Kick the wheels: radiograph-negative ankle injuries in bicycle-spoke accidents

IntroductionBicycle spoke injuries (BSIs) in children are notorious for the presence of Salter Harris type 1 (SH1) fractures. Most patients are therefore treated with cast immobilization. However, the actual prevalence of SH1 following a BSI is unknown. In this study, we aimed to describe a cohort with radiograph-negative BSIs and to identify possible clinical predictors for SH1 which might be useful for adequate risk assessment. MethodsA retrospective cohort study was performed, including all children [≤]12 years visiting our Emergency Department (ED) with a BSI. Patients without radiographic evidence of a fracture were classified as low or high level of suspicion of SH1. Multivariate logistic regression analysis was used to identify independent predictors of a high level of suspicion of SH1. ResultsIn total, 323 patients were included. Ninety-three patients (29%) had a proven fracture; 230 patients were radiograph-negative at first presentation. Of these, 166 patients (72%) were treated with cast immobilization. At follow-up, 32 patients (13.9%) were classified as high level of suspicion of SH1. No clinical variables were found to be predictive for SH1. Local tenderness at the lateral malleolus was associated with a high level of suspicion of SH1, however, this was not statistically significant (OR 2.89, p-value 0.057). ConclusionAlthough BSIs with radiograph-negative ankle injuries are generally treated with cast immobilization, in this cohort only 13.9% had a high level of suspicion of SH1. Lateral malleolus tenderness was associated with a high level of suspicion of SH1 injury, but none of the clinical variables had a significant predictive value.