Biomechanical evaluation of four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs.

PURPOSE: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. METHODS: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate-PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. RESULTS: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. CONCLUSIONS: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods.

Biomechanical evaluation of four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs

Purpose: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. Methods: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate­PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. Results: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. Conclusions: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods.

Thoracoscopy pulmonary biopsy by two portals with a novel pre-tied loop ligature device in rabbits: an experimental study / Biópsia pulmonar por toracoscopia por dois portais com uma nova ligadura de alça pré-amarrada em coelhos: um estudo experimental

Thoracoscopy is replacing open lung biopsies because it is less invasive, usually the technique is done using three portals and intracorporeal suture technique. This study described the feasibility and efficacy of a novel pre tied loop ligature and to propose a thoracoscopic access strategy with two portals to perform lung biopsy in patients under 5 kg. Ten rabbits were positioned in dorsal recumbency. Total thoracoscopic lung biopsy was performed using a combined transdiaphragmatic approach and a right intercostal approach. A pre tied loop ligature was placed to perform a caudal lung lobe biopsy. Insufflation of the thoracic cavity was not performed. The total surgery time was 41.4 ± 14.5 min. The procedure was carried out free of complications that prevented slippage or tightening the knot or that made it come loose after the lung biopsy; there was no serious complication during the surgical procedure. The samples obtained averaged 1x0.64x0.45 cm (Length, Width, Depth) and were considered satisfactory according to the histopathologic evaluation. Thorax radiographs taken before and after the surgeries were compared and showed no pneumothorax or hemothorax. Necropsy confirmed no knot failure occurred at the biopsy site. The use of the novel pre tied loop ligature is a safe and effective technique, avoiding problems with the limited size of the thoracic cavity in small patients.

A toracoscopia está substituindo as biópsias pulmonares abertas por ser menos invasiva. Usualmente a técnica é feita utilizando três portais e ligaduras feitas intra corporalmente. O objetivo deste estudo foi descrever a viabilidade e eficácia de uma nova ligadura com alça pré-amarrada e propor uma estratégia de acesso toracoscópico com dois portais para realizar biópsia pulmonar em pacientes com menos de 5kg. Dez coelhos foram posicionados em decúbito dorsal. A biópsia pulmonar por toracoscopia total foi feita pela abordagem combinada transdiafragmática e abordagem intercostal direita. Uma nova ligadura pré-amarrada foi colocada para realizar uma biópsia do lobo pulmonar caudal. Não foi realizada insuflação da cavidade torácica. O tempo total de cirurgia foi de 41,4 ± 14,5 min. Os procedimentos foram realizados sem complicações que impedissem o escorregamento ou aperto do nó ou que o soltassem após a biópsia pulmonar; não houve nenhuma intercorrência grave durante o procedimento cirúrgico. As amostras coletadas tinham tamanho médio 1x0,64x0,45 cm e foram consideradas satisfatórias de acordo com a avaliação histopatológica. As radiografias de tórax feitas antes e depois das cirurgias foram comparadas e não mostraram pneumotórax ou hemotórax. A necropsia confirmou que não ocorreu falha do nó no local da biópsia. Conclui-se que uso da nova ligadura com alça pré-amarrada é uma técnica segura e eficaz, evitando problemas com o tamanho limitado da cavidade torácica em pacientes pequenos.

Thoracoscopy pulmonary biopsy by two portals with a novel pre-tied loop ligature device in rabbits: an experimental study / Biópsia pulmonar por toracoscopia por dois portais com uma nova ligadura de alça pré-amarrada em coelhos: um estudo experimental

ABSTRACT: Thoracoscopy is replacing open lung biopsies because it is less invasive, usually the technique is done using three portals and intracorporeal suture technique. This study described the feasibility and efficacy of a novel pre tied loop ligature and to propose a thoracoscopic access strategy with two portals to perform lung biopsy in patients under 5 kg. Ten rabbits were positioned in dorsal recumbency. Total thoracoscopic lung biopsy was performed using a combined transdiaphragmatic approach and a right intercostal approach. A pre tied loop ligature was placed to perform a caudal lung lobe biopsy. Insufflation of the thoracic cavity was not performed. The total surgery time was 41.4 ± 14.5 min. The procedure was carried out free of complications that prevented slippage or tightening the knot or that made it come loose after the lung biopsy; there was no serious complication during the surgical procedure. The samples obtained averaged 1x0.64x0.45 cm (Length, Width, Depth) and were considered satisfactory according to the histopathologic evaluation. Thorax radiographs taken before and after the surgeries were compared and showed no pneumothorax or hemothorax. Necropsy confirmed no knot failure occurred at the biopsy site. The use of the novel pre tied loop ligature is a safe and effective technique, avoiding problems with the limited size of the thoracic cavity in small patients.

