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.
