MRI shows a high incidence of carpal fractures in children with posttraumatic radial-sided wrist tenderness

Background and purpose - The epidemiology and optimal diagnostics of wrist injuries in children are not knotwn. We describe fractures revealed by magnetic resonance imaging (MRI) in a prospective population of children and adolescents with posttraumatic radial-sided wrist tenderness, and compare the diagnostic value of radiographs and computed tomography (CT) with that of MRI. Patients and methods - From 2004 to 2007, patients less than 18 years of age who presented at our emergency department were included in the study. 90 wrists in 89 patients underwent clinical, radiographic, and low-field MRI investigation. If plain radiographs or MRI revealed a scaphoid fracture, a supplementary CT scan was performed. Sensitivity and specificity of radiographs and CT for diagnosis of scaphoid fractures was calculated using MRI as the reference standard. Results - 74 fractures were diagnosed in 61 of 90 wrists using MRI; 48 wrists had a scaphoid fracture, 8 had a distal radius fracture, 7 had a capitate fracture, and 3 had a triquetrum fracture. The most common combination of fractures was scaphoid and capitate. The sensitivity of radiographs for visualization of scaphoid fractures was 54% and the specificity was 100%. The sensitivity for other fractures was <50%. The sensitivity of CT for visualization of scaphoid fractures was 96% and it was between 33% and 100% for other fractures. Interpretation - MRI showed a high incidence of fractures in children and adolescents with posttraumatic radial wrist tenderness, and it led to the diagnosis of more fractures than plain radiographs and CT. A scaphoid fracture was the most common carpal injury, followed by fracture of the capitate.