Predictors of functional impairment after pyogenic vertebral osteomyelitis: a retrospective cohort study in the central Denmark region, 2017-2023

INTRODUCTION: Pyogenic vertebral osteomyelitis (PVO) is a serious bacterial infection of the spinal column, causing significant morbidity and mortality. In this study, we aimed to identify factors associated with functional impairment following a PVO episode and to describe the PVO population in the Central Denmark Region from 2017 to 2023. METHODS: Demographic and clinical data from PVO patients' medical records were collected retrospectively. Functional impairment was defined as a decline in functional status from a higher to a lower level during the PVO episode. Risk analyses for functional impairment were conducted using logistic regression. RESULTS: We identified 472 PVO patients from the Central Denmark Region for the outcome analysis. Median age was 71.5 years, and 66.9% were male. Intraspinal and extraspinal abscesses occurred in 28.4% and 35%, respectively. Staphylococcus aureus was identified in 142/484 patients (29.3%), while a definite microbiological etiology was not established for 137/484 patients (28.3%). Functional impairment occurred in 164/472 patients (34.7%). Age ≥70 years (aOR 5.23; CI: 3.29-8.32), chronic kidney disease (aOR 2.10; CI: 1.07-4.11), cardiovascular disease (aOR 1.95; CI 1.24-3.05) and multifocal spinal involvement (aOR 2.56; CI: 1.15-5.7) were identified as factors associated with an increased risk of functional impairment following PVO, while abscesses (intraspinal or extraspinal) and microbiological factors were not significantly associated with functional impairment. CONCLUSION: In this large cohort of PVO patients, chronic kidney disease, cardiovascular disease, increasing age, and multifocal spinal involvement were associated with functional impairment.