This study investigates the effect of the pilot hole size, implant depth, synthetic bone density, and screw size on the pullout strength of the self-tapping screw using analytical, finite element, and experimental methodologies. Stress distribution and failure propagation mode around the implant thread zone are also investigated. Based on the finite element analysis (FEA) results, an analytical model for the pullout strength of the self-tapping screw is constructed in terms of the (synthetic) bone mechanical properties, screw size, and the implant depth. The pullout performance of self-tapping screws is discussed. Results from the analytical and finite element models are experimentally validated.

References

References
1.
Roy-Camille
,
R.
,
Saillant
,
G.
, and
Mazel
,
C.
, 1986, “
Internal Fixation of The Lumbar Spine With Pedicle Screw Plating
,”
Clin. Orthop. Relat. Res.
,
203
, pp.
7
17
.
2.
Sarzier
,
S. J.
,
Evans
,
J. A.
, and
Cahill
,
W. D.
, 2002, “
Increased Pedicle Screw Pullout Strength with Vertebroplasty Augmentation in Osteoporotic Spines
,”
J. Neurosurg.: Spine
,
96
, pp.
309
312
.
3.
Chapman
,
J. R.
,
Harrington
,
R. M.
,
Lee
,
K. M.
,
Anderson
,
P. A.
,
Tencer
,
A. F.
, and
Kowalski
,
D.
, 1996, “
Factors Affecting the Pullout Strength of Cancellous Bone Screws
,”
ASME J. Biomech. Eng.
,
118
, pp.
391
398
.
4.
Hearn
,
T. C.
,
Schatzker
,
J.
, and
Wolfson
,
N.
, 1993, “
Extraction Strength of Cannulated Cancellous Bone Screws
,”
J. Orthop. Trauma
,
7
, pp.
138
141
.
5.
Chen
,
L. H.
,
Tai
,
C. L.
,
Lai
,
P. L.
,
Lee
,
D. M.
,
Tsai
,
T. T.
,
Fu
,
T. S.
,
Niu
,
C. C.
, and
Chen
,
W. J.
, 2009, “
Pullout Strength for Cannulated Pedicle Screws with Bone Cement Augmentation in Severely Osteoporotic Bone: Influences of Radial Hole and Pilot Hole Tapping
,”
Clin. Biomech.
,
24
, pp.
613
618
.
6.
Hsu
,
C. C.
,
Chao
,
C. K.
,
Wang
,
J. L.
,
Hou
,
S. M.
,
Tsai
,
Y. T.
, and
Lin
,
J.
, 2005, “
Increase of Pullout Strength of Spinal Pedicle Screws with Conical Core: Biomechanical Tests and Finite Element Analyses
,”
J. Orthop. Res.
,
23
, pp.
788
794
.
7.
Abshire
,
B. B.
,
McLain
,
F. R.
,
Valdevit
,
A.
, and
Kambic
,
H. E.
, 2001, “
Characteristics of Pullout Failure in Conical and Cylindrical Pedicle Screws after Full Insertion and Back-out
,”
Spine J.
,
1
, pp.
408
414
.
8.
Battula
,
S.
,
Schoenfeld
,
A.
,
Vrabec
,
G.
, and
Njus
,
G. O.
, 2006, “
Experimental Evaluation of The Holding Power/Stiffness of The Self-tapping Bone Screws in Normal and Osteoporotic Bone Material
,”
Clin. Biomech.
,
21
, pp.
533
537
.
9.
Qktenoglu
,
B. T.
,
Ferrara
,
L. A.
,
Andalkar
,
N.
,
Ozer
,
A. F.
,
Sarioglu
,
A. C.
, and
Benzel
,
E. C.
, 2001, “
Effects of Hole Preparation on Screw Pullout Resistance and Insertional Torque: A Biomechanical Study
,”
J. Neurosurg.: Spine
,
94
, pp.
91
96
.
10.
Becker
,
S.
,
Chavanne
,
A.
,
Spitaler
,
R.
,
Kropik
,
K.
,
Aigner
,
N.
,
Ogon
,
M.
, and
Redl
,
H.
