Biomechanical Comparison of Two Conical Coupling Plate Constructs for Cat Tibial Fracture Stabilization

Introduction: Tibial fractures occur commonly in cats with the majority of fractures involving the mid-diaphysis. Cat diaphyseal tibial fractures in which osteosynthesis fails is largely due to plate bending. The objective of this study was to compare the biomechanical characteristics of two conical coupling plate (CCP) constructs in an ex vivo feline tibial fracture gap model.

Materials and Methods: Paired tibiae harvested from 8 recently euthanized cats were randomized into two groups. One tibia was stabilized with a standard 6-hole 2.5 mm CCP and the contralateral tibia was stabilized with a 6-hole 2.5 mm prototype CCP (pCCP). Nondestructive cyclic four-point craniocaudal bending, mediolateral bending, and axial compression testing was performed, and stiffness was recorded. The specimens were then loaded to failure in axial compression.

Results:: During nondestructive testing, the pCCP constructs were significantly stiffer than the CCP constructs in both modes of bending and axial loading. Both constructs demonstrated significantly greater craniocaudal bending stiffness compared with mediolateral bending. Yield load and failure load were significantly greater for the pCCP constructs.

Discussion/Conclusion: The augmented design of the pCCP yielded superior mechanical characteristics compared with the original CCP construct in nondestructive and destructive testing. The superior mechanical properties of the pCCP suggest that this implant would be more suitable for stabilizing complex diaphyseal tibial fractures in cats. Further investigation is needed to prospectively evaluate the clinical performance of the pCCP.

Acknowledgment: Fixin conical coupling implants and financial support for this project were provided by Intrauma, Rivoli, Italy.

No conflict of interest has been declared by the author(s).