RESUMO: A toracoscopia está substituindo as biópsias pulmonares abertas por ser menos invasiva. Usualmente a técnica é feita utilizando três portais e ligaduras feitas intra corporalmente. O objetivo deste estudo foi descrever a viabilidade e eficácia de uma nova ligadura com alça pré-amarrada e propor uma estratégia de acesso toracoscópico com dois portais para realizar biópsia pulmonar em pacientes com menos de 5kg. Dez coelhos foram posicionados em decúbito dorsal. A biópsia pulmonar por toracoscopia total foi feita pela abordagem combinada transdiafragmática e abordagem intercostal direita. Uma nova ligadura pré-amarrada foi colocada para realizar uma biópsia do lobo pulmonar caudal. Não foi realizada insuflação da cavidade torácica. O tempo total de cirurgia foi de 41,4 ± 14,5 min. Os procedimentos foram realizados sem complicações que impedissem o escorregamento ou aperto do nó ou que o soltassem após a biópsia pulmonar; não houve nenhuma intercorrência grave durante o procedimento cirúrgico. As amostras coletadas tinham tamanho médio 1x0,64x0,45 cm e foram consideradas satisfatórias de acordo com a avaliação histopatológica. As radiografias de tórax feitas antes e depois das cirurgias foram comparadas e não mostraram pneumotórax ou hemotórax. A necropsia confirmou que não ocorreu falha do nó no local da biópsia. Conclui-se que uso da nova ligadura com alça pré-amarrada é uma técnica segura e eficaz, evitando problemas com o tamanho limitado da cavidade torácica em pacientes pequenos.

Trans-sinus fixation for correction of deviation of the gnathotheca in a hawk (Caracara plancus).

INTRODUCTION: For birds of prey, the integrity of the beak is extremely important for defence, hygiene, socialization and especially, feeding. This paper describes successful trans-sinus fixation of a lateral deviation of the mandible in a hawk (Caracara plancus). CASE REPORT: The patient was presented with malnutrition and dehydration due to severe left lateral deviation of gnathotheca, with significant malocclusion. Fixation was performed with a 1.0-mm pin and 0.4-mm cerclage, applying contralateral traction to the deviation. The placement of the cerclage enabled full opening of the beak to allow feeding in the postoperative period. At 21 days after surgery, occlusion was perfect and the patient had recovered normal beak function. When clinical follow-up indicated that the bird would be able to survive in the wild, it was released. CONCLUSION: Trans-sinus fixation was effective in correcting lateral deviation of the gnathotheca in a hawk (C. plancus).

Preliminary mechanical evaluation of two novel veterinary angle-stable-threaded interlocking nail systems / Avaliação mecânica preliminar de dois novos sistemas veterinários de haste intramedular bloqueada em ângulo estável roscada

The interlocking nail represents an excellent option as a surgical approach to treat fractures in long bones in veterinary medicine. However, failures were reported mainly due to a slack present in the interface of the rod with the screws. The present study tested and mechanically compare axial compression loads of two novel models of stable angle interlocking nails with threaded holes. Among the two models, one was uniplanar and the other was multiplanar with orthogonally arranged distal holes. Twenty-one specimens made of polylactic acid were used for the implantation of interlocking nail´s rods, divided into three groups: conventional interlocking nail (G1), novel interlocking nail with a stable angle with holes arranged in a single plane (G2), and novel interlocking nail with a stable angle in two planes, with the penultimate hole at 90 degrees from the others (G3). Biomechanical tests were performed using axial, cyclic, and destructive compression load for comparison between them. All the specimens showed plastic deformation in the screws after destructive tests, in both proximal and distal sides, being highly intense in G1. G2 and G3 of the stable angle rods supported higher loads than G1 in all tests performed (P<0.05). The novel stems did not differ statistically from each other (P>0.05). The initial hypothesis that the novel models would provide increased stability was confirmed; however, no differences were demonstrated between them. The screw locking system on the rods allowed high resistance values in the tests performed, proving to be effective and potentially applicable in real clinical situations.

A haste intramedular bloqueada representa excelente opção para abordagem cirúrgica de fraturas em ossos longos na medicina veterinária. Todavia, falhas decorrentes principalmente de "folga" presente na interface da haste com os parafusos foram relatadas. O presente estudo teve como objetivo testar e comparar mecanicamente, por cargas de compressão axial, dois novos modelos de haste intramedular bloqueada de ângulo estável com orifícios roscados, sendo uma delas uniplanar e outra multiplanar com orifícios distais dispostos ortogonalmente. Vinte e um corpos de prova confeccionados em ácido polilático (PLA) foram utilizados para implantação das hastes intramedulares bloqueadas, divididos em três grupos: Haste bloqueada convencional (G1); haste bloqueada nova de ângulo estável com orifícios dispostos em único plano (G2); haste bloqueada nova de ângulo estável em dois planos, com o penúltimo orifício em 90 graus dos demais (G3). Utilizou-se ensaios biomecânicos por carga de compressão axial, cíclicos e destrutivos, para comparação entre eles. Todos mostraram deformação plástica nos parafusos após testes destrutivos, tanto proximais como distais, sendo mais intensa no grupo 1. Os grupos 2 e 3 das hastes de ângulo estável suportaram cargas superiores em relação ao G1 em todos os testes realizados (P<0.05). As hastes novas não diferiram estatisticamente entre si (P>0,05). A hipótese inicial de que os novos modelos proporcionariam maior estabilidade foi confirmada, entretanto não foi demonstrada diferenças entre eles. O sistema de bloqueio roscado dos parafusos nas hastes permitiu valores elevados de resistência nos testes realizados, mostrando-se efetivo e, potencialmente aplicável em situações clínicas reais.

