Objective To explore the application effect of 3D printed heart models in the training of young cardiac surgeons, and evaluate their application value in surgical simulation and skill improvement. MethodsEight young cardiac surgeons were selected form West China Hospital as the trainees. Before training, the Hands-On Surgical Training-Congenital Heart Surgery (HOST-CHS) operation scores of the 8 cardiac surgeons were obtained after operating on 2 pig heart models of ventricular septal defect (VSD). Subsequently, simulation training was conducted on a 3D printed peri-membrane VSD heart model for 6 weeks, once a week. After the training, all trainees completed 2 pig heart VSD repair surgeries. The improvement of doctors’ skills was evaluated through survey questionnaires, HOST-CHS scores, and operation time after training. ResultsBefore the training, the average HOST-CHS score of the 8 trainees was 52.2±6.3 points, and the average time for VSD repair was 54.7±7.1 min. During the 6-week simulation training using 3D printed models, the total score of HOST-CHS for the 8 trainees gradually increased (P<0.001), and the time required to complete VSD repair was shortened (P<0.001). The trainees had the most significant improvement in scores of surgical cognition and protective awareness. The survey results showed that trainees were generally very satisfied with the effectiveness of 3D model simulation training. Conclusion The 3D printed VSD model demonstrates significant application advantages in the training of young cardiac surgeons. By providing highly realistic anatomical structures, 3D models can effectively enhance surgeons’ surgical skills. It is suggested to further promote the application of 3D printing technology in medical education, providing strong support for cultivating high-quality cardiac surgeons.
ObjectiveTo explore the effectiveness of a new point contact pedicle navigation template (referred to as “new navigation template” for simplicity) in assisting screw implantation in scoliosis correction surgery. MethodsTwenty-five patients with scoliosis, who met the selection criteria between February 2020 and February 2023, were selected as the trial group. During the scoliosis correction surgery, the three-dimensional printed new navigation template was used to assist in screw implantation. Fifty patients who had undergone screw implantation with traditional free-hand implantation technique between February 2019 and February 2023 were matched according to the inclusion and exclusion criteria as the control group. There was no significant difference between the two groups (P>0.05) in terms of gender, age, disease duration, Cobb angle on the coronal plane of the main curve, Cobb angle at the Bending position of the main curve, the position of the apical vertebrae of the main curve, and the number of vertebrae with the pedicle diameter lower than 50%/75% of the national average, and the number of patients whose apical vertebrae rotation exceeded 40°. The number of fused vertebrae, the number of pedicle screws, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were compared between the two groups. The occurrence of implant complications was observed. Based on the X-ray films at 2 weeks after operation, the pedicle screw grading was recorded, the accuracy of the implant and the main curvature correction rate were calculated. ResultsBoth groups successfully completed the surgeries. Among them, the trial group implanted 267 screws and fused 177 vertebrae; the control group implanted 523 screws and fused 358 vertebrae. There was no significant difference between the two groups (P>0.05) in terms of the number of fused vertebrae, the number of pedicle screws, the pedicle screw grading and accuracy, and the main curvature correction rate. However, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were significantly lower in trial group than in control group (P<0.05). There was no complications related to screws implantation during or after operation in the two groups. ConclusionThe new navigation template is suitable for all kinds of deformed vertebral lamina and articular process, which not only improves the accuracy of screw implantation, but also reduces the difficulty of operation, shortens the operation time, and reduces intraoperative bleeding.
ObjectiveTo explore the gait trajectory characteristics of patients after total knee arthroplasty (TKA) assisted by three-dimensional (3D) printing navigation template.MethodsTwenty female patients (20 knees) with knee osteoarthritis who were treated with TKA assisted by 3D printing navigation template between February 2017 and February 2018 were selected as the 3D printing group. The patients were 50-69 years old, with an average age of 57.2 years. The disease duration was 4-7 years, with an average of 5.6 years. The osteoarthritis was classified as Kellgren-Lawrence Ⅲ level in 5 cases and Ⅳ level in 15 cases. The preoperative hip-knee-ankle angle (HKA) was (170.8±5.6)°. All patients were varus deformity. According to age and affected side, 20 healthy female volunteers were selected as the control group. The volunteers were 51-70 years old, with an average age of 56.7 years. Preoperative HKA was (178.8±0.6)°. There was significant difference in HKA between the two groups (P>0.05). The HKA, Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and visual analogue scale (VAS) scores of the 3D printing group before and after operation were compared. At 6 months after operation, the gait trajectory characteristics of 3D printing group and control group were analyzed by Vicon gait capture system. The kinematics parameters included velocity, cadence, stride length, maximum knee flexion angle (stance), minimum knee flexion angle (stance), maximum knee flexion angle (swing), mean hip rotation angle (stance), mean ankle rotation angle (stance).ResultsThe incisions of 3D printing group healed by first intention, with no complications. All patients were followed up 7-12 months (mean, 9.0 months). The WOMAC and VAS scores at 6 months after operation were significant lower than those before operation (P<0.05). The HKA was (178.8±0.8)° at 4 weeks after operation and the difference was significant when compared with that before operation (t=39.203, P=0.000). The position of the prosthesis was good. The femoral posterior condyle osteotomy line, surgical transepicondylar axis, and patella transverse line were parallel, varus deformity was corrected, and lower limb alignment was restored to neutral position. Gait analysis at 6 months after operation showed that the differences in all kinematics parameters between the two groups were significant (P<0.05).ConclusionAssisted by 3D printing navigation template, TKA can alleviate pain symptoms and correct deformity, with satisfactory early effectiveness. Compared with healthy people, the early postoperative gait of the patients were characterized by decreasing velocity, cadence, stride length, knee flexion range, and increasing compensatory hip and ankle rotation range.
