Chronic Subclinical Bacterial Colonization of Periprosthetic Capsulectomy Specimens after Implant Removal

Goals/Purpose: Previous studies in the orthopedic literature have shown that slow growing infections surrounding implants can result in chronic pain and other musculoskeletal complaints without overt clinical signs of infection. Propionibacterium acnes in particular, has been linked to delayed subclinical infections in the total shoulder arthroplasty population. The goal of this study was to determine the incidence of bacterial colonization on explanted breast implants and capsules.

Methods/Technique: A retrospective analysis was performed on patients who presented to a single practice for elective breast implant removal and total periprosthetic capsulectomy over a 12 month period. In all cases, capsule tissue was sent for gross pathologic identification, as well as microbiologic examination for aerobic, anaerobic, fungal, and acid-fast bacteria. Aerobic cultures were held for 48 hours, anaerobic cultures were held for seven days, fungal cultures were held for four weeks, and acid-fast cultures were held for six weeks. The resulting data was analyzed to determine the percent of implants which had bacterial growth. Furthermore, the types of bacteria were identified to determine the most commonly encountered microorganisms.

Results/Complications: A total of 200 patients underwent bilateral implant removal with total periprosthetic capsulectomy during the defined period. Of these 400 implants, 27.50% (n=110) were found to have bacterial growth from the cultured capsule tissues, despite the fact that none of the patients were preoperatively exhibiting clinical signs of overt infection. Once speciated, 80.91% (n=89) of the implants with positive cultures were found to be growing Propionibacterium acnes. Other, minor, microorganisms identified included various Staphylococcus species (7.27%, n=8), Streptococcus species (1.81%, n=2) and fungal species (5.45%, n=6)

Conclusion: The presence of bacteria on breast implants and capsules occurs at a relatively high frequency, with Propionibacterium acnes being the overwhelmingly dominate species identified. Given the known correlation between Propionibacterium acnes and nonspecific musculoskeletal complaints from the orthopedic literature, future studies are needed to further understand if there is also a potential link between the presence of Propionibacterium acnes on breast implants and the non-specific symptoms some breast implant patients manifest.