Ex vivo biomechanical testing of Funkquist B dorsal laminectomy between the sixth and seventh cervical vertebrae in dogs / Análise biomecânica ex vivo dos efeitos da laminectomia dorsal Funkquist B entre a sexta e a sétima vertebras cervicais em cães

Dorsal laminectomy is routinely performed for spinal cord compressions or stenosis of the cervical vertebral canal. However, despite good results, relevant complications have been described in dogs. Considering the incomplete understanding of the necessity for complementary surgical stabilization after performing laminectomies in the cervical region, this study compared the resistance and range of motion (ROM) of the cervical spinal column subjected to Funkquist B laminectomy between the sixth and seventh vertebrae in dogs. Forty-four cervical vertebral columns (C2-T1) of dogs, with an average weight of 26.2±3.8 kg, were selected using radiography and computed tomography. Four experimental groups (n=11) were established according to the mechanical test: two control groups (flexion and extension control) and two laminectomy groups (flexion and extension laminectomies). Numerical results of the maximum load for measuring the resistance and ROM of the columns of the two control groups and the two laminectomy groups were compared. The laminectomy groups showed a lower maximum load, regardless of the mechanical test performed (P<0.001). The ROM was not influenced by laminectomy, the type of mechanical test (ventral flexion or extension), or its interaction (P<0.05). There was no interaction between the effect of the laminectomy factors (yes or no) and the effect of the mechanical tests for ventral flexion or extension (P<0.05). In conclusion, Funkquist B dorsal cervical laminectomy between C6 and C7 decreases mechanical resistance with a supraphysiological loading force but does not alter the ROM, suggesting that it can be used without additional mechanical stabilization in dogs.

A laminectomia dorsal é realizada com frequência no tratamento de compressões medulares ou estenose do canal vertebral cervical. No entanto, complicações relevantes têm sido descritas em cães. Considerando que ainda não há entendimento completo da necessidade de estabilização cirúrgica complementar após a realização de uma ou múltiplas laminectomias na região cervical, o objetivo deste estudo foi comparar a resistência e amplitude de movimento (ADM) da coluna cervical submetida à laminectomia Funkquist B entre a sexta e a sétima vértebras em cães. Quarenta e quatro colunas vertebrais cervicais (C2-T1) de cães, com peso médio de 26,2 ± 3,8 kg, foram selecionadas por meio de radiografia e tomografia computadorizada. Quatro grupos experimentais (n = 11) foram estabelecidos de acordo com o teste mecânico realizado: dois grupos controle (flexão e extensão controle) e dois grupos laminectomia (flexão e extensão laminectomia). Os resultados numéricos da carga máxima para medir a resistência e ADM das colunas dos dois grupos de controle e dos dois grupos de laminectomia foram comparados. Os grupos de laminectomia apresentaram menores valores de carga máxima, independentemente do teste mecânico realizado (P < 0,001). A ADM não foi influenciada pela laminectomia, tipo de teste mecânico (flexão ou extensão ventral) ou sua interação (P < 0,05). Não houve interação entre o efeito do fator de laminectomia, sim ou não, ou o efeito do teste mecânico na flexão ou extensão ventral (P < 0,05). A laminectomia cervical dorsal Funkquist B entre C6 e C7 diminui a resistência mecânica com uma força de carga suprafisiológica, mas não altera a ADM, sugerindo que pode ser usada sem estabilização mecânica adicional em cães.

Tibial plateau leveling osteotomy in dogs: an ex vivo comparative study of knee's surrounding structures protection methods

Background: Cranial cruciate ligament failure is one of the leading causes of pelvic limb lameness in dogs and one of the most recommended treatments is tibial plateau leveling osteotomy (TPLO) surgery. However, this procedure may lead to some complications as fractures of the fibula, laceration in varying degrees of the popliteal vasculature and its branches, neuropraxia, neurotmeses, among others. The goals of this study were to compare the effectiveness of 8 methods used during TPLO, to prevent damage to the cranial tibial artery, fibula, tibial and fibular nerve (surgical compresses, specific surgical retractors I and II and an osteotomy technique variation). Materials, Methods & Results: A total of 40 canine cadavers weighing 25.9 ± 3.7 kg were submitted to TPLO. Animals were previously prepared with 1: 4 barium red latex solution, to provide radiopacity of arteries surrounding the knee (n = 80). TPLO was performed using 8 methods to protect the cranial tibial artery, fibula, and tibial and fibular nerves. Each method was used in one of the knees of 5 animals. The contralateral knee was maintained as a control (without protection). The knees were radiographed in orthogonal projections before and after the osteotomies and then anatomically dissected. The evaluated structures were photographed, and the images sent to four blind evaluators (visual macroscopy) to classify the possible injuries. The highest incidence of injuries was identified when protection methods were used. However, this difference was not significant (P > 0.05). No significant differences regarding efficacy were found between all 8 protection methods. Discussion: In this study, the total incidence of injuries following TPLO was 20% was much higher than that presented in the literature which indicates when considering only intraoperative injuries. The dogs cadavers tissue resistance and stiffened latex may have predisposed the osteotomy injury, as soft tissues with greater flexibility are less susceptible to trauma caused by the oscillatory saw. When compared to others cadaveric studies that also evaluated the efficacy of surgical dressings to protect the cranial tibial artery, during TPLO, we also find a higher incidence of damage. Maybe the limb's position was responsible for this difference, once in the after mentioned researches the limb was positioned suspended to simulate a dorsal decubitus position and we choose the limb position with the lateral face resting on the surface of the operating table, and this may have provided extra pressure from the structures towards the osteotomy saw, increasing the occurrence of those damages. Although the present study did not reveal a significant difference for the use of protection methods, we believe that the dimensions of the compresses used herein may have contributed to a higher incidence of injuries. They probably increased the tissue trauma needed for their allocation and led to a lower positioning accuracy for the isolation of these structures. Maybe for the same reason, the specific type II surgical retractor was the only shield that, observationally, did not increase the occurrence of injuries, once less dissection was required to allocate it. The difference in geometric dimensions between the retractors may justify the superiority of the retractor II, since it allows a more careful and apparently less traumatic allocation. Performing TPLO without adopting these protection methods did not lead to a higher risk of injury to the cranial tibial artery, fibula, and tibial and fibular nerves.

