Utilization and Economic Impact of Posterolateral Fusion and Posterior/Transforaminal Lumbar Interbody Fusion Surgeries in the United States

Study Design: Retrospective database study. Objective: To analyze the economic and age data concerning primary and revision posterolateral fusion (PLF) and posterior/transforaminal lumbar interbody fusion (PLIF/TLIF) throughout the United States to improve value-based care and health care utilization. Methods: The National Inpatient Sample (NIS) database was queried by the International Classification of Diseases, Ninth Revision, Clinical Modification codes for patients who underwent primary or revision PLF and PLIF/TLIF between 2011 and 2014. Age and economic data included number of procedures, costs, and revision burden. The National Inpatient Sample database represents a 20% sample of discharges from US hospitals weighted to provide national estimates. Results: From 2011 to 2014, the annual number of PLF and PLIF/TLIF procedures decreased 18% and increased 23%, respectively, in the Unites States. During the same period, the number of revision PLF decreased 19%, while revision PLIF/TLIF remained relatively unchanged. The average cost of PLF was lower than the average cost of PLIF/TLIF. The aggregate national cost for PLF was more than $3 billion, while PLIF/TLIF totaled less than $2 billion. Revision burden (ratio of revision surgeries to the sum of both revision and primary surgeries) remained constant at 8.0% for PLF while it declined from 3.2% to 2.9% for PLIF/TLIF. Conclusion: This study demonstrated a steady increase in PLIF/TLIF, while PLF alone decreased. The increasing number of PLIF/TLIF procedures may account for the apparent decline of PLF procedures. There was a higher average cost for PLIF/TLIF as compared with PLF. Revision burden remained unchanged for PLF but declined for PLIF/TLIF, implying a decreased need for revision procedures following the initial PLIF/TLIF surgery.