Replacement of Destructive Pull-out Test with Modal Analysis in Primary Fixation Stability Assessment of Spinal Pedicle Screw

Document Type : RESEARCH PAPER

Authors

1 1 Biomechanical Engineering Group, Department of Biomedical Engineering, Amirkabir University of Technology, Hafez Avenue, Tehran, Iran 2 Biomechanics Section, KU Leuven- University of Leuven, Celestijnenlaan, Leuven, Belgium

2 Biomechanical Engineering Group, Department of Biomedical Engineering, Amirkabir University of Technology, Hafez Avenue, Tehran, Iran

3 Biomechanics Section, KU Leuven- University of Leuven, Celestijnenlaan, Leuven, Belgium

Abstract

Background: Pedicle screw fixation devices are the predominant stabilization systems adopted for a wide variety of
spinal defects. Accordingly, both pedicle screw design and bone quality are known as the main parameters affecting the
fixation strength as measured by the pull-out force and insertion torque. The pull-out test method, which is recommended
by the standards of the American Society for Testing and Materials (ASTM), is destructive. A non-destructive test method
was proposed to evaluate the mechanical stability of the pedicle screw using modal analysis. Natural frequency (ωn)
extracted from the modal analysis was then correlated with peak pull-out force (PPF) and peak insertion torque (PIT).
Methods: Cylindrical pedicle screws with a conical core were inserted into two different polyurethane (PU) foams with
densities of 0.16 and 0.32 g/cm3. The PIT and PPF were measured according to the well-established ASTM-F543
standard at three different insertion depths of 10, 20, and 30 mm. Modal analysis was carried out through recording
time response of an accelerometer attached to the head of the screw impacted by a shock hammer. The effect of the
insertion depth and foam density on the insertion torque, natural frequency, and pull-out force were quantified.
Results: The maximum values of ωn, PIT, and PPT were obtained at 2,186 Hz, 123.75 N.cm, and 981.50 N, respectively,
when the screw was inserted into the high-density foam at the depth of 30 mm. The minimum values were estimated
at 332 Hz, 16 N.cm, and 127 N, respectively, within the low-density PU at the depth of 10 mm. The higher value of ωn
was originated from higher bone screw stability and thus more fixation strength. According to the regression analysis
outcomes, the natural frequency (ωn) was linearly dependent on the PIT (ωn=14 PIT) and also on the PPF (ωn=1.7
PPF). Coefficients of variation as the results of the modal analysis were significantly less than those in conventional
methods (i.e. pull-out and insertion torque).
Conclusion: The modal analysis was found to be a reliable, repeatable, and non-destructive method, which could be
considered a prospective alternative to the destructive pull-out test that is limited to the in-vitro application only. The
modal analysis could be applied to assess the stability of implantable screws, such as orthopedic and spinal screws.
Level of evidence: V

