Abstract
Objective The aim of this study was to (1) evaluate bending structural properties of a machined
short fibre epoxy (SFE) feline bone surrogate (FBS), (2) compare the bending behaviour
of small angle-stable interlocking nails (I-Loc; Targon) and locking compression plates
(LCP) and (3) evaluate the effect of implant removal on FBS bending strength.
Methods Part 1: Feline cadaveric femurs (n = 10) and FBS (n = 4) underwent cyclic four-point bending and load to failure. Part 2: Fracture gap
FBS constructs (n = 4/group) were stabilized in a bridging fashion with either I-Loc 3 and 4, Targon
2.5 and 3.0, LCP 2.0 and 2.4, then cyclically bent. Part 3: Intact FBS with pilot
holes, simulating explantation, (n = 4/group) underwent destructive bending tests. Bending compliance, angular deformation
and failure moment (FM) were statistically compared (p < 0.05).
Results Native bone and FBS were similar for all outcome measures (p > 0.05). The smallest and largest bending compliance and angular deformation were
seen in the I-Loc 4 and LCP 2.0 respectively (p < 0.05). While explanted Targon FBS had the lowest FM (p < 0.05), I-Loc and LCP constructs FM were not different (p > 0.05).
Conclusion The similar bending properties of short fibre epoxy made FBS and native feline femurs
suggest that this model could be used for mechanical testing of implants designed
for feline long bone osteosynthesis. The I-Loc constructs smaller angular deformation
which also suggests that these implants represent a valid alternative to size-matched
Targon and LCP for feline fracture osteosynthesis. The significantly lower FM of explanted Targon may increase the risk of secondary fracture following implant
removal.
Keywords
interlocking nails - feline - bone surrogate - bending - locking compression plate