A biomechanical study of a novel multi axial circular external fixation device for stabilization of a bovine cadaveric tibial fracture gap model.

BACKGROUND

Circular external fixators are widely used in orthopaedic fracture management but often face limitations in complex fractures due to their rigid structure. The multi axial circular external fixator offers increased flexibility and adjustability, making it a promising alternative for cases involving anatomical variability.

AIMS: The present study aimed to compare the biomechanical properties, including stiffness and strength, of a novel multi-axial circular fixator (MCEF) with a traditional full-ring circular external fixator (CEF) using buffalo tibia fracture model.

METHODS

The study used eighteen buffalo tibiae divided into three groups: intact bones, CEF, and MCEF constructs. Each construct was subjected to axial compression and torsion tests. The constructs were subjected to loads until failure, and load-displacement curves were generated for each sample. Axial compression and torsion tests were performed to evaluate the biomechanical performance of both fixators. Mechanical parameters such as stress, stiffness, yield load, resilience energy, failure load, and maximum torque were measured and analysed. Appropriate statistical tests were performed to compare between groups.

RESULTS

CEF demonstrated higher stiffness in axial compression and bending as compared with MCEF, which showed greater flexibility under both axial and torsional loads. MCEF, however, provided enhanced multi-planar adaptability, making it better suited for fractures in anatomically variable regions. In torsion, CEF exhibited higher maximum torque and torsional strength.

CONCLUSION

CEF provided greater axial and bending stiffness. The MCEF design allows flexibility and adaptability providing better optimization of fracture stabilization in complex fracture patterns, making it a viable alternative in large animal fracture management.