Conclusion

Relapse infection was strongly associated with long-term revision surgery due to construct failure following instrumented treatment for pyogenic spondylodiscitis. A higher comorbidity burden and elevated preoperative CRP were also associated with an increased risk of revision. These findings may help identify patients at increased risk of construct failure who could benefit from closer postoperative surveillance. However, prospective studies are required to validate these associations and determine whether targeted interventions can improve clinical outcomes.