A localized laminar flow device decreases airborne particulates during shoulder arthroplasty: a randomized controlled trial

Abstract

Background: Although the rate of periprosthetic joint infection following shoulder arthroplasty is low, it is a morbid and costly complication. Airborne particulates have long been recognized as a potential source of wound contamination, and operating room-mounted and smaller localized laminar airflow devices have been developed to minimize airborne particulates. This randomized controlled trial evaluated the effectiveness of a localized laminar flow device in reducing the intrusion of ambient airborne particles and bacteria into the surgery site during shoulder arthroplasty as measured by overall particle counts and colony-forming units (CFUs).

Methods: Patients undergoing primary anatomic or reverse shoulder arthroplasty were eligible for participation. After providing informed consent, patients were randomly assigned to the Air Barrier System (ABS) group or control group. For all patients, the ABS was placed on the surgical field; however, it was only turned on by the technician for those randomized to the ABS. Study participants, surgeons, and surgical staff were blinded to group assignment. Bacterial CFUs were collected from within 5 cm of the surgical wound every 10 minutes, whereas airborne particulates were collected every minute. Poisson regression models were used to determine whether differences existed in CFUs and particulate counts between the ABS and control groups.

Results: A total of 43 patients were randomized into the ABS (n = 21) or control (n = 22) group. Surgical time (P = .53) and the average staff count (P = .16) in the operating room did not differ between groups. Poisson regression showed that the ABS group had significantly lower CFUs (β = -0.583, P < .001) along with surgical time and particulates with a diameter ≥ 5 μm. Staff count and particulates with a diameter < 5 μm were not significant predictors of CFUs. Infection was not a primary outcome; however, no postoperative infections have been reported in either study group with a minimum of 1-year follow-up for all patients.

Discussion: This double-blinded, randomized trial demonstrated that a localized laminar flow device dramatically reduced the count of CFUs in the air directly above the wound and beneath the ABS (adjusted for the number of operating room personnel and surgical time). The use of the device was not associated with a longer case duration; however, some additional setup time was required prior to surgical incision to place the device. Further study is required to determine the clinical implications of this finding-specifically, whether such devices result in lower rates of periprosthetic joint infection after shoulder arthroplasty.

Keywords: Laminar flow device; airborne particulates; colony-forming units; operating room airflow; periprosthetic joint infection; randomized controlled trial; shoulder arthroplasty.