Adjacent-segment disease following two-level axial lumbar interbody fusion

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While long-term studies have evaluated adjacent-segment disease (ASD) following posterior lumbar spine arthrodesis, no such studies have assessed the incidence and prevalence of ASD following axial lumbar interbody fusion (AxiaLIF). The aim of this study was to estimate the incidence of ASD following AxiaLIF.


The authors retrospectively reviewed the medical records of 149 patients who underwent two-level index AxiaLIF and had at least 2 years of radiographic and clinical follow-up. ASD and pre- and postoperative lumbar lordosis were evaluated in each patient. ASD was defined as both radiographic and clinically significant disease at a level adjacent to a previous fusion requiring surgical intervention. The mean duration of follow-up was 6.01 years.


Twenty (13.4%) of the 149 patients developed ASD during the data collection period. Kaplan-Meier analysis predicted a disease-free ASD survival rate of 95.3% (95% CI 90.4%–97.7%) at 2 years and 89.1% (95% CI 82.8%–93.2%) at 5 years for two-level fusion. A laminectomy adjacent to a fusion site was associated with 5.1 times the relative risk of developing ASD. Furthermore, the ASD group had significantly greater loss of lordosis than the no-ASD group (p = 0.033).


Following two-level AxiaLIF, the rate of symptomatic ASD warranting either decompression or arthrodesis was found to be 4.7% at 2 years and 10.9% at 5 years. Adjacent-segment decompression and postoperative loss of lumbar lordosis predicted future development of ASD. To the authors’ knowledge, this is the largest reported cohort of patients to undergo two-level AxiaLIF in the United States.

ABBREVIATIONS ASD = adjacent-segment disease; AxiaLIF = axial lumbar interbody fusion.

Article Information

Correspondence Alex P. Michael: Southern Illinois University School of Medicine, Springfield, IL.

INCLUDE WHEN CITING Published online April 19, 2019; DOI: 10.3171/2019.2.SPINE18929.

A.P.M. and M.W.W. contributed equally to this work and share first authorship.

Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

© AANS, except where prohibited by US copyright law.



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    Flowchart demonstrating patient selection criteria for inclusion in survival analysis.

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    Flowchart demonstrating patient selection criteria for inclusion in radiographic analysis of lumbar lordosis.

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    Kaplan-Meier survivorship curves showing the predicted percentage of patients remaining disease free (without reoperation). Shaded areas represent the 95% CIs. Censored patients are denoted by crosses. Survivorship curve representing time until adjacent-level reoperation is denoted with red shading, while time until first reoperation (either index or adjacent) is denoted with blue shading. Figure is available in color online only.





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