UNUSUAL TALUS FRACTURE IN CHILDREN

Abstract

Talus fracture are extremely rare in children. The talus is predominantly made up of cartilage with higher elastic resistance than adult bone thus the pediatric talus bone can sustain higher forces before fractures. The prevalence for paediatric trauma in talus fracture is estimated to be five times rarer than for adult trauma . The most common mechanism of injury in talus fractures is axial loading of the talus against the anterior tibia with the foot in dorsiflexion. The talar neck is the most common fracture site, followed by the talar body.Report:A 9-year-old boy was brought to emergency department following a fall from bicycle after his right foot caught in back wheel. He was unable to weightbear on his right foot and his anterior ankle region was swollen, with no open wounds or abrasions. Radiographs of right ankle revealed a fracture at neck of right talus (Hawkins type II ) then proceed with CT scan to characterize the fracture pattern and extent of injury. His fracture was fixed with two headless cannulated screws size 4.0 under I/I guidance. The patient was advised non-weight bearing with below knee cast for 6 weeks. After 2 months the patient was pain free and had resumed all his activities. X-ray after 1 year showed a consolidation of the fracture without evidence of avascular necrosis. The Hawkins classification can be used to describe the different types of fractures of the talar neck and to predict the risk of avascular necrosis. These injuries can be difficult to diagnose with plain radiograph, and further assessment with CT scan or MRI may be necessary. Undisplaced fracture can be managed non-operatively with cast immobilization and displaced fracture can be treated with either closed or open reduction. Complications are still likely to be encountered in the course of talus fractures treatment considering the precarious blood supply to the bone as well as complex ankle and subtalar articulations. According to Smith et al study with 29 subjects , displaced pediatric talus fractures and those associated with high-energy trauma resulted in more complications ; avascular necrosis (7%), arthrosis (17%),delayed union (3%),neuropraxia (7%) and the need for further surgery (10%).Figure 1 :Xray day 1 post traumaFigure 2:Xray after 1 year post traumaConclusion:Talar fractures in the pediatric age group are very rare. A minimal or undisplaced fracture of talus is less likely to undergo avascular necrosis than a displaced fracture but even with optimal treatment, avascular necrosis may still occur. It is of prime significance that these fractures should be diagnosed well in time to avert complications. Therefore an appropriate length of follow-up is required.