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Multicenter Study
. 2025 Mar;13(2):587-594.
doi: 10.1007/s43390-024-01005-8. Epub 2024 Nov 11.

Zones where reduced implant density leads to correction loss after scoliosis surgery for Lenke 1A adolescent idiopathic scoliosis: a multicenter study

Kaho Yanagisawa  1 , Hiroki Oba  2 , Tetsuro Ohba  3 , Tomohiro Banno  4 , Shoji Seki  5 , Masashi Uehara  1 , Shota Ikegami  1 , Tetsuhiko Mimura  1 , Terue Hatakenaka  1 , Yoshinari Miyaoka  1 , Daisuke Kurogochi  1 , Takuma Fukuzawa  1 , Michihiko Koseki  6 , Yoshiharu Kawaguchi  5 , Hirotaka Haro  3 , Yukihiro Matsuyama  4 , Jun Takahashi  1
Affiliations
Multicenter Study

Zones where reduced implant density leads to correction loss after scoliosis surgery for Lenke 1A adolescent idiopathic scoliosis: a multicenter study

Kaho Yanagisawa et al. Spine Deform. 2025 Mar.

Abstract

Purpose: Investigate zones where implant density should not be reduced in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) Lenke type 1A curves.

Methods: 126 consecutive patients (118 female and 8 male; mean age: 15.1 ± 2.2 years) with Lenke type 1A AIS who underwent PSF using pedicle screw constructs were included. Correction loss which was calculated using immediately postoperative and 2-year postoperative Cobb angle. Implant density was assessed by dividing the instrumented levels into four zones each on the concave and convex sides. The risk factors for significant correction loss were examined using logistic regression analysis. For convex apical zone, correction loss was compared among the three groups of low (0-59%), medium (60-99%), and high (100%) implant density.

Results: Multivariate analysis revealed the apical zone of the convex side (Odds ratio [OR] 1.27; 95% confidence interval [CI] 1.01-1.59; P = 0.04) and the peri-apical zone of the convex side (OR 1.33; 95% CI 1.11-1.59; P = 0.002) as independent predictors of significant correction loss. In the convex apical zone, the median (interquartile range) correction loss of the low implant density, medium implant density, and high implant-density groups was 4.8° (1.5°), 5.3° (0.8°), and 2.2° (0.3°), respectively. The median difference was 2.6° (P = 0.048) between the low implant density and high implant-density group and 3.1° (P < 0.001) between the medium implant density and high implant-density group.

Conclusion: In PSF for AIS Lenke 1A, low implant density in the convex apical zones were significant factors affecting correction loss at 2 years postoperatively. However, the difference in correction loss between groups may not be large enough to consider clinically meaningful. Prospective studies of longer term outcomes are needed to determine whether these results are clinically important.

Keywords: Adolescent idiopathic scoliosis; Implant density; Lenke type 1; Posterior spinal fusion; Screw density; Skip; Zone.

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Conflict of interest statement

Declarations. Conflict of interest: The authors declare no conflicts of interest. Ethical approval: Approval code 5142, Shinshu University School of Medicine. Informed consent: Consent was not required because this study was retrospective study.

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References

    1. Ledonio CG, Polly DW Jr, Vitale MG et al (2011) Pediatric pedicle screws: comparative effectiveness and safety: a systematic literature review from the Scoliosis Research Society and the Pediatric Orthopaedic Society of North America task force. J Bone Joint Surg Am 93(13):1227–1234 - DOI - PubMed
    1. Oba H, Ikegami S, Kuraishi S et al (2020) Perforation rate of pedicle screws using hybrid operating room combined with intraoperative computed tomography navigation for adolescent idiopathic scoliosis: impact of distance from the reference frame and other risk factors. Spine (Phila Pa 1976) 45(20):E1357-e64 - DOI - PubMed
    1. Oba H, Ebata S, Takahashi J et al (2018) Pedicle perforation while inserting screws using o-arm navigation during surgery for adolescent idiopathic scoliosis: risk factors and effect of insertion order. Spine (Phila Pa 1976) 43(24):E1463-e8 - DOI - PubMed
    1. Diab M, Smith AR, Kuklo TR (2007) Neural complications in the surgical treatment of adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 32(24):2759–63 - DOI - PubMed
    1. Kosmopoulos V, Schizas C (2007) Pedicle screw placement accuracy: a meta-analysis. Spine (Phila Pa 1976) 32(3):E111-20 - DOI - PubMed

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