Efficacy and safety of the long-term oral administration of carprofen in the treatment of osteoarthritis in dogs

The aim of this study conducted in France was to confirm the efficacy and safety of the oral administration of carprofen (Rimadyl®) at 4 mg/kg once a day during four months in the treatment of clinically chronic osteoarthritis in dogs. One hundred and ten dogs with chronic clinical signs of osteoarthritis were enrolled. The overall severity of the osteoarthritis condition and the clinical signs of osteoarthritis were assessed using visual analogue scales (VAS) on days 0, 5, 30, 60, 90 and 120. During the same visits, owners were asked to perform their own efficacy assessment through the grading of seven parameters using categorical scales. Hematological analyses were performed on days 0 and 120. Clinical blood chemistry evaluations were performed on days 0, 5, 60 and 120. The percentage of dogs showing a positive treatment effect increased from 12% on day 5 to 74% on day 120. The mean VAS scores significantly decreased throughout the study (P ≤0.05). Gastrointestinal undesirable effects likely to be related to carprofen but with no harmful consequences were observed in 5% of treated dogs. No detrimental effects of the treatment on haematological, renal and hepatic parameters were observed. These results show that carprofen at 4 mg/kg once daily can be safely used over a 4 month period in the treatment of osteoarthritis in dogs and provides a steadily increasing improvement of the clinical signs

Effective mechanical properties of diaphyseal cortical bone in the canine femur

The effective elastic modulus, yield strength, yield strain, ultimate strength, ultimate strain, strain energy density at yield and strain energy density at ultimate failure of femoral diaphyseal cortical bone were investigated on canine femurs. Four femurs representative of the canine population were selected from four statistically-determined clusters based on increasing size and weight comprising the Toy poodle (5 kg), Poodle (12 kg), German shorthaired pointer (25 kg) and Doberman (50 kg). The zones of interest were the lateral, medial, cranial, and caudal quadrants of the mid-diaphysis. Effective mechanical properties were measured using quasi-static three-point bending tests on strips. The averages +/- SD were 15.6 +/- 2.6 GPa for effective elastic modulus, 1743 +/- 32.1 MPa for yield strength, 0.012 +/- 0.003 for yield strain, 251.0 +/- 49.1 MPa for ultimate strength, 0.021 +/- 0.005 for ultimate strain, 10.7 +/- 4.0 J m(-3) x 10(5) for strain energy density at Yield and 33.0 +/- 14.1 J M-3 X 10(5) for strain energy density at ultimate failure. Significant differences were found between dogs and the effective elastic modulus increased with breed weight and size (13.9 GPa for the Toy poodle to 17.2 GPa for the Doberman). The ultimate strength sigma(u) and strain energy density at ultimate failure U-u were significantly lower in the Toy poodle than in the Poodle and German shorthaired pointer indicating that the cortical bone material in the Toy poodle differed from that of the other dogs. Examination of the zones of interest revealed that the cranial quadrant showed the greatest stiffness, whereas strength was highest at the medial site. The caudal cortex was less stiff and strong than the cranial cortex

Biomechanical comparison of two locking plate constructs under cyclic torsional loading in a fracture gap model

OBJECTIVES: The number of locking screws required per fragment during bridging osteosynthesis in the dog has not been determined. The purpose of this study was to assess the survival of two constructs, with either two or three screws per fragment, under cyclic torsion. METHODS: Ten-hole 3.5 mm stainless steel locking compression plates (LCP) were fixed 1 mm away from bone surrogates with a fracture gap of 47 mm using two bicortical locking screws (10 constructs) or three bicortical locking screws (10 constructs) per fragment, placed at the extremities of each LCP. Constructs were tested in cyclic torsion (range: 0 to +0.218 rad) until failure. RESULTS: The 3-screws constructs (29.65 ± 1.89 N.m/rad) were stiffer than the 2-screws constructs (23.73 ± 0.87 N.m/rad), and therefore, were subjected to a greater torque during cycling (6.05 ± 1.33 N.m and 4.88 ± 1.14 N.m respectively). The 3-screws constructs sustained a significantly greater number of cycles (20,700 ± 5,735 cycles) than the 2-screws constructs (15,600 ± 5,272 cycles). In most constructs, failure was due to screw damage at the junction of the shaft and head. The remaining constructs failed because of screw head unlocking, sometimes due to incomplete seating of the screw head prior to testing. CLINICAL SIGNIFICANCE: Omitting the third innermost locking screw during bridging osteosynthesis led to a reduction in fatigue life of 25% and construct stiffness by 20%. Fracture of the screws is believed to occur sequentially, starting with the innermost screw that initially shields the other screws

