Objective: The aim of this study was to compare duration of surgery, intraoperative fluoroscopy exposure, blood loss and the accuracy of pedicular screw placement between 3D model-assisted surgery and conventional surgery for AO spinal C-type injuries. Methods: In this study 32 patients who were admitted with thoracolumbar AO spinal C-type injuries were included. These patients were divided randomly into two groups of 16 where one group was operated on using conventional surgery and the other group was operated on using 3D model-assisted surgery. During surgery, instrumentation time, amount of blood loss and intraoperative fluoroscopy exposure were recorded. Moreover, the status of the screws in the pedicles was assessed as described by Learch and Wiesner’s and regional sagittal angles (RSA) were measured preop and postoperatively. Results: It was found that there was a statistically significant difference in instrumentation time, blood loss and intraoperative fluoroscopy exposure in the 3D model-assisted surgery group (61.9 ± 4.7 min, 268.4 ± 42.7 ml, 16.3 ± 1.9 times) compared to the conventional surgery group (75.5 ± 11.0 min, 347.8 ± 52.2 mL, 19.7 ± 2.4 times) (t=4.5325, P < 0.0001 and t=4.7109, P < 0.0001 and t=4.4937, P < 0.0001, respectively) Although the screw misplacement rate of the conventional surgery group was higher than that of the 3D model-assisted surgery group, the only statistically significant difference was in the medial axial encroachment (t=5.101 P=0.02) . There was no severe misplacement of pedicle screws in either group. There were no statistically significant differences between postoperative RSA angles and were in both groups restored significantly. Conclusion: The results of this study have shown us that the 3D model helps surgeons see patients’ pathoanatomy and determine rod lengths, pedicle screw angles and lengths preoperatively and peroparatively, which in turn shortens operative time, reduces blood loss and fluoroscopy exposure. Level of Evidence: Level I, Therapeutic Study Cite this article as: Öztürk AM, Süer O, Govsa F, Özer MA, Akçalı Ö. Patient-specific three-dimensional printing spine model for surgical planning in AO spine type-C fracture posterior long-segment fixation. Acta Orthop Traumatol Turc. 2022;56(2):138-146.

Objective: The aim of this study was to compare the clinical and radiological outcomes of the conventional versus individualized three-dimensional (3D) printing model-assisted pre-contoured plate fixation in the treatment of patients with acetabular fractures. Methods: The data from 18 consecutive patients who underwent surgery for the acetabular fractures were retrospectively analyzed. The patients were divided into two groups (9 in each): conventional and 3D printed model-assisted. The groups were then compared in terms of the duration of surgery, time of instrumentation, time of intraoperative fluoroscopy, and volume of blood loss. The quality of the fracture reduction was also evaluated postoperatively by radiography and computed tomography in both the groups. The quality of the fracture reduction was defined as good (2 mm) based on the amount of displacement in the acetabulum. Results: The conventional group included 9 patients (9 males; mean age=41.7 years; age range=16-70) with a mean follow-up of 11.9 months (range=8-15); the 3D printed model-assisted group consisted of 9 patients (9 males; mean age=46.2 years; age range=30-66) with a mean follow-up of 10.33 months (range=7-17). The average duration of surgery, mean time of instrumentation, time of intraoperative fluoroscopy, and mean volume of blood loss were 180.5±9 minutes, 36.2±3.6 minutes, 6±1 times, and 403.3±52.7 mL in the 3D printed model-assisted group, and 220±15.6 minutes, 57.4±10.65 minutes, 10.4±2.2 times, and 606.6±52.7 mL in the conventional group, respectively. Procedurally, the average duration of surgery, mean time of instrumentation, and mean time of fluoroscopy were significantly shorter, and the mean volume of blood loss was significantly lower in the 3D printed model-assisted group (p<0.05). The quality of the fracture reduction was good in 7 patients (78%) in the conventional group and 8 patients (89%) in the 3D printed model-assisted group. Conclusion: As compared with the conventional surgery, the 3D printing model-assisted pre-contoured plate fixation technique can improve the clinical and radiological outcomes of the acetabular fractures, with shorter surgery, instrumentation, intraoperative fluoroscopy times, and blood loss. Level of Evidence: Level III, Therapeutic study Cite this article as: Öztürk AM, Süer O, Şirintürk S, Aktuğlu K, Govsa F, Özer MA. A retrospective comparison of the conventional versus three-dimensional printed model-assisted surgery in the treatment of acetabular fractures [published online ahead of print, 2020 May 29]. Acta Orthop Traumatol Turc 2020; 54(4): 385-93.

