Evidence map›Paper›PMID 41266912›Full record

SynthesisEuropean spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society2026

The Lenke paradox: substantial agreement or methodological mirage?

Hussein Akil, Alexa Chedid, Rodrigo Muscogliati, Joe Frem, Gil Kerbaj, Ali Akil, Masood Shafafy, Mohammed Patel, Nasir Quraishi, Elie Najjar

Abstract readSystematic ReviewMeta-Analysis
PubMed Publisher
In one paragraph

Synthesis in European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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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

0 citing papers in PubMed.

No citing paper in PubMed yet.

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

10 authors.

Hussein AkilCentre for Spinal Studies & Surgery, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK. Husseinakill@yahoo.com.
Alexa ChedidGilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon.
Rodrigo MuscogliatiCentre for Spinal Studies & Surgery, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK. rmuscogliati@gmail.com.
Joe FremGilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon.
Gil KerbajGilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon.
Ali AkilGilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon.
Masood ShafafyCentre for Spinal Studies & Surgery, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK.
Mohammed PatelCentre for Spinal Studies & Surgery, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK.
Nasir QuraishiCentre for Spinal Studies & Surgery, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK.
Elie NajjarCentre for Spinal Studies & Surgery, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, UK. elie.njjr@gmail.com.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

STUDY

designSystematic review and meta-analysis.

objectiveTo evaluate inter- and intra-observer reliability of the Lenke classification for adolescent idiopathic scoliosis (AIS) and identify methodological factors influencing agreement. The Lenke system is widely used in AIS surgical planning. While initial reports showed excellent reproducibility, subsequent studies have yielded inconsistent results, particularly for lumbar and sagittal modifiers.

methodsFollowing PRISMA guidelines, five databases (PubMed, Embase, Cochrane CENTRAL, Scopus, and Web of Science) were searched to August 2025. Data on observer characteristics, imaging protocols, measurement methods, and statistical indices (κ, ICC) were extracted. Study quality was assessed with QAREL. Descriptive synthesis and random-effects meta-analysis were performed.

resultsEleven studies (528 radiographs) met inclusion. Inter-observer reliability averaged κ=0.76 (range 0.50-0.96); lumbar κ=0.75 (0.53-0.92); sagittal κ=0.79 (0.41-1.0). Pooled analysis of two studies with confidence intervals yielded κ=0.69 (95% CI 0.56-0.82; I²=21%). Intra-observer reliability was higher (κ≈0.82). Reliability improved with pre-measured radiographs, experienced observers, computer assistance, and short repeat intervals; it was lower with non-premeasured films, mixed cohorts, and longer intervals. Lumbar modifiers were relatively robust, whereas sagittal reproducibility was most vulnerable to methodological bias. One study illustrated the κ paradox, with high agreement but κ=0.41 due to skewed distribution.

conclusionsThe Lenke classification is reliable under controlled conditions but less consistent in everyday practice. Reported κ values should be interpreted within their methodological context. Standardised protocols, transparent reporting, and digital tools may improve reproducibility.

Indexed as

ScoliosisAdolescentHumansLumbar VertebraeObserver VariationRadiographyReproducibility of ResultsAdolescent idiopathic scoliosisLenke classificationMeta-analysisReliabilityReproducibilitySystematic review

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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.