These authors point out that shoulder periprosthetic infections are predominantly caused by bacteria residing in the skin of healthy individuals.
They tested the hypothesis that easy-to-obtain preoperative characteristics were significantly associated with the cutaneous microbiology and the loads of specific bacteria in shoulders having joint replacement.
They identified the microbiology of the unprepared epidermal skin surface and of the dermal edge freshly incised at surgery in 332 patients having primary shoulder arthroplasty.
The load of bacteria in each sample was characterized as a value based on the laboratory report: 0 for “no growth”; 0.1 for “one colony only” or for “broth only”; and 1, 2, 3, and 4 for 1+, 2+, 3+, and 4+ growth, respectively.
Cultures of the unprepared epidermal skin surface showed positive results for a wide variety of organisms, including Cutibacterium in 72%, coagulase-negative Staphylococcus in 61%, and a spectrum of other organisms in 32%.
By contrast, cultures of the freshly incised dermal edge showed a great preponderance of Cutibacterium (34%) in comparison to low levels of coagulase-negative Staphylococcus (8%) and other organisms (2%).
An increased dermal load of Cutibacterium was significantly associated with male sex (p<.001), younger patient age (p<.001), American Society of Anesthesiologists class 1 (p 0.046), use of testosterone supplements (p 0.014), prior shoulder surgery (p 0.046, and higher Cutibacterium loads on the unprepared skin surface (p<.001)
They concluded that although the microbiology of the unprepared skin surface is diverse, the same is not true for the freshly incised dermis, where Cutibacterium is the predominant organism.
Readily available preoperative patient characteristics were significantly associated with the load of Cutibacterium in the incised dermis.
Preoperative cultures of the unprepared skin surface appear to be a new method for predicting the type and load of bacteria found in the freshly incised dermis at the time of surgery.
Comment: Knowledge of the preoperative characteristics of patients likely to have high dermal loads of Cutibacterium may help identify those for whom extraordinary means of prophylaxis (such as Betadine lavage, in-wound topical antibiotics, extended postoperative antibiotics) may be indicated to reduce the risk of periprosthetic infection.
The relationship of male sex, young age, good health, and testosterone supplements to the dermal load of Cutibacterium is consistent with previous observations that higher levels of male sex hormones are associated with increased sebum production in dermal pilosebaceous units and a commensurate increase in the number of Cutibacterium in these dermal structures.
It is of interest that the risk factors for higher loads of Cutibacterium in the dermal incisions for elective shoulder arthroplasty are quite different from the risk factors characteristically associated with periprosthetic infections of the hip and knee, which include older age, female sex, diabetes, high ASA score, obesity, and Medicaid insurance coverage.
We have a new set of shoulder youtubes about the shoulder, check them out at this link.
Be sure to visit "Ream and Run - the state of the art" regarding this radically conservative approach to shoulder arthritis at this link and this link
Use the "Search" box to the right to find other topics of interest to you.
You may be interested in some of our most visited web pages arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'
