Standalone lateral lumbar interbody fusion reduces the risk of adjacent segment surgery.
Academic Article
Overview
abstract
BACKGROUND CONTEXT: The paraspinal muscles play a key role in adjacent segment disease following lumbar fusion surgery. However, the long-term outcomes of muscle-preserving techniques, such as standalone lateral interbody fusion, compared to open posterior fusion remain unclear. PURPOSE: To compare long-term rates, reasons, and timing of revision surgery after standalone lateral fusion versus circumferential lateral+open posterior fusion. STUDY DESIGN/SETTING: Single-center retrospective cohort study. PATIENT SAMPLE: Patients who underwent lateral lumbar interbody fusion with or without open posterior fusion for degenerative conditions between 2006 and 2022. OUTCOME MEASURES: The primary outcomes were overall revision surgery and revision for adjacent segment disease. Secondary outcomes included surgical time, estimated blood loss, and length of hospitalization. METHODS: The institutional database was queried for patients who underwent lateral lumbar interbody fusion with or without posterior pedicle screw instrumentation. Minimum follow-up was 2 years (mean >5 years). Patients with prior lumbar fusions and those undergoing multilevel fusions extending across the thoracolumbar or lumbosacral junctions were excluded. Electronic health records were reviewed for revision surgical procedures in and outside our institution. Kaplan-Meier survival curves and log-rank tests were used, along with multivariable Cox regression to assess the impact of the surgical technique on revision surgery. RESULTS: A total of 785 patients were analyzed, with 485 undergoing standalone lateral lumbar interbody fusion. Standalone fusion was associated with significantly lower overall revision rates (20.6% vs. 27.3%, p=.030) and adjacent segment revision rates (16.1% vs. 23.3%, p=.012) compared to circumferential fusion. However, pseudarthrosis-related revisions were more frequent in the standalone group (1.9% vs. 0.0%, p=.015). Multivariable Cox regression revealed that standalone fusion reduced the hazard of overall revision surgery (HR = 0.727, p=.037), with the most significant effect observed for proximal adjacent segment revisions (HR=0.455, p<.001). Standalone fusion demonstrated shorter surgical time (83 minutes [IQR 51-145] vs. 266 minutes [IQR 167-342]), lower blood loss (50 mL [IQR 50-100] vs. 300 mL [IQR 100-550]), and shorter hospital stays (3 days [IQR 2-5] vs. 4 days [IQR 3-6]) (all p<.001). CONCLUSIONS: Standalone lateral lumbar interbody fusion demonstrates superior long-term revision-free survival, particularly by reducing the risk of proximal adjacent segment revisions. Combined with shorter surgical time and hospitalization, these findings support considering standalone lateral fusion as a valuable option for select patients.
