CESAR AUGUSTO MARTINS PEREIRA

(Fonte: Lattes)
Índice h a partir de 2011
8
Lattes
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Ortopediae Traumatologia, Faculdade de Medicina
LIM/41 - Laboratório de Investigação Médica do Sistema Músculoesquelético, Hospital das Clínicas, Faculdade de Medicina

Filtros

Limpar filtros

Configurações

Resultados de Busca

Agora exibindo 1 - 10 de 29
  • article 12 Citação(ões) na Scopus
    Evaluation of the isometry of different points of the patella and femur for medial patellofemoral ligament reconstruction
    (2016) GOBBI, Riccardo Gomes; PEREIRA, Cesar Augusto Martins; SADIGURSKY, David; DEMANGE, Marco Kawamura; TIRICO, Luis Eduardo Passarelli; PECORA, Jose Ricardo; CAMANHO, Gilberto Luis
    Background: The location of patellar and femoral fixation of the graft in medial patellofemoral ligament reconstructions has been widely discussed. This study aimed to assess the distances between different patellar and femoral fixation points to identify the least anisometric pairs of points. Methods: Ten cadaver knees were attached to an apparatus that simulated an active range of motion of 120, with three metallic markers fixed onto the medial side of the patella, and seven markings onto the medial epicondyle. The examined points included the proximal patella pole (1), the patellar center (3), the midpoint between points 1 and 3 (2), a point directly on the epicondyle (6), points 5 mm anterior (5) and posterior (7) to the epicondyle, points 5 mm anterior to point 5 (4) and 5 mm posterior to point 7 (8), and points 5 mm proximal (9) and distal (10) to the epicondyle. The distances between patella and femur points were measured by a photogrammetry system at 15 degrees intervals. Findings: The pair of points that exhibited the lowest average variability in distance, and hence was the most isometric, was the patella center combined with the anterior to the medial femoral epicondyle. The pairs of points that exhibited the highest average variability in distance, and hence were the least isometric, were the ones located distal or posterior to the medial femoral epicondyle, with less influence by the patellar location. Interpretation: Surgeons should avoid positioning the graft distally or posterior to the epicondyle due to the increase in anisometry.
  • article
    Estudo biomecânico do comportamento de diferentes espessuras de capa de cimento ósseo em novo modelo de prótese modular diafisária femoral em cão submetidas a ensaio de torção
    (2013) NINA, Marcos Ishimoto Della; FERRIGNO, Cassio Ricardo Auada; PEREIRA, Cesar Augusto Martins; ALVES, Flavio Rocha; HERNANDEZ, Arnaldo Jose
    Background: The feasibility of modular cemented prosthesis in the femoral diaphysis was demonstrated in dogs, but several authors report loosening of bone-cement-implant interface as a major complication and have yet to reach a consensus on the ideal cement layer thickness for reducing postoperative morbidity. The objective of this study was to evaluate the stabilization of the prosthesis using different thicknesses of cement layer, subjected to torsion forces. Materials, Methods & Results: For this study 48 femurs from 24 dogs weighing over 15 kg were used. The animals used did not have any prior diagnosis of bone or nutritional diseases, which was an exclusion criteria for this study. All biological materials were obtained immediately after death or euthanasia of the animal, and then subjected to conventional storage in a freezer at a temperature of - 24 degrees C. The prosthesis was composed of a cylindrical part with rods for attachment to the intramedullary canal, made of alloy steel 316L. After thawing the femurs and subsequent stabilization at room temperature we performed osteotomies of the femoral diaphysis with an oscillating saw and the installation of the prosthesis. As preparatory measures for prosthesis fixation with cement, the intramedullary canals were cleaned, washed with saline and aspirated. They were separated in four groups, the first group with eight femurs used a cement mantle of 1.0 to 1.5 mm, the second group, with eight femurs, used a cement mantle of 2.0 to 2.5 mm and the third group, with eight femurs, used a cement layer of 3.0 to 3.5 mm. The femurs were submitted to destructive torsion tests using a universal testing machine with a load cell of 981 N (100 kg) and an essay speed of 22 mm / min. They were evaluated due to the values of torsional rigidity and maximum torque shown by the implant, bone and bone cement interface. The fourth group consisted of the remaining intact femurs, they were evaluated using the same torsion test used on the other groups. The results were analyzed using the Statistical Analysis System (SAS, 2001) and the normality of residuals was previously verified by the Shapiro-Wilk test. It was established to conduct the testing using an external rotation protocol in order to standardize, assuming a situation where the dog was in movement during a uniform curvilinear motion, trying