Evidence map›Paper›PMID 35538122›Full record

ArticleScientific reports2022

The biomechanical fundamentals of crosslink-augmentation in posterior spinal instrumentation.

Frédéric Cornaz, Marie-Rosa Fasser, Jess Gerrit Snedeker, José Miguel Spirig, Mazda Farshad, Jonas Widmer

Abstract read
In one paragraph

Article in Scientific reports, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Frédéric CornazDepartment of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
Marie-Rosa FasserInstitute for Biomechanics, ETH Zurich, Zurich, Switzerland.
Jess Gerrit SnedekerDepartment of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
José Miguel SpirigDepartment of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
Mazda FarshadDepartment of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
Jonas WidmerInstitute for Biomechanics, ETH Zurich, Zurich, Switzerland. jonas.widmer@balgrist.ch.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Posterior screw-rod constructs can be used to stabilize spinal segments; however, the stiffness is not absolute, and some motion can persist. While the effect of crosslink-augmentation has been evaluated in multiple studies, the fundamental explanation of their effectiveness has not been investigated. The aim of this study was to quantify the parameters "screw rotation" and "parallelogram deformation" in posterior instrumentations with and without crosslinks to analyze and explain their fundamental effect. Biomechanical testing of 15 posteriorly instrumented human spinal segments (Th10/11-L4/L5) was conducted in axial rotation, lateral bending, and flexion-extension with ± 7.5 Nm. Screw rotation and parallelogram deformation were compared for both configurations. Parallelogram deformation occurred predominantly during axial rotation (2.6°) and was reduced by 60% (-1.45°, p = 0.02) by the addition of a crosslink. Simultaneously, screw rotation (0.56°) was reduced by 48% (-0.27°, p = 0.02) in this loading condition. During lateral bending, 0.38° of parallelogram deformation and 1.44° of screw rotation was measured and no significant reduction was achieved by crosslink-augmentation (8%, -0.03°, -p = 0.3 and -13%, -0.19°, p = 0.7 respectively). During flexion-extension, parallelogram deformation was 0.4° and screw rotation was 0.39° and crosslink-augmentation had no significant effect on these values (-0.12°, -30%, p = 0.5 and -0°, -0%, p = 0.8 respectively). In axial rotation, crosslink-augmentation can reduce parallelogram deformation and with that, screw rotation. In lateral bending and flexion-extension parallelogram deformation is minimal and crosslink-augmentation has no significant effect. Since the relatively large screw rotation in lateral bending is not caused by parallelogram deformation, crosslink-augmentation is no adequate countermeasure. The fundamental understanding of the biomechanical effect of crosslink-augmentation helps better understand its potential and limitations in increasing construct stiffness.

Indexed as

Bone ScrewsSpinal FusionBiomechanical PhenomenaCadaverFracture Fixation, InternalHumansLumbar VertebraeNeurosurgical ProceduresRange of Motion, ArticularRotation

Identifiers

PMID35538122
PMCPMC9090827

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.