[Treatment of infected total knee arthroplasty. When does implant salvage make sense?].

Infection of a total knee arthroplasty can be classified as acute, chronic and haematogenic with and without implant loosening. A differentiated treatment concept for all types of infection is necessary. Furthermore, specific treatment has to be initiated early, as any delay is associated with a worsening of the prognosis. Treatment of infection with implant salvage may be one therapeutic option if the implant is not loose. According to the current literature, therapy with retention of the prosthesis may be promising: (1) in the case of early infection (<3 weeks of ongoing symptoms), (2) with unconstrained implants, (3) in the case of infection with a single organism that is susceptible to antibiotic therapy, (4) if soft tissue coverage is not affected, and (5) if the immune system is not compromised. Chronic infections, (semi-)constrained implants and soft tissue defects have to be considered as contraindications and implants should be removed. Early and consequent therapy with operative débridement and specific long-term antibiotic therapy are necessary to achieve implant salvage. The additional application of antibiotics addressing bacterial biofilms have helped to improve the prognosis. Due to the fact that revision arthroplasty is often associated with limited function after infection of the total knee joint, retention of the implant has to be considered a therapeutic alternative in early infection.