to mimic a situation where the rotational forces were acting more significantly on the femur. Discussion: In our study the importance of cleaning up the intramedullary canal for proper bone cement penetration, a good reaming of the intramedullary canal and drying the area before the cement implantation was made clear. Statistical analysis showed that the thicknesses of the cement layer ranging from 1 mm to 2.5 mm, although bringing a gradual increase in maximum torque and torsional rigidity, are not sufficient to be statistically significant and may be considered equal in their biomechanical behavior assessed by this study. A similar result was found when we compared the 2 mm to 3.5 mm layers. The comparison that was statistically significant and can be considered in relation to the different biomechanical behavior of the cement layer was seen between the group I of 1 mm to 1.5 mm, and group III of 3 mm to 3.5 mm. Although some results were not statistically significant we must remember that, in absolute values, the torsional rigidity and maximum torque increased linearly with the increasing of the cement layer. From these results we can infer about the real advantage of using a thicker cement layer over an increment in the diameter of the intramedullary component, giving greater resistance to the prosthesis.
  • article 6 Citação(ões) na Scopus
    Laparoscopic Insertion of Various Shaped Trocars in a Porcine Model
    (2019) MORENO, Danilo Galante; PEREIRA, Cesar Augusto Martins; ANNA, Ricardo Kyoiti Sant; AZEVEDO, Rafael Ulysses de; SAVIO, Luiz Felipe; DUARTE, Ricardo Jordao; SROUGI, Miguel; PASSEROTTI, Carlo Camargo
    Background and Objective: The number of laparoscopic procedures increases annually with an estimated 3% of complications, one third of them linked to Verres' needle or trocar insertion. The safety and efficacy of ports insertion during laparoscopic surgery may be related the technique but also to trocar design. This study aims to compare physical parameters of abdominal wall penetration for 5 different trocars. Methods: Eleven pigs were studied. Five different commercially available trocars were randomically inserted at the midline. Real-time video recording of the insertions was achieved to measure the excursion of the abdominal wall and the time and distance the cutting surface of the bladed trocars was exposed inside the abdominal cavity. An especially designed hand sensor was developed and placed between the trocar and the hand of the surgeon to record force required for abdominal wall perforation. Results: Greater deformations and forces occurred in non-bladed as compared to bladed trocars, and in conical trocars as compared to pyramidal pointed ones, except for peritoneum perforation. Greater distance and time of blade exposure occurred in pyramidal laminae as compared to conical. Conclusion: The bladed trocars have lower forces and deformations in their introduction, and should be those that cause less injury and are more suitable for first entry. Conical and pyramidal trocars with the same blade size showed similar force, deformation, time, and distance of exposed blade.
  • article 2 Citação(ões) na Scopus
    Biomechanical evaluation of two extracapsular techniques for cranial cruciate ligament reconstruction in cadaver dogs
    (2016) ODA, Sam Goldy Shoyama; SOUZA, Alexandre Navarro Alves; PEREIRA, Cesar Augusto Martins; ESCOBAR, Andres Sebastian Aristizabal; TARTARUNAS, Angelica Cecilia; MATERA, Julia Maria
    Cranial cruciate ligament rupture (CCLR) is one of the most important orthopedic conditions in dogs, leading to joint instability, pain, osteoarthritis and eventually to meniscal injuries. Several surgical techniques have been described to reestablish joint stability following CCLR, including extracapsular procedures. This study compared the biomechanical effects of two extracapsular stabilization techniques (lateral fabello-tibial suture - LFTS, and modified retinacular imbrication technique - MRIT) using nylon leader line following experimental CCLR in cadaver dogs. Twenty canine cadaveric stifles were used. Joint stiffness, cranial and caudal tibial displacement were evaluated in 4 different experimental scenarios: intact stifle, stifle with CCLR, CCLR treated with lateral fabello-tibial suture (LFTS), and CCLR treated with modified retinacular imbrication technique (MRIT). Results: Mean cranial tibial displacement increased progressively from intact to MRIT, LFTS and CCRL stifles. MRIT resulted in less caudal drawer motion than LFTS. Joint stiffness did not differ significantly between LFTS and MRIT treated stifles. Conclusion: LFTS and MRIT increase joint stability but MRIT is more effective; however none of the techniques studied was able to restore original intact stifle stiffness. Clinical implications of the results presented remain to be determined but kinetic gait analysis studies are warranted to determine whether this biomechanical advantage translates into improved hind limb function in dogs.
