Fusion Construct Length is Associated With Increased Risk of Delayed Reoperation Following Cervical and Lumbar Fusion

Study DesignRetrospective cohort study.ObjectiveTo identify factors associated with delayed reoperation following cervical and lumbar fusion and characterize long-term healthcare utilization.MethodsPatients undergoing cervical or lumbar fusion for degenerative pathology within the PearlDiver Mariner 170 dataset were identified using ICD-10 and CPT codes. Delayed reoperation was assessed using narrow and broad definitions at 2-, 5-, and 10-year follow-up. Kaplan-Meier survivorship analysis and multivariable Cox proportional hazards modeling were performed.ResultsA total of 286,398 cervical and 175,874 lumbar fusion patients met inclusion criteria for the 2-year cohort. By 10 years, narrow delayed reoperation occurred in 11.16% of cervical fusion patients and 14.07% of lumbar fusion patients (p<0.001), while broad delayed reoperation occurred in 14.67% and 17.1%, respectively (p<0.001). Fusion construct length demonstrated the largest observed association with delayed reoperation across cervical and lumbar cohorts. Three-or-more level cervical fusion was associated with a nearly tenfold increase in reoperation risk (HR 9.62, p<0.001), while three-or-more level lumbar fusion demonstrated the highest risk among lumbar constructs (HR 3.79, p<0.001). Lumbar fusion patients demonstrated significantly greater postoperative complication rates and cumulative healthcare utilization burden (p<0.001).ConclusionsDelayed reoperation accumulates progressively following cervical and lumbar fusion and is associated with substantial long-term healthcare burden. Across all analyses, fusion construct length was consistently associated with increased risk of delayed reoperation, exceeding the influence of traditional patient-specific risk factors. These findings highlight construct length as a critical determinant of long-term surgical burden and may improve patient counseling, risk stratification, and operative decision-making.