Infected primary knee arthroplasty: Risk factors for surgical treatment failure

OBJECTIVE: To present epidemiological data and risk factors associated with surgical out-comes favorable or unfavorable for the treatment of infection in infected total knee arthroplasty. METHODS: We reviewed medical records of 48 patients who underwent treatment of primary total knee arthroplasty for infection between January 1994 and December 2008, in the Orthopedics and Traumatology Department of the Santa Casa de Misericórdia de São Paulo. The variables associated with favorable outcome of surgical treatment (debridement and retention or exchange arthroplasty in two days) or unfavorable (arthrodesis or death) infection. RESULTS: A total of 39 cases of infection after primary total knee arthroplasty, 22 progressed to 17 for a favorable outcome and unfavorable outcome. Early infections (OR: 14.0, 95% CI 1.5-133.2, p = 0.016) and diabetes (OR: 11.3, 95% CI 1.4-89.3, p = 0.032) were associated with arthrodesis joint and death respectively. CONCLUSION: Patients with early infection had a higher risk of developing surgical procedure with unfavorable outcome (arthrodesis) and diabetics had higher odds of death after infection of primary knee arthroplasties