[Comparative tridimensional mechanical study of external fixation devices. Clinical deductions]

Area of Science:

• Orthopedics
• Biomechanical Engineering
• Trauma Surgery

Background:

• External fixation devices are crucial for fracture management.
• Comparing stabilization and dynamization capabilities of different external fixators is essential for optimal patient outcomes.
• The Ilizarov, Orthofix, and French Army External Fixator (FESSA) are commonly used devices with distinct mechanical properties.

Purpose of the Study:

• To conduct a tridimensional mechanical study comparing the stabilization provided by the Ilizarov, Orthofix, and FESSA external fixators.
• To evaluate the suitability of each fixator for different fracture types, particularly open and diaphyseal fractures.
• To assess the dynamization capabilities of the Orthofix and FESSA systems.

Main Methods:

• A comparative mechanical study was performed on three external fixator systems.
• Analysis focused on the stability in multiple spatial planes and the degree of instability.
• The study assessed the potential for reduction and dynamization in relation to fracture location (diaphyseal vs. epiphyseal).

Main Results:

• The Ilizarov fixator exhibited significant instability in all planes except transverse movement, deeming it less suitable for open fractures in adults.
• Both Orthofix and FESSA demonstrated stability, though Orthofix showed some transversal instability under compression.
• FESSA offered greater versatility for epiphyseal fracture fixation and superior multidirectional dynamization compared to Orthofix.

Conclusions:

• The French Army External Fixator (FESSA) and Orthofix are more stable than the Ilizarov for fracture treatment.
• FESSA provides enhanced fixation options for epiphyseal fractures and superior multidirectional dynamization.
• The choice of external fixator should consider fracture type and desired mechanical control, with FESSA showing advantages in specific scenarios.