Novel Rabbit Model for the Evaluation of Open Tibia Fractures: Effect of Delayed Surgery on Infection Rate

Abstract

ABSTRACTIntroductionThe objective of this investigation was to evaluate the effects of delayed surgery on infection rates of open tibia fractures in a rabbit model. Our hypothesis was that delaying irrigation and debridement (I&D) would increase the risk of bony and soft tissue infection when antibiotics were withheld.Materials and methodsA drill hole was created in the rabbit tibia and inoculated withStaphylococcus aureus. Animals underwent I&D at controlled delayed times of 6 hours (n = 11), 12 hours (n = 9) and 24 hours (n = 10). A stainless steel pin was inserted to mimic definitive fracture fixation with a metal prosthesis. No antibiotics were administered. Animals were sacrificed at 4 weeks and evaluated for infection.ResultsThe percent of soft tissue infections with I&D delays of 6, 12 and 24 hours were 18, 22 and 40%, respectively [p = 0.59; odds ratio (OR) = 3]. The percentage of animals with osteomyelitis with I&D delays of 6, 12 and 24 hours were 9, 22 and 50%, respectively (p = 0.12; OR = 10).DiscussionIn the current model, delaying I&D from 6 to 24 hours may increase the rate of postoperative osteomyelitis and further investigation is warranted.Kokko KP, Kang QK, Wen X, An YH, Barfield WR, Hartsock LA. Novel Rabbit Model for the Evaluation of Open Tibia Fractures: Effect of Delayed Surgery on Infection Rate. The Duke Orthop J 2013;3(1):48-53. I