Cervical ventral slot in rabbits (Oryctolagus cuniculus). Piezosurgery versus conventional technique.

PURPOSE: To investigate the applicability of piezosurgery for cervical ventral slot (CVS), comparing it with the conventional technique of using high-speed burs for bone wear. METHODS: Thirty rabbits (Oryctolagus cuniculus) were divided into two treatment groups (T1 and T2) corresponding to CVS between C3-C4. In T1, the surgery was performed with piezoelectric apparatus, and in T2 with high-speed burs. The evaluated parameters were: duration of each stage of surgery, temperature variations during CVS, visibility of the surgical field, intra and postoperative complications, and anesthetic monitoring. At 14, 28, and 56 postoperative days, five animals from each treatment group were submitted for histopathological study of the surgical site. RESULTS: Compared with T2, T1 had more precise bone cut, and better visibility of the operative field, although it required longer total surgical time (p = 0.02) and triggered a greater number of intraoperative complications (p < 0.01), microscopic lesions in the spinal cord (p < 0.05), and transient neurological deficits in the postoperatively (p < 0.05). CONCLUSIONS: It is necessary to perform surgical planning and have several tips of the piezoelectric instrument available for the safe use of the piezoelectric device in neurosurgery.

Avaliação por câmera termográfica de implante de co-poliamida associado a elastômero termoplástico em traqueia de coelho / Evaluation of co-polyamide implant comprising a thermoplastic elastomer in rabbit trachea using thermographic camera / Evaluación con cámara termográfica de un implante de copoliamida asociado a un elastómero termoplástico en la tráquea de un conejo

La termografía es eficaz para detectar la temperatura de la superficie corporal y puede utilizarse como método auxiliar para diagnosticar procesos inflamatorios y para evaluar patrones de cicatrización, lo que permite su amplio uso en Medicina Veterinaria. El procedimiento ha ganado protagonismo por ser una técnica no invasiva, indolora, de bajo costo y segura, ya que elimina la necesidad del uso de contrastes, sedación y radiación. El objetivo de este artículo es analizar la eficacia del uso de la termografía en la evaluación de la biocompatibilidad en la reparación del tejido traqueal, así como identificar procesos inflamatorios tras la implantación de la prótesis impresa en nailon con impresión 3D asociada al elastómero termoplástico - PCTPE. Se dividieron quince conejos blancos de Nueva Zelanda (Oryctolagus cuniculus) machos en tres grupos de diferentes períodos de evaluación (siete, 15 y 30 días). Se implantaron prótesis tridimensionales tras la resección completa de tres anillos traqueales. La evaluación de las imágenes termográficas se realizó en el lugar de implantación de la prótesis traqueal justo antes del procedimiento quirúrgico e inmediatamente antes de la eutanasia. Hubo una diferencia significativa entre los grupos, ya los 30 días la temperatura mínima (p = 0,0357), media (p = 0,0135) y máxima (p = 0,0058) fue menor en comparación con los otros grupos...(AU)

Thermography is efficient for detecting body surface temperature and can be used as an auxiliary method for the diagnosis of inflammatory processes and in the evaluation of scarring patterns, which allows its wide use in Veterinary Medicine. The procedure has gained prominence, as it is a non-invasive, painless, low-cost and safe technique, since it does not require the use of contrasts, sedation and radiation. The objective of this article is to analyze the efficiency of the use of thermography in the evaluation of biocompatibility in tracheal tissue repair, as well as to identify inflammatory processes after implantation of the 3D printed impression prosthesis of nylon associated with the thermoplastic elastomer - PCTPE. Fifteen male New Zealand White rabbits (Oryctolagus cuniculus) were divided into three groups of different evaluation periods (seven, 15 and 30 days). Three-dimensional prostheses were implanted after complete resection of three tracheal rings. The evaluation of the thermographic images was performed at the place of implantation of the tracheal prosthesis just before the surgical procedure and immediately before euthanasia. There was a significant difference between the groups, and at 30 days the minimum (p = 0,0357), average (p = 0,0135) and maximum (p = 0,0058) temperature was lower when compared with the other groups...(AU)

