Incidence and surgical management of secondary spine infections: A retrospective case series study of 4,921 consecutive patients.

BACKGROUND

Secondary spine infections lead to increased morbidity, prolonged hospitalization, and subsequent medical and surgical management. We reviewed the incidence, management, and outcomes of secondary spine infections among 4921 consecutive surgical cases.

METHODS

We reviewed our institutional database of 4921 patients undergoing orthopaedic spine surgeries between 2015 and 2025. Patients with surgical site infections requiring operative management were identified. Incidence of surgical site infections, surgical characteristics, spine-related healthcare utilization (ED visits and readmissions), and clinical outcomes were assessed. Analysis was conducted to determine the associations between surgical characteristics, secondary infections, and healthcare utilization.

RESULTS

A total of 170 (3.5%) developed secondary spine infections requiring surgical management. The overall cohort had 45.8% females, while the infection group had 54.7% females (p = 0.023). Non-elective (call) (34.1% vs 26.5%, p = 0.028) and revision cases (33.5% vs 15.0%, p < 0.001) were more common in the secondary infections group compared to the overall cohort. Deformity (14.1% vs 8.9%, p = 0.023) and tumor cases (6.5% vs 3.1%, p = 0.018) were also more common amongst the infection group compared to the overall cohort. Of the secondary infection group: 79 (46.5%) had 2 or more surgeries related to their infection, 54 (31.8%) had 2 or more emergency department visits, and 79 (46.5%) had 2 or more hospital readmissions. The cumulative length of hospitalization averaged 17.9 days (SD 36.4). Of the 149 instrumented cases, 48 (32.2%) required hardware removal and exchange. 111 had positive intraoperative cultures, with Staphylococcus aureus in most cases (52.3%). 139 (81.9%) of patients required 2 or more antibiotics, for an average duration of 72.0 days (SD 153.7) for infection treatment.

CONCLUSION

Incidence of secondary spine infections requiring operative intervention was 3.5%. Secondary spine infections were overrepresented in revision, non-elective, deformity and tumor cases, and resulted in frequent ED visits, hospital readmissions, and multiple operations for infection control.