Keywords


1. Gibson JNA, Waddell G. Surgery for degenerative 
lumbar spondylosis: updated Cochrane Review. J 
Spine 2005;30(20):2312-20.
2. Gaines R. The use of pedicle-screw internal fixation 
for the operative treatment of spinal disorders. J Bone 
and Joint Surgery. 2000;82(10):1458-76.
3. Cappuccino A, Cornwall GB, Turner AW, Fogel GR, 
Duong HT, Kim KD, et al. Biomechanical analysis and 
review of lateral lumbar fusion constructs. J Spine. 
2010;35(26S):S361-S7.
4. Inceoglu S, Ferrara L, McLain RF. Pedicle screw fixation 
strength: pullout versus insertional torque. The spine 
journal. 2004;4(5):513-8.
5. Panjabi MM. Clinical spinal instability and low 
back pain. J electromyography kinesiology. 2003; 
13(4):371-9.
6. Boucher H. A method of spinal fusion. J bone joint 
surgery British volume. 1959;41(2):248-59.
7. Roy-Camille R, Saillant G, Mazel C. Internal fixation of 
the lumbar spine with pedicle screw plating. J Clinical 
orthopaedics related research. 1986(203):7-17.
8. Chen C-S, Chen W-J, Cheng C-K, Jao S-HE, Chueh S-C, 
Wang C-C. Failure analysis of broken pedicle screws 
on spinal instrumentation. J Medical engineering 
physics. 2005;27(6):487-96.
9. Abshire BB, McLain RF, Valdevit A, Kambic HE. 
Characteristics of pullout failure in conical and 
cylindrical pedicle screws after full insertion and 
back-out. The Spine Journal. 2001;1(6):408-14.
10.Kim Y-Y, Choi W-S, Rhyu K-W. Assessment of pedicle 
screw pullout strength based on various screw designs 
and bone densities—an ex vivo biomechanical study. 
The Spine Journal. 2012;12(2):164-8.
11.Vishnubhotla S, McGarry WB, Mahar AT, Gelb DE. A 
titanium expandable pedicle screw improves initial 
pullout strength as compared with standard pedicle 
screws. The Spine Journal. 2011;11(8):777-81.
12.Einafshar M, Hashemi A, Mojgani P. Evalution of 
primary stability of spinal pedicle screws using 
modal analysis, conventional pull-out and insertion 
torque. Iranian Journal of Biomedical Engineering. 
2020;14(3):169-77 .
13.Hitchon PW, Brenton MD, Coppes JK, From AM, Torner 
JC. Factors affecting the pullout strength of selfdrilling and self-tapping anterior cervical screws. J 
Spine 2003;28(1):9-13.
14.Kubiak AJ, Lindqvist-Jones K, Dearn KD, Shepherd 
DE. Comparison of the mechanical properties of two 
designs of polyaxial pedicle screw. J Engineering 
Failure Analysis. 2019;95:96-106.
15.Lill CA, Schneider E, Goldhahn J, Haslemann A, Zeifang 
F. Mechanical performance of cylindrical and dual core 
pedicle screws in calf and human vertebrae. Archives 
of orthopaedic trauma surgery. 2006;126(10):686-94.
16.Seng WRD, Chou SM, Siddiqui SS, Oh JY. Pedicle Screw 
Designs in Spinal Surgery: Is There a Difference? A 
Biomechanical Study on Primary and Revision PullOut Strength. J Spine. 2019;44(3):E144-E9.
17.Seng WR, Chou S, Siddiqui S, Oh J. Pedicle Screw 
Designs in Spinal Surgery. J Spine. 2019;44(3).
18.Yamaguchi Y, Shiota M, Munakata M, Kasugai S, Ozeki 
M. Effect of implant design on primary stability using 
torque-time curves in artificial bone. International 
journal of implant dentistry. 2015;1(1):21.
19.Krijnen MR, Mensch D, van Dieen JH, Wuisman PI, 
Smit TH. Primary spinal segment stability with a 
stand-alone cage: in vitro evaluation of a successful 
goat model. Acta Orthopaedica. 2006;77(3):454-61.
20.ASTM F543. Standard specification and test methods 
for metallic medical bone screws. ASTM International, 
West Conshohocken, PA; 2017. 
21.ASTM F1717. Standard test methods for spinal 
implant constructs in a vertebrectomy model. ASTM 
International, West Conshohocken, PA; 2014. 
22.Yang S-C, Liu P-H, Tu Y-K. Pullout evaluation of 