A termografia é eficiente para detecção da temperatura da superfície corporal e pode ser utilizada como método auxiliar de diagnóstico de processos inflamatórios e na avaliação de padrões cicatriciais, o que permite sua ampla utilização na Medicina Veterinária. O procedimento tem ganhado destaque, pois trata-se de técnica não invasiva, indolor, de baixo custo e segura, pois dispensa a necessidade do uso de contrastes, sedação e radiação.  O objetivo desse artigo é analisar a eficiência do uso da termografia na avaliação da biocompatibilidade em reparação tecidual traqueal, bem como identificar processos inflamatórios após a implantação da prótese impressa em impressão 3D de náilon associado ao elastômero termoplástico- PCTPE. Quinze coelhos machos, da linhagem Nova Zelândia Branco (Oryctolagus cuniculus), foram distribuídos em três grupos de períodos de avaliação diferentes (sete, 15 e 30 dias). As próteses tridimensionais foram implantadas após ressecção completa de três anéis traqueais. A avaliação das imagens termográficas foi efetuada no local de implantação da prótese traqueal no momento anterior ao procedimento cirúrgico e imediatamente antes da eutanásia. Houve diferença significativa entre os grupos, sendo que aos 30 dias a temperatura mínima (p=0,0357), média (p=0,0135) e máxima (p=0,0058) foi menor quando comparado com os demais grupos...(AU)

Biomechanical evaluation of a new femoral stem design for total hip replacement in a canine model.

PURPOSE: To evaluate the biomechanical properties of a novel total hip replacement femoral stem. METHODS: Eight pairs of femurs from dog cadavers were used. The femurs were separated into different groups. A novel femoral stem with a convex proximal portion (Stem B) was biomechanically evaluated and compared to awell-known veterinary collared stem (Stem A). Femoral stems were inserted into the contralateral femurs from the same dog, forming 16 constructs. A flexo-compression load was applied on the axial axis of each sample. Maximum strength, deflection, stiffness, and energy absorption were analysed. RESULTS: Group B constructs showed significantly higher values (p ? 0.05) for the variables, except stiffness. The mean maximum strength was 1,347 ± 357 N for Group A and 1,805 ± 123 N for Group B (p ? 0.0069). The mean deflection was5.54 ± 2.63 mm for Group A and 10.03 ± 3.99 mm for Group B (p ? 0.0056). For the energy variable, the force was 6,203 ± 3,488 N/mm for Group A and 12,885 ± 5,056 N/mm for Group B (p ? 0.0054). Stem B had greater maximum strength, deflection, and energy. CONCLUSIONS: The new stem was effective in neutralizing the impact of axial flexion-compression stresses during biomechanical tests in cadaveric models.

Three-dimensional printed poly (L-lactide) and hydroxyapatite composite for reconstruction of critical bone defect in rabbits.

PURPOSE: To use a 3D printed poly (L-lactide) acid (PLLA) and hydroxyapatite (HA) composite as a bone substitute for reconstruction of a critical bone defect in the radius of rabbits. METHODS: A 1.5 cm ostectomy was performed in the radial diaphysis of 60 New Zealand white rabbits. The rabbits were divided into three groups according to surgical treatment of the bone defect (group I - control, group II - bone graft, group III - 3D PLLA). Each group was divided into four subgroups with different radiographic and histopathologic evaluation times (T1 - 15 days, T2 - 30 days, T3 - 60 days, T4 - 90 days). RESULTS: The implant group had greater clinically lameness (p = 0.02), edema (p = 0.007), pain (p = 0.04) and more complications at the surgical site (p = 0.03). Histologically, this group showed greater congestion (p = 0.04), hemorrhage (p = 0.04) and inflammation. Osteogenesis was microscopically similar between days (p = 0.54) and treatments (p = 0.17), even though radiographically, more effective bone healing occurred in the graft group (II), with more callus and bone bridge formation. CONCLUSIONS: The customization of a 3D PLLA/HA scaffold was successful. However, in animals receiving the polymer-ceramic composite less bone callus and bone bridge was formed compared to the graft group.

Percutaneous application of allogeneic adipose-derived mesenchymal stem cell in dogs submitted to minimally invasive plate osteosynthesis of the tibia.

PURPOSE: To evaluate clinical outcome following minimally invasive plate osteosynthesis (MIPO) associated with percutaneous transplantation of allogeneic adipose-derived mesenchymal stem cells (AD-MSC) at the tibial fracture site in dogs. METHODS: Thirty-six dogs presenting with nonarticular complete tibial fracture were included in this study. All fractures were treated by the same MIPO technique. The animals were divided in group 1 (n = 20) received a percutaneous application of 3 × 106 AD-MSC at the fracture site and group 2 (n = 16) did not receive any adjuvant treatment. Postoperative radiographic examinations were made at 15, 30, 60, 90 and 120 days. RESULTS: Fifty-eight percent of the patients were classified as skeletally immature. The median weight of the animals was 18.8 kg. The mean radiographic union time differed statistically between the AD-MSC group (28.5 days) and the control group (70.3 days). Sixty percent of dogs in group 1 and 56.25% of the group 2 were considered immature. CONCLUSIONS: The use of allogeneic AD-MSC cell therapy and MIPO is a safe, viable and effective technique for promoting bone healing in nonarticular tibial fractures in dogs.

