ArticleJournal of orthopaedic surgery and research2025
Biomechanical evaluation of In-Out-In pedicle screws for atlantoaxial posterior fixation in the presence of high-riding vertebral artery and narrow C2 pedicles: a finite element analysis.
Article in Journal of orthopaedic surgery and research, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
3 citing papers in PubMed.
- Orthopedic Biomaterials in the Clinical Reconstruction of Osteoporotic Atlantoaxial Injuries: A Review.Bioengineering (Basel, Switzerland) · 2026Review
- C1 pedicle screw placement risks in patients with ponticulus posticus: a CTA retrospective simulation study.Journal of orthopaedic surgery and research · 2026Article
- Does stopping at C2 matter? A comparative analysis of alignment and craniocervical compensation in C2-T1 versus C3-T1 posterior cervical fusion.Journal of craniovertebral junction & spineArticle
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
15 authors.
Funding
Abstract
introductionIn patients with high-riding vertebral artery (HRVA) and narrow pedicles, placement of C2 pedicle screws carries a significant risk of vertebral artery injury. The in-out-in pedicle screws (IOIPS) technique offers an alternative posterior fixation strategy. However, the biomechanical performance remains unclear.
methodsA finite element model of the upper cervical spine (C0-C2) was developed to simulate HRVA and narrow pedicles. All posterior fixation constructs utilized C1 pedicle screws, while four different techniques were applied to C2: IOIPS, pedicle screws, pars screws, and translaminar screws. A vertical load of 50 N and a torque of 1.5 Nm were applied at C0 to assess and compare the range of motion (ROM) and stress distribution.
resultsAll four fixation techniques effectively reduced ROMs at the atlantoaxial, with IOIPS demonstrating the lowest ROMs and translaminar screws showing the highest. Pedicle and pars screws exhibited higher von Mises stresses within the implants, while IOIPS achieved a more uniform stress distribution. Translaminar screws had the lowest implant stresses but provided the least stability.
conclusionFor patients with HRVA and narrow C2 pedicles, IOIPS offers superior stability along with relatively low and evenly distributed implant stress, suggesting it is a biomechanically viable fixation technique. However, its application should be reserved for carefully selected cases rather than adopted as a routine surgical strategy.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.