Optimizing bone health for the prevention of revision adult spinal deformity surgery: a break-even analysis.

PURPOSE

To determine the viability of preoperative bone health optimization for the prevention of revision surgery due to osteoporosis among adult spinal deformity (ASD) patients using break-even economic modeling.

METHODS

The cost of a DXA scan and total 2-year cost of revision ASD surgery were obtained from institutional records. 2-Year ASD revision rates among patients with osteoporosis were obtained from the literature. An open-access database was used to determine the mean retail price for Teriparatide, Denosumab, and Zoledronic acid. Total optimization costs included the costs of a DXA scan and medication treatment. Costs were adjusted for inflation using the Consumer Price Index to 2023 U.S. dollars. A break-even economic analysis was performed to determine the absolute risk reduction (ARR) and number needed to treat (NNT) to economically justify each treatment.

RESULTS

DXA scan ($349.28) and revision ASD surgery ($147,731.78) costs were obtained from institutional records. The cost of optimizing patients with DXA and Teriparatide, Denosumab, and Zoledronic acid was $4,410.32, $3,832.78, and $1,552.61, respectively. Each treatment modality was cost-effective at all revision ASD surgery rates. Teriparatide was economically justified if the initial revision rate decreased by 2.99% (NNT = 34), Denosumab by 2.59% (NNT = 39), and Zoledronic acid by 1.05% (NNT = 96).

CONCLUSION

Preoperative bone health optimization among ASD patients undergoing surgery is highly cost-effective in the prevention of revision surgery due to osteoporosis. Teriparatide would need to prevent 1 revision surgery out of 34 ASD surgeries, Denosumab 1 out of 39, and Zoledronic acid 1 out of 96 to break-even on costs.