Background:

Interbody devices have revolutionized lumbar spinal fusion surgery by improving mechanical stability and maximizing fusion potential. Several approaches for interbody fusion exist with two of the most common being anterior lumbar interbody fusion (ALIF) and posterior lumbar interbody fusion (PLIF). This study aims to compare patient data, hospital outcomes, and post-operative complications between an anterior vs. posterior approach to lumbar interbody fusion.

Methods:

This retrospective cohort study utilized the Nationwide Inpatient Sample (NIS) and International Classification of Diseases, 10th edition (ICD10) codes to identify patients (18 +) from 2016 to 2018 who underwent lumbar interbody fusion under an anterior or posterior approach. Patients missing identifiers were excluded from this study. Patients were further investigated by demographic data and the presence of comorbidities. Hospital outcome data was investigated by length of stay (LOS), total hospital charges, mortality, and post-operative complications.

Results:

373,585 patients were included in this study. 257,975 (69%) underwent fusion via a posterior approach, and 115,610 (31%) via an anterior approach. Patients undergoing posterior approach were found to have a greater number of comorbidities than anterior (3.5 vs. 2, respectively, p = <0.001). The posterior approach was associated with decreased LOS (3.59 vs 4.19 days, p = <0.0001) and decreased total hospital charges ($141,700 vs $211,015, p = <0.0001). A posterior approach was found to have lower rates of post-operative complications. For the anterior approach cohort, tobacco dependence (OR=1.31 [1.20-1.42, p = <0.001], diabetes (OR=2.41 [2.33-2.49, p = <0.001], and osteoporosis (OR=1.42 [1.30-1.54, p = <0.001] were found to be significant independent predictors of post-operative pseudoarthrosis. Obesity (OR=1.28 [1.14-1.42, p = <0.001], tobacco dependence (OR=1.48 [1.40-1.56, p = <0.001], diabetes (OR=2.21 [2.10-2.32, p = <0.001], congestive heart failure (OR=1.20 [1.01-1.39, p = 0.04], and osteoporosis (OR=1.65 [1.55-1.75, p = <0.001], were found to be independent predictors of post-operative pseudoarthrosis in the posterior cohort.

Conclusions:

Patients who underwent the anterior approach suffered from increased hospital charges, length of stay, and increased risk of post-operative complications including mortality, wound dehiscence, hematoma/seroma, and pseudoarthrosis. Comorbid disease plays a significant role in the outcome of successful fusion with variable effect depending on the surgical approach. Increasing due diligence in patient selection should be considered when choosing an approach in pre-operative planning.