i. Purpose To determine whether operating in ultra-clean vertical laminar flow and personal isolation “space suits” reduces deep infection rates in total knee replacement compared to a conventional theatre and modern disposal gowns.

ii. Method An analysis of deep infection rates in 373 patients who underwent total knee arthroplasty performed in one operating theatre prior to and after a theatre and clothing upgrade.

Results The infection rate before the introduction of ultraclean air and space suits was 6/166 (3.6%). Afterwards the rate was 1/207 (0.5%). This shows a significant reduction (p< 0.05)

iii. Conclusion Compared to conventional theatres and clothing the use of ultraclean vertical laminar flow and spacesuits significantly reduces the risk of infection in total knee arthroplasty.