Avaliação por câmera termográfica de implante de co-poliamida associado a elastômero termoplástico em traqueia de coelho / Evaluation of co-polyamide implant comprising a thermoplastic elastomer in rabbit trachea using thermographic camera / Evaluación con cámara termográfica de un implante de copoliamida asociado a un elastómero termoplástico en la tráquea de un conejo

La termografía es eficaz para detectar la temperatura de la superficie corporal y puede utilizarse como método auxiliar para diagnosticar procesos inflamatorios y para evaluar patrones de cicatrización, lo que permite su amplio uso en Medicina Veterinaria. El procedimiento ha ganado protagonismo por ser una técnica no invasiva, indolora, de bajo costo y segura, ya que elimina la necesidad del uso de contrastes, sedación y radiación. El objetivo de este artículo es analizar la eficacia del uso de la termografía en la evaluación de la biocompatibilidad en la reparación del tejido traqueal, así como identificar procesos inflamatorios tras la implantación de la prótesis impresa en nailon con impresión 3D asociada al elastómero termoplástico - PCTPE. Se dividieron quince conejos blancos de Nueva Zelanda (Oryctolagus cuniculus) machos en tres grupos de diferentes períodos de evaluación (siete, 15 y 30 días). Se implantaron prótesis tridimensionales tras la resección completa de tres anillos traqueales. La evaluación de las imágenes termográficas se realizó en el lugar de implantación de la prótesis traqueal justo antes del procedimiento quirúrgico e inmediatamente antes de la eutanasia. Hubo una diferencia significativa entre los grupos, ya los 30 días la temperatura mínima (p = 0,0357), media (p = 0,0135) y máxima (p = 0,0058) fue menor en comparación con los otros grupos...

Thermography is efficient for detecting body surface temperature and can be used as an auxiliary method for the diagnosis of inflammatory processes and in the evaluation of scarring patterns, which allows its wide use in Veterinary Medicine. The procedure has gained prominence, as it is a non-invasive, painless, low-cost and safe technique, since it does not require the use of contrasts, sedation and radiation. The objective of this article is to analyze the efficiency of the use of thermography in the evaluation of biocompatibility in tracheal tissue repair, as well as to identify inflammatory processes after implantation of the 3D printed impression prosthesis of nylon associated with the thermoplastic elastomer - PCTPE. Fifteen male New Zealand White rabbits (Oryctolagus cuniculus) were divided into three groups of different evaluation periods (seven, 15 and 30 days). Three-dimensional prostheses were implanted after complete resection of three tracheal rings. The evaluation of the thermographic images was performed at the place of implantation of the tracheal prosthesis just before the surgical procedure and immediately before euthanasia. There was a significant difference between the groups, and at 30 days the minimum (p = 0,0357), average (p = 0,0135) and maximum (p = 0,0058) temperature was lower when compared with the other groups...

A termografia é eficiente para detecção da temperatura da superfície corporal e pode ser utilizada como método auxiliar de diagnóstico de processos inflamatórios e na avaliação de padrões cicatriciais, o que permite sua ampla utilização na Medicina Veterinária. O procedimento tem ganhado destaque, pois trata-se de técnica não invasiva, indolor, de baixo custo e segura, pois dispensa a necessidade do uso de contrastes, sedação e radiação.  O objetivo desse artigo é analisar a eficiência do uso da termografia na avaliação da biocompatibilidade em reparação tecidual traqueal, bem como identificar processos inflamatórios após a implantação da prótese impressa em impressão 3D de náilon associado ao elastômero termoplástico- PCTPE. Quinze coelhos machos, da linhagem Nova Zelândia Branco (Oryctolagus cuniculus), foram distribuídos em três grupos de períodos de avaliação diferentes (sete, 15 e 30 dias). As próteses tridimensionais foram implantadas após ressecção completa de três anéis traqueais. A avaliação das imagens termográficas foi efetuada no local de implantação da prótese traqueal no momento anterior ao procedimento cirúrgico e imediatamente antes da eutanásia. Houve diferença significativa entre os grupos, sendo que aos 30 dias a temperatura mínima (p=0,0357), média (p=0,0135) e máxima (p=0,0058) foi menor quando comparado com os demais grupos...

Bone alignment after minimally invasive plate osteosynthesis of the tibia in dogs / Avaliação do alinhamento ósseo após osteossíntese minimamente invasiva com placa de tíbia em cães

ABSTRACT: This study assessed radiographically changes in tibial alignment in the frontal and sagittal planes in dogs that underwent minimally invasive plate osteosynthesis (MIPO) without the aid of image intensifiers. Radiographs of dogs with complete non-articular tibial fractures submitted to MIPO were included and evaluated, without the aid of a transoperative image intensifier and / or an association of implants. The tibial mechanical angles (mMPTA, mMDTA, mCaPTA and mCrDTA) were measured by three evaluators. The data obtained were compared with results from previously published studies. Twenty-seven animals were included in the study. The mean and standard deviation of the angular changes were as follows: mMPTA, 2.54° ± 3.10 (-1.1º to 8.7º); mMDTA, 0.03º ± 0.16 (-3.44º to 0.79º); mCaPTA, 37º ± 4.29 (-6.23º to 14.87º); and mCrDTA, 8.25° ± 5.53 (-0.2º to 17.28º). There was a negative correlation between "mCaPTA" and "mCrDTA". MIPO of the tibia without using image intensifiers and implant association can potentially cause angular changes, which can lead to clinically relevant deformities after bone healing.

