Computer-assisted corrective osteotomy for malunited diaphyseal forearm fractures.

BACKGROUND Corrective osteotomy for malunited diaphyseal forearm fractures remains a challenging procedure. We developed a computer-assisted system for corrective surgery, including a three-dimensional simulation program and a custom-made osteotomy template, and investigated the results of corrective surgery for malunited diaphyseal forearm fractures with use of this technology. METHODS Twenty patients (fifteen male patients and five female patients) with malunited diaphyseal forearm fractures were managed with three-dimensional corrective osteotomy with a custom-made osteotomy template based on computer simulation. We performed osteotomy of both radius and ulna in fourteen patients and osteotomy of the radius alone in six patients. The median age at the time of surgery was eighteen years (range, eleven to forty-three years). The median duration between the time of injury and the time of surgery was thirty-three months (range, five to 384 months). The minimum duration of follow-up was twenty-four months (median, twenty-nine months; range, twenty-four to forty-eight months). To evaluate the results, we compared preoperative and postoperative data from radiographs, forearm motion, grip strength, and pain. RESULTS The average radiographic deformity angle preoperatively was 21° (range, 12° to 35°) compared with the normal arm; the radiographic deformity angle was improved to 1° (range, 0° to 4°) postoperatively. The distal radioulnar joints of both sides were symmetric on postoperative radiographs regarding the relative lengths of the radius and ulna. In eighteen patients who had a restricted range of forearm motion preoperatively, the mean arc of forearm motion improved from 76° (range, 25° to 160°) preoperatively to 152° (range, 80° to 180°) postoperatively (p < 0.01). However, forearm supination was still restricted by ≥ 70° in three patients who had been younger than ten years old at the time of the initial injury and who had long-standing malunion for ninety-six months or longer. Painful recurrent dislocation of the distal ulna or radial head resolved or decreased in five patients. Average grip strength improved from 82% to 94% compared with that of the contralateral, normal side. CONCLUSIONS Computer-assisted osteotomy can provide excellent radiographic and clinical outcome for the treatment of malunited diaphyseal forearm fractures. Satisfactory restoration of forearm motion can be achieved even in relatively long-standing cases in adults.