Is There Value in the Routine Practice of Discarding the Incision Scalpel From the Surgical Field to Prevent Deep Wound Contamination with C. acnes

Abstract Background Cutibacterium acnes (C. acnes) is found in skin flora of the shoulder and is the most common microbe identified in periprosthetic shoulder infections. The purpose of this study is to determine if there is C. acnes present on the incision scalpel in patients undergoing shoulder arthroplasty despite extensive skin preparation techniques to prevent wound contamination. Methods The authors collected a consecutive case series of patients meeting inclusion criteria. Patients were included if they underwent either primary or revision shoulder arthroplasty at the tertiary-care hospital with the senior author during the study period. Culture swab samples, testing for presence of C. acnes, were collected from 17 consecutive patients who underwent shoulder arthroplasty with a single, fellowship-trained surgeon between November 2019 and March 2020. Culture reports were recorded as “positive” or “negative” after 21 days. Institutional Review Board approval of the study protocol was obtained. The null hypothesis was that there would be no cases with knife blades “culture positive” for C. acnes. Results 17 patients were identified and fit inclusion criteria. There were 12 males (mean age 64.3y, range 48y-79y) and 5 females (mean age 69.8y, range 59y-79y). Two patients (11.8%) were found to have C. acnes growth on the skin knife. Both patients were males over the age of 70 undergoing primary reverse shoulder arthroplasty with no history of previous shoulder infections. Conclusion The presence of C. acnes on the skin blade in 2 patients validates concerns that there is C. acnes present in dermal tissue despite extensive attention to eradication of these microbes. There was a high rate of C. acnes contamination on scalpel blades used for initial skin incisions and the authors conclude that there is value in discarding these blades from the surgical field.