Open tibial fractures: risk factors for infection in conversion of external fixator to intramedullary nail at a tertiary academic hospital

Maku Mm,Sas Olorunju,Mv Ngcelwane

doi:10.17159/2309-8309/2018/v17n2a3

Abstract

Aim: To determine the rate of infection in open tibial fractures treated by conversion of an external fixation into an intramedullary nail, and to identify the factors contributing to the infections. Methods: The study included a total of 52 patients. Multiple variables were assessed as risk factors that could lead to infection in open tibial fractures treated primarily with an external fixator and later converted into an intramedullary nail. The factors looked at were: age, average time taken from injury to debridement, average time taken from admission to debridement, antibiotics administration, facility that admitted the patient before intramedullary nail, average time for conversion of external fixator into intramedullary nail insertion, type of soft tissue management, initial Gustilo and Anderson classification and retrospective re-classification of fractures, existence of superficial sepsis or pin-tract infection, radiologic evidence of infection, the Injury Severity Score and the type of external fixator used. A p value < 0.05 was used as the threshold for level of significance. Results: The average follow-up was 37 weeks (median 24 weeks). We had a 40% infection rate CI [27%, 55%]. Factors that were found to be the most statistically significant (p≤0.05) were amount of soft tissue injury and fracture comminution; this is after the fractures were retrospectively re-classified. All other factors looked at were not statistically significant as risk factors for infection (p>0.05). Conclusion: The study suggests that correct classification of open tibial fractures, with recognition of soft tissue injury and bone comminution, is important in reducing infection rates and in ensuring proper initial management of these fractures. Treatment should be based on the classification done in theatre during the initial debridement, rather than on presentation in the trauma unit. Level of evidence: Level 4

Highlights

Open tibia fractures are common long bone fractures, often resulting in extensive bone and soft tissue damage.[1]
During data collection, when looking at the description of the wound, soft tissue damage and periosteal stripping, and reviewing the extent of comminution of the fractures on X-ray (XR), we found some fractures that were initially classified as Gustilo and Anderson (GA) I which were GA II, some that were classified as GA II fractures which were GA IIIA and some GA IIIA whose severity of injury was underestimated
In the study done by Yokoyama et al.[2], it was found that there was no significant difference among patients with a high or low Injury Severity Score (ISS) in the incidence of deep infection. This corresponds with the results of our study, where we found that the ISS was not a statistically significant factor in contributing to deep infection in open tibia fractures

Summary

Introduction

Open tibia fractures are common long bone fractures, often resulting in extensive bone and soft tissue damage.[1] The subcutaneous location of the tibia as well as its poor blood supply makes it susceptible to non-unions and infections.[2] Injuries to the neurovascular structures are a known complication.[1]. The management of open tibial fractures comprises thorough wound debridement, immediate bone stabilisation with an external fixator, and coverage of bone with soft tissue. This aids in enabling early mobilisation and restoration of limb function. This treatment is not without its complications, infection being a major one

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