North Texas Research Forum 2026
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Division
North Texas
Hospital
Medical City Denton
Specialty
Orthopedic Surgery
Document Type
Poster
Publication Date
2026
Keywords
external fixation, MRI, magnetic resonance imaging
Disciplines
Diagnosis | Medicine and Health Sciences | Orthopedics
Abstract
Introduction Much controversy remains regarding the ability of patients with an external fixator in place to undergo Magnetic Resonance Imaging (MRI). The main concern for radiology departments is that the external fixator system components can lead to adverse events due to interactions of the external fixator and the magnet of the MRI. However, there is no clear evidence to support these claims or theories in the current literature. Yet, MRI’s are denied daily across the country for patients having an external fixator in place. Numerous patients with an external fixator would likely benefit from an MRI to prevent delayed care, such as patients with traumatic spine injuries, traumatic brain injuries, or patients with multiligamentous extremity injuries. In order to determine if there are magnetic properties of external fixators, this study aims to use a testing magnet to see if there are any magnetic interactions between the external fixators and the magnet.
Methods A 1000 gauss handheld test magnet was obtained. A #10 scalpel blade, Adson forceps, and a needle driver were used as control test items. The Synthes large external fixation system, Synthes small external fixation system, Stryker Hoffmann 3 external fixation system, Smith & Nephew MAVERICK external fixation system, the Arthrex ArthroFX external fixation system were tested. The bars, bar to pin connectors, Schanz screws and rod to rod connectors were tested for each external fixation system. The Synthes small external fixation system does not have a bar to pin connector, and this was not tested for this system. For each item, the magnet was tested at the following three locations: 1cm away from the object, 0.5cm away from the object, and in direct contact with the object. A positive result of magnetism was an object being attracted to the magnet with direct contact or movement, and a negative result being no attraction. Results were recorded for the objects.
Results All three control items exhibited positive magnetism at 1cm of distance, 0.5cm of distance, and direct contact. All of the external fixator components exhibited no signs of magnetism and had negative magnetism testing at 1cm of distance, 0.5cm of distance, and direct contact. All of the following components of the external fixator were negative for magnetism, including: the bars, bar to pin connectors, the rod to rod connectors, or Schanz screws.
Conclusion In this magnetism testing of external fixator components, all of the external fixator components demonstrated negative testing for magnetism. The external fixator components do not appear to have any magnetic properties or attraction. This research further supports the safety of patients obtaining an MRI with an external fixator in place
Original Publisher
HCA Healthcare Graduate Medical Education
Recommended Citation
Puga, Troy B.; Box, McKenna W.; Ward, Lyn D.; and Riehl, John T., "Handheld Magnet Screening of External Fixator Components: A Laboratory Assessment of Gross Ferromagnetism Relevant to MRI Safety" (2026). North Texas Research Forum 2026. 69.
https://scholarlycommons.hcahealthcare.com/northtexas2026/69