Year: 2026
Type: article
Abstract: Atlantoaxial instability (AAI) necessitates surgical stabilization to prevent neurological compromise. This finite element study compares the biomechanical performance of four atlantoaxial fixation constructs under physiological loading: standalone atlantoaxial cage (AAC), C1-C2 pedicle screws (C1-C2 PS), C1 pedicle screws with transarticular screws (C1 PS + TA), and a combined 360° construct (C1-C2 PS + AAC). A validated C0-C7 FE model with simulated AAI was subjected to flexion, extension, lateral bending, and axial rotation. Results demonstrated that the 360° construct provided the highest stability, with the lowest range of motion in all directions. It also significantly reduced peak von Mises stress on screws (by up to 91.7%) and cages (by up to 57.2%) compared to standalone constructs, while minimizing vertebral stress (over 90% reduction vs. C1-C2 PS). Adjacent disc stress remained largely unaffected by fixation type, with consistent stress concentrations at the C2-C3 level. The C1-C2 PS + AAC configuration offers superior biomechanical stability, enhanced load sharing, and reduced implant and bone stress, supporting its potential as an optimal strategy for complex AAI fixation.
Source: Scientific Reports
Authors: Nanjian Xu, Yang Wang, Weihu Ma, Jun Gu
Institution: Ningbo No.6 Hospital
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,690
OpenAlex ID: W7166101273
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