RESUMO: Este estudo teve como objetivo avaliar radiograficamente as alterações no alinhamento da tíbia nos planos frontal e sagital em cães submetidos à osteossíntese minimamente invasiva com placa (MIPO) sem o auxílio de intensificadores de imagem. Foram incluídas e avaliadas radiografias de cães com fraturas completas da tíbia não articulares submetidos a MIPO, sem o auxílio de intensificador de imagem transoperatório e/ou associação de implantes. Os ângulos mecânicos tibiais (mMPTA, mMDTA, mCaPTA e mCrDTA) foram mensurados por três avaliadores. Os dados obtidos pela média de todas as avaliações foram comparados com resultados de estudos previamente publicados. Vinte e sete animais foram incluídos no estudo. A média e desvio padrão das alterações angulares foram os seguintes: mMPTA= 2,54° ± 3,10 (-1,1º a 8,7º); mMDTA= 0,03º ± 0,16 (-3,44º a 0,79º); mCaPTA= 37º ± 4,29 (-6,23º a 14,87º); e mCrDTA= 8,25 ° ± 5,53 (-0,2º a 17,28º). Houve uma correlação negativa entre "mCaPTA" e "mCrDTA". A realização de MIPO em tíbia sem o uso de intensificadores de imagem e associação de implantes pode causar alterações angulares, o que pode levar a deformidades clinicamente relevantes após a cicatrização óssea.

Capital femoral physeal dysplasia in cats submited to ostectomy of the femoral head and neck / Displasia femoral capital em felinos submetidos a ostectomia da cabeça e colo femoral

ABSTRACT: This report described pathological fracture of the femoral head (physeal dysplasia) in four male cats (three mixed breed and one Bengal), with an average age of 16 months, treated by an ostectomy of the femoral head and neck. Three cats were neutered and one entire. All presented with mild intermittent lameness in the pelvic limbs. Displacement of the femoral epiphysis and resorption of the femoral neck were present and excision of the femoral head and remaining neck was performed in all cases. Hstological examination showed mild foci of compaction and trabecular fibrosis with deposition of fibrous connective tissue, permeated by granulation tissues, consistent with the original diagosis. Limb function improved in all patients from 2 to 4 weeks postoperatively. Diagnosis of physeal dysplasia is challenging and treatment is different from acute traumatic fractures. Femoral head and neck excision was considered a good alternative in these patients.

RESUMO: Este trabalho descreve a fratura patológica da cabeça do femur (displasia fiseal) em quatro machos (três raças mistas e um Bengal), com idade média de 16 meses, que foram tratados com ostectomia da cabeça e colo femorais. Três gatos eram castrados e um inteiro. Todos apresentaram leve claudicação intermitente nos membros pélvicos. O deslocamento da epífise femoral e a reabsorção do colo femoral estavam presentes, a excisão da cabeça e colo femoral foi realizada em todos os casos. O exame histológico mostrou focos de compacteção e fibrose trabecular com deposição de tecido conjuntivo fibroso, permeado por tecidos de granulação, consistentes com o suposto diagnóstico. A função dos membros melhorou em todos os paciente entre dois a quatro semanas pós-operatório. O diagnóstico da displasia fiseal pe desafiador e o tratamento é diferente das fraturas traumáticas agudas. A excisão de cabeça e colo femoral é considerada uma boa alternativa nesses pacientes.

Biomechanical evaluation of a new femoral stem design for total hip replacement in a canine model

ABSTRACT Purpose To evaluate the biomechanical properties of a novel total hip replacement femoral stem. Methods Eight pairs of femurs from dog cadavers were used. The femurs were separated into different groups. A novel femoral stem with a convex proximal portion (Stem B) was biomechanically evaluated and compared to awell-known veterinary collared stem (Stem A). Femoral stems were inserted into the contralateral femurs from the same dog, forming 16 constructs. A flexo-compression load was applied on the axial axis of each sample. Maximum strength, deflection, stiffness, and energy absorption were analysed. Results Group B constructs showed significantly higher values (p ? 0.05) for the variables, except stiffness. The mean maximum strength was 1,347 ± 357 N for Group A and 1,805 ± 123 N for Group B (p ? 0.0069). The mean deflection was5.54 ± 2.63 mm for Group A and 10.03 ± 3.99 mm for Group B (p ? 0.0056). For the energy variable, the force was 6,203 ± 3,488 N/mm for Group A and 12,885 ± 5,056 N/mm for Group B (p ? 0.0054). Stem B had greater maximum strength, deflection, and energy. Conclusions The new stem was effective in neutralizing the impact of axial flexion-compression stresses during biomechanical tests in cadaveric models.

Comparison of intraoperative nociception and postoperative acute pain after traditional or minimally invasive ovariohysterectomy in dogs

