Microbiology and injury characteristics in severe open tibia fractures from combat.

BACKGROUND: Type III open tibia fractures are common combat injuries. The purpose of the study was to evaluate the effect of injury characteristics and surveillance cultures on outcomes in combat-related severe open tibia fractures.
METHODS: We conducted a retrospective study of all combat-related open Gustilo and Anderson (G/A) type III diaphyseal tibia fractures treated at our centers between March 2003 and September 2007.
RESULTS: One hundred ninety-two Operation Iraqi Freedom/Operation Enduring Freedom military personnel with 213 type III open tibial shaft fractures were identified. Fifty-seven extremities (27%) developed a deep infection and 47 extremities (22%) ultimately underwent amputation at an average follow-up of 24 months. Orthopedic Trauma Association type C fractures took significantly longer to achieve osseous union (p = 0.02). G/A type III B and III C fractures were more likely to undergo an amputation and took longer to achieve fracture union. Deep infection and osteomyelitis were significantly associated with amputation, revision operation, and prolonged time to union. Surveillance cultures were positive in 64% of extremities and 93% of these cultures isolated gram-negative species. In contrast, infecting organisms were predominantly gram-positive.
CONCLUSIONS: Type III open tibia fractures from combat unite in 80.3% of cases at an average of 9.2 months. We recorded a 27% deep infection rate and a 22% amputation rate. The G/A type is associated with development of deep infection, need for amputation, and time to union. Positive surveillance cultures are associated with development of deep infection, osteomyelitis, and ultimate need for amputation. Surveillance cultures were not predictive of the infecting organism if a deep infection subsequently develops.