The Patients´ quality of life and outcome after surgical treatment for primary spinal infection.

Introduction: Surgical intervention can be an option in the treatment of primary spinal infection as a means to control infection, improve severe paralysis and save lives. However, there is a knowledge gap regarding how the patients fare after restitution, in terms of patient-reported outcomes (PROMs). This study aims to assess the outcomes 1 year after surgical treatment for primary spinal infection using PROMs by analyzing data with available cases from the national Swedish spine registry (Swespine).

Methods: This retrospective case-control cohort study included 907 patients who underwent surgery for primary spinal infection, registered in Swespine between 2006 and 2023. Among them, 82 patients had complete baseline and one-year follow-up data. Variables included age, sex, BMI, mortality rate, reoperation rate, and preoperative and one-year postoperative scores for the EQ-5D index, EQ-visual analogue scale (VAS), and Numerical Rating Scale (NRS) for back/neck and leg/arm pain. Patient status at one year post-surgery were calculated using ANCOVA analysis and compared with a cohort of healthy controls (n = 273) and with the I year follow-up of patients surgically treated for degenerative lumbar spine disease (n = 89,478). Patients' return to work 1 year after the surgery were also assessed via postal questionnaires.

Results: One year post-surgery, spinal infection patients showed significant improvements in the EQ-5D index, EQ-VAS, and NRS scores (p-values: <0.001, < 0.001, 0.002, 0.001). The EQ-5D index improvement exceeded the minimum clinically important difference (MCID) of 0.24, but NRS improvements fell below the MCID threshold of 2.5. Despite improvements, the postoperative EQ-5D index remained significantly lower in the spinal infection group than in population-based controls (control: 0.93, infection: 0.49; p < 0.001). Additionally, EQ-5D and EQ-VAS improvements were less pronounced compared to degenerative disease patients (infection: 0.51, 57.3; degenerative: 0.65, 67.2; p < 0.001). The reoperation rate was 18.2%, and half of the working patients (20/40) had not resumed work within a year.

Conclusion: Surgical treatment for spinal infection improves life quality and pain. However, pain relief remains suboptimal, as the improvements do not reach the MCID. One year postoperatively, PROMs in spinal infection patients remain worse than those in population-based controls and degenerative disease patients, suggesting persistent symptoms despite healing and restitution of the spinal infection.