[Accurate osteotomy assisted by individualized navigation templates for the treatment of children cubitus varus].

OBJECTIVE: To investigate the feasibility and accuracy of a new navigation template for osteotomy in cubitus varus based on computer assistant design and 3D printing technology.

METHODS: The preoperative CT images of 15 children with cubitus varus from June 2015 to June 2016 were collected. According to the above data, the individual osteotomy navigate template match the distal humerus was designed by the software and printed by the 3D printer. Accurate osteotomy was performed with the assistant of the navigate template in the operation. Internal fixation of the osteotomy site was performed with 2 Kirschner wires. After surgery, a long arm plaster was applied with 20° of elbow flexion. All the patients underwent radiographic and clinical evaluations before surgery and at the follow-up examination.

RESULTS: During the operation, the navigate template with the individual design of 3D printing technology matched the bony markers of distal humerus. Accurate and simple osteotomy were performed along the resected surface of the navigation template. None of the cases required any kinds of revision surgery or had any complaint of cosmetic appearance. Average union time was 6.7 weeks(ranged, 6 to 8 weeks). Twelve patients got an excellent result and 2 got a good result according to the criteria described by Bellemore. There were no cases with complications of infection or ulnar nerve palsy or joint stiffness.

CONCLUSIONS: With the help of 3D printing technology, the accurate osteotomy in cubitus varus assisted by individualized navigate template can be realized. This technology can restore normal anatomical structure of the elbow joint to the greatest extent. It is worthy of popularization and application.