Decompression alone or with fusion for degenerative lumbar spondylolisthesis (Nordsten-DS): five year follow-up of a randomised, multicentre, non-inferiority trial.

Name: Αlpha¹ Rigor Record — Decompression alone or with fusion for degenerative lumbar spondylolisthesis (Nordsten-DS): five year follow-up of a randomised, multicentre, non-inferiority trial.
Item: Decompression alone or with fusion for degenerative lumbar spondylolisthesis (Nordsten-DS): five year follow-up of a randomised, multicentre, non-inferiority trial.
Rating: 96
Author: Αlpha¹

Kgomotso EL, Hellum C, Fagerland MW, Solberg T, Brox JI, Storheim K, Hermansen E, Franssen E, Weber C, Brisby H, Algaard KRH, Furunes H, Banitalebi H, Ljøstad I, Indrekvam K, Austevoll IM, Nordsten collaborators

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Αlpha¹ Rigor Review — 2.25★ (Weak), 0 critical, 3 high issues for “Decompression alone or with fusion for degenerative lumbar spondylolisthesis (Nordsten-DS): five year follow-up of a randomised, multicentre, non-inferiority trial.”

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Αlpha¹ Editorial

This rigor review was examined and confirmed by Αlpha¹ Editorial · August 16, 2026

Αlpha¹ Rigor Review

Rigor Reviewed

2.25 / 5

Weak — serious problems found

Interventional Study

Critical

High-priority

How this rating was calculated▸

Started at 5★ — deductions

IntegrityIntegrity concern ×3−1.5★
ClaimsEfficacy rests on an unvalidated surrogate endpoint−0.5★
ClaimsTreatment effect not shown to be clinically meaningful−0.5★
ReportingData & code availability partially met−0.25★

Model-reported confidence: highReviewer agreement: highEngine: 7.39.0Source: full text

Not verified in this report

No data or code availability links were detected to verify.

Problems surfaced5 types

Numerical inconsistencies1

Values that contradict each other or are impossible for the stated sample: recomputed p-values and test statistics, GRIM/GRIMMER checks on summary numbers, percentages against their own counts, totals against their parts, and estimates against their own confidence intervals.

Internal contradictions in the reported numbersAssessed

Overstated conclusions3

Conclusions that reach past what the paper's own results support — including a significance claim that no longer holds when the statistic is recomputed, and efficacy resting on an unvalidated surrogate endpoint.

Efficacy rests on an unvalidated surrogate endpointAssessed
Treatment effect not shown to be clinically meaningfulAssessed
Conclusions only partially backed by the presented evidenceAssessed

Reporting gaps1

Required detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.

Data/code availability incompleteAssessed

This Αlpha¹ Rigor Review uses AI Rigor Reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

This is a well-conducted and well-reported randomized non-inferiority trial with rigorous design, appropriate statistical methods, and transparent reporting. The main weakness is the vague data availability statement, which lacks a concrete access mechanism or timeframe.

Both independent reviewers agreed on all dimension statuses and study type (interventional). The statistics verification component checked 3 tests (all consistent); coverage is limited to tests with a test statistic and df or an effect estimate with CI. No retracted or non-existent references were found. The copyedit pass flagged 4 minor issues (typos, consistency).

3 major claims checked against the paper's own evidence: 1 only partially supported (evidence backs part of the claim; gaps or caveats remain); the rest adequately supported.

Premise concern: surrogate not validated for clinical benefit; effect size not shown to be clinically meaningful.

Recomputed 3 tests: 3 consistent, 0 inconsistent; 3 via agent-written checks.

3 integrity concerns flagged (0 high).

Reporting

Eight Dimensions7 pass · 1 warn

The introduction cites prior randomized trials and meta-analyses indicating decompression alone is sufficient up to two years, but notes contradictory longer-term results. The rationale for the trial is to assess non-inferiority at five years, addressing the gap in longer-term evidence. Limitations of prior research (sparse and contradictory outcomes beyond two years) are explicitly acknowledged.

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 90% conf

The paper establishes a clear scientific premise by citing prior RCTs and meta-analyses, and justifies the need for longer-term follow-up data.

Evidence

direct quote[Introduction, paragraph 3]

“More recently, evidence from randomised controlled trials and meta-analyses have indicated that decompression alone is sufficient for up to two years of follow-up. By contrast, one randomised controlled trial found that additional instrumented fusion gave superior results to decompression alone. Results from randomised controlled trials that include outcomes from more than two years after surgery are sparse and contradictory.”