Ex vivo cyclic mechanical behaviour of 2.4 mm locking plates compared with 2.4 mm limited contact plates in a cadaveric diaphyseal gap model

OBJECTIVES: To compare the mechanical properties of locking compression plate (LCP) and limited contact dynamic compression plate (LC-DCP) constructs in an experimental model of comminuted fracture of the canine femur during eccentric cyclic loading. METHODS: A 20 mm mid-diaphyseal gap was created in eighteen canine femora. A 10-hole, 2.4 mm stainless steel plate (LCP or LC-DCP) was applied with three bicortical screws in each bone fragment. Eccentric cyclic loadings were applied at 10 Hertz for 610,000 cycles. Quasistatic loading / unloading cycles were applied at 0 and 10,000 cycles, and then every 50,000 cycles. Structural stiffness was calculated as the slope of the linear portion of the load-displacement curves during quasistatic loading / unloading cycles. RESULTS: No bone failure or screw loosening occurred. Two of the nine LCP constructs failed by plate breakage during fatigue testing, whereas no gross failure occurred with the LC-DCP constructs. The mean first stiffness of the LCP constructs over the course of testing was 24.0% lower than that of constructs stabilized by LC-DCP. Construct stiffness increased in some specimens during testing, presumably due to changes in bone-plate contact. The first stiffness of LC-DCP constructs decreased by 19.4% and that of locked constructs by 34.3% during the cycling period. A biphasic stiffness profile was observed: the second stiffness was significantly greater than the first stiffness in both groups, which allowed progressive stabilization at elevated load levels. CLINICAL SIGNIFICANCE: Because LCP are not compressed to the bone, they may have a longer working length across a fracture, and thus be less stiff. However, this may cause them to be more susceptible to fatigue failure if healing is delayed

Comparaison des Propriétés Mécaniques en Flexion 4 Points des Plaques Vissées pour Vis de 3,5 et 4,5 mm

Comparaison des Propriétés Mécaniques en Flexion 4 Points des Plaques Vissées pour Vis de 3,5 et 4,5 m

Vis verrouillées vs vis standard : étude ex vivo de montages pontant une fracture comminutive diaphysaire

La cicatrisation des fractures comminutives diaphysaires constitue une préoccupation majeure en orthopédie vétérinaire, vu leur incidence élevée, leur fort taux de complications et le défi thérapeutique que leur traitement constitue. L’un des implants les plus récents pour l’ostéosynthèse de pontage de telles fractures est la plaque de compression à verrouillage (LCP), utilisable avec des vis standard ou des vis verrouillées. Malgré les quelques études cliniques et biomécaniques comparant les plaques LCP avec vis verrouillées à d’autres types de plaque (DCP, LC-DCP), l’avantage réel des vis verrouillées demeure inconnu et non quantifié. Le but de cette étude est de comparer les propriétés mécaniques de montages par plaques LCP équipées de vis standard ou verrouillées, pontant un modèle de fracture comminutive diaphysaire

Biomechanical comparison of two locking plate constructs under cyclic loading in four-point bending in a fracture gap model: two screws versus three screws per fragment

OBJECTIVES: The number of locking screws required per fragment during bridging osteosynthesis has not been fully determined in the dog. The purpose of this study was to assess the survival of two constructs, with either two or three screws per fragment, under cyclic bending. METHODS: A 10-hole, 3.5-mm stainless steel locking compression plate was fixed 1 mm away from a bone surrogate in which the fracture gap was 47 mm. Two groups of 10 constructs, prepared with either two or three bicortical locking screws placed at the extremities of each fragment, were tested in a load-controlled 4-point bending test (range 0.7 to + 7 Nm) until failure. RESULTS: The 3-screw constructs were stiffer than the 2-screw constructs (19.73 ± 0.68 N/mm vs. 15.52 ± 0.51 N/mm respectively) and the interfragmentary relative displacements were higher for the 2-screw constructs (11.17 ± 0.88%) than for the 3-screw constructs (8.00 ± 0.45%). The difference between the number of cycles to failure for the 3-screw constructs (162,448 ± 30,073 cycles) and the 2-screw constructs (143,786 ± 10,103 cycles) was not significant. Failure in all constructs was due to plate fracture at the level of the compression holes. CLINICAL SIGNIFICANCE: Omission of the third innermost locking screw during bridging osteosynthesis subjected to bending forces led to a 20% reduction in construct stiffness and increased relative displacement (+39.6%) but did not change fatigue life

