The Neurosurgery Signal — Signal, Not Noise

Rapid review note

Journal Club is a rapid, AI-assisted appraisal layer. It highlights study design, effect estimates, and practice relevance, but it is still a briefing, not a replacement for the paper.

For education only. Not medical advice.

Paper snapshot

Rapid study overview

Open paper

DOI

10.1056/NEJMoa1513721

PMID

N/A

PICO

Population

Adults 50 to 80 years old with lumbar spinal stenosis at 1 or 2 adjacent levels, with or without degenerative spondylolisthesis, treated at 7 Swedish hospitals.

Intervention

Decompression plus instrumented fusion surgery.

Comparator

Decompression surgery alone.

Outcomes

Oswestry Disability Index at 2 years, walking distance, long-term clinical outcomes, reoperation, hospital stay, and cost.

Design

Type

Multicenter open-label randomized controlled trial

Randomized

Yes

Multicenter

Yes

Blinded

N/A

Follow-up

Primary 2 years; 5-year follow-up available in eligible patients

Primary endpoint

Oswestry Disability Index score at 2 years.

Secondary endpoints

Six-minute walk test
Clinical outcomes at 5 years
Hospital stay, operative burden, and repeat lumbar surgery

Practice impact

What this means

This trial is straightforward: adding fusion to decompression for lumbar spinal stenosis did not improve disability or walking outcomes, but it did make surgery bigger, longer, and more expensive. Unless a patient has a separate structural reason to need fusion, decompression alone should usually remain the default.

Bottom line

Routine fusion should not be added to decompression for lumbar spinal stenosis simply because stenosis is present, because it did not improve patient outcomes and increased operative burden and hospitalization.

Strength of evidence

high

Recommendation

change practice

Why it matters

This was a randomized multicenter trial with no clinical advantage for adding fusion.
Fusion increased length of stay, bleeding, operating time, and cost.
The neutral result persisted even when patients with spondylolisthesis were considered.

What would change my mind

A randomized trial identifying a clearly defined instability subgroup that gains a large patient-centered benefit from routine fusion.
Long-term data showing a clinically important reduction in reoperation or disability that outweighs the added operative burden.

Critical appraisal

How strong is the paper?

Methods critique

Risk of bias

The trial was open-label and the primary analysis was per-protocol rather than pure intention-to-treat, which can bias patient-reported outcomes if crossover or nonadherence differs by group.

Confounding

Randomization should have balanced measured and unmeasured confounders, and outcomes were stratified by the presence or absence of degenerative spondylolisthesis.

Missing data

The primary analysis excluded 14 patients who did not receive the assigned treatment and 5 lost to follow-up, so the main result depends on a nonrandom subset of the randomized cohort.

Multiplicity

The paper reports several clinical, walking, economic, and long-term outcomes without presenting a formal multiplicity adjustment for the secondary analyses.

Notes

This was a pragmatic surgical trial across 7 Swedish hospitals.
The study directly addresses the common practice of adding fusion to decompression for stenosis.
Resource use clearly differed between groups even though patient-reported outcomes did not.

Stats check

NNT

N/A

Effect sizes

There was no significant difference in ODI at 2 years: mean 27 with fusion versus 24 with decompression alone (P=0.24).
There was no significant difference in the 6-minute walk test: 397 m with fusion versus 405 m with decompression alone (P=0.72).
Additional lumbar surgery during mean 6.5-year follow-up occurred in 22% after fusion versus 21% after decompression alone.

Absolute effects

Mean hospital stay was 7.4 days with fusion versus 4.1 days with decompression alone.
There were no meaningful clinical differences at 2 years or among patients eligible for the 5-year analysis.
Fusion added longer operating time, more bleeding, and higher surgical costs.

Concerns

The primary analysis was per-protocol, not strict intention-to-treat.
The main benefit often cited for fusion was not seen in either patients with or without spondylolisthesis.
Open-label surgical trials can still be influenced by expectation effects on patient-reported outcomes.

External validity

Who it applies to

Adults with 1- or 2-level lumbar spinal stenosis who are candidates for decompression, including many patients with degenerative spondylolisthesis.

Who it does not

Patients with clear deformity, instability outside the trial population, trauma, infection, tumor, or other reasons fusion would be required on structural grounds.

Generalizability notes

The trial was pragmatic and multicenter, which supports broad applicability to routine spine practice.
The result is most useful when the decision is whether to add fusion routinely rather than because of obvious mechanical instability.
Longer hospital stay and higher cost with fusion are likely transferable to many healthcare systems.

Evidence trace

Source trace and metadata

Citations (4)

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methods_critique.missing_data

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p. 1

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stats_check.effect_sizes

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p. 1

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stats_check.absolute_effects

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p. 1

claim_id

practice_impact.bottom_line

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p. 1

Metadata

Generated at

2026-03-08T15:20:00-05:00

Version

manual-pdf-repair-v1