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. 2021 Feb 5:8:593609.
doi: 10.3389/fbioe.2020.593609. eCollection 2020.

Cyclic Damage Accumulation in the Femoral Constructs Made With Cephalomedullary Nails

Farah Hamandi  1 , Alyssa Whitney  1 , Mark H Stouffer  2 , Michael J Prayson  2 , Jörn Rittweger  3 , Tarun Goswami  1
Affiliations

Cyclic Damage Accumulation in the Femoral Constructs Made With Cephalomedullary Nails

Farah Hamandi et al. Front Bioeng Biotechnol. .

Abstract

Background: The purpose of this study was to evaluate the risk of peri-prosthetic fracture of constructs made with cephalomedullary (CM) long and short nails. The nails were made with titanium alloy (Ti-6Al-4V) and stainless steel (SS 316L). Methods: Biomechanical evaluation of CM nail constructs was carried out with regard to post-primary healing to determine the risk of peri-implant/peri-prosthetic fractures. Therefore, this research comprised of, non-fractured, twenty-eight pairs of cadaveric femora that were randomized and implanted with four types of fixation CM nails resulting in four groups. These constructs were cyclically tested in bi-axial mode for up to 30,000 cycles. All the samples were then loaded to failure to measure failure loads. Three frameworks were carried out through this investigation, Michaelis-Menten, phenomenological, and probabilistic Monte Carlo simulation to model and predict damage accumulation. Findings: Damage accumulation resulting from bi-axial cyclic loading in terms of construct stiffness was represented by Michaelis-Menten equation, and the statistical analysis demonstrated that one model can explain the damage accumulation during cyclic load for all four groups of constructs (P > 0.05). A two-stage stiffness drop was observed. The short stainless steel had a significantly higher average damage (0.94) than the short titanium nails (0.90, P < 0.05). Long titanium nail group did not differ substantially from the short stainless steel nails (P > 0.05). Results showed gender had a significant effect on load to failure in both torsional and bending tests (P < 0.05 and P < 0.001, respectively). Interpretation: Kaplan-Meier survival analysis supports the use of short titanium CM nail. We recommend that clinical decisions should take age and gender into consideration in the selection of implants.

Keywords: biomechanics; cephalomedullary nail; damage accumulation; femur; gender.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Organization and test plan for each pair of femurs.
FIGURE 2
FIGURE 2
(A) Testing set-up for a single-leg stance with torque applied at the distal end of the femur, (B) Testing set-up for four-point bending moment along the femur shaft (Under ASTM D6272-17e 1 under B testing type).
FIGURE 3
FIGURE 3
(A) Load to failure (LTF) in the four groups of CM nail fixation in torsion, (B) load to failure versus gender, and (C) load to failure versus two age groups.
FIGURE 4
FIGURE 4
Failure at the distal screw due to torsion.
FIGURE 5
FIGURE 5
(A) Load to failure in the four groups of CM nail fixation in bending, (B) load to failure versus gender, and (C) load to failure versus two age groups.
FIGURE 6
FIGURE 6
Failure along the shaft due to bending.
FIGURE 7
FIGURE 7
Kaplan–Meier survival analysis indicating no significant difference between the four CM fixation groups and 20% of the fixation with the four groups was estimated to survive 30,065 cycles.
FIGURE 8
FIGURE 8
(A) Comparison of stiffness reduction between nail types during cyclic loading and (B) General model of stiffness reduction during cyclic loading.
FIGURE 9
FIGURE 9
(A) Comparison of damage accumulation between nail types during cyclic loading and (B) General model of damage accumulation during cyclic loading.
FIGURE 10
FIGURE 10
(A) Initial stiffness and (B) final stiffness in the four groups of CM nail fixation.
FIGURE 11
FIGURE 11
Damage in the four groups of CM nail fixation.
FIGURE 12
FIGURE 12
Fitted model of short IMHS nail data. Fitted model of short Intertan nail data. Fitted model of long IMHS nail data. Fitted model of long Intertan nail data. Damage was calculated using equation 1.
FIGURE 13
FIGURE 13
Damage versus gender.
FIGURE 14
FIGURE 14
Damage versus age.
FIGURE 15
FIGURE 15
The difference between the experimental data and the predicted data for each type of internal fixation nail constructs (95% confidence interval).
FIGURE 16
FIGURE 16
Experiential and predicted damage in the four groups of CM nail fixation.
FIGURE 17
FIGURE 17
The sensitivity plot demonstrating the relation between damage, density, and stiffness.
FIGURE 18
FIGURE 18
(A) Bivariate fit of final damage by density (B) Final damage versus density showing the exponential fit with the analytical equation.
FIGURE 19
FIGURE 19
Damage accumulation for each CM nail through Monte Carlo simulations for 500 variables.
FIGURE 20
FIGURE 20
A lognormal distribution curves for each CM nail damage through Monte Carlo simulations for 500 variables.
FIGURE 21
FIGURE 21
Contour plot of experiential versus predicted damage in the four groups of CM nail fixation.
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References

    1. Bong M. R., Koval K. J., Egol K. A. (2006). The history of intramedullary nailing. Bull. NYU Hosp. Jt. Dis. 64 94–97. - PubMed
    1. Boone C., Carlberg K. N., Koueiter D. M., Baker K. C., Sadowski J., Wiater P. J., et al. (2014). Short versus long intramedullary nails for treatment of intertrochanteric femur fractures (OTA 31-A1 and A2). J. Orthop. Trauma 28 e96–e100. - PubMed
    1. Bottlang M., Doornink J., Lujan T. J., Fitzpatrick D. C., Marsh J. L., Augat P., et al. (2010). AAOS supplement selected scientific exhibits: effects of construct stiffness on healing of fractures stabilized with locking plates. J. Bone Joint Surg. Am. 92 (Suppl. 2), 12–22. 10.2106/jbjs.j.00780 - DOI - PMC - PubMed
    1. Breceda A., Sands A., Zderic I., Schopper C., Schader J., Gehweiler D., et al. (2020). Biomechanical analysis of peri-implant fractures in short versus long cephalomedullary implants following pertrochanteric fracture consolidation. Injury 10.1016/j.injury.2020.09.037 Online ahead of print - DOI - PubMed
    1. Centers for Disease Control and Prevention (2018). Home and Recreational Safety. Falls Among Older Adults: Hip Fractures Among Older Adults. Atlanta, GU:Centers for Disease Control and Prevention.

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