Preoperative Sterilization Preparation of the Shoulder: A Comparative Study Evaluating Gauze Sponge and Commercially Available Applicator Prep Stick

Background: Surgical site infection (SSI) remains a concern in shoulder surgery, especially during arthroplasty. While many studies have explored the characteristics and efficacy of different sterilizing solutions, no study has evaluated the method of application. The purpose of this study was to compare two popular pre-surgical preparatory applications (two 4 x 4 cm gauze sponges and applicator stick) in their ability to cover the skin of the shoulder. Methods: Two orthopedic surgeons simulated the standard pre-surgical skin preparation on 22 shoulders of volunteer subjects. Each surgeon alternated between an applicator stick and two sterile 4x4 cm gauze sponges. Skin preparation was performed with a commercially available solution that can be illuminated under UV-A light. Advanced imageanalysis software was utilized to determine un-prepped areas. A two-tailed paired t-test was performed to compare percentage of un-prepped skin. Results: The applicator stick method resulted in a significantly higher percentage of un-prepped skin (27.25%, Range 10-49.3) than the gauze sponge method (15.37%, Range 5-32.8, P=0.002). Based on image evaluation, most unprepped areas were present around the axilla. Conclusion: Based on our findings, the use of simple gauze sponges for pre-surgical preparatory application of sterilization solution may result in a lower percent of un-prepped skin than commercially available applicator stick. Orthopaedic surgeons and operating room staff should be careful during the pre-surgical sterile preparation of the shoulder, especially the region around the axilla, in order to reduce the potential risk of surgical site infection. Level of evidence: III