Paper #40 - Benzoyl peroxide and clindamycin topical skin preparation decreases Propionibacterium acnes deep colonization in shoulder arthroscopy

Abstract

Background: Propionibacterium acnes is a gram-positive anaerobic pathogen that can lead to devastating postoperative shoulder infections. Inoculation of the shoulder is thought to occur during skin incision due to colonization of the bacterium in the dermal layer. Dermatology literature demonstrates effective reduction of P. acnes colonization on the skin utilizing a combination benzoyl peroxide 5% and clindamycin phosphate 1% topical gel. The objective of this study was to investigate whether a benzoyl peroxide and clindamycin preoperative surgical skin preparation reduces the incidence of P. acnes inoculation of the shoulder joint during arthroscopy, and to determine the time-related effects of the topical medication on P. acnes colonization. Methods: 49 consecutive shoulder arthroscopy patients from November 2014 to September 2015 were prospectively enrolled. 42 patients completed 21 day cultures and were followed for three months. The first culture was a skin culture was taken at the pre-operative visit from the standard posterior, anterosuperior and anterolateral arthroscopic portal sites. A topical benzoyl peroxide 5% and clindamycin 1% gel was then applied to the shoulder with instructions to apply it every night prior to day of surgery. Routine prophylaxis was used with either Cephalexin 1 gram IV or Vancomycin 1 gram IV or Erythromycin 500 mg IV. The second culture was a skin culture was repeated at the three portal sites in the operating room prior to surgical preparation with 4% chlorhexidine solution, followed by a 2% chlorhexidine gluconate and 70% isopropyl alcohol paint. Shoulder arthroscopy proceeded as indicated with the third culture obtained from within the shoulder at the surgical site via a cannula. Results: Superficial P. acnes colonization of the skin remained similar to prior studies at 57 % (24 of 42 patients.) The topical gel was effective at eliminating 71% (17 of 24 patients) of P. acnes skin colonization by day of surgery. 75 % (3 of 4) of positive intraoperative superficial cultures were found on shoulders that only had 1 preoperative application of benzoyl peroxide and clindamycin. With >1 application (≥2 days prior to surgery), the topical gel was found to be 87.7% (7 of 8 patients) effective in decreasing P. acnes superficial colonization. Surgical site deep colonization was reduced to 4.7% (2 of 42 patients) compared our previous study of 19.6%. Ten control “air swab” cultures were all culture negative at 21 days. Conclusions: Benzoyl peroxide and clindamycin skin preparation is effective in reducing deep shoulder colonization of P. acnes in shoulder arthroscopy. It should be considered for use as a prophylactic topical skin preparation prior to shoulder procedures with a time-related effect of >1 application. Level of Evidence: Level II, prospective cohort study.