ArticleFrontiers in bioengineering and biotechnology2026
Direction-dependent biomechanical effects of transverse process hooks versus pedicle screws at the uppermost instrumented vertebra in adult spinal deformity: a finite element analysis.
Article in Frontiers in bioengineering and biotechnology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
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
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Proximal junctional complications are often driven by abrupt mechanical transition at the uppermost instrumented vertebra (UIV). This study used patient-specific finite element analysis to compare biomechanical effects of transverse process hooks and pedicle screws at the UIV, specifically examining how hook orientation influences anterior-posterior load sharing. A validated nonlinear three-dimensional T7-L2 spinal model was developed using data from a 60-year-old woman. Three UIV constructs were evaluated at T9: bilateral pedicle screws (BPS) and downward and upward facing transverse process hook (TPH) configurations. Under a 500-N follower load and 8-Nm bending moments, we analyzed facet joint load (FJL), range of motion (ROM), intradiscal pressure, and mechanical failure risk. In flexion, FJL at the UIV+1/UIV level decreased by 6.2% and 19.6% in the downward-facing and upward-facing TPH models, respectively, compared with the BPS model. In extension, FJL decreased by 4.2% in the upward-facing TPH model, but increased by 32.4% in the downward-facing TPH model, relative to the BPS model. Both TPH models preserved greater UIV ROM than the bilateral pedicle screw model, with the upward-facing configuration achieving the highest flexion ROM (2.1°) and the downward-facing configuration achieving the highest extension ROM (3.2°). In the BPS model, UIV screw pull-out risk was 136% in flexion. Conversely, the risks of transverse process breakage for the downward-facing and upward-facing TPH models were substantially lower (50% and 42%, respectively). Hook constructs increased screw pull-out risk at the UIV-1 level compared with the BPS model. Using the TPH at the UIV can facilitate a biomechanical "soft landing" by preserving segmental motion and reducing posterior load at adjacent levels. These effects are orientation-dependent, with the upward-facing TPH configuration potentially offering greater advantage in preserving segmental motion during flexion. Surgical strategies should be tailored to individual bone quality due to potential stress transfer to the UIV-1 level.
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.