sawbone experiment in different types of pedicle 
screws combined with bone cement augmentation 
for severe osteoporotic spine. J Acta of bioengineering 
biomechanics. 2018;20(2).
23.Einafshar M, Hashemi A, van Lenthe GH. Homogenized 
finite element models can accurately predict 
screw pull-out in continuum materials, but not in 
porous materials. J Computer Methods Programs in 
Biomedicine. 2021:105966.
24.Hashemi A, Bednar D, Ziada S. Pullout strength of 
pedicle screws augmented with particulate calcium 
phosphate: an experimental study. The spine journal. 
2009;9(5):404-10.
25.Sandén B, Olerud C, Larsson S, Robinson Y. Insertion 
torque is not a good predictor of pedicle screw 
loosening after spinal instrumentation: a prospective 
study in 8 patients. Patient safety in surgery. 
2010;4(1):14.
26.Ricci WM, Tornetta III P, Petteys T, Gerlach D, Cartner 
J, Walker Z, et al. A comparison of screw insertion 
torque and pullout strength. J orthopaedic trauma. 
2010;24(6):374-8.
27.Brasiliense LB, Lazaro BC, Reyes PM, Newcomb 
AG, Turner JL, Crandall DG, et al. Characteristics of 
immediate and fatigue strength of a dual-threaded 
pedicle screw in cadaveric spines. The Spine Journal. 
2013;13(8):947-56.
28.Akpolat YT, Inceoglu S, Kinne N, Hunt D, Cheng WK. 
Fatigue performance of cortical bone trajectory screw 
compared with standard trajectory pedicle screw. J 
Spine. 2016;41(6):E335-E41.
29.Karami KJ, Buckenmeyer LE, Kiapour AM, Kelkar PS, 
Goel VK, Demetropoulos CK, et al. Biomechanical 
evaluation of the pedicle screw insertion depth effect 
on screw stability under cyclic loading and subsequent 
pullout. J Clinical Spine Surgery. 2015;28(3):E133-E9.
30.Steiner JA, Christen P, Affentranger R, Ferguson SJ, van Lenthe GH. A novel in silico method to quantify 
primary stability of screws in trabecular bone. J 
Orthopaedic Research. 2017;35(11):2415-24.
31.Demir T, Basgül C. The pullout performance of pedicle 
screws: Springer; 2015.
32.Gehrke SA, Marin GW. Biomechanical evaluation 
of dental implants with three different designs: 
Removal torque and resonance frequency analysis in 
rabbits. Annals of Anatomy-Anatomischer Anzeiger. 
2015;199:30-5.
33.Javed F, Ahmed HB, Crespi R, Romanos GE. Role of 
primary stability for successful osseointegration 
of dental implants: factors of influence and 
evaluation. Interventional Medicine Applied Science. 
2013;5(4):162-7.
34.Einafshar M, Hashemi A, van Lenthe H. Can periotest® 
quantify spinal pedicle screw stability in agreement 
with pull-out test and acoustic modal analysis? . 
26th Congress of European Society of Biomechanics; 
11/07/20212021. p. 376. 
35.Vidyasagar L, Salms G, Apse P, Teibe U. Investigation of 
initial implant stability with different dental implant 
designs. A pilot study in pig ribs using resonance 
frequency analysis. Stomatologija. 2004;6(2):35-9.
36.Muhamed A, Georges C, Mustafa M, Abdulgani A. 
Implant stability: methods and recent advances. 
Journal of Dental Medical Sciences. 2017;16(8):13-23.
37.Rondon A, Sariali E, Vallet Q, Grimal Q. Modal analysis 
for the assessment of cementless hip stem primary 
stability in preoperative THA planning. J Medical 
engineering physics. 2017;49:79-88.
38.Leuridan S, Goossens Q, Pastrav L, Roosen J, Mulier M, 
Denis K, et al. Determination of replicate composite 
bone material properties using modal analysis. J 
the mechanical behavior of biomedical materials. 
2017;66:12-8.
39.Rodrigues JD, Lopes H, De Melo F, Simoes J. 
Experimental modal analysis of a synthetic composite 
femur. Experimental mechanics. 2004;44(1):29-32.
40.Goossens Q, Vancleef S, Leuridan S, Pastrav LC, Mulier 
M, Desmet W, et al. The Use of a Vibro-Acoustic 