Hyperparathyroïdie secondaire d origine nutritionnelle et ostéogénèse imparfaite chez les carnivores domestiques

L Hyperparathyroïdie secondaire nutritionnelle et l ostéogénèse imparfaite sont deux maladies bien différentes par leur étiologie, mais très similaires sur les plans épidémiologique, clinique et radiographique. Elles concernent les carnivores domestiques en croissance et provoquent une ostéopénie sévère résultant en de multiples fractures pathologiques. L hyperparathyroïdie nutritionnelle a pour origine un régime déséquilibré en Calcium et Phosphore suite à une alimentation uniquement à base de viande ou d abats. L ostéogénèse imparfaite provient d une mutation dans les gènes codant pour le collagène de type I, protéine constituant la matrice ostéoïde. L anamnèse permet une orientation diagnostique, qui doit être confirmée par des examens complémentaires pertinents. Avec un traitement bien mené et en l absence de complications, l hyperparathyroïdie présente un bon pronostic, alors que les options thérapeutiques de l ostéogénèse imparfaite ne sont encore à l étude que chez l humain.TOULOUSE3-BU Santé-Centrale (315552105) / SudocTOULOUSE-EN Vétérinaire (315552301) / SudocSudocFranceF

Contribution à l étude du syndrome obstructif des voies respiratoires chez le Bulldog anglais (étude clinique, morphologique et généalogique)

Une convention européenne sur le bien être animal rédigée en 1987 vise directement les races de chiens dont la morphologie prédispose à des pathologies. Dans cet ouvrage, l auteur a choisi d étudier le syndrome obstructif des voies respiratoires chez le Bulldog Anglais, race de chien à la morphologie hypertypée. La première partie étudie l évolution de la morphologie du Bulldog Anglais vers son type actuel et les clés de sa sélection. Ensuite une étude bibliographique du syndrome obstructif des voies respiratoires est proposée. La deuxième partie étudie 21 Bulldogs atteints de ce syndrome, pour lesquels une étude clinique, morphologique et généalogique a été réalisée dans le but d objectiver l étendue et la gravité de cette affection, ainsi que les causes de son incidence particulièrement élevée dans cette race. Enfin, à partir des informations recueillies au cours des deux parties précédentes, des solutions sont proposées pour produire des Bulldogs Anglais sains.TOULOUSE3-BU Santé-Centrale (315552105) / SudocTOULOUSE-EN Vétérinaire (315552301) / SudocSudocFranceF

Biomécanique en torsion dynamique de montages clou-plaque sur fémurs canins

Dans le cadre du traitement des fractures diaphysaires fémorales comminutives, visant à respecter le concept d ostéosynthèse biologique, l auteur se propose de comparer 3 montages combinés, constitués d'un clou centromédullaire et d'une plaque VCP pour vis de 2,0 et 2,7 mm de diamètre, en faisant varier l implantation des vis servant à la fixation de la plaque. L étude a été réalisée sur 8 fémurs canins, appareillés successivement avec les trois différents montages. Ils ont été soumis à des tests en torsion statique et dynamique, avec mesures du couple et de l'angle de torsion, permettant d évaluer l influence de différents type d implantation de vis et les effets de l application d une torsion dynamique sur les propriétés mécaniques du montage. Les essais de validation du banc de torsion et du système de mesures sur des poutres en aluminium ont montré une bonne justesse des résultats. Les résultats des tests sur les fémurs appareillés ont mis en évidence le rôle majeur de l'implantation bicorticale des 2 vis les plus périphériques sur la plaque et la faible répercussion de l'implantation monocorticale des autres vis sur les propriétés mécaniques des montages en torsion. Ces mêmes résultats ont également indiqués une absence de lâchage des implants, jusqu à 6100 cycles de sollicitation dynamique, malgré un certain desserrage des 2 vis les plus proches de la partie encastrée des fémurs.TOULOUSE-EN Vétérinaire (315552301) / SudocTOULOUSE3-BU Santé-Centrale (315552105) / SudocSudocFranceF