National trends in the utilization of lumbar disc replacement for lumbar degenerative disc disease over a 10-year period, 2010 to 2019

BACKGROUND: Lumbar fusion (LF) is commonly performed to manage lumbar degenerative disc disease (LDDD) that has failed conservative measures. However, lumbar disc replacement (LDR) procedures are increasingly prevalent and designed to preserve motion in carefully selected patients. METHODS: A retrospective cohort study was performed using the National Inpatient Sample (NIS), queried from 2010 to 2019 to identify patients undergoing single and double-level LF or LDR with a diagnosis of LDDD using International Classification of Diseases (ICD) 9th (ICD-9) and 10th (ICD-10) revision diagnostic and procedure codes. Propensity score matching (PSM) with a ratio of 2:1 was performed. All cost estimates reflect reported hospital costs adjusted to December 2019 United States Dollars. RESULTS: A total of 1,129,121 LF cases (99.3%) and 8,049 LDR cases (0.7%) were identified, with 364,637 (32.3%) and 712 (8.8%) comprising two-level surgeries, respectively. 1,712 LDRs were performed in 2010 (1.27% of all), decreasing to 565 in 2013 (0.52%), and increased slightly to 870 in 2019 (0.74%). LDR patients were significantly more likely to be younger (mean age 41.2 vs. 57.1, P<0.001) and healthier (mean ECI 0.88 vs. 1.80, P<0.001). On matched analysis, LDR hospital costs were $4,529 less (P<0.001) and length of stay was 0.65 days shorter (P<0.001) than LF patients. LDR patients had lower rates of any complication (7.0% vs. 13.2%, P<0.001), neurologic complication (3.0% vs. 4.2%, P=0.006), and blood transfusion (3.1% vs. 8.1%, P<0.001) compared to LF patients. CONCLUSIONS: The prevalence of LDR procedures decreased from 2010–2017 but began to increase again in 2018 and 2019. Single-level LDR was associated with reduced costs and length of stay (LOS), and lower rates of blood transfusion compared to LF in patients with LDDD.