Biomechanical study on different internal fixation methods for treating Mayo type IIA olecranon fractures of the ulna.

The aim of this experiment is to compare the biomechanical strength of six distinct internal fixation techniques for Mayo type IIA olecranon fractures using biomechanical analysis. This study utilized tensile tests on artificial, shape-mimicking olecranon bones to assess their biomechanical properties. A tensile test was performed on the artificial, shape-mimicking olecranon bone at a 90° angle, with the tensile load applied at a rate of 2 mm/min until the test displacement reached 2 mm, at which point the test was halted. Throughout the test, the testing system was able to collect load and displacement data in real-time and simultaneously monitor the changes in the load-displacement relationship. The maximum loads for groups A-F were (75.34 ± 2.54), (85.53 ± 2.45), (106.57 ± 3.57), (115.21 ± 11.96), (92.76 ± 3.22), and (147.19 ± 4.29) N, respectively, and the stiffnesses were (33.46 ± 2.96), (39.29 ± 1.12), (51.07 ± 3.22), (53.76 ± 5.26), (40.99 ± 1.34), and (71.66 ± 1.77) N/mm, respectively. When the implantation depth of the Kirschner wires reached four times the standard deviation depth, its maximum load and stiffness performance were superior to those of the double cortical Kirschner wire tension band fixation.