CESAR AUGUSTO MARTINS PEREIRA
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
LIM/41 - Laboratório de Investigação Médica do Sistema Músculoesquelético, Hospital das Clínicas, Faculdade de Medicina
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- 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 CamargoBackground 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.
- Early versus late repair of rotator cuff tears in rats(2018) CAVINATTO, Leonardo; MALAVOLTA, Eduardo Angeli; PEREIRA, Cesar Augusto Martins; MIRANDA-RODRIGUES, Manuela; SILVA, Luiza Campos Moreira; GOUVEIA, Cecilia Helena; NETTO, Cesar de Cesar; MATTAR, Rames Junior; FEREIRA NETO, Arnaldo AmadoBackground: In the event of a traumatic rotator cuff tear, patients are routinely advised that early surgical intervention produces an optimal repair, despite a lack of direct evidence to support this recommendation. To address this knowledge gap, massive rotator cuff tears in rats were assessed by biomechanical and bone morphometric analyses after early or late repair. Methods: Combined supraspinatus and infraspinatus tendon tears of the left shoulder were created in 21 adult Wistar rats, which were divided into 2 groups. The tendons of the injured shoulder in the animals in group I were surgically repaired 8 weeks after the injury. Under the same anesthesia, the same injury was created on the right shoulder, which was immediately repaired. The rats from group I were euthanized 8 weeks after the repairs. No repair was performed in the rats from group II, which were euthanized 8 weeks after the injury. Tissues from both groups were harvested and biomechanically tested for supraspinatus tendon and bone morphometry analysis of the humeral head. Results: All biomechanical properties were significantly increased in the early repair group compared with the late repair group. No significant differences were observed in bone morphometry of the humeral head when early and late repair groups were compared. Conclusion: Early surgical repair of a massive rotator cuff tear leads to improved biomechanical properties of the tissue after healing. Proximal humerus bone morphometry was unaffected by surgical repair timing.
- Assessment of the function and resistance of sternoclavicular ligaments: A biomechanical study in cadavers(2014) NEGRI, J. H.; MALAVOLTA, E. A.; ASSUNCAO, J. H.; GRACITELLI, M. E. C.; PEREIRA, C. A. M.; BOLLIGER NETO, R.; CROCI, A. T.; FERREIRA NETO, A. A.Background: Few biomechanical studies have assessed the resistance of the ligamentous structures of the sternoclavicular joint, and none have reproduced the physiological movements of the joint. Determiningthe structures that are injured in sternoclavicular dislocations is important for the surgical planning of acute or chronic ligament reconstruction. Methods: Forty-eight joints from 24 human cadavers were studied, and they were divided into 4 groups of 12 joints each (retraction, protraction, depression and elevation). Biomechanical testing assessed primary and secondary failures. The mechanical resistance parameters between movements that occurred on the same plane (depression versus elevation, protraction versus retraction) were compared. Results: The posterior sternoclavicular ligament was the most injured structure during the protraction test, but it was not injured during retraction. The anterior sternoclavicular ligament was the most affected structure during retraction and depression. The costoclavicular ligament was the most affected structure during elevation. Joint resistance was significantly greater during protraction movements when compared to retraction (P < 0.05). Conclusion: The anterior sternoclavicular ligament was the most affected structure during retraction and depression movements. During protraction, lesions of the posterior sternoclavicular ligament were most frequent during elevation, and the costoclavicular ligament was the most frequently injured ligament. The resistance of the sternoclavicular joint was significantly greater during protraction movement when compared to retraction.
- Medial Patellofemoral Ligament, Medial Patellotibial Ligament, and Medial Patellomeniscal Ligament: Anatomic, Histologic, Radiographic, and Biomechanical Study(2017) HINCKEL, Betina B.; GOBBI, Riccardo G.; DEMANGE, Marco K.; PEREIRA, Cesar Augusto M.; PECORA, Jose Ricardo; NATALINO, Renato Jose M.; MIYAHIRA, Luciana; KUBOTA, Bruno S.; CAMANHO, Gilberto LuisPurpose: To describe the anatomy (quantitative macroscopic and histologic), radiographic parameters of the insertions, and biomechanical characteristics of the medial ligamentous restrictors of the patella (medial patellofemoral ligament [MPFL], medial patellotibial ligament [MPTL], and medial patellomeniscal ligament [MPML]) in cadaveric knees. Because the MPTL and the MPML are not as well known as the MPFL, they were the focus of this study. Methods: MPFLs, MPTLs, and MPMLs from 9 knees were dissected. Histologic evaluations were conducted. Length, width, and insertion relations with anatomic references were determined. Metallic spheres were introduced into the insertion points of each ligament, and anteroposterior and lateral radiographs were taken. The distances of the insertions from the baselines were measured on radiographs. Tensile tests of the ligaments were performed. Results: All the samples showed dense connective tissue characteristic of ligaments. The MPTL was inserted into the proximal tibia (13.7 mm distal to the joint line) and in the distal end of the patella (3.6 mm proximal to the distal border). The MPTL had a length of 36.4 mm and a width of 7.1 mm. The MPML was inserted into the medial meniscus and distally in the patella (5.7 mm proximal to the distal border). Per radiography, on the anteroposterior view, the tibial insertion of the MPTL was 9.4 mm distal to the joint line and in line with the medial border of the medial spine. On the lateral view, the patellar insertions of the MPTL and MPML were 4.8 and 6.6 mm proximal to its distal border, respectively. The MPTL was stiffer than the MPFL (17.0 N/mm vs 8.0 N/mm, P =.024) and showed less deformation in the maximum tensile strength (8.6 mm vs 19.3 mm, P =.005). Conclusions: The MPTL inserts into the proximal tibia and into the distal pole of the patella. The MPML inserts into the medial meniscus and into the distal pole of the patella. They present with identifiable anatomic and radiographic parameters. Grafts commonly used for ligament reconstructions should be adequate for reconstruction of the MPTL. Clinical Relevance: The study contributes to the anatomic, radiographic, and biomechanical knowledge of the MPTL to improve the outcomes of its reconstruction.
