An augmented fixation method for distal fibular fractures in elderly patients: a biomechanical evaluation

This biomechanical investigation compared two fixation techniques for distal fibular fractures. Elderly cadaver lower extremities with simulated fibula fractures underwent fixation either with a plate and intramedullary Kirschner wires (K-wires) with or without the addition of three screws inserted through the four cortices of the fibula and the tibia. The specimens were axially loaded to body weight on a materials testing machine, and the supinated foot was externally rotated to failure. Displacement at the fracture site was monitored with an extensometer. Comparing the augmented technique with the technique without additional screws, mean stiffness was 460 +/- 100 and 320 +/- 200 N-mm/deg, strength at failure was 31 +/- 10 and 19 +/- 7 N-m, strength at 30 degrees external rotation was 15 +/- 5 and 10 +/- 6 N-m, and axial deformation was 0.04 +/- 0.06 mm and 0.10 +/- 0.04 mm, respectively. All differences were statistically significant.