Highlights
- •Significantly smaller peak force during nail extraction with a radius of curvature of 1.0 m
- •No difference in peak force between 1.0 m and 1.5 m radius of curvature while implant extraction
- •Plastic deformation was observed in all femur nails post extraction
Abstract
Background
The impact of the nail radius of curvature, as one of the most important design features
in modern femoral nails on the ease of nail removal, remains unknown. Therefore, the
aim of this study was to investigate force, energy, and nail deformation of different
nail designs.
Methods
Nail insertion and extraction was performed on six pairs of fresh-frozen human cadaveric
femora on a material testing machine with two different nail systems – Trochanter
femoral nail ADVANCED™ Nailing System with a radius of curvature of 1.0 m and Proximal
Femoral Nail Antirotation System with a radius of curvature of 1.5 m. Deformation
was measured after insertion (plastic and elastic deformations) and extraction (plastic
deformations).
Findings
The peak force during nail removal was significantly lower in the first group (274.5 ± 130.4 N)
compared to the second group (695.2 ± 158.8 N, p = 0.001). Plastic deformation was observed in all implants, being significantly larger
in the Proximal Femoral Nail Antirotation System (p = 0.027). There was a strong positive correlation between the first peak force during
nail removal and nail insertion (r = 0.802, p = 0.002) as well as between extracting energy and insertion energy (r = 0.943, p < 0.001).
Interpretation
The results from this study showed that a radius of curvature of 1.0 m is easier to
remove from the set of cadaver femora. Furthermore, our findings support the idea
of further reducing the nail radius of curvature below 1.0 m in order to more closely
match the anatomy of populations with strong-bowed femora.
Keywords
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Article info
Publication history
Published online: February 10, 2023
Accepted:
February 8,
2023
Received:
October 12,
2022
Identification
Copyright
© 2023 Published by Elsevier Ltd.
