Inpatient National Trends and Aggregate Costs of Primary and Revision Lumbar Fusion in the United States from 2016 to 2022.

Abstract

Background context: With increasing utilization of lumbar fusions and a growing emphasis on value-based care, a contemporary understanding of national trends in procedural volume and cost is needed. While prior studies have demonstrated increases in lumbar fusion volume in past decades, they did not include more recent years or provide a granular breakdown distinguishing primary and revision procedures.

Purpose: This study aimed to define recent national trends in the utilization, aggregate costs, and revision burden of lumbar fusions in the United States.

Study design/setting: Retrospective database analysis of inpatient lumbar fusion procedures captured in the National Inpatient Sample (NIS).

Patient sample: Adult patients undergoing elective lumbar fusion between 2016 and 2022 OUTCOME MEASURES: National trends in procedural volume, aggregate hospital costs (inflation-adjusted to 2022), and annual revision burden were analyzed.

Methods: Adult patients undergoing elective lumbar fusion were identified from the NIS using ICD-10-PCS codes. Encounters were stratified into primary versus revision procedures; "revision" was defined as fusion construct revision/removal. Primary fusions were further categorized by approach (posterolateral fusion [PLF], posterior/transforaminal lumbar interbody fusion [PLIF/TLIF], and anterolateral interbody fusion).

Results: The analysis included 1,029,610 primary and 183,110 revision lumbar fusions. Overall primary fusion volume remained stable (compound annual growth rate [CAGR] -0.77%), while aggregate costs continued to rise (CAGR +1.41%). This was driven by a shift in surgical approach, with a decline in PLIF/TLIF procedures (CAGR -2.70%) and a rise in more costly anterolateral interbody fusion procedures (CAGR +5.78%). PLF predominated among patients aged 65 and older. Revision surgeries represented a substantial proportion of all fusions, with a total revision burden of 15.1% over the study period. Revisions were associated with higher mean costs than primary PLF and PLIF/TLIF procedures, accounting for $8.2 billion in aggregate costs.

Conclusion: While the rapid growth of inpatient lumbar fusion volume has stabilized, the economic burden continues to increase. This trend is driven by a shift toward more costly surgical techniques and the persistent, high cost of revision surgery. These findings highlight the need for value-based care initiatives to focus on the clinical and economic drivers of procedural choice for both primary and revision fusions.