Decreasing time trend in SSI incidence for orthopaedic procedures: surveillance matters!

Infection is the most common reason for early revision after hip and knee arthroplasty, and the revision rate is increasing. Surgical site infection (SSI) surveillance data are important to assess the true infection rate. There is little information regarding the potential time trend in SSI incidence following orthopaedic surgery.

To evaluate whether a time trend exists in SSI incidence due to surveillance following orthopaedic surgery.

The SSI rates after hip and knee replacements and osteosynthesis of trochanteric femoral fractures and ankle fractures were recorded prospectively from May 1998 to October 2008 according to the criteria of the US Centers for Disease Control and Prevention. In total, 4177 procedures were analysed, 65.8% of which were performed on female patients. Linear regression was used to analyse trends in SSI rates.

SSI incidence decreased significantly from 7% in the first year to 3% in the last year; a 57% relative reduction. The duration of surgery was the only significant predictor for infection (P < 0.001) in a logistic regression model that also included age, American Society of Anesthesiologists' score and level of emergency.

Surveillance following orthopaedic procedures showed a significant decrease in SSI incidence over the 11-year surveillance period. The causality between surveillance and SSI incidence is difficult to prove, but surveillance with feedback probably influences several procedures that affect the quality of health care, even if duration of surgery is the only significant predictor of this effect.