Fixation technique influences the monotonic properties of equine mandibular fracture constructs.
Authors: Peavey Christina L, Edwards Ryland B, Escarcega Anthony J, Vanderby Ray, Markel Mark D
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Fixation Techniques for Equine Mandibular Fractures Optimal treatment of interdental space fractures in horses remains clinically challenging, prompting this 2003 biomechanical investigation comparing four fixation approaches: dynamic compression plating (DCP), external fixation (EF), external fixation with interdental wiring (EFW), and intraoral splinting with interdental wiring (ISW). Using 27 equine mandibles subjected to monotonic cantilever bending until failure, researchers measured stiffness, yield strength, and ultimate failure loads across all constructs. DCP fixation demonstrated superior stiffness compared to all other techniques (P <.05), whilst ISW constructs achieved the highest yield loads; notably, unaugmented external fixation proved biomechanically inferior to all other methods, with the greatest osteotomy gap widths at both 50 Nm (P =.09) and 100 Nm (P <.05). The findings suggest that DCP remains the gold standard for complex comminuted fractures due to its exceptional rigidity, yet for uncomplicated interdental space fractures, intraoral splinting with tension-band wiring offers sufficient stability with substantially lower invasiveness and cost, whilst unaugmented external fixators should be abandoned in favour of tension-band augmentation to significantly enhance construct strength. These results provide evidence-based guidance for selecting fixation techniques according to fracture complexity and clinical circumstances.
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Practical Takeaways
- •Use DCP fixation for comminuted (complex) interdental space fractures where maximum stability is needed; consider supplemental tension-band wiring to improve fatigue resistance
- •For simple interdental space fractures, intraoral splint with interdental wires provides adequate biomechanical stability while minimizing invasiveness and cost
- •If using external skeletal fixators, always add interdental tension-band wiring to significantly improve construct strength; external fixation alone is inadequate
Key Findings
- •Dynamic compression plates (DCP) provided greatest stiffness among osteotomized mandibles (P<0.05), but intraoral splint with interdental wires (ISW) showed greatest yield load
- •External fixator (EF) alone was biomechanically inferior to all other constructs with lowest yield and failure loads and greatest osteotomy gap width
- •Tension-band wiring (EFW and ISW) significantly enhanced construct strength and osteotomy gap stability, with failure loads similar to DCP constructs
- •DCP stiffness advantage may be offset by lower yield values predisposing to earlier fatigue failure without supplemental fixation