Analysis of Procedural Costs and Outcomes Between Autograft, BMP-2, and Viable Cellular Allograft in Lumbar Interbody Fusions.

STUDY DESIGN/

SETTING

Retrospective, multisurgeon cohort at a single academic center with ≥2-year follow-up.

OBJECTIVE

To identify dominant, modifiable drivers of intraoperative cost in lumbar interbody fusion and evaluate outcome profiles between graft types.

SUMMARY OF BACKGROUND DATA: Instrumentation and biologics are major cost contributors in lumbar fusion, yet prior reports often aggregate spending into broad categories, obscuring which specific supply decisions drive expenditure. Biologics such as bone morphogenic protein (BMP) and viable cellular allografts (VCA) have achieved high clinical utility, but their cost-effectiveness remains uncertain. Granular cost analyses are needed to clarify how graft selection influences expenditures and outcomes.

METHODS

Adults aged 18 to 89 years undergoing primary 1- to 2-level lumbar interbody fusion between March 2015 and July 2023 for degenerative pathology were included. Itemized procedural supplies were priced in 2023 USD, and operating room (OR) time was valued using a standardized cost per minute. Pareto analysis summarized cost domains. Multivariable linear, logistic, and Cox regression models were adjusted for demographics, diagnosis, surgeon, approach, level(s), fixation, laminectomy, and operative duration.

RESULTS

Among 955 cases, 111 (11.6%) used iliac crest bone graft (ICBG), 257 (26.9%) local autograft, 263 (27.5%) VCA, and 324 (33.9%) BMP. OR time, interbody devices, grafts, and fixation accounted for 95% of the total direct procedural cost. Grafting exhibited the widest interquartile cost range ($3200). Median total procedural costs were significantly higher (adjusted P <0.001-0.005) for VCA (1 level: $16,949; 2 level: $24,424) and BMP ($14,654; $26,193) compared with ICBG ($14,093; $17,757) and local autograft ($11,962; $18,352). Inpatient opioid use, length of stay, 90-day complications, readmissions, revisions, and postoperative Oswestry disability index and EuroQol-5D scores were comparable across groups (adjusted P >0.05).

CONCLUSIONS

Most direct procedural cost concentrated in OR time, interbody devices, and grafts. BMP and VCA markedly increased intraoperative expenditures without measurable improvement in outcomes. Autologous grafting demonstrated the most favorable cost-value profile.

LEVEL OF EVIDENCE: Level III.