The high stiffness of conventional intramedullary (IM) nails may result in stress shielding and subsequent bone loss following healing in long bone fractures. It can also delay union by reducing compressive loads at the fracture site, thereby inhibiting secondary bone healing. This paper introduces a new approach for the optimization of a fiber-reinforced composite nail made of carbon fiber (CF)/epoxy based on a combination of the classical laminate theory, beam theory, finite-element (FE) method, and bone remodeling model using irreversible thermodynamics. The optimization began by altering the composite stacking sequence and thickness to minimize axial stiffness, while maximizing torsional stiffness for a given range of bending stiffnesses. The selected candidates for the seven intervals of bending stiffness were then examined in an experimentally validated FE model to evaluate their mechanical performance in transverse and oblique femoral shaft fractures. It was found that the composite nail having an axial stiffness of 3.70 MN and bending and torsional stiffnesses of 70.3 and 70.9 Nm2, respectively, showed an overall superiority compared to the other configurations. It increased compression at the fracture site by 344.9 N (31%) on average, while maintaining fracture stability through an average increase of only 0.6 mm (49%) in fracture shear movement in transverse and oblique fractures when compared to a conventional titanium-alloy nail. The long-term results obtained from the bone remodeling model suggest that the proposed composite IM nail reduces bone loss in the femoral shaft from 7.9% to 3.5% when compared to a conventional titanium-alloy nail. This study proposes a number of practical guidelines for the design of composite IM nails.

References

References
1.
Braten
,
M.
,
Terjesen
,
T.
, and
Rossvoll
,
I.
,
1995
, “
Femoral Shaft Fractures Treated by Intramedullary Nailing. A Follow-Up Study Focusing on Problems Related to the Method
,”
Injury
,
26
(
6
), pp.
379
383
.
2.
Cheung
,
G.
,
Zalzal
,
P.
,
Bhandari
,
M.
,
Spelt
,
J. K.
, and
Papini
,
M.
,
2004
, “
Finite Element Analysis of a Femoral Retrograde Intramedullary Nail Subject to Gait Loading
,”
Med. Eng. Phys.
,
26
(
2
), pp.
93
108
.
3.
Wolff
,
J.
,
Maquet
,
P.
, and
Furlong
,
R.
,
1986
,
The Law of Bone Remodelling
,
Springer-Verlag
,
Berlin
.
4.
Mantripragada
,
V. P.
,
Lecka-Czernik
,
B.
,
Ebraheim
,
N. A.
, and
Jayasuriya
,
A. C.
,
2013
, “
An Overview of Recent Advances in Designing Orthopedic and Craniofacial Implants
,”
J. Biomed. Mater. Res., Part A
,
101
(
11
), pp.
3349
3364
.
5.
Woo
,
S. L.
,
Lothringer
,
K. S.
,
Akeson
,
W. H.
,
Coutts
,
R. D.
,
Woo
,
Y. K.
,
Simon
,
B. R.
, and
Gomez
,
M. A.
,
1984
, “
Less Rigid Internal Fixation Plates: Historical Perspectives and New Concepts
,”
J. Orthop. Res.
,
1
(
4
), pp.
431
449
.
6.
Poitout
,
D. G.
,
2004
,
Biomechanics and Biomaterials in Orthopedics
,
Springer
,
London
.
7.
Tayton
,
K.
,
Johnson-Nurse
,
C.
,
Mckibbin
,
B.
,
Bradley
,
J.
, and
Hastings
,
G.
,
1982
, “
The Use of Semi-Rigid Carbon-Fibre-Reinforced Plastic Plates for Fixation of Human Fractures. Results of Preliminary Trials
,”
J. Bone Jt. Surg., Br.
,
64
(
1
), pp.
105
111
.
8.
Ali
,
M. S.
,
French
,
T. A.
,
Hastings
,
G. W.
,
Rae
,
T.
,
Rushton
,
N.
,
Ross
,
E. R. S.
, and
Wynn-Jones
,
C. H.
,
1990
, “
Carbon Fibre Composite Bone Plates. Development, Evaluation and Early Clinical Experience
,”
J. Bone Jt. Surg., Ser. B
,
72
(
4
), pp.
586
591
.
9.
Fujihara
,
K.
,
Huang
,
Z. M.
,
Ramakrishna
,
S.
,
Satknanantham
,
K.
, and
Hamada
,
H.
,
2003
, “
Performance Study of Braided Carbon/PEEK Composite Compression Bone Plates
,”
Biomaterials
,
24
(
15
), pp.
2661
2667
.
10.
Metzinger
,
A. J.
,
Grant
,
S. R.
, and
Yambor
,
J. N.
,
2009
, “
Composite Intramedullary Nail
,” U.S. Patent No. 2009/0088752 A1.
11.
Morawska-Chochół
,
A.
,
Chłopek
,
J.
,
Domalik-Pyzik
,
P.
