Implant salvage in infected total knee arthroplasty

In a retrospective study of 60 infected total knee arthroplasties (TKAs), attempted implant salvage of 39 knees was performed with surgical debridement and antibiotic therapy. In seven of the 39 knees (17.9%), infection was successfully eradicated, with a mean follow-up examination of 4.1 years. In comparing knees with successful salvage to those with persistent infection, the following factors strongly correlated with successful salvage: (1) short duration of symptoms of infection (less than 2 weeks); (2) susceptible gram-positive organism (Streptococcus or Methicillin-sensitive Staphylococcus aureus); (3) absence of prolonged postoperative drainage or the development of a sinus tract; and (4) no prosthetic loosening or roentgenographic evidence of infection. Only five knees in this series satisfied all these criteria, and in each case, implant salvage with eradication of infection and maintenance of good knee function was achieved. Although a higher salvage rate was obtained with the less-constrained prostheses, an infected hinge prosthesis did not preclude successful implant salvage. No patient with a draining sinus tract (0/17), infection with a virulent organism (0/9), or earlier revision arthroplasty (0/9) had successful salvage of the infected implant. Of the 22 knees with postoperative drainage for longer than two weeks or failure of primary wound healing at the time of TKA, only two were successfully salvaged and both required a local muscle flap. Therefore, early aggressive management of persistently draining wounds after TKA is imperative. In TKA complicated by infection, implant salvage with aggressive surgical debridement and antibiotic therapy should be strongly considered, provided that these strict criteria for attempted salvage are adhered.