Application of 3-Dimensional Printing Technology in Rotational Osteotomy of Congenital Radioulnar Synostosis

To investigate whether computer-aided design (CAD) and 3-dimensional printing technology can assist in accurate completion of ulna-radius proximal rotational osteotomy in congenital radioulnar synostosis (CRUS). We treated 1 right arm and 4 left arms of 4 boys with a mean age of 5.2 years (range, 4.3–6.0 years) between July 2018 and April 2019. Computed tomography (CT) scans of the forearm were performed on the children before surgery. Using the CT data, the pronation angle of the forearm was measured. An individualized dial with a matching forearm diameter was designed before surgery to control the angle of the rotational osteotomy. Ulna and radius models, and individualized dials, were prepared for each patient using 3-dimensional printing technology. Preoperative simulated surgery was performed using the 3-dimensional printed models. During the surgery, 2 Kirschner wires were used as operating levers for rotation, and rotational angle correction was precisely controlled using the dial. The cast and internal fixation were removed after x-ray examination showed that the osteotomy had healed, about 5 weeks after surgery. The rotational osteotomies were completed in a single operation, and the correction angle was 60°. No complications occurred after the operation. All patients showed functional improvements in activities of daily living. For CRUS patients, models and dials made with CAD and 3-dimensional printing technology can assist in precise rotational osteotomy. Therapeutic V.