HORIZONTAL LAMINAR AIR FLOW MAY INCREASE INFECTION RATE IN TKA BUT DOES NOT ALTER INFECTION RATE AFTER THA

Abstract

Purpose: Infection after TJA is a rare but devastating complication. Horizontal laminar airflow has been advocated to reduce infection rate.

Methods: 896 consecutive primary and revision total joint arthroplasties of the hip and knee were retrospectively reviewed. The first 751 were performed before February 2004 in a horizontal laminar air flow room; the final 146 were performed without laminar flow from February 2004 through May 2005. All patients received the same perioperative antibiotics, wound management, and rehabilitation program. Body exhaust systems were worn in all cases.

Results: There were a total of 10 infections (1.1%) requiring surgical treatment, including 6 deep knee infections (0.67%), and four (0.45%) wounds (3 knees and 1 hip) with delayed healing or superficial infections. 9 of the infections occurred in the laminar flow group (1.2%), including all 6 deep knee infections (6/456=1.3%), 2 knee and 1 hip wound infection. Only 1 infection (0.68%), in a knee wound, occurred in the non-laminar flow group. There were no deep hip infections. Statistically, more knees became infected than hips overall (9/550=1.64% vs 1/346=0.29%)(p< 0.01) and more knees developed deep infection with laminar flow than without (6/456=1.2% vs 0/94=0.00%)(p< 0.1).

Conclusions: Laminar air flow did not alter the infection rate in THA, but may have increased infection rate in TKA. Infection is multifactorial, and longer follow up of the non-laminar flow group may reduce the differences seen. Nevertheless, this data agrees with other published data and is of significant concern for the TKA surgeon and patient alike.