Comparison of Short and Long Arm Plaster Casts for Displaced Fractures in the Distal Third of the Forearm in Children

BACKGROUND: Various methods of cast immobilization have been recommended for the treatment of distal forearm fractures in children. The purpose of this study was to determine if short arm casts are as effective as long arm casts in the treatment of displaced fractures of the distal third of the forearm in these patients. METHODS: In a prospective randomized trial, consecutive patients, four years of age or older, who presented to The Women's and Children's Hospital of Buffalo with a displaced fracture of the distal third of the forearm were randomized to treatment with a short or long arm plaster cast. Radiographs were analyzed for displacement, angulation, and deviation at the time of injury, after reduction, and at subsequent follow-up intervals. The cast index at the fracture level, used to assess the quality of the cast molding, was determined from the postreduction radiographs. Changes between postreduction and final values for displacement, angulation, and deviation; the ranges of motion of both wrists and elbows; the need for physical therapy; and responses to a questionnaire used to evaluate the effects of the cast on activities of daily living were compared between the groups. RESULTS: One hundred and thirteen of the 151 patients who were assessed for eligibility were analyzed. The follow-up rate was 92%, and the average duration of follow-up was eight months. Sixty long arm casts and fifty-three short arm casts were used. There were no significant differences between the two groups with regard to patient demographics, initial fracture characteristics, mechanism of injury, cast index, or the change in displacement, angulation, or deviation during treatment. The fractures that lost reduction in the cast had significantly higher cast indices, indicating poor cast-molding. A comparison of partially and completely displaced fractures revealed no difference between the groups with regard to the change between the postreduction and final amount of displacement. Patients treated with a short arm cast missed fewer school days and were less likely to require assistance with various activities of daily living. CONCLUSIONS: A well-molded short arm cast can be used as effectively as a long arm cast to treat fractures of the distal third of the forearm in children four years of age and older, and they interfere less with daily activities.