The long-term success of spinal instrumentation depends on the initial stability of pedicle screws (PS), yet current intraoperative assessments rely on surgeon subjectivity. This study introduces a quantitative, non-invasive approach—the Impact-Based Analysis Method (IBAM)—to support intraoperative decision-making. The IBAM measures screw stability using low-amplitude impacts delivered with an instrumented hammer on the surgical screwdriver after screw insertion. An IBAM indicator, defined as the average time difference between the two earliest local maxima in the force signal, was analyzed under varying stability conditions in artificial bone samples. Experimental factors included bone density (ρ), insertion depth (D), and pilot hole diameter (ϕ). The IBAM indicator was compared with the PS pull-out force for each configuration. Although the main effects showed opposite trends for the pull-out force and the IBAM indicator, their relative magnitudes were similar (ρ∼35%, D∼25%, ϕ∼15%). The relationship between the pull-out force and the IBAM indicator followed a power-law model (adjusted R2 = 0.85) with a negative exponent. As screw stability increased, the pull-out force rose while the IBAM indicator decreased, demonstrating complementary sensitivity to bone-implant interface changes. While results are promising, the simplified experimental design limited the ability to fully capture bone-implant interaction complexity. Future studies should aim to validate IBAM in vivo to confirm its clinical applicability.
NaikAMacInnisBRShafferA, et al. Trends in technology for pedicle screw placement: a temporal meta-analysis. Spine2023; 48(11): 791–799. https://doi.org/10.1097/BRS.0000000000004604
2.
PernaFBorghiRPillaF, et al. Pedicle screw insertion techniques: an update and review of the literature. Musculoskelet Surg2016; 100(3): 165–169. https://doi.org/10.1007/s12306-016-0438-8
3.
GaoXFraulobMHaïatG. Biomechanical behaviours of the bone-implant interface: a review. J R Soc Interface2019; 16(156): 20190259. https://doi.org/10.1098/rsif.2019.0259
4.
YangSSunTZhangL, et al. Stress distribution of different pedicle screw insertion techniques following single-segment TLIF: a finite element analysis study. Orthop Surg2023; 15(4): 1153–1164. https://doi.org/10.1111/os.13671
5.
AmiroucheFSolitroGFMagnanBP. Stability and spine pedicle screws fixation strength-a comparative study of bone density and insertion angle. Spine Deform2016; 4(4): 261–267. https://doi.org/10.1016/j.jspd.2015.12.008
SilvaPRosaRCShimanoAC, et al. Effect of pilot hole on biomechanical and in vivo pedicle screw–bone interface. Eur Spine J2013; 22(8): 1829–1836. https://doi.org/10.1007/s00586-013-2810-9
8.
CostaFVillaTAnasettiF, et al. Primary stability of pedicle screws depends on the screw positioning and alignment. Spine J2013; 13(12): 1934–1939. https://doi.org/10.1016/j.spinee.2013.03.046
KrennMHPiotrowskiWPPenzkoferR, et al. Influence of thread design on pedicle screw fixation. Laboratory investigation. J Neurosurg Spine2008; 9(1): 90–95. https://doi.org/10.3171/SPI/2008/9/7/090
11.
GalbuseraFVolkheimerDReitmaierS, et al. Pedicle screw loosening: a clinically relevant complication?Eur Spine J2015; 24(5): 1005–1016. https://doi.org/10.1007/s00586-015-3768-6
12.
JanssenIRyangYMGemptJ, et al. Risk of cement leakage and pulmonary embolism by bone cement-augmented pedicle screw fixation of the thoracolumbar spine. Spine J2017; 17(6): 837–844. https://doi.org/10.1016/j.spinee.2017.01.009
13.
VargheseVSaravana KumarGKrishnanV. Effect of various factors on pull out strength of pedicle screw in normal and osteoporotic cancellous bone models. Med Eng Phys2017; 40: 28–38. https://doi.org/10.1016/j.medengphy.2016.11.012
14.
KaramiKJBuckenmeyerLEKiapourAM, et al. Biomechanical evaluation of the pedicle screw insertion depth effect on screw stability under cyclic loading and subsequent pullout. Clin Spine Surg2015; 28(3): E133–E139. https://doi.org/10.1097/BSD.0000000000000178
15.
SeongWJGramiSJeongSC, et al. Comparison of push-In versus Pull-Out tests on bone-implant interfaces of rabbit tibia dental implant healing model. Clin Implant Dent Relat Res2013; 15(3): 460–469. https://doi.org/10.1111/j.1708-8208.2011.00357.x
ChevalierYMatsuuraMKrügerS, et al. Micro-CT and micro-FE analysis of pedicle screw fixation under different loading conditions. J Biomech2018; 70: 204–211. https://doi.org/10.1016/j.jbiomech.2017.12.023
18.
RouyinANazemiHArjmandN, et al. Effect of pedicle screw misplacement on the pull-out strength using personalized finite element modeling. Comput Biol Med2024; 183: 109290. https://doi.org/10.1016/j.compbiomed.2024.109290
19.
EinafsharMHashemiAvan LentheGH. Replacement of destructive pull-out test with modal analysis in primary fixation stability assessment of Spinal Pedicle Screw. Arch Bone Jt Surg2022; 10(2): 204–212. https://doi.org/10.22038/ABJS.2021.54294.2712
NakashimaDMikamiKKikuchiS, et al. Laser resonance frequency analysis of pedicle screw stability: a cadaveric model bone study. J Orthop Res2021; 39(11): 2474–2484. https://doi.org/10.1002/jor.24983
22.
