The incidence rate, trend and microbiological aetiology of prosthetic joint infection after total knee arthroplasty: A 13 years' experience from a tertiary medical center in Taiwan.

BACKGROUND/
PURPOSE: Total knee arthroplasty (TKA) improves the patient's quality of life by relieving pain, correcting the deformity, and helping the patient resume normal activities. However, post-TKA prosthetic joint infection leads to implant failure, is difficult to treat, and causes a significant burden both economically and health-wise. Therefore, an understanding of the current trends in this infection and microbiology data is essential for preventing and treating it.
METHODS: A retrospective study was conducted on 10,768 patients who underwent primary TKA at Taipei Veterans General Hospital, Taiwan, from 2002 to 2014. The incidence of post-TKA prosthetic joint infection in different time periods was investigated, and microbiological results in early- (<3 months post-TKA) and delay-onset prosthetic joint infection were analyzed.
RESULTS: The 2 years incidence of post-TKA prosthetic joint infection was 1.93% (2002-2006), 1.05% (2007-2010), and 0.76% (2011-2014). The incidence of post-TKA prosthetic joint infection decreased significantly from 2002 to 2014. Although Staphylococcus species was most commonly isolated, a significantly higher proportion of gram-negative bacteria were isolated from early-onset compared with delay-onset post-TKA prosthetic joint infection patients: 9/29 (31.0%) versus 13/100 (13%); p = 0.023.
CONCLUSIONS: The results showed that the risk of post-TKA prosthetic joint infection is decreasing. Microbiology results showed that early-onset post-TKA prosthetic joint infection is associated with a higher risk of gram-negative bacterial infection. Physicians should be aware of this risk in order to correctly select empirical agents.