Assessing Demographic Characteristics, Microbiology, and Mortality Outcomes Associated With Vertebral Osteomyelitis: A National Single-Center Cohort Study in Malta.

Background Vertebral osteomyelitis (VO) is an uncommon but potentially debilitating spinal infection associated with delayed diagnosis, prolonged hospitalization, and significant morbidity. General international consensus indicates that the incidence of VO is increasing, which likely reflects an aging population and an increase in use of advanced imaging. This paper aims to describe the demographic characteristics, risk factors, microbiology, and short-term outcomes associated with VO in Malta. Methods We performed a retrospective single-centre cohort study of adult patients (>18 years old) diagnosed with VO at Mater Dei Hospital during the 2024 calendar year. Cases were identified through an internal VO registry. Since Mater Dei Hospital is the only national tertiary referral centre in Malta, the cohort is likely to be representative of the country's population. Medical records, electronic notes, imaging reports, and microbiology results were reviewed to extract the relevant clinical data. Results Twenty-three patients who were diagnosed with VO in 2024 were identified. The mean age was 63.1 years (range 27-87), and the majority of patients were male (69.6%). The mean length of admission was 39.3 days (range 3-153), with a median of 20 days, representing a significant hospitalization burden. The majority of cases involved the lumbar spine, with back pain being the most common presenting complaint. Associated risk factors and comorbidities included diabetes mellitus, chronic kidney disease, intravenous drug use, and preceding urinary tract infections. None of the patients had undergone prior spinal surgery or spinal procedures, consistent with a predominantly haematogenous pattern. A causative organism was identified in 19 cases (82.6%), with the most commonly isolated organism being