Park (2004) — Adjacent segment disease after lumbar or lumbosacral fusion: review of the literature.

Adjacent Segment Disease after Lumbar or Lumbosacral Fusion: Review of the Literature.

·Spine·2004·1,281 citations·Spine

Ji et al. (2026) retrospectively analyzed 500 patients undergoing PLIF to identify independent risk factors for adjacent segment disease, examining novel individual-level variables including systemic inflammation markers, paraspinal muscle quality on MRI, bone density by CT Hounsfield units, cage subsidence, and nonunion alongside traditional biomechanical predictors.

Study Snapshot

Design

Retrospective cohort

Setting: Single center, Nantong, China

Funding: National Natural Science Foundation

Objective

Determine whether systemic inflammation, muscle degeneration, and surgical factors predict ASD after PLIF

Outcome(s)

Independent risk factors for adjacent segment disease after PLIF

Subjects

500 PLIF patients (ASD n=96, non-ASD n=404)

Inclusion

Lumbar degenerative disease requiring PLIF
Symptoms unrelieved by conservative treatment
Follow-up >2 years with complete imaging

Follow-up

Mean 36 months

Statistics

Independent samples t-testChi-square / Fisher's exact testMultivariable logistic regressionHosmer-Lemeshow test

Key Findings

19.2% of PLIF patients developed ASD over ~36 months mean follow-up; of those, 71 of 96 required readmission for treatment — underscoring that this is a clinically consequential entity, not just an imaging finding
Cage subsidence was the strongest independent risk factor (OR 3.13, P<0.001); nonunion independently doubled risk (OR 2.25, P=0.01) — both are modifiable surgical targets
Elevated NLR independently predicted ASD (OR 2.14, P<0.001), implicating systemic inflammation as a driver beyond biomechanics alone
Paraspinal muscle quality on preoperative MRI independently predicted ASD across three separate measures:
–Lower psoas muscle index (OR 0.89, P=0.02)
–Lower multifidus muscle index (OR 0.58, P=0.01)
–Higher multifidus fat infiltration rate (OR 1.04, P=0.03)
PI-LL mismatch did not independently predict ASD on multivariate analysis — authors suggest this may reflect posture adopted after ASD develops rather than a true predisposing factor

Clinical Relevance

Before PLIF, check CT Hounsfield units for bone quality, calculate NLR from routine labs, and assess paraspinal muscle quality on MRI — patients with low muscle indices, elevated NLR, or poor bone density are at highest ASD risk and may benefit from targeted prehabilitation and anti-inflammatory optimization.

Intraoperatively, prioritize anterior cage placement and solid fusion to avoid the two most potent modifiable risk factors: cage subsidence (OR 3.1) and nonunion (OR 2.3).

Supplemental

Adjacent Segment Disease after Lumbar or Lumbosacral Fusion: Review of the Literature.

Park, McGillicuddy, et al.·Spine·2004·1,281 citations·Spine

Adjacent Segment Disease after Lumbar or Lumbosacral Fusion: Review of the Literature.

Study Snapshot

Key Findings

Clinical Relevance

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Adjacent Segment Disease after Lumbar or Lumbosacral Fusion: Review of the Literature.

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Adjacent Segment Disease after Lumbar or Lumbosacral Fusion: Review of the Literature.

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Key Findings

Clinical Relevance

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Adjacent Segment Disease after Lumbar or Lumbosacral Fusion: Review of the Literature.

Study Snapshot

Key Findings

Clinical Relevance

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