  • article 41 Citação(ões) na Scopus
    Biomechanical study of strength and stiffness of the knee anterolateral ligament
    (2016) HELITO, Camilo Partezani; BONADIO, Marcelo Batista; ROZAS, Joao Stefan; WEY, Joao Marcelo Pedroso; PEREIRA, Cesar Augusto Martins; CARDOSO, Tulio Pereira; PECORA, Jose Ricardo; CAMANHO, Gilberto Luis; DEMANGE, Marco Kawamura
    Background: Recent studies clearly characterize the anatomical parameters of the knee anterolateral ligament (ALL). The potential clinical importance of this ligament is exemplified by some patients with possible combined Anterior Cruciate Ligament (ACL) and ALL rupture who do not progress satisfactorily following isolated ACL reconstruction. Previous biomechanical studies have assessed the resistance parameters of the ALL in order to address potential reconstruction strategies; however, these have reported conflicting results. Thus, this study aimed to evaluate the linear resistance of the ALL by means of a biomechanical study in cadaveric knees. Methods: Fourteen cadaveric knees were used. The ALL was dissected, and all structures that connect the femur and the tibia, except for the ALL, were sectioned. The ALL was subjected to a tensile test with the knee around 30 to 40 degrees, in a way that the ALL was aligned with the machine. The strength at the maximum resistance limit, deformation and stiffness of the ALL were evaluated. Results: The mean maximum strength of the ALL was 204.8 +/- 114.9 N. The stiffness was 41.9 +/- 25.7 N/mm and the deformation 10.3 + /- 3.5 mm. Conclusion: The ALL has a mean ultimate tensile strength of 204.8 N. This suggests that simple bands of all autologous or homologous grafts commonly used in clinical practice for ligament reconstruction around the knee possess the required biomechanical resistance characteristics for ALL reconstruction.
  • article 1 Citação(ões) na Scopus
    Comparison of Cervical Stabilization with Transpedicular Pins and Polymethylmethacrylate versus Transvertebral Body Polyaxial Screws with or without an Interbody Distractor in Dogs
    (2022) MARINHO, Paulo V. T.; FERRIGNO, Cassio R. A.; COSTA, Ronaldo C. da; PEREIRA, Cesar A. M.; REGO, Mario A. F.; BREGADIOLI, Thales; PAES, Fernanda
    Objective The main aim of this study was to compare the biomechanical properties of caudal cervical vertebral stabilization using bicortical transpedicular pins with polymethylmethacrylate (PMMA) versus transvertebral body polyaxial screws and connecting rods with or without an interbody distractor. Study Design Ten canine cervical vertebral columns (C2-T3) were used. Four models (intact, transvertebral body polyaxial screw with interbody distractor [polyaxialthorn distractor], transvertebral body polyaxial screw without interbody distractor [ polyaxial - distractor] and bicortical transpedicular pins/polymethylmethacrylate [pin-PMMA]) were applied to C6-7 sequentially on the same specimens. Angular range of motion (AROM) in the form of flexion and extension was measured at C4-5, C5-6 and C6-7 in all groups. Results Treated vertebral specimens had significantly less AROM than unaltered specimens. There was no significant difference in AROM between the experimental groups at C6 and C7. Angular range of motion ratio in flexion-extension was 80.8, 72.7 and 78.3% for polyaxial + distractor, polyaxial - distractor and pin-PMMA groups, respectively, which were less than the intact group. There was no significant increase in the range of motion of the adjacent vertebrae after stabilization. Conclusion Stabilization obtained with transvertebral body polyaxial screws was comparable to that from the well-established bicortical pins/PMMA construct. Association of an intervertebral distractor did not change AROM of the polyaxial screw constructs.
