[Infected knee arthroplasty. A treatment algorithm at the Kantonsspital Liestal, Switzerland].

The algorithm differentiates between several surgical treatment options depending on the duration of the infection, on the amount of soft tissue damage, on the stability of the implant and the type of micro-organism. If the symptoms of infection exist for less then 3 weeks, a radical debridement is indicated under the condition of a stable implant and good soft tissue conditions. A one-stage exchange is possible with satisfactory conditions of soft tissue and the absence of difficult-to-treat, resistant micro-organisms. In patients with sinustracts or compromised soft tissue, a two-stage exchange is necessary. The placement of a spacer combined with a short interval of 2-3 weeks until reimplantation is possible for easy-to-treat bacteria. For difficult-to-treat micro-organisms, an interval of 8 weeks without spacer until reimplantation is necessary. While stabilised by a fixateur extern, antimicrobial treatment is administered for the first 6 weeks. If the tissue specimens at reimplantation two weeks later do not show growth of bacteria or signs of acute inflammation, antimicrobial treatment can be discontinued. For all other above-mentioned treatment protocols, we administer antimicrobial treatment for a total of 6 months. We present the results of 40 consecutive infected total knee arthroplasties treated according to our algorithm, including a detailed presentation of the two-stage revision procedure.