Pedicle screw insertion with patient-specific 3D-printed guides based on low-dose CT scan is more accurate than free-hand technique in spine deformity patients: a prospective, randomized clinical trial

BackgroundScrew misplacement incidence can be as high as 15-30% in spine deformity surgery, with possible devastating consequences. Some technical solutions to prevent misplacement require expensive devices. MySpine(TM) comprises a low-dose CT scan of the patient's spine to build a virtual model of the spine to plan the screw trajectories and a 3D-printed patient-specific guide system to prepare the screw trajectories and to implant the screws in the vertebrae in order to increase reproducibility and safety of the implants. The aim of this open-label, single-center, prospective randomized clinical trial with independent evaluation of outcomes was to compare the accuracy of free-hand insertion of pedicle screws to MySpine(TM) 3D-printed patient-specific guides.MethodsTwenty-nine patients undergoing surgical correction for spinal deformity were randomized to Group A (pedicle screws implantation with MySpine(TM)) or Group B (free-hand implantation). Group A received 297 pedicle screws, and Group B 243 screws. Forty-three screws in Group A crossed over to free-hand implantation. Screw position was graded according to Gertzbein in grades 0, A, B or C, with grades 0 or A considered as safe area. Total fluoroscopy dose and time were compared in six patients of each group.ResultsComparing the two study groups, we observed a statistically significant difference between the two groups (p<0.05), with 96.1% of screws in the safe area in Group A versus a 82.9% in Group B. Group-A patients had a mean effective dose of 0.23mSv compared to 0.82mSv in Group B. Patient-specific, 3D-printed pedicle screw guides increase safety in a wide spectrum of deformity conditions. In addition, the total radiation dose is reduced, even considering the need of a low-dose preoperative CT for surgical planning.Level of evidenceI.Graphical abstractThese slides can be retrieved under Electronic Supplementary Material. [GRAPHICS] .