,
Szaraniec
,
B.
, and
Grzyśka
,
E.
,
2014
, “
Magnesium Alloy Wires as Reinforcement in Composite Intramedullary Nails
,”
Bio-Med. Mater. Eng.
,
24
(
2
), pp.
1507
1515
.
12.
Samiezadeh
,
S.
,
Avval
,
P. T.
,
Fawaz
,
Z.
, and
Bougherara
,
H.
,
2014
, “
Biomechanical Assessment of Composite Versus Metallic Intramedullary Nailing System in Femoral Shaft Fractures: A Finite Element Study
,”
Clin. Biomech. (Bristol, Avon)
,
29
(
7
), pp.
803
810
.
13.
Bradley
,
J. S.
,
Hastings
,
G. W.
, and
Johnson-Nurse
,
C.
,
1980
, “
Carbon Fibre Reinforced Epoxy as a High Strength, Low Modulus Material for Internal Fixation Plates
,”
Biomaterials
,
1
(
1
), pp.
38
40
.
14.
Bagheri
,
Z. S.
,
El Sawi
,
I.
,
Schemitsch
,
E. H.
,
Zdero
,
R.
, and
Bougherara
,
H.
,
2013
, “
Biomechanical Properties of an Advanced New Carbon/Flax/Epoxy Composite Material for Bone Plate Applications
,”
J. Mech. Behav. Biomed. Mater.
,
20
, pp.
398
406
.
15.
Bailie
,
J. A.
,
Ley
,
R. P.
, and
Pasricha
,
A. A.
,
1997
, “
Summary and Review of Composite Laminate Design Guidelines
,” NASA Langley Research Center, Hampton, VA, Technical Report No. NASA, NAS1-19347.
16.
Kollár
,
L. P.
, and
Springer
,
G. S.
,
2003
,
Mechanics of Composite Structures
,
Cambridge University Press
,
Cambridge, UK
.
17.
Tayton
,
K.
, and
Bradley
,
J.
,
1983
, “
How Stiff Should Semi-Rigid Fixation of the Human Tibia be? A Clue to the Answer
,”
J. Bone Jt. Surg., Br.
,
65
(
3
), pp.
312
315
.
18.
Papini
,
M.
,
Zdero
,
R.
,
Schemitsch
,
E. H.
, and
Zalzal
,
P.
,
2007
, “
The Biomechanics of Human Femurs in Axial and Torsional Loading: Comparison of Finite Element Analysis, Human Cadaveric Femurs, and Synthetic Femurs
,”
ASME J. Biomech. Eng.
,
129
(
1
), pp.
12
19
.
19.
Heiner
,
A. D.
,
2008
, “
Structural Properties of Fourth-Generation Composite Femurs and Tibias
,”
J. Biomech.
,
41
(
15
), pp.
3282
3284
.
20.
Montanini
,
R.
, and
Filardi
,
V.
,
2010
, “
In Vitro Biomechanical Evaluation of Antegrade Femoral Nailing at Early and Late Postoperative Stages
,”
Med. Eng. Phys.
,
32
(
8
), pp.
889
897
.
21.
Bitsakos
,
C.
,
Kerner
,
J.
,
Fisher
,
I.
, and
Amis
,
A. A.
,
2005
, “
The Effect of Muscle Loading on the Simulation of Bone Remodelling in the Proximal Femur
,”
J. Biomech.
,
38
(
1
), pp.
133
139
.
22.
Duda
,
G. N.
,
Schneider
,
E.
, and
Chao
,
E. Y.
,
1997
, “
Internal Forces and Moments in the Femur During Walking
,”
J. Biomech.
,
30
(
9
), pp.
933
941
.
23.
Frankel
,
V. H.
, and
Nordin
,
M.
,
1980
,
Basic Biomechanics of the Skeletal System
,
Lea & Febiger
, New York.
24.
Avval
,
P. T.
,
Klika
,
V.
, and
Bougherara
,
H.
,
2014
, “
Predicting Bone Remodeling in Response to Total Hip Arthroplasty: Computational Study Using Mechanobiochemical Model
,”
ASME J. Biomech. Eng.
,
136
(
5
), p.
051002
.
25.
Li
,
M. G.
,
Rohrl
,
S. M.
,
Wood
,
D. J.
, and
Nivbrant
,
B.
,
2007
, “
Periprosthetic Changes in Bone Mineral Density in 5 Stem Designs 5 Years After Cemented Total Hip Arthroplasty. No Relation to Stem Migration
,”
J. Arthroplasty
,
22
(
5
), pp.
689
691
.
26.
Aro
,
H. T.
,
Wahner
,
H. T.
, and
Chao
,
E. Y.
,
1991
, “
Healing Patterns of Transverse and Oblique Osteotomies in the Canine Tibia Under External Fixation
,”
J. Orthop. Trauma
,
5
(
3
), pp.
351
364
.
27.
Wang
,
C.