Objective To evaluate the effect of the 3D-printed heart model on congenital heart disease (CHD) education through systematic review and meta-analysis. Methods The literature about the application of the 3D-printed heart model in CHD education was systematically searched by computer from PubMed, Web of Science, and EMbase from inception to November 10, 2022. The two researchers independently screened the literature, extracted data and evaluated the quality of the literature. Cochrane literature evaluation standard was used to evaluate the quality of randomized controlled trials, and JBI evaluation scale was used for cross-sectional and cohort studies. ResultsAfter screening, 23 literatures were included, including 7 randomized controlled trials, 15 cross-sectional studies and 1 cohort study. Randomized controlled trials were all at low-risk, cross-sectional studies and and the cohort study had potential bias. There were 4 literatures comparing 3D printing heart model with 2D image teaching and the meta-analysis result showed that the effect of 3D printing heart model on theoretical achievement was more significant compared with 2D image teaching (SMD=0.31, 95%CI –0.28 to 0.91, P=0.05). Conclusion The application of the 3D-printed heart model in CHD education can be beneficial. But more randomized controlled trials are still needed to verify this result.
Objective To explore the design points of a three-dimensional (3D) printed customized cementless intercalary endoprosthesis with an intra-neck curved stem and to evaluate the key points and mid-term effectiveness of its application in the reconstruction of ultrashort bone segments in the proximal femur. Methods Between October 2015 and January 2021, 17 patients underwent reconstruction with a 3D printed-customized cementless intercalary endoprosthesis with an intra-neck curved stem. There were 11 males and 6 females, the age ranged from 10 to 76 years, with an average of 30.1 years. There were 9 cases of osteosarcoma, 4 cases of Ewing sarcoma, 2 cases of chondrosarcoma, 1 case of liposarcoma, and 1 case of myofibroblastoma. The disease duration was 5-14 months, with an average of 9.5 months. Enneking staging included 16 cases of stage ⅡB and 1 case of stage ⅢB. The distances from the center of the femoral head to the body midline and the acetabular apex were measured preoperatively on X-ray images. Additionally, the distances from the tip of the intra-neck curved stem to the body midline and the acetabular apex were measured at immediate postoperatively and last follow-up. The neck-shaft angle was also measured preoperatively, at immediate postoperatively, and at last follow-up. The status of osseointegration at the bone-prosthesis interface and bone growth into the prosthesis surface were assessed by X-ray films, CT, and Tomosynthesis-Shimadzu metal artefact reduction technology (T-SMART). The survival status of the patients, presence of local recurrence or distant metastasis, and occurrence of postoperative complications were assessed. The recovery of lower limb function was evaluated pre- and post-operatively using the Musculoskeletal Tumor Society (MSTS) scoring system, and pain relief was evaluated using the visual analogue scale (VAS) scores. Results The patient’s femoral resection length was (163.1±57.5) mm, the remaining proximal femoral length was (69.6±9.3) mm, and the percentage of femoral resection length/total femoral length was 38.7%±14.6%. All 17 patients were followed up 25-86 months with an average of 58.1 months. During the follow-up, 1 patient died of lung metastasis at 46 months postoperatively, and the remaining 16 patients survived tumor-free. There was no complication such as periprosthetic infection, delayed incision healing, aseptic loosening, prosthesis fracture, or periprosthetic fracture. No evidence of micromotion or wear around the implanted stem of the prosthesis was detected in X-ray and T-SMART evaluations. There was no significant radiolucent lines, and radiographic evidence of bone ingrowth into the bone-prosthesis interface was observed in all stems. There was no significant difference in the distance from the tip of the curved stem to the body midline and the apex of the acetabulum at immediate postoperatively and last follow-up compared with the distance from the center of the femoral head to the body midline and the apex of the acetabulum before operation, respectively (P>0.05), and there was no significant difference in the above indexes between immediate postoperatively and last follow-up (P>0.05). The differences in the neck-shaft angle at various time points before and after operation were also not significant (P>0.05). At last follow-up, the MSTS score was 26.1±1.2 and the VAS score was 0.1±0.5, which were significantly improved when compared with those before operation [19.4±2.1 and 5.7±1.0, respectively] (t=14.735, P<0.001; t=21.301, P<0.001). At last follow-up, none of the patients walked with the aid of crutches or other walkers. Conclusion The 3D printed customized cementless intercalary endoprosthesis with an intra-neck curved stem is an effective method for reconstructing ultrashort bone segments in the proximal femur following malignant tumor resection. The operation is reliable, the postoperative lower limb function is satisfactory, and the incidence of complications is low.
