Below- vs above-elbow cast for distal radius fractures: is elbow immobilization really effective for reduction maintenance?

Purpose: The choice of the cast length in conservative management of distal radius fractures still represents a debated controversy. Historically, the elbow is immobilized to reduce the risk of secondary displacement; however, short-arm casts are currently felt to be equally effective with less complications and better patient comfort. This paper investigates whether immobilization of the elbow is actually effective in reducing the risk of loss of reduction in conservatively manipulated distal radius fractures. Methods: We retrospectively studied 297 consecutive patients with distal radius fractures requiring manipulation and subsequently immobilized with above-elbow cast or below-elbow cast. Maintenance of reduction, radial height, radial inclination, and volar tilt were assessed after the reduction and at 35 days. Appropriate statistical analysis was performed to correct data selection bias and to assess any difference in the effectiveness among the two treatments. Results: The mean difference of loss of radial height, inclination, and volar tilt between the two groups was 0.8 mm, 0.4°, and 0.9° respectively, being not statistically significant. Average difference in reduction maintenance probability between the two groups stratified with a statistical propensity score was 1.2%. Conclusions: Above- and below-elbow casts had comparable performance in maintaining reduction of manipulated distal radius fractures.