,
Wang
,
L. Z.
, and
Fan
,
Y. B.
,
2013
, “
Long-Term Prediction of Bone Density Distribution for Retained Intramedullary Nail
,” World Congress on Medical Physics and Biomedical Engineering, Beijing, May 26–31, 2012, pp. 161–164.
28.
Allen
,
J. C.
, Jr.
,
Lindsey
,
R. W.
,
Hipp
,
J. A.
,
Gugala
,
Z.
,
Rianon
,
N.
, and
Leblanc
,
A.
,
2008
, “
The Effect of Retained Intramedullary Nails on Tibial Bone Mineral Density
,”
Clin. Biomech. (Bristol, Avon)
,
23
(
6
), pp.
839
843
.
29.
Eyres
,
K. S.
, and
Kanis
,
J. A.
,
1995
, “
Bone Loss After Tibial Fracture. Evaluated by Dual-Energy X-Ray Absorptiometry
,”
J. Bone Jt. Surg., Br.
,
77
(
3
), pp.
473
478
.
30.
Kapp
,
W.
,
Lindsey
,
R. W.
,
Noble
,
P. C.
,
Rudersdorf
,
T.
, and
Henry
,
P.
,
2000
, “
Long-Term Residual Musculoskeletal Deficits After Femoral Shaft Fractures Treated With Intramedullary Nailing
,”
J. Trauma
,
49
(
3
), pp.
446
449
.
31.
Sha
,
M.
,
Guo
,
Z.
,
Fu
,
J.
,
Li
,
J.
,
Yuan
,
C. F.
,
Shi
,
L.
, and
Li
,
S. J.
,
2009
, “
The Effects of Nail Rigidity on Fracture Healing in Rats With Osteoporosis
,”
Acta Orthop.
,
80
(
1
), pp.
135
138
.
32.
Kaiser
,
M. M.
,
Wessel
,
L. M.
,
Zachert
,
G.
,
Stratmann
,
C.
,
Eggert
,
R.
,
Gros
,
N.
,
Schulze-Hessing
,
M.
,
Kienast
,
B.
, and
Rapp
,
M.
,
2011
, “
Biomechanical Analysis of a Synthetic Femur Spiral Fracture Model: Influence of Different Materials on the Stiffness in Flexible Intramedullary Nailing
,”
Clin. Biomech.
,
26
(
6
), pp.
592
597
.
33.
Perez
,
A.
,
Mahar
,
A.
,
Negus
,
C.
,
Newton
,
P.
, and
Impelluso
,
T.
,
2008
, “
A Computational Evaluation of the Effect of Intramedullary Nail Material Properties on the Stabilization of Simulated Femoral Shaft Fractures
,”
Med. Eng. Phys.
,
30
(
6
), pp.
755
760
.
34.
Flinck
,
M.
,
von Heideken
,
J.
,
Janarv
,
P. M.
,
Wåtz
,
V.
, and
Riad
,
J.
,
2014
, “
Biomechanical Comparison of Semi-Rigid Pediatric Locking Nail Versus Titanium Elastic Nails in a Femur Fracture Model
,”
J. Child. Orthop.
,
9
(
1
), pp.
77
84
.
35.
Green
,
J. K.
,
Werner
,
F. W.
,
Dhawan
,
R.
,
Evans
,
P. J.
,
Kelley
,
S.
, and
Webster
,
D. A.
,
2005
, “
A Biomechanical Study on Flexible Intramedullary Nails Used to Treat Pediatric Femoral Fractures
,”
J. Orthop. Res.
,
23
(
6
), pp.
1315
1320
.
36.
Heffernan
,
M. J.
,
Gordon
,
J. E.
,
Sabatini
,
C. S.
,
Keeler
,
K. A.
,
Lehmann
,
C. L.
,
O'donnell
,
J. C.
,
Seehausen
,
D. A.
,
Luhmann
,
S. J.
, and
Arkader
,
A.
,
2014
, “
Treatment of Femur Fractures in Young Children: A Multicenter Comparison of Flexible Intramedullary Nails to Spica Casting in Young Children Aged 2 to 6 Years
,”
J. Pediatr. Orthop.
,
35
(
2
), pp.
126
129
.
37.
Kim
,
C.
, and
White
,
S. R.
,
1996
, “
Analysis of Thick Hollow Composite Beams Under General Loadings
,”
Compos. Struct.
,
34
(
3
), pp.
263
277
.
38.
Shadmehri
,
F.
,
Derisi
,
B.
, and
Hoa
,
S. V.
,
2011
, “
On Bending Stiffness of Composite Tubes
,”
Compos. Struct.
,
93
(
9
), pp.
2173
2179
.
39.
Vasiliev
,
V. V.
, and
Morozov
,
E.
,
2013
,
Advanced Mechanics of Composite Materials and Structural Elements
,
Elsevier Science
,
Oxford, UK
.
You do not currently have access to this content.