Subcutaneous lavage with a 0.05% chlorhexidine gluconate solution leads to decreased Cutibacterium acnes deep culture rate in primary total shoulder arthroplasty: A prospective, randomized controlled trial.

Abstract

Background: Cutibacterium acnes (C acnes) is commonly responsible for periprosthetic joint infections (PJI) after total shoulder arthroplasty (TSA). Chlorhexidine gluconate (CHG) has been shown to decrease the prevalence of C acnes when used in preoperative skin preparations. However, the bacterium is found within the dermal layer of the skin and unable to be completely eradicated with preoperative skin preparations. This study aims to determine if the use of 0.05% CHG lavage of the subcutaneous tissues decreases the incidence of positive superficial and deep C acnes cultures in primary TSA.

Methods: This was a prospective, two-arm, single-surgeon, single-blinded, randomized, controlled trial. All patients scheduled for a primary anatomic or reverse TSA were screened for enrollment at a single institution. Patients were randomized to a saline irrigation or a 0.05% CHG irrigation of the exposed dermal and subcutaneous layer after incision. Five culture samples were taken during surgery. The first was taken from the skin prior to incision and followed by a baseline superficial subcutaneous culture before lavage. Following lavage, one additional superficial and two deep cultures were taken prior to bony preparation. All cultures were incubated and examined for C acnes growth for 21 days. The study was adequately powered at 85% with a Type I error rate of 0.05. An ordinal regression analysis for each culture swab site was performed to determine odds ratios, with the irrigation group (saline/CHG) serving as the independent variable.

Results: 126 patients were enrolled into two groups: normal saline (n=63) and CHG (n=63). The two groups did not have any significant differences in baseline demographic characteristics. The study group that underwent normal saline irrigation had more than double the risk of C acnes contamination at the deep surgical level compared with the group that had 0.05% CHG as the surgical irrigation solution (OR = 2.21, 95% CI: 1.12-4.37). Furthermore, when male patients were isolated the risk of C acnes contamination at the deep surgical level was even more pronounced (OR = 2.84, 95% CI:1.25-6.48).

Conclusions: The use of a 0.05% CHG irrigation solution in the subcutaneous layer leads to a significantly decreased rate of positive deep cultures of C acnes in TSA. Furthermore, in male patients the decrease in rate of positive deep cultures is even more substantial. We recommend its use in the subcutaneous layer during primary TSA to limit the risk of deep C acnes contamination and potentially decrease the risk of PJI.