JAAOS - 2026-04-22 - Journal Article
Demographic and Radiographic Predictors of Subsequent Fusion Within 2 Years of Isolated Posterior Lumbar Decompression.
Ezeonu T, Dalton J, Fano A, Lee Y, Narayanan R, Ng M, Singh A, Christianson A, Goodman P, Pena J, Canseco JA, Hilibrand AS, Vaccaro AR, Schroeder GD, Kepler CK
Topics
Key Takeaway
Among 202 patients undergoing isolated posterior lumbar decompression, 21.3% required fusion within 2 years, with Charlson Comorbidity Index (OR 1.32) as the only independent predictor — not MRI-based degeneration markers.
Summary Depth
Choose how much analysis to show on this article page.
Summary
This study asked which preoperative demographic and MRI factors predict subsequent fusion within 2 years of isolated 1-2 level posterior lumbar decompression at L3-S1. Multivariable logistic regression of 202 patients showed CCI was the sole independent predictor (OR 1.32, 95% CI 1.03–1.72); paradoxically, patients who did NOT require fusion had higher facet degeneration scores and greater prevalence of Pfirrmann grade 5 disks (37.8% vs 18.6%). No MRI parameter — including facet tropism, sagittally aligned facets, disk height, or foraminal stenosis severity — independently predicted revision fusion.
Key Limitation
The 2-year fixed endpoint captures early revision but cannot determine whether the absence of fusion in highly degenerated patients reflects appropriate durability or merely delayed inevitable revision beyond the study window.
Original Abstract
INTRODUCTION
Isolated posterior lumbar decompression (PLD) is commonly performed for degenerative indications. However, the various factors that predict revision surgery for subsequent fusion remain poorly understood. To this end, the purpose of the current study was to investigate demographic and lumbar imaging findings at the time of PLD that are associated with subsequent fusion.
METHODS
Adult patients who underwent isolated 1-2-level PLD between L3-S1 (2014 to 2020) were retrospectively identified. Subsequent fusion within 2 years was determined. Preoperative lumbar magnetic resonance imaging (MRI) was reviewed for (1) sagittally aligned facet (SAF) joints, (2) facet tropism, (3) facet degeneration, (4) disk height, and (5) Pfirrmann grade. Radiology reports were used to categorize the foraminal stenosis severity. Associations between MRI findings before PLD and the need for revision surgery for fusion were investigated using multivariable logistic regression.
RESULTS
Among the 202 PLD patients, 21.3% underwent fusion within 2 years. Patients requiring fusion had a higher Charlson comorbidity index (2.07 ± 2.19 versus 1.30 ± 1.73, P = 0.023). No differences were observed in facet tropism, SAF joints, disk height, or stenosis severity between the subsequent fusion and no fusion groups. Patients who did not undergo fusion had higher average facet degeneration scores (1.90 ± 0.76 versus 1.64 ± 0.71, P = 0.030) and a greater proportion of Pfirrmann grade 5 disks (37.8% versus 18.6%, P = 0.013). Multivariable regression identified CCI as the only independent predictor of subsequent fusion (odds ratio: 1.32, cI, 1.03 to 1.72, P = 0.034).
CONCLUSION
This study found that higher CCI at the time of PLD is an independent predictor of requiring fusion within 2 years. Increased lumbar degeneration alone was not associated with a greater risk of fusion. Decreased remaining motion, lower functional demands, or a greater propensity for autofusion may have lowered the need for subsequent fusion among these PLD patients with greater degeneration. Further research is needed to support these results.