Reconnaître les signes de gravité systémique d’une infection ostéoarticulaire

Bone and joint infection (BJI) are heterogeneous: acute infections, chronic infections, prothetic infections, osteomyelitis, diabetic foot infections... Acute infections are not diagnostic problems. Staphylococcus aureus is mostly involved and cause noisy clinical manifestation (fever, pain ± functional impairment, redness, heat and edema). Chronic infections mainly concerned prosthetic joint infection and usually are not therapeutic emergencies but a diagnostic challenge. Indeed, the management of this type of infection combine prolonged antibiotic therapy (12 weeks) with heavy operative procedure. Overall, BJIs very rarely show signs of systemic severity, however there are some elements of poor prognosis to be aware of. The SOFA quick score (qSOFA) can be used at bedside. This score includes the following clinical items: respiratory rate ≥ 22 / min, upper function disorders, systolic blood pressure ≤ 100 mmHg. A qSOFA score ≥ 2 implicated a transfer in intensive care unit. The sepsis criteria were simplified in 2016 during the “Surviving sepsis campaign”. The new recommendations define sepsis as life-threatening organ dysfunction due to a dysregulated host response to infection. BJIs imply the functional prognosis but the risk of sepsis is low. Bacteriemia during BJIs occurs in 20% of cases. In case of sepsis during BJI, the probabilistic antibiotic therapy must include an anti-gram positive cocci. The involvement of methicillin-resistant Staphylococcus aureus and Ponto-Valentine Staphylococcus aureus in BJIs should be identified early in order to limit the consequences through appropriate aggressive medico-surgical management.