Cadaveric biomechanical comparison of the conventional dual plating and a novel pin and plate method of fixation in distal humerus fractures

Fixation of distal humerus fractures using pre-contoured, orthogonal plates presents several challenges, particularly in osteoporotic patients or extremely distal or comminuted fractures. To address such shortcomings, we proposed a novel fixation technique employing 2mm pins and a plate. As the final phase of a multi-stage, method refinement and non-inferiority evaluation, we aimed to compare the biomechanical performance of this new technique against the conventional approach. 20 humeri were allocated into two groups and after fixation by one of the approaches, underwent two rounds of non-destructive testing. Two supporting pins initially used in the new fixation group were removed between rounds to assess their biomechanical contribution. Subsequent test-to-failure trials were also conducted. Results indicated no significant difference in compression, anterior and posterior bending, and torsional loading, with the new fixation performing better in medial and lateral bending. Similar overall results were observed after the removal of supporting pins, with a predictable reduction in torsional stiffness in the new fixation group. In failure testing, both groups performed similarly in anterior bending, though the conventional group endured significantly higher torsional loads. In summary, the new technique demonstrated biomechanical non-inferiority and may be a viable alternative under certain circumstances, with significantly lower implant costs. Level of Evidence: Level II