Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jan 12:9:1004642.
doi: 10.3389/fsurg.2022.1004642. eCollection 2022.

Will the adjustment of insertional pedicle screw positions affect the risk of adjacent segment diseases biomechanically? An in-silico study

Chenyi Huang  1 , Zongchao Liu  1 , Zhangchao Wei  1 , Zhongxin Fang  2 , Zhipeng Xi  3 , Ping Cai  4 , Jingchi Li  1
Affiliations

Will the adjustment of insertional pedicle screw positions affect the risk of adjacent segment diseases biomechanically? An in-silico study

Chenyi Huang et al. Front Surg. .

Abstract

Background: The fixation-induced biomechanical deterioration will increase the risk of adjacent segment diseases (ASD) after lumbar interbody fusion with Bilateral pedicle screw (BPS) fixation. The accurate adjustment of insertional pedicle screw positions is possible, and published studies have reported its mechanical effects. However, no studies clarified that adjusting insertional screw positions would affect the postoperative biomechanical environment and the risk of ASD. The objective of this study was to identify this issue and provide theoretical references for the optimization of insertional pedicle screw position selections.

Methods: The oblique lumbar interbody fusion fixed by BPS with different insertional positions has been simulated in the L4-L5 segment of our previously constructed and validated lumbosacral model. Biomechanical indicators related to ASD have been computed and recorded under flexion, extension, bending, and axial rotation loading conditions.

Results: The change of screw insertional positions has more apparent biomechanical effects on the cranial than the caudal segment. Positive collections can be observed between the reduction of the fixation length and the alleviation of motility compensation and stress concentration on facet cartilages. By contrast, no pronounced tendency of stress distribution on the intervertebral discs can be observed with the change of screw positions.

Conclusions: Reducing the fixation stiffness by adjusting the insertional screw positions could alleviate the biomechanical deterioration and be an effective method to reduce the risk of ASD caused by BPS.

Keywords: adjacent segment diseases; arm of force; biomechanical deterioration; insertional screw positions; pedicle screw fixation.

PubMed Disclaimer

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
Surgical simulations and multi indicators model validation: Valin−vitro, indicators measured by published in-vitro studies; Valin−silico, indicators computed by the current in-silico study; F-E, flexion-extension; L-R, left-lateral; B, bending; AR, axial rotation.
Figure 2
Figure 2
Comparison of overall and surgical segment's ROM between surgical models with different insertional screw positions. F, Flexion; E, Extension; B, Bending; AR, Axial rotation.
Figure 3
Figure 3
Comparison of cranial and caudal adjacent segments’ ROM between surgical models with different insertional screw positions. F, Flexion; E, Extension; B, Bending; AR, Axial rotation.
Figure 4
Figure 4
Comparison of FCF between surgical models with different insertional screw positions. F, Flexion; E, Extension; B, Bending; AR, Axial rotation.
Figure 5
Figure 5
Comparison of indicators related to the cranial and caudal disc degeneration between surgical models with different insertional screw positions. F, Flexion; E, Extension; B, Bending; AR, Axial rotation.
Figure 6
Figure 6
Diagrams of OLIF fixed by PFS with different insertional screw positions, and the highly adjustable of percutaneous BPS insertion. M-M: Screws were inserted into the middle positions of both cranial and caudal vertebral bodies; B-T: Screws were inserted into the bottom of the cranial and the top of the caudal vertebral bodies (Shortest fixation length of PFS); T-B: Screws were inserted into the top of the cranial and the bottom of the caudal vertebral bodies (Longest fixation length of PFS); BB: Screws were inserted into the bottom of both cranial and caudal vertebral bodies (The downward movement of PFS); TT: Screws were inserted into the top of both cranial and caudal vertebral bodies (The upward movement of PFS).
See this image and copyright information in PMC

References

    1. Xu M, Yang J, Lieberman IH, Haddas R. Finite element method-based study of pedicle screw-bone connection in pullout test and physiological spinal loads. Med Eng Phys. (2019) 67:11–21. 10.1016/j.medengphy.2019.03.004 - DOI - PubMed
    1. Hsieh YY, Chen CH, Tsuang FY, Wu LC, Lin SC, Chiang CJ. Removal of fixation construct could mitigate adjacent segment stress after lumbosacral fusion: a finite element analysis. Clin Biomech (Bristol Avon). (2017) 43:115–20. 10.1016/j.clinbiomech.2017.02.011 - DOI - PubMed
    1. Tsuang FY, Tsai JC, Lai DM. Effect of lordosis on adjacent levels after lumbar interbody fusion, before and after removal of the spinal fixator: a finite element analysis. BMC Musculoskelet Disord. (2019) 20(1):470. 10.1186/s12891-019-2886-4. - DOI - PMC - PubMed
    1. Galbusera F, Bellini CM, Anasetti F, Ciavarro C, Lovi A, Brayda-Bruno M. Rigid and flexible spinal stabilization devices: a biomechanical comparison. Med Eng Phys. (2011) 33(4):490–6. 10.1016/j.medengphy.2010.11.018 - DOI - PubMed
    1. Chuang WH, Lin SC, Chen SH, Wang CW, Tsai WC, Chen YJ, et al. Biomechanical effects of disc degeneration and hybrid fixation on the transition and adjacent lumbar segments: trade-off between junctional problem, motion preservation, and load protection. Spine. (2012) 37(24):E1488–97. 10.1097/BRS.0b013e31826cdd93 - DOI - PubMed

LinkOut - more resources