Finite element analysis of Bi-condylar Tibial Plateau fractures to assess the effect of coronal splits

Computational analysis of the biomechanical stability of internal fixation of the lateral tibial plateau fracture: A mechanical stability study

The selection of internal fixation as the primary fixation modality for the patient is one of the challenges for the surgeon treating the patient in question. A model of the lateral tibial plateau fracture was established. Three different configurations of internal fixators namely L bone plate, T bone plate, and screw-washer were analyzed. Three stages after surgery were simulated to assess the displacement of bone plates, screws, washers, and the stress shielding ratio in the fracture area.At three stages after surgery, the T bone plate showed better stability for patients during rehabilitation compared with the remaining two schemes, and the screw-washer scheme was the least stable due to the larger internal fixation displacement and stress shielding ratio in the fracture area. In contrast, the L bone plate scheme showed better stability in the early stages after surgery but was second only to the screw-washer scheme in the middle and late stages after surgery. The T bone plate showed better stability and became a new selection for surgeons to treat related patients. At three stages after surgery, the T bone plate has better biomechanical stability compared to the L bone plate and screw-washer schemes.

Newly designed plate for the treatment of posterolateral tibial plateau fractures: a finite element analysis

BACKGROUND

This study investigated the biomechanical properties of a new plate used for the treatment of posterolateral tibial plateau fractures using finite element analysis.

METHODS

The study groups were as follows: group PM, model of the new plate with posteromedial tibial plateau fracture; group PL, model of the new plate with posterolateral tibial plateau fracture; and group PC, model of the new plate with posterior tibial plateau fracture. We used two loading modes: uniform loading on the entire plateau, and loading on the posterior plateau. Data such as the displacement of the fracture and distribution of stress on the new plate and screws were recorded and analyzed.

RESULTS

When the whole plateau was loaded, the displacement of fractures in groups PM, PL, and PC were 0.273, 0.114, and 0.265 mm, respectively. The maximum stresses on the plates in groups PM, PL, and PC were 118.131 MPa, 44.191 MPa, and 115.433 MPa. The maximum stresses on the screws in Groups PM, PL, and PC were 166.731, 80.330, and 164.439 MPa, respectively. When the posterior tibial plateau was loaded, the displacement of the fractures in groups PM, PL, and PC was 0.410, 0.213, and 0.390 mm, respectively. The maximum stresses on the plates in groups PM, PL, and PC were 194.012 MPa, 72.806 MPa, and 185.535 MPa. The maximum stresses on the screws in Groups PM, PL, and PC were 278.265, 114.839, and 266.396 MPa, respectively.

CONCLUSION

The results of this study revealed that titanium plates have good fixation effects in all groups; therefore, the use of the new plate for posterolateral tibial plateau fractures appears to be safe and valid.

Biomechanical analysis of internal fixation system stability for tibial plateau fractures

Background: Complex bone plateau fractures have been treated with bilateral plate fixation, but previous research has overemphasized evaluating the effects of internal fixation design, plate position, and screw orientation on fracture fixation stability, neglecting the internal fixation system's biomechanical properties in postoperative rehabilitation exercises. This study aimed to investigate the mechanical properties of tibial plateau fractures after internal fixation, explore the biomechanical mechanism of the interaction between internal fixation and bone, and make suggestions for early postoperative rehabilitation and postoperative weight-bearing rehabilitation. Methods: By establishing the postoperative tibia model, the standing, walking and running conditions were simulated under three axial loads of 500 N, 1000 N, and 1500 N. Accordingly, finite element analysis (FEA) was performed to analyze the model stiffness, displacement of fractured bone fragments, titanium alloy plate, screw stress distribution, and fatigue properties of the tibia and the internal fixation system under various conditions. Results: The stiffness of the model increased significantly after internal fixation. The anteromedial plate was the most stressed, followed by the posteromedial plate. The screws at the distal end of the lateral plate, the screws at the anteromedial plate platform and the screws at the distal end of the posteromedial plate are under greater stress, but at a safe stress level. The relative displacement of the two medial condylar fracture fragments varied from 0.002-0.072 mm. Fatigue damage does not occur in the internal fixation system. Fatigue injuries develop in the tibia when subjected to cyclic loading, especially when running. Conclusion: The results of this study indicate that the internal fixation system tolerates some of the body's typical actions and may sustain all or part of the weight early in the postoperative period. In other words, early rehabilitative exercise is recommended, but avoid strenuous exercise such as running.

Treatment of C1.1 (AO‑41) tibial plateau fracture: A finite element analysis of single medial, lateral and dual plating

Bicondylar tibial plateau fractures pose many challenges in surgical treatment. The aim of the present study was to analyze three methods of reduction, single medial, single lateral, and dual plating, for the treatment of a bicondylar tibial plateau fracture, through finite element analysis (FEA). A simple metaphyseal fracture, type C1.1 (AO-41) was modeled on a CT-derived 3D model of the knee. Lateral and medial proximal tibial polyaxial plates with screws were modeled and placed accordingly for the three methods of reduction. Simulation of physiological type loading corresponding to the maximal weight acceptance phase during a slow walking gait cycle was performed using FEA. Values of stress and strain were recorded near the fracture lines. Dual plating provided a decrease of stress and strain in the tibial plateau area. However, the differences in the values among the three cases were small. The stress concentration areas were located in the vicinity of the fracture, predominantly in the area of the tibial plateau. Considering the limitations of the present study, the results revealed that dual plating leads to smaller stress and strain values near the fracture lines in the tibial plateau area. However, values obtained for single lateral plating are close in range. Considering the complexity of the surgical approach for dual plating, single lateral plating may be a solution for good reduction with fewer surgical risks and complications. Further studies on the C1.1 fracture (AO-41) are needed to analyze the complex issue of reducing and stabilizing such a fracture and to characterize the postoperative state while providing predictable parameters for an optimal result.

Reporting checklist for verification and validation of finite element analysis in orthopedic and trauma biomechanics

Finite element analysis (FEA) has become a fundamental tool for biomechanical investigations in the last decades. Despite several existing initiatives and guidelines for reporting on research methods and results, there are still numerous issues that arise when using computational models in biomechanical investigations. According to our knowledge, these problems and controversies lie mainly in the verification and validation (V&V) process as well as in the set-up and evaluation of FEA. This work aims to introduce a checklist including a report form defining recommendations for FEA in the field of Orthopedic and Trauma (O&T) biomechanics. Therefore, a checklist was elaborated which summarizes and explains the crucial methodologies for the V&V process. In addition, a report form has been developed which contains the most important steps for reporting future FEA. An example of the report form is shown, and a template is provided, which can be used as a uniform basis for future documentation. The future application of the presented report form will show whether serious errors in biomechanical investigations using FEA can be minimized by this checklist. Finally, the credibility of the FEA in the clinical area and the scientific exchange in the community regarding reproducibility and exchangeability can be improved.