Single Bone Intramedullary Fixation of the Ulna in Pediatric Both Bone Forearm Fractures: Analysis of Short-term Clinical and Radiographic Results

Background: Although single bone intramedullary (IM) fixation has been advocated in the treatment of unstable diaphyseal forearm fractures, some reports have questioned the ability of single bone fixation to maintain adequate reduction. The purpose of this investigation is to report the radiographic and early clinical results of single bone IM fixation for diaphyseal forearm fractures and to identify factors leading to loss of reduction of the radius after ulnar fixation. Methods: A retrospective analysis of 38 children who underwent single bone IM fixation of the ulna for both bone forearm fractures was performed. Mean age was 9 years (range: 4-14 y). Preoperative, postoperative, and final follow-up radiographs were examined for radiographic alignment. Patient data (including age, fracture type, delay to fixation, open vs. percutaneous reduction and fixation, and time to implant removal) was collected to identify predictors for loss of reduction of the radius. Loss of reduction of the radius was defined as 10 degrees or greater change of angulation in either the frontal or lateral plane from initial postoperative radiographs to final follow-up. Multivariate analysis was used to determine associations between patient factors and loss of reduction. Results: All patients went on to bony union with restoration of forearm rotation. Twenty-five patients (66%) healed with < 10 degrees of angulation of the radius, whereas 11 patients (29%) had between 10 and 20 degrees of angulation at final follow-up. Two patients demonstrated greater than 20 degrees of radial angulation requiring additional surgical care. There was no statistically significant association between any patient factors and loss of radial reduction, though there was a trend for increased radial angulation in patients who had sustained open fractures. Conclusions: Single-bone IM fixation of the ulna is a safe and efficacious option for the treatment of unstable diaphyseal forearm fractures in children. Owing to the increased risk of loss of radial reduction, however, consideration should be made for IM fixation of both bones in older children and cases of open fractures.