Laminar airflow ceiling size: no impact on infection rates following hip and knee prosthesis

Laminar airflow (LAF) systems are widely used, at least in orthopedic surgery. However, there is still controversial discussion about the influence of LAF on surgical site infection (SSI) rates. The size of the LAF ceiling is also often a question of debate. Our objective is to determine the effect of this technique under conditions of actual rather than ideal use.

Cohort study using multivariate analysis with generalized estimating equations method.

Data for hip and knee prosthesis procedures from hospitals participating in the German national nosocomial infection surveillance system (KISS) from July 2004 to June 2009 were used for analysis.

A total of 33,463 elective hip prosthesis procedures due to arthrosis (HIP-A) from 48 hospitals, 7,749 urgent hip prosthesis procedures due to fracture (HIP-F) from 41 hospitals, and 20,554 knee prosthesis (KPRO) procedures from 38 hospitals were included.

The data were analyzed for hospitals with and without LAF in the operating rooms and by the size of the LAF ceiling. The endpoints were severe SSI rates.

The overall severe SSI rate was 0.74 per 100 procedures for HIP-A, 2.39 for HIP-F, and 0.63 for KPRO. For all 3 prosthesis types, neither LAF nor the size of the LAF ceiling was associated with lower infection risk.

The data demonstrate consistency and reproducibility with the results from earlier registry studies. Neither LAF nor ceiling size had an impact on severe SSI rates.