  • article 0 Citação(ões) na Scopus
    Avaliação mecânica e de composição de liga metálica de dois tamanhos de anéis para fixador externo circular de três diferentes fabricantes para cães
    (2014) SANTOS, Jaqueline Franca dos; FERRIGNO, Cassio Ricardo Auada; PEREIRA, Cesar Augusto Martins; ABURAYA, Jim Heiji; DRIGO, Evandro; SOUZA, Alexandre Navarro Alves de; CAQUIAS, Daniela Fabiana Izquierdo
    Background: Circular external skeletal fixator Ilizarov is a fixation method widely used to stabilize fractures. The method is performed using several components but the ring stands out as the fundamental component of this device, and compression loads in the same plane of the ring are mainly due to the wires connected from one side to another of the implant. The axial load is reached on the rings with a proper tension distractor device connected to the wires and fixed with bolts, washers and nuts during surgical procedure. Additional loads to axial tension are employed during patient's physical activities after surgery. The study aimed to compare the resistance to axial compression load and analyze the alloy composition of the Ilizarov rings with different diameter sizes and alloys. Materials, Methods & Results: We tested two diameters of rings acquired from three manufacturers for mechanical axial compression. Manufacture sample (N = 30 rings of each trademark) was divided into two groups (60 and 80 diameter mm). The tests to evaluate strength and deformation parameters were performed in a universal testing machine Kratos (R) 3.000 MP KE model, equipped with a load cell of 3000 N with test speed of 10 mm per minute. We also evaluated the elemental alloy composition by the method of the TTPIXE (Thick Target Proton Induced X-Ray Emission) in external PIXE. The Kolmogorov-Smirnov test was used to confirm normal distribution of the data. The comparison between results from manufacturers A, B and C for the two diameters was performed with one-way ANOVA with a post hoc Tukey's test for normal distribution and Kruskal-Wallis with a post hoc Dunn's test was used for means comparison without Gaussian distribution. The level of significance was set at 5 % (P < 0.05). The results presented that metal alloy of circular external skeletal fixator rings are mainly composed of aluminum and there are differences in aluminum percentage of alloy composition between different trademarks. Differences between tree manufactures were also founded in the resistance to axial mechanical compression tests. The rings of both diameters (60 and 80 mm) provided from manufacturer A were more rigid than other trademarks. A greater resilience was also founded in the 80 mm ring of trademark A than B and C. Discussion: Several trademarks of veterinary orthopedic implants are available but the mechanical properties of these implants are unknown. The selection of material for the implant should starts with the identification of the properties required for the application in question and thus meets the expected behavior. Due to the features displayed for each element and examining the alloy components manufacturer for the two diameters tested, it was found that it was an alloy with a lower concentration of aluminum with the addition of copper or copper and zinc, which increases the strength and stiffness of the material. Despite trademarks differences in axial resistance and alloy composition, we believe that the rings provided from all three manufacturers have a good quality based in the minimum values which demonstrated higher resistance to axial loads. Apparently, the mechanical properties of these rings suggest that other factors could be responsible for implant failure. Future studies are encouraged to detect if the other circular external skeletal fixator Ilizarov components could be responsible for implant loss.
  • article 0 Citação(ões) na Scopus
    Tenorrhaphy in horses: comparison of the mechanical properties of two different suture patterns and suture materials
    (2017) CORREA, R. R.; PEREIRA, C. A. M.; FRIAS, N. C.; BACCARELLI, D. C.; ZOPPA, A. L. V.
