# Cost and Utilization Trends of Lumbar Fusion

## TL;DR

Lumbar fusion surgery in the US increased in use and cost from 2002 to 2023, with more complex procedures and outpatient settings becoming common.

## Contribution

The study provides updated national trends on lumbar fusion utilization, costs, and procedural complexity over 21 years.

## Key findings

- Adjusted inpatient hospital costs for lumbar fusion increased by 265.3% from 2002 to 2023.
- Multilevel and anterior-posterior column fusions became more common over time.
- Outpatient lumbar fusion procedures increased from 2.1% in 2016 to 9.8% in 2022.

## Abstract

What changes in lumbar fusion surgery utilization and costs occurred between 2002 and 2023?

In this cross-sectional study of more than 5 million lumbar fusion admissions, adjusted inpatient hospital and mean inpatient per-procedure costs increased. There were increased trends toward fusions involving 2 or more disc levels and in anterior-posterior column fusion in more recent years as well as a trend toward procedures in outpatient facilities.

In this study, lumbar fusion trends were marked by greater utilization of multilevel and anterior-posterior approaches and greater use in the outpatient setting.

This cross-sectional study evaluates whether approaches to lumbar fusion surgery, utilization of the procedure, and costs have changed between 2002 and 2023 in the United States.

The increasing cost of lumbar fusion has invited payment reforms, such as mandatory price limits by Medicare in 2026.

To examine the cost, utilization, and procedural case-mix trends for different types of lumbar fusion from 2002 to 2023 in the United States.

This cross-sectional analysis used survey-weighted data from the 2002 to 2023 National Inpatient Sample (NIS) and the 2016 to 2022 Nationwide Ambulatory Surgical Sample (NASS). From this nationally representative sample of inpatient and hospital-owned outpatient discharges, information on US adults aged 20 years and older undergoing lumbar fusion for any indication from January 2002 to December 2023 were included.

Lumbar fusion of any type (1-disc level or multilevel as well as single vertebral column or both anterior-posterior columns) with nonfusion surgery as a comparison.

The main outcomes were the survey-weighted annual total of procedures, the mean age of patients undergoing lumbar fusion, the inflation-adjusted hospital costs, and the annual procedure rates per 100 000 population.

A total of 5 033 772 lumbar fusion admissions between 2002 and 2023 were included. In 2023, the cohort of patients undergoing 274 750 procedures had a mean (SD) age of 63.2 (12.9), with 142 815 (52.0%) female patients. Excluding 54 620 complex fusions, which were mostly multilevel anterior-posterior column fusions, there were 164 105 (50.1%) multilevel fusions, and 109 130 (51.3%) combined anterior-posterior column fusions. The age-adjusted population rate of inpatient fusion procedures increased from 60.1 (95% CI, 58.8-90.3) per 100 000 in 2002 (148 823 admissions) to a peak of 89.9 (95% CI, 89.6-90.3) in 2016 (284 180 admissions), before declining to 80.0 (95% CI, 79.7-80.4) by 2023 (273 235 admissions). Lumbar fusion performed in hospital-owned outpatient facilities was minimal in 2016 (6132 procedures, or 2.1% of total lumbar fusions) and 6.9 per 100 000 (27 331 procedures, or 9.8% of total lumbar fusions) in 2022. Adjusted inpatient hospital costs increased 265.3% from $3.86 (95% CI, $3.81-$3.92) billion in 2002 to $14.1 (95% CI, $13.9-$14.2) billion in 2023, and mean inpatient per-procedure cost increased from $25 849 (95% CI, $25 684-$26 015) in 2002 to $45 458 (95% CI, $45 207-$45 709) in 2023. Lumbar fusion primarily shifted from single column at 1 or 2 disc levels in 2002 (mean cost, $24 515; 95% CI, $24 361-$24 669) to multilevel anterior-posterior column fusion in 2023 (mean cost, $55 034; 95% CI, $54 420-$55 650).

In this cross-sectional study, lumbar fusion trends were marked by greater utilization of procedures overall, and especially involving multilevel and combined anterior-posterior column approaches and by greater use in the outpatient setting. Costs also increased at both the national and per-procedure levels.