TABLE II.

Summary of Osteomyelitis Risk Factors Associated With Open Fractures of the Long Bones^a

Risk factor	Tibia	Femur	Upper extremity
Gustilo-Anderson (GA) fracture severity
GA-IIIa		✓
GA-IIIb	✓		✓
GA-IIIc	✓		✓b
Amputationc	✓	✓	✓b
OTA OFC: Muscle
Loss of muscle but function remains	✓	✓
Dead muscle/loss of function	✓	✓
OTA OFC: Skin
Cannot be approximated			✓
Extensive degloving			✓
Use of antibiotic beads	✓	✓	✓
Time periodd	✓	✓	✓
Initial stabilization outside combat zone			Reduced risk
Foreign body
Fragment only	✓
Fragment plus orthopedic implant	✓	✓
Implant only
Blast injury mechanism	✓

Abbreviation: OTA OFC, Orthopaedic Trauma Association Open Fracture Classification.

^aAs there was high correlation between the GA classification system and OTA OFC system, risk factors for each of the long bone groups were assessed in two separate models: one including GA and one for OTA OFC. Models were also rerun for the tibia and femur populations after excluding transtibial and transfemoral amputations, respectively. Findings from all models are included in the summary table. ✓ indicates increased risk.

^bDue to limited numbers, GA-IIIc and amputations were combined for examination as risk factors in the multivariate model.

^cAmputations include transtibial, transfemoral, and transradial/transhumeral for the tibia, femur, and upper extremity groups, respectively.

^dSustaining an injury between the earlier years (2003-2006) was compared to 2007-2009 (used as the reference).