Many variations of ovariohysterectomy techniques have been described, including the traditional one and minimally invasive procedures. Non-laparoscopic Snook hook technique is an alternative for performing minimally invasive ovariohysterectomy. Few studies have been carried out in order to assess pain in animals submitted to minimally invasive surgeries, especially involving one of the most performed surgical procedures in veterinary practice. The aim of this study was to evaluate surgical duration, intraoperative nociception and acute postoperative pain after traditional ovariohysterectomy or minimally invasive non-laparoscopic technique in dogs using Snook hook. The hypothesis is that non-laparoscopic minimally invasive ovariohysterectomy would be faster and less painful than the conventional technique. Thirty dogs were divided into Traditional Group (TG = 15) and Minimally Invasive Group (MIG = 15). Heart rate, respiratory rate, systolic blood pressure, body temperature, oxyhemoglobin saturation, end-tidal carbon dioxide concentration (ETCO2) and end-tidal isoflurane concentration were evaluated before the surgery begins (M0), during incision (M1), clamping of the first ovarian pedicle (M2), second ovarian pedicle (M3), uterine cervix (M4), abdominal suture (M5) and at the end of surgery (M6). The modified Glasgow Pain Scale was used for acute postoperative pain assessment and Visual Analogue Scale (VAS) was used to assess the sensitivity of surgical wound. The level of significance established for all statistical analysis was 5%. Statistical differences were not observed between groups considering total surgical time and postoperative acute pain intensity (P > 0.05), in spite of MIG having shorter duration of surgery. There was no statistical difference between groups considering all intraoperative parameters except respiratory rate (TG < MIG; P < 0.05) and ETCO2 (MIG < TG; P < 0.05) at the moment of traction of the first ovarian pedicle (M2). Pain assessment by VAS showed statistical difference 24h after the end of surgery (TG < MIG) (P < 0.05). Both procedures were similar regarding intraoperative nociception and acute postoperative pain. It is possible that the sensation of pain in both procedures was blocked by the effectiveness of analgesics, once they might cause an inhibition of painful behaviors limiting a possible difference in pain identification. Higher respiratory stress observed in MIG at M2 and higher pain score by VAS noted in MIG 24 h after the end of surgery can be justified by greater traction of ovarian pedicle, due to limited surgical access of minimally invasive technique. Minimally invasive ovariohysterectomy non-laparoscopic seems to be potentially faster, probably due to the smaller size of the abdominal incision, which takes less time to be closed. In the present study, both techniques were performed by an experienced surgeon, providing safe procedures, nevertheless it is important to emphasize that iatrogenic injury can be caused by surgeons non-proficient in the Snook hook technique, considering the limited visualization of anatomical abdominal structures. Data obtained indicate that traditional ovariohysterectomy and non-laparoscopic Snook hook technique promote similar intraoperative nociception and acute postoperative pain, however minimally invasive procedure is potentially faster with less surgical trauma.(AU)

Capital femoral physeal dysplasia in cats submited to ostectomy of the femoral head and neck / Displasia femoral capital em felinos submetidos a ostectomia da cabeça e colo femoral

This report described pathological fracture of the femoral head (physeal dysplasia) in four male cats (three mixed breed and one Bengal), with an average age of 16 months, treated by an ostectomy of the femoral head and neck. Three cats were neutered and one entire. All presented with mild intermittent lameness in the pelvic limbs. Displacement of the femoral epiphysis and resorption of the femoral neck were present and excision of the femoral head and remaining neck was performed in all cases. Hstological examination showed mild foci of compaction and trabecular fibrosis with deposition of fibrous connective tissue, permeated by granulation tissues, consistent with the original diagosis. Limb function improved in all patients from 2 to 4 weeks postoperatively. Diagnosis of physeal dysplasia is challenging and treatment is different from acute traumatic fractures. Femoral head and neck excision was considered a good alternative in these patients.(AU)

Este trabalho descreve a fratura patológica da cabeça do femur (displasia fiseal) em quatro machos (três raças mistas e um Bengal), com idade média de 16 meses, que foram tratados com ostectomia da cabeça e colo femorais. Três gatos eram castrados e um inteiro. Todos apresentaram leve claudicação intermitente nos membros pélvicos. O deslocamento da epífise femoral e a reabsorção do colo femoral estavam presentes, a excisão da cabeça e colo femoral foi realizada em todos os casos. O exame histológico mostrou focos de compacteção e fibrose trabecular com deposição de tecido conjuntivo fibroso, permeado por tecidos de granulação, consistentes com o suposto diagnóstico. A função dos membros melhorou em todos os paciente entre dois a quatro semanas pós-operatório. O diagnóstico da displasia fiseal pe desafiador e o tratamento é diferente das fraturas traumáticas agudas. A excisão de cabeça e colo femoral é considerada uma boa alternativa nesses pacientes.(AU)

Percutaneous application of allogeneic adipose-derived mesenchymal stem cell in dogs submitted to minimally invasive plate osteosynthesis of the tibia

Purpose To evaluate clinical outcome following minimally invasive plate osteosynthesis (MIPO) associated with percutaneous transplantation of allogeneic adipose-derived mesenchymal stem cells (AD-MSC) at the tibial fracture site in dogs. Methods Thirty-six dogs presenting with nonarticular complete tibial fracture were included in this study. All fractures were treated by the same MIPO technique. The animals were divided in group 1 (n = 20) received a percutaneous application of 3 × 106 AD-MSC at the fracture site and group 2 (n = 16) did not receive any adjuvant treatment. Postoperative radiographic examinations were made at 15, 30, 60, 90 and 120 days. Results Fifty-eight percent of the patients were classified as skeletally immature. The median weight of the animals was 18.8 kg. The mean radiographic union time differed statistically between the AD-MSC group (28.5 days) and the control group (70.3 days). Sixty percent of dogs in group 1 and 56.25% of the group 2 were considered immature. Conclusions The use of allogeneic AD-MSC cell therapy and MIPO is a safe, viable and effective technique for promoting bone healing in nonarticular tibial fractures in dogs.(AU)