Session IX - Pediatrics and Spine
A Comparison of Short- and Long-Arm Plaster Casts for Displaced Distal-Third Pediatric Forearm Fractures: A Prospective
Randomized Trial
Gavin R. Webb, MD1; Robert Galpin, MD, FRCSC2; Douglas G. Armstrong, MD2; Daniel R. Schlatterer, DO, MS1;
Purpose: A recent review reported that as many as 75% of all pediatric forearm fractures involve the distal one-third of the forearm. Various methods of cast immobilization have been recommended to prevent the recurrence of angulation or displacement in these fractures. Most of the reports in the literature support the use of long-arm casts for treatment of these fractures. However, there is also support for the use of a well-molded short-arm cast to treat these injuries. To date there has not been a comparative study that examined the difference in effectiveness between long- and short-arm casts for treatment of these fractures. This prospective randomized trial was designed to determine whether there is a difference between these two treatment methods.
Methods: After obtaining Institutional Review Board-approval, all patients with displaced distal one-third forearm fractures requiring reduction that were treated at our institution between March, 2002 and June, 2003 were included unless they met specific exclusion criteria. Patients who agreed to participate were randomized to either a short- or long-arm cast, which was applied after a reduction was performed. The subjects then followed up at standard intervals. Pre- and post-reduction displacement, angulation and deviation values were determined from radiographic measurements. Cast indexes were measured from the initial post-reduction films by dividing the sagittal by coronal width at the fracture site to evaluate the adequacy of the mold. A previous study showed the normal ratio to be 0.7 in pediatric forearms. Changes in displacement, angulation, and deviation in follow-up films were calculated and averaged for both cast types. Levene's test for equality of variances and a t-test for equality of means were used to verify that there were no differences between the groups in fracture type, initial fracture characteristics, mechanism, age, or sex. Loss of reduction in the cast was defined as more than 25% displacement, 10° of angulation, or 10° of deviation. The cases of lost reduction were examined to determine influence of fracture type, pre- and post-reduction displacement and angulation, cast index, and cast type. Wrist and elbow range of motion was averaged, and the need for physical therapy was compared between patients with the two cast types. A questionnaire evaluating the impact of the cast on activities of daily living was given at the conclusion of treatment. A phone interview was conducted at least 6 months later to determine whether there were any refractures.
Results: There were 102 eligible patients in the specified timeframe, 8 of whom refused to participate. Six patients met one or more of the exclusion criteria, and 10 patients were lost to follow-up, leaving 78 patients for analysis. The average age was 9.7 years (range, 4 to 16), and 75% of the subjects were male. The average follow-up was 7 months, and the follow-up rate was 89%. There were 46 long-arm casts and 32 short-arm casts. There were no significant differences between the two groups in initial fracture characteristics, mechanism, age, sex, cast index, post-reduction or final displacement, angulation, or deviation. There were 11 cases of lost reduction in the cast, 9 from long-arm casts and 2 from short arm casts. The only significant difference between groups was cast index in the long-arm casts (.778 lost reduction versus .715 maintained reduction (P = 0.04)). Initial elbow range of motion was significantly less in the long-arm casts, but there was no difference in final range of motion between the two groups. One long-arm cast patient required physical therapy to regain elbow range of motion. Results from the questionnaire demonstrated that patients that had long-arm casts were significantly more likely to miss school, require help to dress, be unable to shower or write, require help in school, and have difficulty with activities of daily living.
Conclusion/Significance: Distal-third forearm fractures are common injuries in the pediatric population. Most of the literature supports use of long-arm casts to treat these fractures. This prospective randomized trial showed no significant difference in the treatment results from use of long- or short-arm casts. There were more cases of lost reduction in long-arm than short-arm casts. The questionnaire supports the idea that it is more difficult for the pediatric population to function in a cast that immobilizes the elbow. This study supports the use of well-molded short-arm casts for the treatment of displaced distal-third pediatric forearm fractures.