Surgical field contamination in elective total shoulder replacement

Introduction: Reverse total shoulder arthroplasty (RTSA) has become a widely accepted surgical treatment for various complex shoulder conditions, including rotator cuff tear arthropathy (RCTA), massive irreparable cuff tears (MIRCTs), primary osteoarthritis, fractures in the elderly, and failed previous shoulder replacements. RTSA has shown excellent clinical outcomes in alleviating pain and restoring shoulder function in challenging cases where traditional anatomic shoulder replacements are less effective. The reverse design relies on the deltoid muscle rather than the rotator cuff to power shoulder motion, making it a valuable option when the rotator cuff is irreparably damaged. As the number of patients undergoing RTSA continues to rise, so too does the incidence of complications associated with this procedure. The most common complications include periprosthetic infection, dislocation of the prosthesis, periprosthetic fracture, and neurological injuries. Periprosthetic joint infection (PJI), can be a severe complication following shoulder arthroplasty with the potential for significant consequences. While the reported incidence of PJI following primary RSA varies, most studies report a range between 3% and 4%. However, the infection risk has been documented to be as low as 0.5% and as high as 6.7% in some series. Cutibacterium acnes (C. acnes), formerly known as Propionibacterium acnes, and coagulase-negative staphylococci (CoNS) are prevalent pathogens in shoulder joint infections, often leading to low-grade postoperative infections. The shoulder region's high C. acnes prevalence poses a heightened infection risk compared to hip or knee surgeries, as this bacterium, residing in hair follicles and sebaceous glands, is challenging to completely eradicate despite rigorous skin preparation efforts. Several studies have consistently identified male gender as a notable risk factor for developing PJI following shoulder arthroplasty. In particular, men are 1.5 to 3.5 times more likely to experience this complication compared to women. In addition to gender, younger patient age has also been associated with a higher risk of shoulder PJI. The reasons for this association are not entirely clear but may relate to factors such as activity level or comorbidities. The risk of surgical site infection (SSI) is minimized through prevention methods, such as chlorhexidine shower the night before the surgery, hair removal the morning of the surgery. In addition, once in the operating theatre, a 7,5% iodopovidone and 50% 4 isopropyl alcohol solution is used to wash the shoulder area. The antibiotic prophylaxis will include the use of cefazolin or, in case of allergic patients, vancomycin. perioperative antibiotic prophylaxis and sterile drapes positioned just before the beginning of the surgery. Even though all these precautions are taken before surgery contamination by C. acnes is still present.