Clinical features of septic discitis in the UK: a retrospective case ascertainment study and review of management recommendations

Septic discitis is a rare but important cause of spinal pain caused by intervertebral disc infection. This retrospective observational case series analysis will examine the clinical features and management of septic discitis in 23 patients and compare with a similar 2001 study. We will also review the evidence behind management recommendations to identify areas for future research. The incidence of septic discitis was 2 per 100,000 per year. Patients presented with spinal pain (96 %), fever (70 %) and raised inflammatory markers. All patients had blood cultures and 52 % had targeted microbiological analysis. Staphylococcus aureus was the most common causative organism (39 %). Treatment was most often with intravenous flucloxacillin or ceftriaxone. CT-guided sampling for culture before commencing antibiotics increased organism detection from 33 to 67 %, and organism identification reduced the antibiotic course from an average of 142 days to 77 days. An increased number of significant co-morbid conditions were associated with worse outcomes. Results broadly resembled the 2001 study. Key differences were increased use and yield of magnetic resonance imaging and computerised tomography (CT) scanning and more frequent use of intravenous antibiotics. Comparisons between the studies suggest that improvements in the consistency of management have been slow. We suggest this due to the large spectrum of disease and the lack of guidelines in the UK. It is widely recommended to perform blood cultures and CT-guided biopsies before starting antibiotics, but it is unclear how long to withhold antibiotics if cultures remain negative. Six weeks of intravenous followed by 6 weeks of oral therapy is often suggested as treatment, whereas some recommend using inflammatory markers to guide antibiotic duration. Larger studies addressing these specific questions are required to provide more definitive guidance for these clinical decisions.