These authors performed routine perioperative testing in 53 patients who underwent revision shoulder arthroplasty. In addition to routine tissue and fluid culture, the retrieved shoulder implants underwent sonication with culture of the sonicate fluid.
25 (47%) were classified as infected. Propionibacterium was the identified pathogen in 19 of 25 cases. Other cultured organisms were CNSS (4/25 [16%]), methicillin resistant Staphylococcus aureus (2/25 [8%]), group B streptococcus (1/25 [4%]), and Enterobacter cloacae (1/25 [4%]). Two (8%) cases were polymicrobial, with both CNSS and P. acnes identified in each.
Using the cutoff value of >20 colony forming units (CFU)/mL to exclude contaminants, implant sonication culture had a low sensitivity (56%) but high specificity (93%) .
Without using a cutoff value, implant sonication culture had a high sensitivity (96%) but low specificity (64%).
Standard intraoperative cultures (tissue and fluid) had a better overall performance compared with the cutoff and non-cutoff sonication results.
The authors concluded that implant sonication fluid culture in revision shoulder arthroplasty showed no significant improvement in diagnostic utility over standard intraoperative cultures.
Comment: In our laboratory, explanted prosthesis are submitted to vortexing, which is an alternative approach to sonication for shaking loose bacteria that may be encased in a biofilm on the implant. Our experience indicates that implants studied in this way provide an important source of culture positive specimens harvested at the time of revision arthroplasty. In a recent study (see this link) only 32.6% of the fluid cultures were positive in comparison with 66.5% of the soft-tissue cultures and 55.6% of the cultures of the explant specimens.
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The reader may also be interested in these posts:
Consultation for those who live a distance away from Seattle.
Click here to see the new Shoulder Arthritis Book.
Click here to see the new Rotator Cuff Book
Information about shoulder exercises can be found at 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 including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'
See from which cities our patients come.
See the countries from which our readers come on this post.