, 2008, “
Assessment of Different Screw Augmentation Techniques and Screw Designs in Osteoporotic Spines
,”
Eur. Spine J.
,
17
, pp.
1462
1469
.
11.
Turner
,
I. G.
, and
Rice
,
G. N.
, 1992, “
Comparison of Bone Screw Holding Strength in Healthy Bovine and Osteoporotic Human Cancellous Bone
,”
Clin. Mater.
,
9
, pp.
105
107
.
12.
Hadjipavlou
,
A. G.
,
Nicodemus
,
C. L.
,
Al-Hamdan
,
F. A.
,
Simmons
,
J. W.
, and
Pope
,
M. H.
, 1997, “
Correlation of Bone Equivalent Mineral Density to Pullout Resistance of Triangulated Pedicle Screw Construct
,”
J. Spinal Disord.
,
10
, pp.
12
19
.
13.
Zdero
,
R.
,
Rose
,
S.
,
Shcemitsch
,
E. H.
, and
Papini
,
M.
, 2007, “
Cortical Screw Pullout Strength and Effective Shear Stress in Synthetic Third Generation Composite Femurs
,”
ASME J. Biomech. Eng.
,
129
, pp.
289
293
.
14.
Chao
,
C. K.
,
Hsu
,
C. C.
,
Wang
,
J. L.
, and
Lin
,
J.
, 2008, “
Increasing Bending Strength and Pullout Strength in Conical Pedicle Screws Biomechanical Tests and Finite Element Analyses
,”
J. Spinal Disord. Tech.
,
21
, pp.
130
138
.
15.
Zdero
,
R.
,
Elfallah
,
K.
,
Olsen
,
M.
, and
Schemitsch
,
E. H.
, 2009, “
Cortical Screw Purchase in Synthetic and Human Femurs
,”
ASME J. Biomech. Eng.
,
131
, p.
094503
.
16.
George
,
D. C.
,
Krag
,
M. H.
,
Johnson
,
C. C.
,
Van Hal
,
M. E.
,
Haugh
,
L. D.
, and
Grobler
,
L. J.
, 1991, “
Hole Preparation Techniques for Transpedicle Screws. Effects on Pull-out Strength from Human Cadaveric Vertebrae
,”
Spine
,
16
, pp.
181
184
.
17.
Coe
,
J. D.
,
Warden
,
K. E.
,
Herzig
,
M. A.
, and
McAfee
,
P. C.
, 1990, “
Influence of Bone Mineral Density on The Fixation of Thoracolumbar Implants. A Comparative Study of Transpedicular Screws, Laminar Hooks, and Spinous Process Wires
,”
Spine
,
15
, pp.
902
907
.
18.
Fung
,
Y. C.
, 1981,
Biomechanics: Mechanical Properties of Living Tissues
,
Springer
,
New York
, Chap. 12.
19.
Sell
,
P.
,
Collins
,
M.
, and
Dave
,
J.
, 1988, “
Pedicle Screws: Axial Pull-out Strength in The Lumbar Spine
,”
Spine
,
13
, pp.
1075
1076
.
20.
Szivek
,
J. A.
,
Thomas
,
M.
, and
Benjamin
,
J. B.
, 1993, “
Technical Note Characterization of a Synthetic Foam as A Model for Human Cancellous Bone
,”
J. Appl. Biomater
,
4
, pp.
269
272
.
21.
Szivek
,
J. A.
,
Thompson
,
J. D.
, and
Benjamin
,
J. B.
, 1995, “
Characterization of Three Formulations of A Synthetic Foam as Models for A Range of Human Cancellous Bone Types
,”
J. Appl. Biomater.
,
6
, pp.
125
128
.
22.
“Concrete Damaged Plasticity,” ABAQUS Analysis User’s Manual, Version 6.10, 2010, Dassault systemes, Inc.
23.
ASTM F543-07
, 2009, “
Standard Specification and Test Methods for Metallic Medical Bone Screws
,”
Annual Books of ASTM Standards
, Volume 13.01,
American Society for Testing and Materials
,
Philadelphia
, pp.
134
153
.
You do not currently have access to this content.