Table 1. Classification of prosthetic joint infections.

Classification	Characteristic
According to the route of infection
Perioperative	Inoculation of microorganisms into the surgical surgery or immediately thereafter
Hematogenous	Through blood or lymph spread from a distant focus of infection
Contiguous	Contiguous spread from an adjacent focus of infection (eg, penetrating trauma, pre-existing osteomyelitis, skin and soft tissue lesions)
According to the onset of symptoms after implantation
Early infection (< 3 mo)	Predominantly acquired during implant surgery or the following 2 to 4 d and caused by highly virulent organisms
Delayed or low-grade infection (3–24 mo)	Predominantly acquired during implant surgery and caused by less virulent organisms
Late infection (> 24 mo)	Predominantly caused by hematogenous seeding from remote infections

Table reproduced with permission from EMH Swiss Medical Publishers Ltd. and authors.⁵⁰