Three-Dimensional Corrective Osteotomy of Malunited Fractures of the Upper Extremity with Use of a Computer Simulation System

Background: Three-dimensional anatomical correction is desirable for the treatment of a long-bone deformity of the upper extremity. We developed an original system, including a three-dimensional computer simulation program and a custom-made surgical device designed on the basis of simulation, to achieve accurate results. In this study, we investigated the clinical application of this system using a corrective osteotomy of malunited fractures of the upper extremity. Methods: Twenty-two patients with a long-bone deformity of the upper extremity (four with a cubitus varus deformity, ten with a malunited forearm fracture, and eight with a malunited distal radial fracture) participated in this study. Three-dimensional computer models of the affected and contralateral, normal bones were constructed with use of data from computed tomography, and a deformity correction was simulated. A custom-made osteotomy template was designed and manufactured to reproduce the preoperative simulation during the actual surgery. When we performed the surgery, we placed the template on the bone surface, cut the bone through a slit on the template, and corrected the deformity as preoperatively simulated; this was followed by internal fixation. All patients underwent radiographic and clinical evaluations before surgery and at the time of the most recent follow-up. Results: A corrective osteotomy was achieved as simulated in all patients. Osseous union occurred in all patients within six months. Regarding cubitus varus deformity, the humerus-elbow-wrist angle and the anterior tilt of the distal part of the humerus were an average of 2 degrees and 28 degrees, respectively, after surgery. Radiographically, the preoperative angular deformities were nearly nonexistent after surgery. All radiographic parameters for malunited distal radial fractures were normalized. The range of forearm rotation in patients with forearm malunion and the range of wrist flexion-extension in patients with a malunited distal radial fracture improved after surgery. Conclusions: Corrective osteotomy for a malunited fracture of the upper extremity with use of computer simulation and a custom-designed osteotomy template can accurately correct the deformity and improve the clinical outcome.