Biomechanical comparison of the non-locking bone plate, locking bone plate, and double-rod clamp internal fixation in a canine femoral model.

Background and aim: Canine femoral fractures are prevalent in veterinary medicine, necessitating effective fixation methods to ensure stability and promote healing. Conventional bone plate fixation methods, including non-locking and locking plates, have inherent limitations, such as periosteal damage and mechanical failure. This study aims to evaluate the biomechanical performance of three fixation methods - non-locking bone plates, locking bone plates, and a novel double-rod clamp internal fixation system - using finite element analysis (FEA).

Materials and methods: A computed tomography-based canine femur model was created to simulate a midshaft commin-uted fracture with a 20 mm gap. Three fixation configurations were modeled: A non-locking bone plate, a locking bone plate, and a double-rod clamp system. FEA was performed to assess implant stress and proximal fragment displacement under physiological axial loading. Mesh refinement and multiple loading conditions were incorporated to enhance computational accuracy.

Results: The non-locking bone plate exhibited the highest implant stress (1160.22 MPa), surpassing the material yield strength and indicating a risk of mechanical failure. The double-rod clamp system demonstrated lower stress (628.34 MPa), whereas the locking bone plate had the lowest stress (446.63 MPa). Proximal fragment displacement was highest in the non-locking bone plate (2.37 mm), followed by the double-rod clamp system (0.99 mm), with the locking bone plate exhibiting the least displacement (0.34 mm), suggesting superior stability.

Conclusion: The double-rod clamp system emerged as a promising alternative, offering a balance between stability and stress distribution while minimizing periosteal damage. While the locking bone plate provided the greatest stability, the double-rod clamp fixation demonstrated favorable mechanical properties and could serve as a cost-effective and minimally invasive alternative in veterinary orthopedics.