The Journal of Bone and Joint Surgery (American). 2009;91:1907-1912.
doi:10.2106/JBJS.G.01237
© 2009 The Journal of Bone and Joint Surgery, Inc.
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Letters to the Editor: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when Letters to the Editor are posted
Right arrow Alert me if a correction is posted
Services
Right arrow E-mail this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My File Cabinet
Right arrow Download to citation manager
Right arrow Rights and Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Cavanaugh, D. L.
Right arrow Articles by Dahners, L. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Cavanaugh, D. L.
Right arrow Articles by Dahners, L. E.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us   Add to Facebook   Add to Technorati   Add to Twitter  
What's this?

Better Prophylaxis Against Surgical Site Infection with Local as Well as Systemic Antibiotics

An in Vivo Study

Daniel L. Cavanaugh, BS, BA1, John Berry, BS, BA2, Seth R. Yarboro, MD3 and Laurence E. Dahners, MD4

1 3208 Drew Hill Lane, Chapel Hill, NC 27514. E-mail address: daniel_cavanaugh{at}med.unc.edu
2 226D McCauley Street, Chapel Hill, NC 27516-2558. E-mail address: john_berry{at}med.unc.edu
3 1104 Oak Tree Drive, Chapel Hill, NC 27517. E-mail address: seth_yarboro{at}med.unc.edu
4 Department of Orthopaedics, University of North Carolina, CB #7055, Bioinformatics Building, Chapel Hill, NC 27599-7055. E-mail address: led{at}med.unc.edu

Investigation performed at the Department of Orthopaedics, University of North Carolina, Chapel Hill, North Carolina

Disclosure: In support of their research for or preparation of this work, one or more of the authors received, in any one year, outside funding or grants of less than $10,000 from the National Institutes of Health. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.

Background: Prophylactic systemic antibiotics significantly lower the risk of postoperative infection, and injection of antibiotics directly into the wound cavity has been found to be even more effective. In this study, we investigated the efficacy of direct injection of antibiotics into a wound cavity after wound closure, both alone and in combination with systemic administration of antibiotics. We hypothesized that a combination of preoperative systemic administration and postoperative local injection would be the most effective treatment.

Methods: Rats were divided into six treatment groups: no treatment, local gentamicin, systemic cefazolin, local cefazolin, systemic cefazolin plus local gentamicin, and systemic cefazolin plus local cefazolin. A wound cavity was opened along the femur, an implant was placed, and the wound was inoculated with 2.5 x 108 colony forming units of Staphylococcus aureus. Systemic antibiotics were injected subcutaneously thirty minutes before the initial incision. Local antibiotics were injected percutaneously into the wound cavity after closure. The rats were killed at forty-eight hours postoperatively, and quantitative cultures were performed.

Results: All groups that received antibiotics showed significantly lower bacterial counts than the no-treatment control group (p < 0.0003). Local gentamicin treatment decreased the number of colony-forming-unit isolates by approximately two orders of magnitude as compared with the number in the group treated with systemic cefazolin (p = 0.00005) and five orders of magnitude as compared with the number in the control group (p = 0.00003). The combination of systemic cefazolin and local gentamicin decreased the bacterial count by approximately seven orders of magnitude as compared with the count in the no-treatment control group and significantly decreased the count as compared with that in the group treated with local gentamicin alone (p = 0.00006).

Conclusions: As we hypothesized, the combination of systemic cefazolin and local gentamicin proved to be the most effective regimen. Local injection of gentamicin proved more effective than systemic administration of cefazolin but was not as effective as the combination of both antibiotics. The initially high concentrations of locally applied antibiotic and the utilization of two different classes of antibiotics may have contributed to the observed efficacy.

Clinical Relevance: If our findings are supported by those in clinical trials, the combination of local gentamicin and systemic cefazolin could prove valuable as a regimen for prophylaxis against surgical wound infection.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Facebook Facebook   Add to Technorati Technorati   Add to Twitter Twitter    What's this?