- The rotation of the humeral head does not alter radiographic evaluation of the head-shaft angle(2016) MALAVOLTA, Eduardo A.; ASSUNCAO, Jorge H.; PAGOTTO, Raphaella A.; AVELINO, Rafael L.; GRACITELLI, Mauro E. C.; PEREIRA, Cesar A. M.; JACOMO, Alfredo L.; FERREIRA NETO, Arnaldo A.Background: The head-shaft angle is used to plan osteotomies and arthroplasties and to assess the radiographic outcomes of surgical treatment for proximal humerus fractures. There are no published data showing whether different degrees of arm rotation interfere with the evaluation of this angle. Methods: Eighteen humeri from adult cadavers were used. Radiographs were taken with the specimens initially placed in a true anteroposterior position and then subsequently positioned with internal and external rotations of 10 degrees, 20 degrees, and 30 degrees. All radiographs were evaluated by 3 shoulder and elbow surgeons at 2 different times 3 months apart. The head-shaft angle was measured using a picture archiving and communication system. Results: For the humerus in the neutral position, the head-shaft angle was 137 degrees +/- 4 degrees. With the anatomic specimen positioned with increasing external and internal rotations, there was a maximum difference of 2 degrees compared with the value observed in the neutral position, which was not a significant difference (P = .911). Measurements of the head-shaft angle showed a good interobserver correlation coefficient, with a value of 0.788 (0.728-0.839) for all measurements. The intraobserver correlation coefficient ranged from moderate to excellent (0.536-0.938). Conclusion: The head-shaft angle did not change significantly with varying degrees of humeral rotation. The interobserver correlation coefficient showed good reliability, and the intraobserver correlation was moderate to excellent. (C) 2016 Journal of Shoulder and Elbow Surgery Board of Trustees.
- 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.
- Posterolateral anatomical reconstruction restored varus but not rotational stability: A biomechanical study with cadavers(2015) SERBINO JUNIOR, Jose Wilson; ALBUQUERQUE, Roberto Freire da Mota; PEREIRA, Cesar Augusto M.; REZENDE, Marcia Uchoa de; LASMAR, Rodrigo Campos Pace; HERNANDEZ, Arnaldo JoseBackground and aim: Lesions to the posterolateral corner (PLC) of the knee are rarely isolated injuries, and they are potentially devastating, leading to progressive chondral injury, with important functional impairment The objectives of this biomechanical study were to evaluate angular deformation with two loads and considering four flexion angles of the knee, varus and external rotation and in three situations of integrity, reconstruction and injury of posterolateral knee structures. Methods: The posterolateral structures of 10 cadaveric knees were submitted to three biomechanical assays: in the ""intact condition"", ""injured"", and ""reconstructed"". The technique used for the reconstruction was the one proposed by LaPrade et al., but with autografts of hamstring tendons instead. A device was designed to apply loads of 2 and 5 N m, with zero, 30 degrees, 60 degrees and 90 degrees of knee flexion, in varus or in external rotation, measuring angular deformation with photogoniometry. Results: The anatomical reconstruction of the PLC proposed here did restore varus stability in all flexion angles (p < 0.005), but not rotational stability. External rotation deformation at 90 degrees was similar in all test conditions. In knee extension, external rotation was stabilized only at 2 Nm. At 60 degrees, external rotation was partially stabilized (p < 0.05). Conclusions: The anatomical PLC reconstruction using hamstring tendons restored varus but not external rotational stability. Clinical Relevance: The reconstruction of posterolateral corner injuries with autologous allografts is very important for regions were tissue banks are not available. This technique may be a first step to achieve this goal.