Application of computer-aided design osteotomy template for treatment of cubitus varus deformity in teenagers: A pilot study

Background: Treatment of cubitus varus deformity from a malunited fracture is a challenge. Anatomically accurate correction is the key to obtaining good functional outcomes after corrective osteotomy. The aim of this study was to attempt to increase the accuracy of treatment by use of 3-dimensional (3D) computer-aided design. We describe a novel method for ensuring an accurate osteotomy method in the treatment of cubitus varus deformity in teenagers by means of 3D reconstruction and reverse engineering. Materials and methods: Between January 2006 and May 2008, 12 male and 6 female patients with cubitus varus deformities underwent scanning with spiral computed tomography (CT) preoperatively. The mean age was 15.7 years, ranging from 13 to 19 years. Three-dimensional CT image data of the affected and contralateral normal bones of cubitus were transferred to a computer workstation. Three-dimensional models of cubitus were reconstructed by use of MIMICS software. The 3D models were then processed by Imageware software. An osteotomy template that best fitted the angle and range of osteotomy was "reversely" built from the 3D model. These templates were manufactured by a rapid prototyping machine. The osteotomy templates guide the osteotomy of cubitus. Results: An accurate angle of osteotomy was confirmed by postoperative radiography. After 12 to 24 months' follow-up, the mean postoperative carrying angle in 18 patients with cubitus varus deformity was 7.3 degrees (range, 5 degrees to 11 degrees), with a mean correction of 21.9 degrees (range, 12 degrees to 41 degrees). Conclusions: The patient-specific template technique is easy to use, can simplify the surgical act, and generates highly accurate osteotomy in cubitus yams deformity in teenagers. Level of evidence: Level IV, Case Series, Treatment Study. (C) 2011 Journal of Shoulder and Elbow Surgery Board of Trustees.