (Odent et al. 2011). The purpose of this study was to define porcine spinal growth using computed tomography (CT) in order to determine spinal growth potential.

Placement of subcutaneous ureteral bypasses without fluoroscopic guidance in cats with ureteral obstruction: 19 cases (2014–2016)

Objectives The purpose of this study was to describe the perioperative and postoperative complications as well as short-term and long-term outcomes in cats with ureteral obstructions treated by placement of a subcutaneous ureteral bypass (SUB) device without imaging control. The second objective of this study was to compare cats treated by SUB device with cats treated by traditional surgical intervention. Methods Data were obtained retrospectively from the medical records (2014–2016) of cats that underwent SUB placement (SUB cats) and cats that underwent traditional ureteral surgery (C cats). Results Nineteen SUB devices were placed without fluoroscopic, radiographic or ultrasonographic guidance in 13 cats. Fifteen traditional interventions (ureterotomy and neoureterocystostomy) were performed in 11 cats. Successful placement of the SUB device was achieved in all cats with only one major intraoperative complication (kinking of the kidney catheter) and one minor intraoperative complication (misplacement of the kidney catheter). Eleven SUB cats recovered from the surgical procedure; two SUB cats and three C cats died during the anaesthesia recovery period. Postoperative SUB complications included anaemia (n = 2), urinary tract infection (UTI) (n = 4), non-infectious cystitis (n = 5) and SUB device obstruction (n = 1). Postoperative traditional surgery complications included anaemia (n = 7), UTIs (n = 6), non-infectious cystitis (n = 1), re-obstruction (n = 4) and ureteral stricture (n = 1). Median postoperative duration of hospitalisation (3 days) was significantly shorter for SUB cats than for C cats (P = 0.013). Ten SUB cats (76.9%) and four C cats (40%) were still alive at a median follow-up of 225 days and 260 days, respectively. Owners were completely (90%) or mostly (10%) satisfied with the SUB device placement. Conclusions and relevance SUB device placement appears to be an effective and safe option for treating ureteral obstruction in cats, and this study has shown that fluoroscopic guidance is not essential in all cases.

Robert Jones bandage pressure range assessment using a pressure mapping system and application to band calibration

The Robert Jones bandage (RJ) is a widely used bandage among veterinary surgeons to maintain physiological position of the limbs. It is a 3-layer composite bandage, which realization involves the use of several types of bands in a specific arrangement to give the bandage all its properties. Its proper making is difficult and requires experience, as the bandage needs to be not too tight or not too loose. This issue is a recurrent matter with every type of compression bandage (Rimaud et al. 2014). For the realization of a RJ, various types of bands can be used, depending on the surgeon but each layer has its own function that cannot be changed. The purpose of this study is to measure the pressure under a RJ bandage with a pressure mapping system and to evaluate the properties of some commonly used bands. The final application of these results is to propose a band calibration system to apply the correct pressure as a function of the band’s deformation.