Development and biomechanical study of a novel tibial external fixation device in synthetic tibial fracture models.

BACKGROUND: This study developed a novel tibial external fixation device and compared its biomechanical properties with those of conventional fixation systems. METHODS: Fracture models were created using Sawbones tibial models and allocated to three groups according to fixation type: internal fixation plate, traditional clamp-rod external fixation, and novel tibial external fixation. Mechanical testing, including axial compression, torsion, four - point bending, and fatigue testing, was carried out on each fracture fixation model using the MTS Bionix biomechanical testing system. Stiffness values were calculated to evaluate the mechanical properties of the novel tibial external fixation device under various conditions. FINDINGS: The internal fixation plate exhibited significantly higher axial stiffness than the novel tibial external fixation device (P < 0.05), with both constructs substantially exceeding the traditional clamp-rod external fixation device. The novel tibial external fixation device demonstrated significantly superior torsional resistance and lateral stress resistance compared to both the internal fixation plate and traditional clamp-rod external fixation device (P < 0.05). Furthermore, the novel device exhibited no significant signs of fatigue damage during cyclic loading. INTERPRETATION: The novel tibial external fixation device demonstrated favorable torsional and bending stiffness, adequate axial stability relative to the traditional external fixator, and strong fatigue resistance. These biomechanical characteristics, together with its relatively straightforward installation procedure, provide a foundational mechanical basis for subsequent preclinical research, while its actual clinical applicability still requires validation from further in vivo and clinical studies.