Outcomes and Costs Associated With Cervical Spinal Fusion Surgery

OBJECTIVES: A 2007 meta-analysis of cervical fusion outcomes reported fusion rates of 89.5%. Despite innovation, there is no evidence to suggest improved fusion rates since that study. Our study evaluated the two-year healthcare utilization associated with cervical fusion surgery using contemporary data.

METHODS: Patients with cervical-only fusion surgery between October 2015 and December 2020 and ≥ two years continuous enrollment post-surgery in the Merative MarketScan Commercial Claims database were identified. Outcomes included two-year complication and reoperations rates, and costs. Variables included patient demographics, index surgery approach, number of levels fused and instrumentation use. Descriptive analytics were conducted for all outcomes. Healthcare costs were adjusted to 2022 inflation and analyzed using generalized linear models.

RESULTS: 28,674 patients with average age 51, including 53% females, were identified in the database. Half of all patients were treated in the inpatient setting, 40% in outpatient, and 10% in ambulatory surgical care. The average Elixhauser index patient comorbidity score was 1.6 (standard deviation (SD): 1.5) and nearly 24% patients had ≥ 3 comorbidities. Obesity and diabetes affected 14% and 16% cases, respectively. Degenerative disc disease (DDD) and deformity were diagnosed in 87% and 8% cases, respectively, and 58% cases had two or more levels fused. At 2-year follow-up, new cervical operations affected 12% cases, but only one third of those cases had a diagnosis of spinal fusion complication at the time of the new procedure. Pseudarthrosis was reported in 6% cases, and infection in 2.2% cases. Healthcare costs associated with pseudoarthrosis or infection, without reoperation, averaged $33,055 (95% confidence interval (CI): $24,514-$51,596) and $108,173 (95%CI: $86,890-$129,455), respectively. When reoperations were performed, costs increased by $49,354 (95%CI: $39,113-$59,596).

CONCLUSIONS: By 2-year post-operative, 12% patients with cervical fusion underwent additional cervical surgery, suggesting outcomes consistent with those reported in the 2007 meta-analysis.