Intraoperative bacterial contamination in total hip and knee arthroplasty is associated with operative duration and peeling of the iodine-containing drape from skin.

BACKGROUND: Surgical site infection (SSI) and periprosthetic joint infection are the most important problems after total hip arthroplasty (THA) and total knee arthroplasty (TKA). This study aimed to examine the risk factors for intraoperative bacterial contamination in THA and TKA.
METHODS: One hundred and seven hips underwent THA, while 74 knees underwent TKA. After the implant was placed, a swab sample for bacterial culture was collected around the skin incision. At the time of specimen collection, patients were separated into two groups based on whether the iodine-containing drape remained adhered to the skin (group DR) or the iodine-containing drape was peeled off (group ND). Patient characteristics, including age, height, body weight, body mass index, operative duration, intraoperative blood loss, surgical procedures, and condition of the iodine-containing drape, were compared between patients with positive and negative bacterial cultures.
RESULTS: In THA, which had a shorter operative duration than TKA (p < 0.001), there was one case of bacterial contamination. In TKA, there were ten cases of positive bacterial contamination, all in group ND. Postoperative SSI occurred in one case. The binomial logistic regression analyses confirmed that TKA [OR 16.562 (95% CI 2.071 to 132.430), p < 0.01] was a high risk factor of bacterial contamination compared to THA and the group ND [OR 0.000 (95% CI 0.000), p < 0.001] had a low risk of bacterial contamination compared to the group DR. In TKAs, operative duration was the risk factor of bacterial contamination [OR 1.026 (95% CI 1.000 to 1.054), p < 0.01].
CONCLUSIONS: Intraoperative bacterial contamination increases in procedures with long operating time and may be suppressed by proper use of an iodine-containing drape.