    Traumatic distal limb injuries resulting in tendon rupture are common in equine practice. Several complications have been associated with tendon repair in horses. The aim of this study was to compare the biomechanical properties of two tenorrhaphy techniques using two different suture materials. Twenty-four equine deep digital flexor tendon specimens were transected and sutured with the double locking loop pattern (polypropylene, group 1; polyglactin, group 2) or the single locking loop pattern with peripheral epitendon suture (polypropylene, group 3; polyglactin, group 4). Specimens were submitted to mechanical strain testing. Maximum, minimum and peak strain, and maximum, minimum and peak gap formation were evaluated. ANOVA and the non-parametric Kruskal-Wallis and Mann-Whitney tests were used (P<0.05). Higher maximum strength values were documented in group 3. Minimum strength values were higher in groups 3 and 4 than 1 and 2, but did not differ significantly between groups 3 and 4. Peak strength values were higher in groups 1 and 2 than 4, but did not differ significantly from group 3. Gap formation was greater in groups 1 and 2 than 3 and 4. The single locking loop pattern with epitendon suture performed with polypropylene had greater resilience, yielded lesser gap formation (3 mm) and is the pattern of choice for clinical application based on the results of this study.
  • article 1 Citação(ões) na Scopus
    Description of an evaluation system for knee kinematics in ligament lesions, by means of optical tracking and 3D tomography,
    (2014) FERNANDES, Tiago Lazzaretti; RIBEIRO, Douglas Badillo; ROCHA, Diogo Cristo da; ALBUQUERQUE, Cyro; MARTINS PEREIRA, César Augusto; PEDRINELLI, André; HERNANDEZ, Arnaldo José
    Objective: To describe and demonstrate the viability of a method for evaluating knee kine matics, by means of a continuous passive motion (CPM) machine, before and after anterio cruciate ligament (ACL) injury. Methods: This study was conducted on a knee from a cadaver, in a mechanical pivot-shif simulator, with evaluations using optical tracking, and also using computed tomography. Results: This study demonstrated the viability of a protocol for measuring the rotation an translation of the knee, using reproducible and objective tools (error<0.2mm). The mech anized provocation system of the pivot-shift test was independent of the examiner an always allowed the same angular velocity and traction of 20 N throughout the movement. Conclusion: The clinical relevance of this method lies in making inferences about the in viv behavior of a knee with an ACL injury and providing greater methodological quality in futur studies for measuring surgical techniques with grafts in relatively close positions.
  • article 4 Citação(ões) na Scopus
    Thick Graft Versus Double-Bundle Technique on Posterior Cruciate Ligament Reconstruction: Experimental Biomechanical Study with Cadavers
    (2019) MARADEI-PEREIRA, João Alberto Ramos; KOKRON, Alexandre Estevão Vamos; PEREIRA, César Augusto Martins; AMATUZZI, Marco Martins
    Abstract Objective To evaluate the biomechanical effect of graft thickness compared with the double-bundle technique on posterior cruciate ligament (PCL) reconstruction in human cadaveric knees. Methods A total of 9 human cadaveric knees were tested in 5 conditions: intact knee (INT); single-bundle reconstruction with a 10-mm quadriceps tendon (SB); double-bundle reconstruction with a 10 mm-quadriceps tendon for the anterolateral bundle and a 7-mm doubled semitendinosus tendon for the posteromedial bundle (DB); single-bundle reconstruction with a 10-mm quadriceps tendon plus a 7-mm doubled semitendinosus tendon (SBT); and PCL-deficient (NoPCL). The posterior tibial translation (PTT) was measured in response to a 134-N posterior tibial load at 0º, 30º, 60º e 90º of knee flexion. Results The PTT values of the DB and SBT techniques were always significantly lower (better stability) than those of the SB technique. The PTT values of the SBT technique were significantly lower than those of the DB technique at 60º (p = 0.005) and 90º (p = 0.001). Conclusions Graft enlargement improves knee stability in isolated PCL reconstructions, whereas the graft division in the two-bundle technique worsens this stability at 60º and 90º of knee flexion. The findings of the present study suggest that knee stability in PCL reconstructions may be improved with the use of thicker grafts in the SB technique rather than performing the DB technique.