Abstract
PURPOSE: Using finite element analysis, to compare the stress and deformation of six different internal fixation methods for distal femoral fractures to obtain the optimal internal fixation method. METHODS: Create six groups based on different placement methods and fixation methods: 5-hole lateral plate (SP); 5-hole lateral plate + two medial screws (SP + D); 5-hole lateral plate + one trans-plate screw (SP + O); 5-hole lateral plate + one cross screw (SP + C); 5-hole lateral plate + elastic nail (SP + S); 5-hole lateral plate + medial T-shaped plate (SP + T). Observe the displacement distribution and maximum displacement at the fracture site, and stress distribution on the medial fracture fragment and internal fixation. RESULTS: After applying the load, mechanical indicators for internal fixation and bone blocks were obtained for all six models by finite element method. The model with a lateral single plate showed max internal fixation stress of 221.75 MPa, which was greater than other models. On the other hand, the model with a 5-hole lateral plate and medial T-shaped plate showed the smallest internal fixation stress (125.74 MPa) and the smallest total femoral deformation (0.99416 mm). CONCLUSION: The combination of a 5-hole lateral plate and a medial T-shaped plate demonstrated significant biomechanical advantage compared to the other five groups. Although the 5-hole lateral plate model is slightly inferior compared to the 5-hole lateral plate and medial T-shaped plate, it remains an effective and safe fixation solution for AO/OTA 33C1 type fractures.