Periprosthetic joint infections at a teaching hospital in 1990-2007.

BACKGROUND: Periprosthetic joint infections (PJIs) are major complications associated with high costs and substantial morbidity. We sought to evaluate hip and knee arthroplasty infection rates at our hospital, compare them in periods before and after implementation of measures to reduce PJIs (1990-2002 and 2003-2007) and identify associated risk factors.

METHODS: We retrospectively reviewed records of patients who received primary hip or knee total joint prostheses at our centre between Jan. 1, 1990, and Dec. 31, 2007, and were readmitted for the treatment of infection related to their surgery. We also reviewed data from a prospective surveillance protocol of total hip (THA) and knee arthroplasty (TKA) infections that started in November 2005. We ascertained the annual rates of deep, superficial and hematogenous infections.

RESULTS: During the periods studied, 2403 THAs and 1220 TKAs were performed. For THA, the average rates of deep, superficial and hematogenous infections were 2.0%, 0.8% and 0.3%, respectively. For TKA, the rates were 1.6%, 0.7% and 0.2%, respectively. Of 106 infected joints, 84 (79.2%) presented risk factors for infection. Efforts to reduce the infection rate at our institution began in 2003. We achieved a 44% decrease in the deep infection rate for THA (2.5% v. 1.4%; p = 0.06) and a 45% decrease for TKA (2.0% v. 1.1%, p = 0.20) between the periods studied.

CONCLUSION: Knowing the actual infection rate associated with different procedures in specific settings is essential to identify unexpected problems and seek solutions to improve patient care. Although we do not know what specific improvements were successful, we were able to decrease our infection rates to levels comparable to those reported by similar care centres.