Based Method to Determine the Composite Material 
Properties of a Replicate Clavicle Bone Model. Journal 
of Functional Biomaterials. 2020;11(4):69.
41.Einafshar M, Mojgani P, Kazemi M, Hashemi A. Initial 
stability analysis of spine pedicular screws using 
modal analysis method. The Biennial International 
Conference on Experimetnal Solid Mechanics2020. 
42.Einafshar M, Hashemi A. New Biomechanical 
Approach for Evaluation of Spinal Pedicle Screw 
Fixation Stability. Journal of Medical and Biological 
Engineering. 2021;41:447-55. 
43.Leuridan S, Goossens Q, Pastrav L, Roosen J, Mulier M, 
Denis K, et al. Determination of replicate composite 
bone material properties using modal analysis. 
Journal of the mechanical behavior of biomedical 
materials. 2017;66:12-8.
44.Henyš P, Leuridan S, Goossens Q, Mulier M, Pastrav L, 
Desmet W, et al. Modal frequency and shape curvature 
as a measure of implant fixation: A computer study 
on the acetabular cup. J Medical engineering physics. 
2018;60:30-8.
45.Goossens Q, Pastrav L, Roosen J, Mulier M, Desmet 
W, Vander Sloten J, et al. Acoustic analysis to 
monitor implant seating and early detect fractures 
in cementless THA: An in vivo study. Journal of 
Orthopaedic Research. 2020:1-10.
46.Newland DE, Ungar EE. Mechanical vibration analysis 
and computation. Acoustical Society of America; 
1990.
47.Ritto T, Sampaio R, Aguiar R. Uncertain boundary 
condition Bayesian identification from experimental 
data: A case study on a cantilever beam. Mechanical 
Systems Signal Processing. 2016;68:176-88.
48.Einafshar M, Hashemi A. New method for 
biomechanical investigation of orthopedic bone 
screws with modal analysis. 25th Congress of 
European Society of Biomechanics. 2019:622.
49.Comuzzi L, Iezzi G, Piattelli A, Tumedei M. An In Vitro 
Evaluation, on Polyurethane Foam Sheets, of the 
Insertion Torque (IT) Values, Pull-Out Torque Values, 
and Resonance Frequency Analysis (RFA) of NanoShort 
Dental Implants. J Polymers. 2019;11(6):1020.
50.Kahraman S, Bal B, Asar N, Turkyilmaz I, Tözüm T. 
Clinical study on the insertion torque and wireless 
resonance frequency analysis in the assessment 
of torque capacity and stability of self-tapping 
dental implants. Journal of Oral Rehabilitation. 
2009;36(10):755-61.
51.ASTM F1839. Standard specification for rigid 
polyurethane foam for use as a standard material for 
testing orthopaedic devices and instruments. ASTM 
International, West Conshohocken, PA; 2016. 
52.Einafshar M, Rouhi G, Aghighi M, Mortazavi SJ. 
Alteration of the Thrust Force Versus Number of 
Drill Bit Usage in Cortical Bone Drilling. Journal of 
Orthopedic Spine Trauma. 2016;2:1-5.
53.Einafshar M, Shahrezaee M, Shahrezaee MH, 
Sharifzadeh SR. Biomechanical Evaluation of 
Temperature Rising and Applied Force in Controlled 
Cortical Bone Drilling: an Animal in Vitro Study. The 
Archives of Bone Joint Surgery. 2020;8(5):605-12.
54.Muhamed A, Georges C, Mustafa M, Abdulgani A. 
Implant stability: methods and recent advances. J 
Dental Medical Sciences. 2017;16(8):13-23.
55.Einafshar M, Hashemi A, van Lenthe H. The role 
of interface stresses on implant stability. An 
experimental- computational approach. 26th 
Congress of European Society of Biomechanics; 
11/07/2021; Milan, Italy2021. p. 420. 
56.Osterhoff G, Morgan EF, Shefelbine SJ, Karim 
L, McNamara LM, Augat P. Bone mechanical 
properties and changes with osteoporosis. J Injury. 
2016;47:S11-S20.
57.Nakashima D, Ishii K, Matsumoto M, Nakamura M, 
Nagura T. A study on the use of the Osstell apparatus 
to evaluate pedicle screw stability: An in-vitro study 
using micro-CT. J PloS one. 2018;13(6):e0199362.