Evaluation of a simple and low-cost external fixator

Area of Science:

• Orthopedic biomechanics
• Trauma surgery devices
• Biomedical engineering

Background:

• External fixation is increasingly utilized for fracture treatment.
• Existing commercial devices are often complex and costly, limiting access in developing nations.
• A need exists for simpler, more affordable external fixation solutions.

Purpose of the Study:

• To biomechanically evaluate a novel, low-cost external fixator, the AG (Alinoor-Goh) fixator.
• To compare the AG fixator's performance against a commercially available AO fixator.
• To assess the AG fixator as a potential alternative for long-bone fracture management.

Main Methods:

• A fractured-bone model (perspex) was created and stabilized using both AG and AO fixators.
• Six Schanz pins were used for immobilization in each fixator setup.
• Biomechanical testing involved four loading modes: axial compression, anterior-posterior bending, medial-lateral bending, and torsion. Stiffness was calculated from load-displacement curves.

Main Results:

• The AG fixator exhibited stiffness values comparable to the AO fixator across all tested loading modes.
• Specific stiffness results: Axial compression (AG: 55.7 N/mm vs. AO: 57.7 N/mm), AP bending (AG: 56.8 N/mm vs. AO: 57.4 N/mm), ML bending (AG: 11.4 N/mm vs. AO: 11.6 N/mm), Torsion (AG: 1.16 N.mm/degree vs. AO: 1.16 N.mm/degree).
• No statistically significant differences in stiffness were observed between the two fixator types.

Conclusions:

• The AG (Alinoor-Goh) fixator demonstrates equivalent biomechanical stability to the AO fixator under various loading conditions.
• The AG fixator presents a simple, versatile, and cost-effective alternative for treating long-bone fractures.
• This device holds significant potential for improving fracture management, particularly in resource-limited healthcare environments.