A Peri-Operative Cost Analysis Comparing Single-Level Minimally Invasive and Open Transforaminal Lumbar Interbody Fusion

Presented at SMISS Annual Forum 2013
By Kern Singh MD
With Frank M. Phillips MD, Miguel Pelton BS, Sreeharsha V. Nandyala BA, Alejandro Marquez-Lara MD, Steven J. Fineberg MD, Matthew Oglesby , Gunnar B. Andersson MD, PhD,

Disclosures: Kern Singh MD A; CSRS Resident Grant. B; DePuy, Zimmer, Stryker, CSRS, ISASS, AAOS, SRS, Vertebral Column - ISASS. D; Avaz Surgical, LLC, Vital 5, LLC. F; Zimmer, Stryker, Pioneer, Lippincott Williams & Wilkins, Th Frank Phillips MD D; Nuvasive, SI-Bone, Providence, Theracell, Vital 5, Spinal Motion, Spinal Kinetics, Axiomed, Cross Trees, F; Nuvasive, DePuy, Medtronic, Stryker, Miguel Pelton BS None, Sreeharsha Nandyala BA None, Alejandro Marquez-Lara MD None, Steven Fineberg MD None, Matthew Oglesby None, Gunnar Andersson MD, PhD A; ORA medical. B; Bioset; United Healthcare; Zimmer;Bioventus;Pioneer surgical;ISTO. D; Biomerix; Crosstrees; Ouroboros; Pioneer; Spartec; Spinal Kinetics.,

Introduction: Emerging literature suggests superior clinical short and long-term outcomes of MIS (Minimally Invasive Surgery) TLIFs (Transforaminal Lumbar Interbody Fusion) versus open fusions. Few studies to date have analyzed the cost differences between the two techniques and their relationship to acute clinical outcomes

Methods: This study was a non-randomized, non-blinded prospective review. Sixty-six consecutive patients undergoing a single-level TLIF (open/MIS) were analyzed (33 open, 33 MIS). Every patient in the study had a diagnosis of either degenerative disc disease or spondylolisthesis and stenosis. Operative time (minutes), Length of stay (LOS, days), estimated blood loss (EBL, cc), anesthesia time (minutes),Visual Analog Scale (VAS) scores, and hospital cost/payment amount were assessed. The MIS and Open TLIF groups were compared based on clinical outcomes measures and hospital cost/payment data using SPSS version 20.0 (Chicago, IL) for statistical analysis. The two groups were compared using bivariate chi-squared analysis. Mann-Whitney tests were used for non- normal distributed data.

Results: Average surgical time was shorter for the MIS than the Open TLIF group (115.8 minutes versus 186 minutes respectively; p=0.001).Length of stay was also reduced for the MIS versus the Open group (2.3 days versus 2.9 days respectively; p=0.018). Average anesthesia time and EBL was also lower in the MIS group (p<0.001). VAS scores decreased for both groups, although these scores were significantly lower for the MIS group (p<0.001). Financial analysis demonstrated lower total hospital direct costs (blood, imaging, implant, lab, pharmacy, PT/OT/Speech, room and board)in the MIS versus the Open group ($19,512 v. $23,550, p <0.001). Implant costs were similar (p=0.686) in both groups although these accounted for about two-thirds of the hospital direct costs in the MIS cohort ($13,764) and half of these costs ($13,778) in the open group. Hospital payments were $6,248 higher for open TLIF patients compared to the MIS group (p=0.267).

Conclusion: MIS TLIF technique demonstrated significant reductions of operative time, LOS, anesthesia time, VAS Scores and EBL compared to the open technique. This reduction in peri-operative parameters translated into lower total hospital costs over a 60 day peri-operative period. Although hospital reimbursements appear higher in the open group over the MIS group, shorter surgical times and length of stay days in the MIS technique provide opportunities for hospitals to reduce utilization of resources and to increase surgical case volume.