Objective: We report an investigation of the clinical results in cases of infection following total knee arthroplasty (TKA).
Methods: The treatment strategy for infected artificial knees at our hospital is to perform debridement and irrigation soon after the infection is diagnosed in an attempt to preserve the components. If the infection is not brought under control by this treatment, the components are removed and a two-stage revision is performed. A total of 35 patients (35 joints) were treated for postoperative infection following TKA at our hospital. The following aspects were investigated for 32 patients (32 joints) who could be followed up for more than 1 year after treatment for infection: 1. the presence of risk factors for infection, 2. the timing of infection onset, 3. the time from the onset of infection until treatment was started, 4. causative organism, and 5. clinical outcome.
Results: In the 32 patients with infection after TKA who were followed up, twelve prosthetic joints (37.5%) were ultimately preserved, while the other 20 (62.5%) were removed. Among patients in whom treatment was started within 2 weeks of the onset of infection, 12 of 16 joints (75.0%) were preserved, but for cases in which treatment was started after 2 weeks, None of 16 joints were preserved. The prosthetic joint was preserved in all 5 cases for which Streptococcus was the cause of infection in the joint. In contrast, only 1 of 9 prosthetic joints (11.1%) infected with methicillin-resistant Staphylococcus aureus and none of the 5 joints infected with Staphylococcus epidermidis were preserved. Of the 20 joints from which the prosthesis was removed, a two-stage revision was completed in 16 joints with a mean waiting period of 7.1 weeks. Infection was controlled in 14 of these 16 joints (87.5%).
Conclusion: In patients suffering infection after TKA, 37.5% of the components could ultimately be preserved. The time from onset of infection until the start of treatment and the causative organism are thought to be important factors in selecting the type of treatment and in the prognosis of infection.
