ANDRE PEDRINELLI
Projetos de Pesquisa
Unidades Organizacionais
Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina
LIM/41 - Laboratório de Investigação Médica do Sistema Músculoesquelético, Hospital das Clínicas, Faculdade de Medicina
LIM/41 - Laboratório de Investigação Médica do Sistema Músculoesquelético, Hospital das Clínicas, Faculdade de Medicina
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- 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 JoséObjective: 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.
- A BIOMECHANICAL COMPARISON OF MATCHED FOUR-STRAND AND FIVE-STRAND SEMITENDINOSUS-GRACILIS GRAFTS(2021) BARROS, Marcos Amstalden; COSTA, Sandokan Cavalcante; JARAMILLO, Diego Eduardo Rubio; ALMEIDA, Adriano Marques de; PEREIRA, Cesar Augusto Martins; FERNANDES, Tiago Lazzaretti; NARDELLI, Julio Cesar Carvalho; ANNICHINO, Marcel Fruschein; PEDRINELLI, Andre; HERNANDEZ, Arnaldo JoseIntroduction: Recent studies have shown that the likelihood of semitendinosus-gracilis graft rupture is inversely correlated to its diameter. A graft can be prepared in a five-strand or four-strand fashion to increase its diameter. However, the biomechanical superiority of five-strand semitendinosus-gracilis grafts is still under debate. Objective: This study aimed to evaluate the biomechanical characteristics of matched four-strand and five-strand human semitendinosus-gracilis grafts. Methods: We evaluated semitendinosus-gracilis tendons harvested from ten fresh human male and female cadavers, aged 18-60 years. Four-strand or five-strand grafts were prepared with the tendons and fixed to wooden tunnels with interference screws. Each graft was submitted to axial traction at 20 mm/min until rupture; the tests were donor matched. Data were recorded in real time and included the analysis of the area, diameter, force, maximum deformation and stiffness of the grafts. Results: The diameter, area and tunnel size were significantly greater in the five-strand grafts than in the four-strand grafts. There were no significant differences in biomechanical properties. The area and diameter of the graft were positively correlated to stiffness, and inversely correlated to elasticity. There was no significant correlation between graft size and maximum force at failure, maximum deformation or maximum tension. Conclusion: Five-strand hamstring grafts have greater area, diameter and tunnel size than fourstrand grafts. There were no significant differences in biomechanical properties. In this model using interference screw fixation, the increases in area and diameter were correlated with an increase in stiffness and a decrease in elasticity.
- The biomechanical effects of graft rotation on ACL reconstruction tunnel mismatch(2017) OLIVEIRA, Danilo Ricardo Okiishi de; GARCIA, Eduardo Takahashi; FUSO, Fernando Augusto Freitas; PEREIRA, Cesar Augusto Martins; LAGES, Marco Martins; ALMEIDA, Adriano Marques de; FERNANDES, Tiago Lazzaretti; PEDRINELLI, Andre; HERNANDEZ, Arnaldo JoseBone block protrusion out of the tibial tunnel due to a relatively long graft is a common complication in anterior cruciate ligament surgical reconstruction with a patellar tendon. One possible solution is to shorten the patellar tendon graft already fixed in the femur by applying external rotation. This study aimed to evaluate the degree of shortening and biomechanical changes in porcine patellar grafts subjected to relatively higher degrees of rotation. Data obtained with rotations of 0A degrees, 540A degrees, 720A degrees, and 900A degrees were compared. Forty patellar porcine ligaments were subjected to biomechanical tests of degree of shortening, modulus of elasticity and maximum tension in the tendon before rupture. Tests were conducted using a universal mechanical testing machine and a computerized system for acquiring strength and deformation data. Progressive shortening of the patellar ligament occurred with rotations of 0A degrees, 540A degrees and 720A degrees. However, the degree of shortening showed no statistically significant difference as rotation increased from 720A degrees to 900A degrees. Decreased modulus of elasticity was observed compared with the graft rotation at 0A degrees in all groups tested, but no statistically significant differences were observed among 540A degrees, 720A degrees and 900A degrees. The maximum tension of the patellar tendon showed no change before rupture, regardless of the degree of rotation. Rotating the patellar tendon is an efficient method for shortening a relatively long graft; however, more biomechanical studies are necessary to recommend this technique in clinical practice owing to the resulting decrease in graft stiffness that could compromise knee stability.