Spine - 2026-07-21 - Journal Article
Measuring Variability and Value of Single- and Two-Level Anterior Cervical Discectomy and Fusion Using Impact Scores.
Bansal A, Nguyen KT, Yamanouchi K, Nemani VM, Leveque JC, Farrokhi F, Louie PK
Topics
Key Takeaway
Interbody devices account for 30.9% of 1-level and 40.9% of 2-level ACDF intraoperative supply costs, with OVI and UPO varying more than 2.5-fold across surgeons performing identical procedures.
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Summary
This single-institution retrospective study of 369 1- and 2-level ACDF cases across five surgeons used impact scores, TDABC, OVI, and UPO to quantify intraoperative supply cost variability and procedural value independent of institutional pricing. The five highest-impact cost categories for 1-level ACDF were interbody (30.9%), plate (27.8%), retractor/dilator (17.4%), screw (13.8%), and drill (12.5%), with interbody proportion rising significantly at 2-level (40.9%, P<0.001). Biologics and interbody devices showed the greatest inter-surgeon variability, and value metrics OVI and UPO differed by more than 2.5-fold across surgeons performing the same procedure.
Key Limitation
Five surgeons at a single institution make inter-surgeon variability findings statistically underpowered and non-generalizable to practice settings with different implant contracts or payer mixes.
Original Abstract
STUDY DESIGN
Retrospective single-institution cohort study.
OBJECTIVE
To characterize intraoperative supply cost variability across surgeons and procedural levels in 1- and 2-level ACDF using impact scores, and to describe within-procedure value using time-driven activity-based costing (TDABC), the Operative Value Index (OVI), and Unit Price per Outcome (UPO).
SUMMARY OF BACKGROUND DATA
Intraoperative supply costs in ACDF vary widely and are dominated by implant selection, yet absolute cost figures are institution-specific and cannot be compared across sites. Impact scores express each supply category's proportional share of total intraoperative supply cost, enabling normalized benchmarking independent of pricing.
METHODS
A retrospective review of 369 ACDF cases (Current Procedural Terminology [CPT] code 22551, 1- and 2-level) performed by five surgeons was conducted. Supply items were categorized and impact scores calculated as each category's share of total intraoperative supply cost (0 to 100 per case). Staff costs were estimated using TDABC. Neck Disability Index (NDI) and quality-adjusted life year (QALY) were collected at baseline and up to 12 months. OVI and UPO were derived from NDI and total intraoperative cost.
RESULTS
Demographics were similar between groups. The five highest-impact categories for 1-level ACDF were interbody (30.9%), plate (27.8%), retractor/dilator (17.4%), screw (13.8%), and drill (12.5%); for 2-level: interbody (40.9%), plate (22.1%), screw (13.8%), retractor/dilator (12.7%), and drill (9.6%). Interbody scores increased significantly with level (P<0.001). Biologic and interbody categories showed the greatest inter-surgeon variability. OVI and UPO varied more than 2.5-fold across surgeons performing the same procedure.
CONCLUSION
Impact scores reveal that interbody devices dominate ACDF supply cost and grow with added levels, while biologics exhibit the greatest inter-surgeon variability. OVI and UPO provide within-procedure value benchmarks independent of institutional pricing.