Study design:

Retrospective observational population-based study OBJECTIVES: Aims of this study were to determine the time trend of demographics, complications, and outcomes for patients undergoing posterior/transforaminal (PLIF/TLIF) or anterior/lateral lumbar interbody fusion (ALIF/LLIF) and to compare the differences in the time trends between both procedures.

Methods:

The ACS-NSQIP database was queried for patients undergoing PLIF/TLIF and ALIF/LLIF procedures. Outcomes were analyzed for differences between two time periods in the PLIF/TLIF and ALIF/LLIF cohorts separately (2009-2013 and 2015-2019). Longitudinal time trends of the two procedures were determined by difference-in-differences (DID) analysis. Statistical significance was defined as p<0.05.

Results:

For both approaches, there was an increase in age and ASA class over time, accompanied by a significant decrease in blood transfusions and morbidity. The DID analysis showed a greater change in age (DID:-1.8%; p<0.001) and more patients rated ASA class 3 (DID: -2.4%; p=0.033) in the ALIF/LLIF patients compared to PLIF/TLIF. Length of stay (LOS) declined significantly over time in both cohorts, with a greater reduction observed for patients who underwent ALIF/LLIF compared to PLIF/TLIF (DID: 0.2%; p=0.014). There were no changes in readmission rates over time in either cohort (PLIF/TLIF DID: 0.6%; p=0.080; ALIF/LLIF DID: -0.2%; p=0.696).

Conclusions:

Time trends for PLIF/TLIF and ALIF/LIIF showed a significant increase in the number of older patients with complex medical status undergoing surgery. Despite these trends, there were decreases in overall postoperative morbidity, incidence of blood transfusion, and LOS, without increasing readmission. These results suggest general improvement in surgical and perioperative management of lumbar fusion over time with greater gains found in ALIF/LLIF specific care compared to PLIF/TLIF.