Be vigilant for secondary periprosthetic joint infection.

Periprosthetic joint infection (PJI) is caused by haematogenous spread from a distant primary infection in 70% of deep infections. It can potentially be avoided by prompt recognition and treatment of the primary infection focus in susceptible patients. Streptococci are commonly implicated in such secondary infections. Group A, B, C and G streptococci can cause invasive, potentially life-threatening infection. Risk factors include diabetes, immunodeficiency and venous insufficiency Any patient with a joint replacement should be counselled to seek early attention for any soft tissue or dental infection. A course of antibiotics should be considered in any wound in which there has been significant contamination. Patients at risk of infection through impaired physical defences such as chronic venous insufficiency should be treated appropriately and consideration should be given to prophylactic treatment of varicose veins if there are early signs of chronic venous insufficiency. Mild, uncomplicated cellulitis can be treated with oral antibiotics, simple penicillin agents such as amoxicillin or flucloxacillin should be administered. Patients should be referred to hospital for consideration of parenteral antibiotics if they are exhibiting signs of systemic sepsis such as tachycardia, pyrexia or hypotension. PJI should be suspected if a patient with a joint replacement develops pain in that joint after a soft tissue, respiratory tract or dental infection. In cases of suspected PJI prompt orthopaedic advice should be sought and antibiotics withheld.