[Septic arthritis and spondylodiscitis : Rare but feared diseases]

Septic arthritis and spondylodiscitis are relatively rare but severe diseases with increasing incidence. Septic arthritis is an emergency situation with high morbidity (40 %) and fatality rates (11 %). The infection occurs via a hematogenous route by direct inoculation or per continuitatem. Patients with pre-existing destructive joint diseases or under immunosuppressive treatment are particularly at risk. It is mandatory to sample synovial fluid for isolation of the relevant pathogen and quantification of leucocytes before starting antibiotic therapy. In order to preserve the joint, early evacuation of the infected synovial space is necessary. Spondylodiscitis is characterized by infection of the vertebra and neighboring discs mainly via a hematogenous route. Immunosuppressed and older patients are primarily at risk of infection. Back pain represents the main symptom but due to its unspecific character and the frequent absence of fever, diagnosis is often delayed. In Europe Staphylococcus aureus is the most prevalent pathogen, whereas tuberculosis is the most frequent causal agent worldwide. Magnetic resonance imaging (MRI) respresents the method of choice for the radiological diagnostics. In stable patients isolation of the pathogen should be achieved before starting antimicrobial therapy (e.g. blood cultures or tissue samples by computed tomography guided puncture or biopsy). The recommended duration of pathogen-specific antibiotic therapy for native spondylodiscitis is normally 6 weeks.