Introduction

Pyogenic spondylodiscitis is a severe spinal infection with a rising incidence across Europe. Population-based data from several European countries, including Germany and the Scandinavian region, indicate a marked increase over the past two decades, likely reflecting demographic aging, higher comorbidity burden, improved imaging techniques, and increased survival of multimorbid patients. In Germany alone, the incidence has doubled from 5.4 to 11.0 cases per 100,000 inhabitants within two decades. At hospital admission, up to 50% of patients present with neurological deficits secondary to vertebral destruction or spinal epidural abscess (Younes et al., 2026a; Thavarajasingam et al., 2023). In selected early-stage cases without instability or neurological compromise, conservative treatment with targeted antibiotic therapy, analgesia, and immobilization may be sufficient (Pluemer et al., 2023; Valancius et al., 2013; Kramer et al., 2025). However, several European cohort studies have reported improved outcomes with early surgical intervention in appropriately selected patients, including reduced mortality and shorter hospital stay (Neuhoff et al., 2025a, 2025b; Von Der et al., 2025; Abboud et al., 2023). Consequently, surgical treatment for pyogenic spondylodiscitis has become increasingly common across Europe.

Despite advances in surgical techniques and perioperative management, instrumented spinal stabilization carries a substantial risk of complications. A proportion of patients require reoperation. Revision surgery in this context is most frequently necessitated by construct failure, which may arise from mechanical instability (e.g., screw loosening, implant breakage, loss of correction) or biological causes such as persistent or recurrent infection (Younes et al., 2026a; Valancius et al., 2013; Neuhoff et al., 2024, 2025a; Keric et al., 2017; Schömig et al., 2022; Acharya et al., 2024). These events often manifest clinically as recurrent pain, neurological deterioration, or progressive deformity and require surgical correction (Schatlo et al., 2023; Lin et al., 2012; Jin et al., 2022; Ackshota et al., 2019; Younes et al., 2026b). Reported overall revision rates following surgical treatment of pyogenic spondylodiscitis range from 5% to 15%, exceeding 20% in high-risk populations and in patients with extensive infection or severe bone destruction (Jin et al., 2022; Zawar et al., 2023; Uzumcugil et al.; Younes et al., 2026c). However, while previous studies have primarily reported overall revision rates, data specifically addressing revision surgery due to construct failure and its predictors remain scarce. Klute et al. evaluated 24 patients who underwent 360° fusion of the thoracolumbar spine using expandable vertebral body replacement cages for destructive vertebral osteomyelitis. Six patients (25%) developed construct-related complications, including vertebral body replacement dislocation, material irritation, and screw dislocation, resulting in revision surgery in five cases (Klute et al., 2024). Beyond this small series, evidence regarding the incidence and determinants of construct-related revision remains limited. A better understanding of the factors associated with construct failure is essential to optimize patient selection, refine surgical strategies, and improve postoperative management. Therefore, the present study aimed to identify risk factors associated with revision surgery due to construct failure following instrumented treatment for pyogenic spondylodiscitis of the cervical, thoracic, and lumbar spine.