Association of Cutibacterium avidum Colonization in the Groin With Obesity: A Potential Risk Factor for Hip Periprosthetic Joint Infection

Background An increase in the incidence of hip periprosthetic joint infections (PJIs) caused by Cutibacterium avidum has recently been detected after implantation of hip arthroplasties with an anterior surgical approach. We raised the question of whether skin colonization with C. avidum differs between the anterior and the lateral thigh as areas of surgical incision fields. Methods Between February and June 2017, we analyzed skin scrapings from the groin and the anterior and lateral thigh in all patients undergoing a primary hip arthroplasty. We anaerobically cultured plated swabs for Cutibacterium spp. for at least 7 days. Univariate logistic regression analysis was used to explore associations between body mass index (BMI) and colonization rate at different sites. Results Twenty-one of 65 patients (32.3%) were colonized with C. avidum at any side, mainly at the groin (n=16, 24.6%), which was significantly higher than at the anterior (n=5, 7.7%, P= 0.009) or lateral (n=6, 9.2%) thigh (P=0.019). Patients colonized with C. avidum did not differ in age or sex compared to non-colonized patients, but BMI was significantly higher (30.1 kg/m2 and 25.6 kg/m2, respectively, P=0.019). Furthermore, increased BMI was associated with colonization at the groin (odds ratio per unit BMI increase: 1.15, 95% confidence interval: 1.03-1.29, P=0.014). Conclusions The groin, rather than the anterior thigh, showed colonization for C. avidum in obese patients. Further studies are needed to evaluate current skin disinfection and draping protocols for hip arthroplasty surgeries, in particular in obese patients