Objective: It was aimed at evaluating the effect of the size of the pedicle screw placed on the fractured vertebra on the long-term radiological and clinical results of short-segment posterior instrumentation applied in the surgical treatment of thoracolumbar vertebral fractures. Methods: This retrospective study included 36 patients who underwent short-segment posterior instrumentation surgery for a single-level thoracolumbar (T11-L2) fracture between January 2015 and March 2021. The patients included in the study were divided into 2 groups according to the size of the pedicle screw placed in the fractured vertebra (group A: intermediate screw 4.5 mm, ≤35 mm+less than 50% of the vertebral corpus length, m/f: 13/4, n: 17, age: 36.5; group B: intermediate screw 5.5 mm, ≥40 mm+more than 70% of the vertebral corpus length, m/f: 11/8, n: 19, age: 42.6). All patients were periodically evaluated clinically and radiologically. Vertebral compression angle (VCA), anterior and posterior vertebral body height (ABH-PBH), intraoperative parameters (instrumentation time and intraoperative fluoroscopy number), and complications were compared between the 2 groups. Results: Both groups were comparable with respect to age, sex, level of injury, AO classification, mechanism of injury, and American Spinal Cord Injury Association impairment scale. Restoration of VCA and vertebral corpus heights was achieved sufficiently in both groups after operation (P < .0001). There was no significant difference between the 2 groups in terms of early postoperative VCA, VCA measured at final follow-up, or loss of correction in VCA. At the last follow-up, PBH was statistically significantly better preserved in group B (P=.0424). There was no difference between the 2 groups in terms of operation time and the number of intraoperative fluoroscopies. Implant failure was observed in 1 patient in group A. Conclusion: This study has revealed that using a long, thick pedicle screw placed in the fractured vertebra can better preserve the PBH at the final follow-up. No correlation was found between the size of the intermediate screw and the preservation of the correction in the postoperative vertebral heights and VCA during the follow-up. Level of Evidence: Level III, Therapeutic Study. Cite this article as: Öztürk AM, Süer O, Aydemir S, Kılıçlı B, Akçalı Ö. The effect of the size of pedicle screw on the long-term radiological and clinical results of short-segment posterior instrumentation in the management of thoracolumbar vertebral fractures. Acta Orthop Traumatol Turc., 2024;58(1):20-26.

Objective: This study aimed to compare the outcomes of traditional surgery (TS) with those of a 3-dimensional model-assisted surgery (3DS) in hallux valgus (HV) surgery with distal chevron osteotomy. Methods: This randomized controlled trial study included 30 patients randomly grouped as TS and 3DS. In the 3DS group, the surgery was simulated on the 3D model before surgery, and that simulation was used as a guide during surgery. Various parameters, such as angles of the HV, intermetatarsal (IM), and distal metatarsal articular, were measured pre-surgery and during the final follow-up. The extent of lateralization of the first metatarsal (FM) head and plantar displacement of the FM head were assessed. Metrics like the duration of the osteotomy+lateralization+K wire fixation, tourniquet time, and fluoroscopy usage were recorded. All assessments were conducted independently and blindly. Patients remained unaware of their group allocation and the randomization procedure. Results: Both groups showed no statistical differences in gender, operated side, age, or follow-up duration. For instance, in the 3DS group (n=15, age: 44.6 ± 9.6 years, male/female: 14/1, side right/left: 11/4, follow-up duration: 29.4 ± 8.7 months) and TS group (n=15, age: 44.8 ± 9.6 years, male/female: 13/2, side right/left: 10/5, follow-up duration: 28.8 ± 8.4 months). The 3DS group, however, showed better metrics with osteotomy+lateralization+K wire fixation, tourniquet duration, and number of fluoroscopies at 12.4 ± 1.2 minutes, 41.5 ± 3.8 minutes, 2.5 ± 0.6 times. In contrast, the TS group recorded 17.1 ± 1.5 minutes, 50.8 ± 3.4 minutes, and 3.3 ± 0.8 times, respectively (P < .001 for all). The 3DS group also achieved a more significant restoration of the IM angle (P < .001). Postsurgery, the 3DS group demonstrated superior outcomes in FM head lateralization, FM shortening, and plantar displacement (P < .001, P < .001 and P = .006, respectively, for all metrics). Only 1 patient in the 3DS group experienced a pin-tract infection, which was treated with wound care and oral antibiotics. Conclusion: Simulating surgery on a 3D model and using it as a guide significantly enhances surgical outcomes. Benefits include reduced operation time, tourniquet duration, decreased fluoroscopy usage, and improved first-ray alignment. The 3DS method also ensures better lateralization of the first metatarsal head and correction of the IM. Although 3D model-assisted HV chevron osteotomy surgery provides ideal deformity correction, it does not significantly affect postoperative functional outcomes. Level of Evidence: Level I, Therapeutic Study. Cite this article as: Süer O, Özer MA, Govsa F, Öztürk AM, Aktuğlu SK. Impact of surgery simulation using a 3-dimensional printed model on outcomes of hallux valgus surgery with distal chevron osteotomy: A randomized controlled trial. Acta Orthop Traumatol Turc., 2024;58(2):95-101.