Does Three-dimensional Printing Plus Pedicle Guider Technology in Severe Congenital Scoliosis Facilitate Accurate and Efficient Pedicle Screw Placement?

Abstract

Background Three-dimensional (3-D) printing offers the opportunity to create patient-specific guides for pedicle screw placement based on CT-generated models. This technology might allow for more-accurate placement of pedicle screws in patients with severe congenital scoliosis who have rotated vertebrae and small pedicles, but to our knowledge, this premise has not been tested. Questions/purposes (1) Is the use of 3-D printing and pedicle guider technology as or more accurate than the use of the freehand technique for pedicle-screw placement in patients with severe congenital scoliosis? (2) Does surgical time differ with the use of these guiders? (3) Are complications less common in patients treated with this new approach to pedicle-screw placement? Methods A prospective controlled study was conducted of patients with severe congenital scoliosis (major curve ≥ 90°) from June 2016 to June 2018. During this period, we treated 93 patients with congenital scoliosis; 32 had severe scoliosis with a major curve ≥ 90°. The patients were divided into a pedicle guider group (n = 15) and a control group (n = 17) based on their willingness to use pedicle guider technology, which was considered a research technology. With the numbers available, there were no between-group differences in terms of age, sex, BMI, or parameters related to curve severity or flexibility, and all patients in both groups had severe curves. Preoperative and postoperative low-dose CT scans were performed in the two groups. In the pedicle guider group, custom software was used to design the pedicle guider, and a 3-D printer was used to print a physical spinal model and pedicle guiders. The pedicle guiders were tested on the surface of the physical spinal model before surgery to ensure proper fit, and then used to assist pedicle screw placement during surgery. A total of 244 screws were implanted with the help of 127 pedicle guiders (254 guiding tunnels) during surgery in the PG group. Five predesigned pedicle guiders were abandoned due to an unstable match, and the success rate of assisted screw placement using a pedicle guider was 96% (244 of 254). The freehand technique was used in the control group, which relied on anatomic localization to place pedicle screws. The accuracy of pedicle screw placement was evaluated with CT scans, which revealed whether screws had broken through the pedicle cortex. We compared the groups in terms of accuracy (defined as unanticipated breaches less than 2 mm), surgical time, time to place pedicle screws, and screw-related complications. Results A higher proportion of the screws placed using pedicle guider technology were positioned accurately than were in the control group (93% [227 of 244] versus 78% [228 of 291]; odds ratio, 3.69 [95% CI, 2.09–6.50]; p<0.001). With pedicle guider use, operative time (296 ± 56 versus 360 ± 74; 95% CI, -111 to -17; p = 0.010), time to place all screws (92 ± 17 versus 118 ± 21; 95% CI, -39 to -12; p = 0.001), and mean time to place one screw (6 ± 1 versus 7 ± 1; 95% CI, -2 to 0; p = 0.011) decreased. One patient in the pedicle guider group and four in the control group experienced screw-related complications; the sample sizes and small number of complications precluded statistical comparisons. Conclusions In this small, preliminary study, we showed that the accuracy of the surgical technique using spinal 3-D printing combined with pedicle guider technology in patients with severe congenital scoliosis was higher than the accuracy of the freehand technique. In addition, the technique using pedicle guider technology appeared to shorten operative time. If these findings are confirmed in a larger study, pedicle guider technology may be helpful for situations in which intraoperative CT or O-arm navigation is not available. Level of Evidence Level II, therapeutic study.

Three-Dimensional Printing for Preoperative Planning and Pedicle Screw Placement in Adult Spinal Deformity: A Systematic Review

“…In our review, 3DP applications, including 3DP screw guides and planning models, have resulted in statistically decreased operative durations and increased pedicle screw placement accuracy. 1,18,19,28,31 Compared with conventional imaging (eg, intraoperative fluoroscopy), 3DP screw placement guides provide improved screw placement accuracy rates, 19,20,[31][32][33][34][35] and models enhance intrateam communication and planning, 21,[23][24][25]28,36 and reduced fluoroscopy time. 19,20 In one retrospective study of 126 adolescent idiopathic scoliosis patients with a Lenke 1 deformity, Yang et al 1 showed that 3DP models used for surgical planning resulted in reduced operative duration and blood loss.…”

Clinical assessment of three-dimensional printing assisted osteotomy guide plates in precise osteotomy of adult talipes equinovarus

“…Although 3D printing assisted guide plates have been diffusely applied in clinical correction researches of cubitus varus deformity, developmental dysplasia of the hip, spinal scoliosis, hallux valgus and other deformities [17][18][19][20], while the application in ATE malformation correction has been rarely reported. Previously, Windisch et al [21] applied 3D printing technology to fabricate a physical model of ATE malformation with a magnification of 4 times for surgeons to accurately analyze all bone and joint deformities, and perform preoperative planning, but this application only played the most basic role of 3D printing.…”

The Value of Three-Dimensional Printing Spine Model in Severe Spine Deformity Correction Surgery

“…[21] Luo et al demonstrated that accuracy of the surgical technique using spinal 3D printing technology in patients with severe congenital scoliosis was higher than that of the free-hand technique, and it appeared to shorten operative time. [22] It is reported that the intraoperative navigation system or robotic assistant system have been used to enhance the accuracy of pedical screw insertion in the treatment of spine degenerative and some spine deformity disease, [23] and it turns out to be fesiable and effective. [24,25] However, in severe spine deformity surgery, the evidence was unpowered and insu cient.…”