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Journal Club

Spine

Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis.

N Engl J Med | 2007

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/NEJMoa070302

PMID

17538085

PICO

Population

Surgical candidates with degenerative spondylolisthesis and spinal stenosis from 13 centers in 11 U.S. states, with at least 12 weeks of symptoms and image confirmation.

Intervention

Standard decompressive laminectomy (with or without fusion).

Comparator

Usual nonsurgical care (e.g., physical therapy, analgesics).

Outcomes

SF-36 bodily pain and physical function scores (100-point scales), modified Oswestry Disability Index (100-point scale) at 6 weeks, 3 months, 6 months, 1 year, and 2 years.

Design

Type

Randomized controlled trial with an observational cohort.

Randomized

Yes

Multicenter

Yes

Blinded

Not applicable: outcomes were patient-reported and not blinded.

Follow-up

2 years.

Primary endpoint

SF-36 bodily pain and physical function scores and modified Oswestry Disability Index at 2 years.

Secondary endpoints

  • Treatment effects at 3 months, 6 months, and 1 year.
  • Crossover rates between treatment groups.

Practice impact

What this means

This multicenter RCT compared surgery vs. nonsurgical care for degenerative spondylolisthesis. Intention-to-treat analysis was negative due to 40% crossover, but as-treated analysis showed surgery improved SF-36 scores by ~18 points and Oswestry by -16.7 at 2 years. Consider surgery for motivated patients, but discuss crossover risks and lack of definitive RCT evidence.

Bottom line

Surgery shows greater improvement in pain and function over 2 years compared to nonsurgical care in as-treated analysis, but high crossover limits RCT conclusions.

Strength of evidence

moderate

Recommendation

consider change

Why it matters

  • As-treated analysis with regression control shows significant benefits for surgery.
  • Intention-to-treat analysis was negative due to high crossover.
  • Consistent with clinical experience but not definitive from RCT.

What would change my mind

  • Longer-term follow-up beyond 2 years showing sustained benefits or harms.
  • RCT with lower crossover rates confirming surgical superiority.
  • Cost-effectiveness analysis comparing surgical and nonsurgical strategies.

Critical appraisal

How strong is the paper?

Methods critique

Risk of bias

High crossover (approximately 40% in each direction in randomized cohort) compromises intention-to-treat analysis.

Confounding

As-treated analysis controlled for baseline factors with regression, but residual confounding possible due to non-randomized nature.

Missing data

Not explicitly reported in excerpt; analysis likely used available data.

Multiplicity

Multiple time points and outcomes analyzed; no correction for multiplicity mentioned.

Notes

  • Intention-to-treat analysis showed no significant effects; as-treated analysis favored surgery.
  • Observational cohort had lower crossover (17% to surgery, 3% to nonsurgical).

Stats check

NNT

Not reported in excerpt.

Effect sizes

  • Treatment effect at 2 years: 18.1 for bodily pain (95% CI 14.5 to 21.7).
  • Treatment effect at 2 years: 18.3 for physical function (95% CI 14.6 to 21.9).
  • Treatment effect at 2 years: -16.7 for Oswestry Disability Index (95% CI -19.5 to -13.9).

Absolute effects

  • Sample size: 304 patients in randomized cohort, 303 in observational cohort.
  • Crossover rate in randomized cohort: approximately 40% in each direction at 1 year.

Concerns

  • High crossover limits validity of randomized comparison.
  • As-treated analysis is observational and may be biased.

External validity

Who it applies to

Surgical candidates with degenerative spondylolisthesis and spinal stenosis in U.S. multicenter settings.

Who it does not

Patients with acute symptoms, non-surgical candidates, or those in non-U.S. settings.

Generalizability notes

  • Includes diverse U.S. centers, enhancing generalizability.
  • High crossover may reflect real-world practice but complicates trial interpretation.

Evidence trace

Source trace and metadata

Citations (3)

claim_id

methods_critique.risk_of_bias

locator

p. 2257 Results

quote

The one-year crossover rates were high in the randomized cohort (approximately 40% in each direction).

claim_id

stats_check.effect_sizes

locator

p. 2257 Results

quote

The treatment effects at 2 years were 18.1 for bodily pain (95% confidence interval [CI], 14.5 to 21.7), 18.3 for physical function (95% CI, 14.6 to 21.9), and -16.7 for the Oswestry Disability Index (95% CI, -19.5 to -13.9).

claim_id

practice_impact.rationale

locator

p. 2257 Results

quote

In nonrandomized as-treated comparisons with careful control for potentially confounding baseline factors, patients treated surgically showed substantially greater improvement in pain and function during a period of 2 years than patients...

Metadata

Generated at

2026-03-06T13:41:29.251Z

Version

top 100 cited in past 20 years