Optimization of Skin Preparation to Reduce Cutibacterium Acnes Colonization in Superficial and Deep Samples During Prosthetic Shoulder Surgery in Male Patients

This study is looking at the best way to prepare the skin before shoulder replacement surgery to reduce the risk of infection from a common bacteria called Cutibacterium acnes. This bacteria lives naturally on the skin, especially around the shoulder, and can sometimes contaminate the surgical site during joint replacement procedures. Researchers are comparing different skin preparation methods to find out which approach most effectively reduces bacterial contamination. Only male patients scheduled for shoulder replacement surgery are included, as men tend to have higher levels of this particular bacteria on their skin. You may be eligible if: - You are a male patient aged 18 or older - You have no history of prior surgery on the affected shoulder - You are scheduled for glenohumeral shoulder arthroplasty (partial or total) for osteoarthritis, avascular necrosis, massive rotator cuff tear, or old fracture - You are affiliated with a social security system and have given written consent You may NOT be eligible if: - You are having revision surgery or surgery for acute trauma - You are taking immunosuppressive drugs or have inflammatory rheumatism - You have progressive cancer - You have allergies to the skin preparation products used (Povidone Iodine, benzoyl peroxide) - You have a skin condition or active acne treatment in the shoulder area Talk to your doctor to see if this trial is right for you.