Publications by authors named "Charles Leonardo Israel"

4 Publications

  • Page 1 of 1

Biomechanical Study of Different Femoral Fixation Devices in the Reconstruction of the Medial Patellofemoral Ligament in Porcine Knees.

Rev Bras Ortop (Sao Paulo) 2020 Dec 22;55(6):771-777. Epub 2020 Jul 22.

Serviço de Ortopedia e Traumatologia, Santa Casa de Misericórdia de Porto Alegre, RS, Brasil.

 To evaluate different femoral fixation devices for medial patellofemoral ligament reconstruction and compare their effectiveness regarding fixation strength up to failure in porcine knees.  Thirty porcine knees were used, divided into three groups of 10 knees. The removed grafts were dissected from the extensor tendons of porcine feet. In each group, the graft was fixed to the femur with an interference screw, an anchor, or adductor tenodesis. The three methods were subjected to biomechanical tests using a universal Tensile testing machine at a speed of 20 mm/minute.  The highest average linear resistance under lateral traction occurred in group 1, "screw fixation" (185.45 ± 41.22 N), followed by group 2, "anchor fixation" (152.97 ± 49, 43 N); the lower average was observed in group 3, "tenodesis fixation" (76.69 ± 18.90 N). According to the fixed error margin (5%), there was a significant difference between groups (  < 0.001); in addition, multiple comparison tests (between group pairs) also showed significant differences. Variability was small, since the variance coefficient was lower than 33.3%.  Interference screws in bone tunnels and mountable anchors fixation with high resistance wire are strong enough for femoral fixation in porcine medial patellofemoral ligament reconstruction. Adductor tenodesis, however, was deemed fragile for such purpose.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-0040-1708520DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7748938PMC
December 2020

Biomechanical Analysis of Two Types of Humerus Supracondylar Fracture Fixation in Anatomical Model.

Rev Bras Ortop (Sao Paulo) 2019 May 27;54(3):261-267. Epub 2019 Jun 27.

Serviço de Ortopedia Pediátrica, Hospital São Vicente de Paulo, Passo Fundo, RS, Brasil.

 To analyze the stability of humerus supracondylar fracture fixation with Kirschner wires comparing intramedullary and lateral (Fi), and two parallel lateral wires (FL) fixation in experimental models, to define which configuration presents greater stability.  A total of 72 synthetic humeri were cross-sectioned to simulate the fracture. These bones were divided into two equal groups and the fractures were fixed with parallel Kirschner wires (FL) and with a lateral and intramedullary (Fi) wire. Then, the test specimens were subjected to stress load tests on a universal test machine, measured in Newtons (N). Each group was subdivided into varus load, valgus, extension, flexion, external rotation and internal rotation. An analysis of the data was performed comparing the subgroups of the FL group with their respective subgroups of the Fi group through the two-tailed t test.  The two-tailed t test showed that in 4 of the 6 evaluated conditions there was no significant statistical difference between the groups (  > 0.05). We have found a significant difference between the group with extension load with a mean of 19 N (FL group) and of 28.7 N (Fi group) (  = 0.004), and also between the groups with flexural load with the mean of the forces recorded in the FL group of 17.1 N and of 22.9 N in the Fi group (  = 0.01).  Fixation with one intramedullary wire and one lateral wire, considering loads in extension and flexion, presents greater stability when compared to a fixation with two lateral wires, suggesting similar clinical results.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-0039-1688756DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6597430PMC
May 2019

Biomechanical Evaluation of Different Tibial Fixation Methods in the Reconstruction of the Anterolateral Ligament in Swine Bones.

Rev Bras Ortop (Sao Paulo) 2019 Apr 10;54(2):183-189. Epub 2019 May 10.

Laboratório de Bioengenharia, Biomecânica e Biomateriais, Universidade de Passo Fundo, Passo Fundo, RS, Brasil.

 The present study aims to evaluate different methods of tibial fixation in the reconstruction of the anterolateral ligament (ALL). In addition, the present paper aims to compare the effectiveness of these methods and their mechanisms of failure in swine knees.  A total of 40 freshly frozen swine limbs were divided into 4 groups of 10 specimens, according to the tibial fixation technique used. In group A, the tibial fixation of the tendon graft was made through an anchor passing the graft. In group B, the tibial fixation was performed through a metal interference screw in a single bone tunnel. In group C, the tibial fixation included an anchor associated with a tendinous suture (but not with a wire crossing the tendon). In group D, two confluent bony tunnels were drilled and combined with an interference screw in one of them.  The lowest mean force (70.56 N) was observed in group A, and the highest mean force (244.85 N) was observed in group B; the mean values in the other 2 groups ranged from 171.68 N (group C) to 149.43 N (group D). Considering the margin of error (5%), there was a significant difference between the groups (  < 0.001).  Fixation with an interference screw in a single tunnel bone showed the highest tensile strength among the evaluated techniques.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rbo.2017.09.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6529319PMC
April 2019

Numerical analysis of multi-level versus short instrumentation for the treatment of thoracolumbar fractures.

Eur J Orthop Surg Traumatol 2015 Jul 3;25 Suppl 1:S213-7. Epub 2015 Mar 3.

Orthopedics and Traumatology Institute, Passo Fundo, Rio Grande do Sul, Brazil.

Purpose: The research analyses the strength of metallic implants in posterior spinal instrumentation for the treatment of thoracolumbar fractures, considering extended and short fixation techniques on the immediate post-surgical load. Considering that short fixation may bring the advantage of a less invasive surgical procedure to the patient and may also result in lower costs, this evaluation becomes necessary.

Methods: Three-dimensional modelling of the thoracolumbar spine was initially performed. CT images were captured and converted for analysis with the ANSYS program. Both treatment techniques were analysed for stresses, and strains generated in the immediate postoperative period, when the fracture is still not healed.

Results: The maximum stress obtained for long fixation by the theory of Von Mises was 230 MPa, and it was located in the rod area next to the L2 vertebra. The maximum stress obtained for short fixation was 274.24 MPa, and it was located in the pedicle screw on the T12 vertebra.

Conclusions: There were no significant differences between the two techniques, since the observed stresses are well below the flow stress of the material, ensuring good safety factor (ranging from 3.5 to 4.1).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00590-015-1612-7DOI Listing
July 2015
-->