[Ankle injuries without fracture in children. Prospective study with magnetic resonance in 116 patients]

Appropriate assessment of ankle injuries in children and adolescents is a common emergency room problem. Many imaging techniques have been proposed, but with no consensus on the reality of anatomic lesions in ankles free of fractures, complicating the therapeutic decision. We analyzed the lesions observed with magnetic resonance imaging (MRI) in a large number of acute ankles in children.

This prospective study was conducted in a pediatric emergency room. The study population included all children aged eight to 15 years who presented an isolated injury of the ankle without fracture on the plain x-ray. History taking and physical examination were standardized. MRI was performed within three days of the initial physical examination. All the radiographic documents were examined by an experienced radiologist blinded to the results of the physical examination.

During the study period, 116 patients were included. One hundred two MRI series were examined. Minor ligament injury was noted in 20 patients and ligament tear in five, including three with a closed distal tibial growth plate. Minor bone injury was noted in 42 patients and fracture in seven. None of these fractures were visible on the plain x-ray, even after knowledge of the MRI. Injuries were more frequent in boys. Injuries were more frequent when the pain was localized on the lateral aspect of the ankle and when there was an edema.

Despite an abundant literature on ankle sprains, prospective studies are scarce in the pediatric population. We have found that MRI is particularly well-adapted for children because it allows a complete examination of anatomic lesions involving the bone or ligaments without the inconveniences of injections, pain, or radiation. Our clinical and imaging findings show that ankle sprains are real in children. We were however unable to identify any clinical factors predictive of ligament and/or bone injury. Other studies should be conducted to better understand the nosological context of ankle sprain in children and adolescents. Further study will enable a better evidence-based approach to individually adapted therapy.