Abstract
Objectives The purpose was to compare the biomechanical properties of a 1.5 mm locking compression
plate (1.5 LCP) to the 1.5 mm straight plate (1.5 P), 1.5 mm straight plate stacked
(1.5 PSt) and 2.0 mm straight plate (2.0 P) in compression and torsion. We hypothesized
that biomechanical properties of the 1.5 LCP would be equivalent to properties of
the 1.5 P and would represent an alternative for the treatment of radial fractures
in miniature breed dogs in which those plates would be used.
Materials and Methods A 1 mm fracture gap model was created with a bone surrogate stabilized with a six-hole
plate. Sixteen constructs were built for each of the four plate configurations. Eight
constructs from each group were tested in compression to failure and eight constructs
were tested in torsion to failure.
Results In compression testing, the 1.5 LCP was stiffer than the 1.5 P, and had similar stiffness
than the 1.5 PSt and the 2.0 P. The load at yield of the 1.5 LCP was slightly lower
than the 1.5 P. In torsion, the 1.5 LCP and 1.5 P had similar stiffness, but 1.5 LCP
was slightly stronger than 1.5 P. The 1.5 PSt and 2.0 P were overall superior to the
1.5 LCP but only marginally so for the 1.5 PSt.
Clinical Relevance The 1.5 LCP can be considered biomechanically equivalent to the 1.5 P under the present
experimental conditions. The use of the 1.5 LCP can be considered as an option for
radial fracture repair in dogs in which a 1.5 P would have otherwise been used. The
use of a locking plate to improve overall success rate, in these fractures, remains
to be confirmed clinically.
Keywords
locking compression plates - biomechanical properties - fracture fixation - radial
fracture - dog
