A practical guide to the diagnosis and management of bone and joint infections.

Infectious arthritis arises from haematogenous spread of organisms through the synovial membrane or from the direct extension of a contiguous infection. The diagnosis rests on the isolation of the pathogen(s) from joint fluid obtained by aspiration or from debridement. Synovial fluid analysis and Gram stains provide clues to the aetiology. The treatment of septic arthritis includes appropriate antimicrobial therapy and joint drainage. Bone infections are currently classified by the Waldvogel or Cierny-Mader classification. Cierny-Mader staging allows stratification and development of comprehensive treatment guidelines for each stage. Osteomyelitis therapy emphasises early diagnosis and aggressive treatment. Radiographs and bone cultures are the mainstays of diagnosis. Radionuclide scans, computerised tomography or magnetic resonance imaging may be obtained when the diagnosis of osteomyelitis is equivocal or to help gauge the extent of the infection. Medical therapy includes improving any host deficiencies, initial antibiotic selection and antibiotic modification based on culture results. Surgical treatment involves debridement of necrotic bone and tissue, obtaining appropriate cultures, managing dead space and, when necessary, obtaining bone stability.