NakashimaDIshiiKMatsumotoM, et al. A study on the use of the osstell apparatus to evaluate pedicle screw stability: an in-vitro study using micro-CT. PLoS One2018; 13(6): e0199362. https://doi.org/10.1371/journal.pone.0199362
23.
MichelABoscRMeningaudJP, et al. Assessing the acetabular cup implant primary stability by impact analyses: a cadaveric study. PLoS One2016; 11(11): e0166778. https://doi.org/10.1371/journal.pone.0166778
24.
Albini LomamiHDamourCRosiG, et al. Ex vivo estimation of cementless femoral stem stability using an instrumented hammer. Clin Biomech2020; 76: 105006. https://doi.org/10.1016/j.clinbiomech.2020.105006
25.
HubertARosiGBoscR, et al. Using an impact hammer to estimate elastic modulus and thickness of a sample during an osteotomy. J Biomech Eng2020; 142(7): 071009. https://doi.org/10.1115/1.4046200
26.
LamassoureLGiuntaJRosiG, et al. Using an impact hammer to perform biomechanical measurements during osteotomies: Study of an animal model. Proc Inst Mech Eng H2021; 235(7): 838–845. https://doi.org/10.1177/09544119211011824
27.
LamassoureLGiuntaJRosiG, et al. Anatomical subject validation of an instrumented hammer using machine learning for the classification of osteotomy fracture in rhinoplasty. Med Eng Phys2021; 95: 111–116. https://doi.org/10.1016/j.medengphy.2021.08.004
28.
Bas dit NuguesMRosiGHériveauxY, et al. Using an instrumented hammer to predict the rupture of bone samples subject to an osteotomy. Sensors2023; 23(4): 2304. https://doi.org/10.3390/s23042304
29.
Bas dit NuguesMLamassoureLRosiG, et al. An instrumented hammer to detect the rupture of the pterygoid plates. Ann Biomed Eng2025; 53(1): 59–70. https://doi.org/10.1007/s10439-024-03596-9
30.
PoudrelASBouffandeauADemeetOL, et al. Characterization of the concentration of agar-based soft tissue mimicking phantoms by impact analysis. J Mech Behav Biomed Mater2024; 152: 106465. https://doi.org/10.1016/j.jmbbm.2024.106465
31.
BouffandeauAPoudrelASBrossierC, et al. Assessment of the mechanical properties of soft tissue phantoms using impact analysis. Sensors (Basel)2025; 25: 1344. https://doi.org/10.3390/s25051344
32.
ASTM International. Standard specification and test methods for metallic medical bone screws. ASTM F543-23. ASTM International, 2023. https://doi.org/10.1520/F0543-23
33.
WeidlingMWendlerTSchoenfelderS, et al. Recommendations for standardised screw pull-out from polyurethane foam - the influence of density variations of the test foam and the insertion method. Med Eng Phys2022; 100: 103750. https://doi.org/10.1016/j.medengphy.2022.103750
34.
BoxGEPWilsonKB. On the experimental attainment of optimum conditions. In: KotzSJohnsonNL (eds) Breakthroughs in Statistics: Methodology and Distribution. Springer, 1992, pp.270–310. https://doi.org/10.1007/978-1-4612-4380-9_23
35.
KimYYChoiWSRhyuKW. Assessment of pedicle screw pullout strength based on various screw designs and bone densities-an ex vivo biomechanical study. Spine J2012; 12(2): 164–168. https://doi.org/10.1016/j.spinee.2012.01.014
36.
PaikHDmitrievAELehmanRA, et al. The biomechanical effect of pedicle screw hubbing on pullout resistance in the thoracic spine. Spine J2012; 12(5): 417–424. https://doi.org/10.1016/j.spinee.2012.03.020
37.
MichelANguyenVHBoscR, et al. Finite element model of the impaction of a press-fitted acetabular cup. Med Biol Eng Comput2017; 55(5): 781–791. https://doi.org/10.1007/s11517-016-1545-2
38.
PoudrelASNguyenVHRosiG, et al. Influence of the biomechanical environment on the femoral stem insertion and vibrational behavior: a 3-D finite element study. Biomech Model Mechanobiol2023; 22(2): 611–628. https://doi.org/10.1007/s10237-022-01667-1
39.
MichelABoscRVayronR, et al. In vitro evaluation of the acetabular cup primary stability by impact analysis. J Biomech Eng2015; 137(3): 031011. https://doi.org/10.1115/1.4029505
40.
MichelABoscRSailhanF, et al. Ex vivo estimation of cementless acetabular cup stability using an impact hammer. Med Eng Phys2016; 38(2): 80–86. https://doi.org/10.1016/j.medengphy.2015.10.006
41.
TijouARosiGVayronR, et al. Monitoring cementless femoral stem insertion by impact analyses: an in vitro study. J Mech Behav Biomed Mater2018; 88: 102–108. https://doi.org/10.1016/j.jmbbm.2018.08.009
42.
MehmanparastHPetitYMac-ThiongJM. Comparison of pedicle screw loosening mechanisms and the effect on fixation strength. J Biomech Eng2015; 137(12): 121003. https://doi.org/10.1115/1.4031821
43.
BoscRTijouARosiG, et al. Influence of soft tissue in the assessment of the primary fixation of acetabular cup implants using impact analyses. Clin Biomech2018; 55: 7–13. https://doi.org/10.1016/j.clinbiomech.2018.03.013
