Risk of orthopaedic implant infection during bacteraemia.

Orthopaedic implant material can get infected via haematogenous spread from a distant source at any point after implantation. The sources of haematogenous orthopaedic implant infections have been studied only for prosthetic joints. The most common source of infection has varied, but it can be, for example from the skin and soft tissues, cardiovascular system and dental infections. The risk for developing a periprosthetic joint infection (PJI) during bacteraemia is dependent on the pathogen: it is highest for Staphylococcus aureus and beta-haemolytic streptococci, but low for gram-negative bacteria. The risk for developing a (PJI) during Staphylococcus aureus bacteraemia (SAB) has varied between 12 and 41%; the risk for developing an infection in any orthopaedic implant in the extremities during SAB is probably almost the same as for prosthetic joints, but data are very limited. The risk of developing an infection in spinal implants during bacteraemia is not known, as it has not been studied. Especially in the case of SAB, infected orthopaedic implants are usually symptomatic, so asymptomatic implants do not routinely require further diagnostic work-up, such as synovial fluid aspiration.