Application of the Guiding Template Designed by Three-dimensional Printing Data for the Insertion of Sacroiliac Screws: a New Clinical Technique.

This study is aimed to explore the clinical application of the guiding template designed by three-dimensional printing data for the insertion of sacroiliac screws. A retrospective study of 7 cases (from July 2016 to December 2016), in which the guiding template printed by the threedimensional printing technique was used for the insertion of sacroiliac screws of patients with posterior ring injuries of pelvis, was performed. Totally, 4 males and 3 females were included in template group, aged from 38 to 65 years old (mean 50.86±8.90). Of them, 5 had sacral fractures (3 with Denis type I and 2 with type II) and 2 the separation of sacroiliac joint. Guiding templates were firstly made by the three-dimensional printing technique based on the pre-operative CT data. Surgical operations for the stabilization of pelvic ring by applying the guiding templates were carried out. A group of 8 patients with sacroiliac injuries treated by percutaneous sacroiliac screws were analyzed as a control group retrospectively. The time of each screw insertion, volume of intra-operative blood loss, and the exposure to X ray were analyzed and the Matta's radiological criteria were used to evaluate the reduction quality. The Majeed score was used to evaluate postoperative living quality. The visual analogue scale (VAS) was applied at different time points to judge pain relief of coccydynia. All the 7 patients in the template group were closely followed up radiographically and clinically for 14 to 20 months, mean (16.57±2.44) months. Totally 9 sacroiliac screws for the S1 and S2 vertebra were inserted in the 7 patients. The time length for each screw insertion ranged from 450 to 870 s, mean (690.56±135.68) s, and the number of times of exposure to X ray were 4 to 8, mean (5.78±1.20). The intra-operative blood loss ranged from 45 to 120 mL, mean (75±23.32) mL. According to Matta's radiology criteria, the fracture and dislocation reduction were excellent in 6 cases and good in 1. The pre-operative VAS score ranged from 5.2 to 8.1, mean (7.13±1.00). The average one-week/six-month post-operative VAS was (5.33±0.78) and (1.33±0.66), respectively (P<0.05 when compared with pre-operative VAS). The 12-month postoperative Majeed score ranged from 86 to 92, mean (90.29±2.21). The three-dimensional printed guiding template for sacroiliac screw insertion, which could significantly shorten the operation time, provide a satisfied outcome of the stabilization of the pelvic ring, and protect doctors and patients from X-ray exposure, might be a practical and valuable new clinical technique.