Application of computer simulation in the treatment of traumatic cubitus varus deformity in children

Cubitus varus deformity is common in children. The purpose of this study was to assess the usefulness of computer simulation based on three-dimensional computed tomography (3D-CT) reconstruction with regard to preoperative planning and surgical treatment in children with traumatic cubitus varus deformity. The study included 13 patients with traumatic cubitus varus deformity between January 2012 and January 2015. The original 3D-CT data were transferred to Mimics 10.01 software. Special tools were used for simulation of supracondylar lateral wedge osteotomy of the humerus. Intraoperative elbow arthrography was used to identify the articular surface of the elbow joint for assisting the judgment of the osteotomy site. Kirschner wires were used to determine the osteotomy plane and angle. The osteotomy site was fixed by crossing Kirschner wires and steel wire tension band. Of the 13 patients, 11 were male and 2 were female. The left side was affected in 8 patients, and the right side was affected in 5 patients. The patient age ranged from 2 years to 14 years (mean age, 6 years and 7 months). The varus angle ranged from 12° to 35° (mean angle, 20°). The carrying angle on the contralateral side ranged from 5° to 18° (mean angle, 10°). The varus deformities showed good correction. The 13 patients were followed up for 24 to 60 months (mean follow-up, 38 months). According to the Flynn score of elbow joint function after surgery: 10 patients had excellent function, 2 had good function, and 1 had fair function. The excellent rate was 92.3%. At the final follow-up, the ipsilateral carrying angle ranged from 4° to 15° (mean angle, 11°). Computer simulation based on 3D-CT reconstruction can provide good information on the right humeral osteotomy position and osteotomy angle. It can guide the actual operation and provide better results after surgery. Intraoperative elbow arthrography is useful to determine the level of elbow joint osteotomy, and it can assist in the operation. Level of evidence: Level IV-retrospective case, treatment study.