Variability and contributions to cost associated with anterior versus posterior approaches to lumbar interbody fusion

Abstract

Objective: Lumbar interbody fusions are being performed with increased frequency in the last decade. Anterior and posterior interbody techniques have demonstrated relatively similar success rates. Nonetheless, despite increased attention to cost-effective care delivery, approach-related differences in procedural cost and predictors for these differences remain poorly defined. The purpose of this investigation was to characterize the variability in cost for anterior versus posterior-based lumbar interbody fusions and to identify key predictors of procedural cost.

Methods: We evaluated the records of all patients who underwent a primary anterior (ALIF) or posterior/transforaminal (PLIF/TLIF) lumbar interbody fusion with concomitant posterior fusion from 2016 to 2020 at four hospitals in a major metropolitan area. We reviewed the records of all included patients and abstracted demographics, insurance status, approach, operative time, diagnosis, surgeon, institution, open versus minimally invasive technique, and components of procedural costs. Costs based upon interbody approach were compared via multivariable adjusted analyses using negative binomial regression.

Results: We included 139 interbody fusion procedures; 98 were performed via posterior approach (TLIF/PLIF) and 41 using an anterior approach. Anterior techniques were associated with significantly increased costs as compared to posterior procedures (anterior, $16316 [SE 556] vs. posterior, $9415 [SE 345]; p < 0.001). This determination remained significant following multivariable adjusted analysis (regression coefficient -0.22, 95% CI -0.34, -0.10, p < 0.001). Multivariable analysis also indicated that surgeon, invasiveness, and procedure time were significant predictors of total cost.

Conclusion: Our findings demonstrate that anterior interbody techniques are, on average, 173% (anterior, $16316 [SE 556] vs. posterior, $9415 [SE 345]; p < 0.001) more expensive than posterior-based procedures. Given the relative equipoise of these different approaches for many clinical applications, these findings should be considered in an ecosystem increasingly attentive to cost effective care delivery. This work has also provided specific procedural variables for surgeons and systems to target when optimizing procedural costs.

Keywords: ALIF; Cost; Interbody Fusion; PLIF; TLIF; Value.