ObjectiveTo evaluate the clinical significance of individualized reference model of sagittal curves by three-dimensional (3D) printing technique and computer-aided navigation system for lumbar spondylolisthesis. MethodsBetween February 2011 and October 2012, 66 patients with lumbar spondylolisthesis underwent posterior lumbar interbody fusion (PLIF) by traditional operation in 36 cases (control group) and by individualized reference model of sagittal curves by 3D printing technique and computer-aided navigation system in 30 cases (trial group). There was no significant difference in gender, age, disease duration, segment, type of disease, degree of spondylolisthesis, and preoperative the visual analogue scale (VAS) of low back pain and leg pain between 2 groups (P>0.05). The operation time, blood loss, fluoroscopy times, VAS score of low back pain and leg pain were compared between 2 groups; the sagittal screw angle (SSA), accuracy rate of pedicle screw, Taillard index, disc height recovery rate, and sagittal angle recovery rate were compared between 2 groups. ResultsThere was no significant difference in operation time and blood loss between 2 groups (P>0.05). But fluoroscopy times of control group were significantly higher than those of trial group (P<0.05). One case had radicular symptoms after operation in control group. The patients of 2 groups were followed up 24-36 months (mean, 26 months). The VAS scores of low back pain and leg pain at last follow-up were significantly better than pre-operative scores in 2 groups (P<0.05); VAS score of low back pain in trial group at last follow-up was significantly lower than that in control group (P<0.05). The accuracy rate of pedicle screw was 81.9% (118/144) in control group and 91.7% (110/120) in trial group, showing significant difference (χ2=5.25, P=0.03). There was significant difference in SSA between 2 groups at immediate after operation (t=-6.21, P=0.00). At immediate after operation and last follow-up, Taillard index, disc height recovery rate, and sagittal angle recovery rate in trial group were significantly better than those in control group (P<0.05). ConclusionPLIF by individualized reference model of sagittal curves by 3D printing technique and computer-aided navigation system can effectively correct spondylolisthesis, recover the lumbar sagittal angle and improve the VAS score of low back pain though it has similar operation time and blood loss to traditional PLIF.
ObjectiveTo review research progress on the design, manufacturing, and clinical application of three-dimensional (3D) printed customized prosthesis in acetabular reconstruction of hip revision surgery. MethodsThe related research literature on 3D printed customized prosthesis and its application in acetabular reconstruction of hip revision surgery was searched by key words of “3D printed customized prosthesis”, “revision hip arthroplasty”, “acetabular bone defect”, and “acetabular reconstruction” between January 2013 and May 2024 in Chinese and English databases, such as CNKI, Wanfang database, PubMed, etc. A total of 34 271 articles were included. After reading the literature titles, abstracts, or full texts, the literature of unrelated, repetitive, low-quality, and low evidence level was screened out, and a total of 48 articles were finally included for analysis and summary. ResultsThe bone growth and mechanical properties of 3D printed customized prosthesis materials are better than those of non-3D printed customized prosthesis, which further solves the problem of elastic modulus mismatch between the implant and natural bone caused by “stress shielding”; the porous structure and antibacterial coating on the surface of 3D printed customized prosthesis have good anti-bacterial effect. 3D printed customized prosthesis can perfectly match the patient’s individual acetabular anatomical characteristics and defect type, thus improving the accuracy of acetabular reconstruction and reducing the surgical time and trauma. Conclusion3D printed customized prosthesis can be used for precise and efficient individualized acetabular reconstruction in hip revision surgery with good early- and mid-term effectiveness. More optimized production technics and procedures need to be developed to improve the efficiency of clinical application and long-term effectiveness.