ArticleActa orthopaedica2025
Mechanical axial instability of segmental pedicle screw instrumentation for adolescent idiopathic scoliosis: a retrospective cohort study of tulip screw versus dual locking cup instrumentation.
Article in Acta orthopaedica, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.
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
1 citing paper in PubMed.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
background and purposeThe effects of axial instability in the rod-screw interface resulting in axial slippage between screws and rods are largely unknown. We aimed to assess the incidence of axial slip and loss of correction by comparing tulip screw versus dual locking cup in spinal instrumentations of patients treated with posterior spinal fusion for adolescent idiopathic scoliosis (AIS). We also aimed to assess whether axial slip would affect health-related quality of life.
methodsThis study consists of 194 patients who underwent posterior spinal fusion for AIS during 2012-2022. All patients had a minimum of 2 years' follow-up. There were 98 patients treated with segmental tulip pedicle screw instrumentation and 96 patients with segmental dual locking cup constructs. Axial slip was defined as ≥ 2 mm and was assessed by measuring the rod exceeding the last pedicle screw and the distance between the 2 lowest screws on the same rod. Loss of correction was assessed by comparing postoperative and 2-year radiographic measurements. Health-related quality of life was assessed using the SRS-24 questionnaire.
resultsAxial slip occurred only between the lowest instrumented vertebra and the vertebra above it on the convex side of the deformity. At 2 years of follow-up, axial slippage of 2 mm or more was observed more often in the dual locking group, which was observed in 24 (25%) patients in the dual locking cup group and 11 (11%) patients in the tulip group (risk ratio [RR] 2.2, 95% confidence interval [CI] 1.2-4.4). Minimum of 10° loss of major curve correction was found in 1 (1%) patient in the tulip group and 9 (9%) patients in the dual locking group (RR 9.1, CI 1.2-100).
conclusionAxial slip was significantly less frequent in the tulip group than in the dual locking cup group. This suggests that tulip screw instrumentation may offer superior mechanical stability in posterior spinal fusion for AIS. Axial slip was not associated with health-related quality of life outcomes.
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.