1550. Osteomyelitis Risk Factors related to Combat Trauma Open Tibia Fracture
Session: Poster Abstract Session: Clinical Infectious Diseases: Combat Wounds
Saturday, October 10, 2015
Room: Poster Hall
Background: Orthopedic injuries predominate during wartime, often complicated by deep soft tissue or bone infections.  Among long bones, tibia injuries typically have the highest infection rates therefore we focused on osteomyelitis risk factors in open tibia fractures sustained in combat.

Methods: Data from U.S. military with orthopedic injuries during combat in Iraq or Afghanistan (Mar 2003 - Dec 2009) were obtained from the Military Health System Data Repository and the DoD Trauma Registry. Open fractures were classified using a modified Gustilo-Anderson (GAm) adding below the knee amputation (BKA) as a separate category, and Orthopaedic Trauma Association (OTA) criteria.  Case definition was based on ICD-9 diagnosis of osteomyelitis and confirmed by medical chart review.  Patients sustaining an open tibia fracture and not meeting osteomyelitis criteria were classified as controls.  Variables of interest (demographic, injury and early treatment characteristics) were examined using univariate and multivariate logistic regression analyses.

Results: A total of 216 subjects sustained open tibia fractures; 131 cases and 85 controls; 86% of these injured in Iraq, 75% due to blast, 51% received any blood transfusion in the first 24 hours, 48% received antibiotic beads and 26% had a BKA.  Iraq operations, blast injury, antibiotic bead use and GAm were all independently associated with an increased risk of osteomyelitis; with those experiencing a BKA at greatest risk (OR= 9.3; 95% CI: 2.7-32). After excluding subjects with BKA, blast and antibiotic bead use remained in the model, however, OTA muscle classification (= 3 [dead muscle/extensive defect] at greatest risk, OR= 8.1; 95% CI: 2.2-30.2) and injury prior to 2007 (OR= 2.6; 95% CI: 1.1-6.3) became significantly associated with osteomyelitis. 

Conclusion: The findings demonstrate that the greatest risk of tibia osteomyelitis occurs among those who have an early BKA. The risk of osteomyelitis with significant muscle loss is similar among those without BKA. A declining risk later in the war coincides with systematic changes in early wound care (e.g., increased use of negative pressure wound therapy and decreased use of high pressure irrigation) providing indirect support for these practices.

David Tribble, MD, DrPH1, Benjamin Potter, MD2, Louis Lewandowski, MD2, Joseph Petfield, MD3, Daniel Stinner, MD3, Amy Weintrob, MD1,2,4, Anuradha Ganesan, MD, MPH5,6, Margot Krauss, MD, MPH, FACPM7, Jamie Fraser, MPH8,9, Joseph Hsu, MD10, Denise Bennett-Carter, MPH8,11, Adriana Mcclung, BS4,12, Lauren Greenberg, MPH7, Jiahong Xu, MS7 and Clinton K. Murray, MD, FIDSA13, (1)Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Bethesda, MD, (2)Walter Reed National Military Medical Center, Bethesda, MD, (3)San Antonio Military Medical Center, JBSA Fort Sam Houston, TX, (4)Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, (5)Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Rockville, MD, (6)Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, (7)Westat, Rockville, MD, (8)Infectious Disease Clinical Research Program, Rockville, MD, (9)Henry M Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, (10)Carolinas Medical Center, Charlotte, NC, (11)Henry M Jackson Foundation for the Advancement of Military Medicine, Inc, Bethesda, MD, (12)San Antonio Military Medical Center, Fort Sam Houston, MD, (13)Infectious Disease Service, Brooke Army Medical Center, Fort Sam Houston, TX

Disclosures:

D. Tribble, None

B. Potter, None

L. Lewandowski, None

J. Petfield, None

D. Stinner, None

A. Weintrob, None

A. Ganesan, None

M. Krauss, None

J. Fraser, None

J. Hsu, None

D. Bennett-Carter, None

A. Mcclung, None

L. Greenberg, None

J. Xu, None

C. K. Murray, None

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