Spinal fusion is a standard operation for treating moderate and severe intervertebral disc diseases. In recent years, the proportion of three-dimensional printing interbody fusion cage in spinal fusion surgery has gradually increased. In this paper, the research progress of molding technology and materials used in three-dimensional printing interbody fusion cage at present is summarized. Then, according to structure layout, three-dimensional printing interbody fusion cages are classified into five types: solid-porous-solid (SPS) type, solid-porous-frame (SPF) type, frame-porous-frame (FPF) type, whole porous cage (WPC) type and others. The optimization process of three-dimensional printing interbody fusion cage and the advantages and disadvantages of each type are analyzed and summarized in depth. The clinical application of various types of 3D printed interbody fusion cage was introduced and summarized later. Lastly, combined with the latest research progress and achievements, the future research direction of three-dimensional printing interbody fusion cage in molding technology, application materials and coating materials is prospected in order to provide some reference for scholars engaged in interbody fusion cage research and application.
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.
Objective To explore the clinical methods of resection of elbow tumor and total elbow replacement with custom personalized prosthesis based on three dimensional (3-D) printing navigation template. Methods In August 2016, a 63-year-old male patient with left elbow joint tumor was treated, with the discovery of the left distal humerus huge mass over 3 months, with elbow pain, activity limitation of admission. Computer-assisted reduction technique combined with 3-D printing was used to simulate preoperative tumor resection, a customized personal prosthesis was developed; tumor was accurately excised during operation, and the clinical result was evaluated after operation. Results The time was 46 minutes for tumor resection, and was 95 minutes for personalized implant and allograft bone without fluoroscopy. X-ray and CT examination at 1 week after operation showed good position of artificial elbow joint; the anteversion of ulna prosthesis was 30° and the elbow carrying angle was 15°, which were consistent with the simulated results before surgery. The finger flexion was normal at 1 month after operation; the range of motion was 0-130° for elbow flexion and extension, 80° for forearm pronation, and 80° for forearm supination. The elbow function was able to meet the needs of daily life at 7 months after operation, and no recurrence and metastasis of tumor were observed. Conclusion For limb salvage of elbow joint, computer aided design can make preoperative surgical simulation; the navigation template can improve surgical precision; and the function of elbow joint can be reconstructed with customized and personlized prosthesis for total elbow replacement.
ObjectiveTo explore the effectiveness and advantage of three-dimensional (3D) printing technology in treatment of internal or external ankle distal avulsed fracture.MethodsBetween January 2015 and January 2017, 20 patients with distal avulsed fracture of internal or external ankle were treated with the 3D guidance of shape-blocking steel plate fixation (group A), and 18 patients were treated with traditional plaster external fixation (group B). There was no significant difference in gender, age, injury cause, disease duration, fracture side, and fracture type between 2 groups (P>0.05). Recording the fracture healing rate, fracture healing time, the time of starting to ankle functional exercise, residual ankle pain, and evaluating ankle function recovery of both groups by the American Orthopaedic Foot and Ankle Society (AOFAS) score.ResultsAll patients were followed up 8-24 months, with an average of 15.5 months. In group A: all incisions healed by first intention, the time of starting to ankle functional exercise was (14±3) days, fracture healing rate was 100%, and the fracture healing time was (10.15±2.00) weeks. At 6 months, the AOFAS score was 90.35±4.65. Among them, 13 patients were excellent and 7 patients were good. All patients had no post-operative incision infection, residual ankle pain, or dysfunction during the follow-up. In group B: the time of starting to ankle functional exercise was (40±10) days, the fracture healing rate was 94.44%, and the fracture healing time was (13.83±7.49) weeks. At 6 months, the AOFAS score was 79.28±34.28. Among them, 15 patients were good, 2 patients were medium, and 1 patient was poor. During the follow-up, 3 patients (16.67%) had pain of ankle joint with different degrees. There were significant differences in the postoperative fracture healing rate, fracture healing time, the time of starting to ankle functional exercise, and postoperative AOFAS score between 2 groups (P<0.05).ConclusionApplication of 3D printing technology in treatment of internal or external ankle distal avulsed fracture is simple, safe, reliable, and effective. In particular, it is an ideal treatment for avulsed fracture.
ObjectiveTo investigate the surgical strategies and clinical efficacy of transmitral septal myectomy in the treatment of recurrent left ventricular outflow tract obstruction (LVOTO) after alcohol septal ablation. MethodsThe clinical data of patients with recurrent LVOTO after alcohol septal ablation from July 2020 to July 2021 in the Department of Cardiac Surgery, Guangdong Provincial People's Hospital were retrospectively analyzed. Patients were preoperatively evaluated by echocardiography, cardiac magnetic resonance imaging, cardiac computed tomography, 3D modeling and printing technology. A personalized surgical strategy was preoperatively developed according to multimodality imaging assessment, while visual exploration was performed on the digital model and simulated surgical resection was performed on the printed model. Results Two female patients were enrolled, aged 62 years and 64 years, respectively. Totally endoscopic transmitral extended myectomy was successfully performed on both patients with aortic cross-clamping time of 96 min and 85 min, respectively. LVOTO was relieved immediately (subaortic peak pressure gradient decreased from 100 mm Hg to 4 mm Hg and from 84 mm Hg to 6 mm Hg, respectively) and the mitral regurgitation significantly improved after the procedure. No patient had complete atrioventricular block or required permanent pacemaker implantation. The patients were discharged uneventfully without postoperative complications. ConclusionPersonalized totally endoscopic transmitral extended myectomy combined with multimodality imaging assessment and 3D modeling and printing has an acceptable clinical effect in patients with recurrent LVOTO after alcohol septal ablation. The procedure can precisely resect the hypertrophic septal myocardium while avoiding serious complications such as septal perforation or complete atrioventricular block.
ObjectiveTo summarize the research progress of tissue engineering technology to promote bone tissue revascularization in osteonecrosis of the femoral head (ONFH).MethodsThe relevant domestic and foreign literature in recent years was extensively reviewed. The mechanism of femoral head vascularization and the application progress of tissue engineering technology in the promotion of ONFH bone tissue revascularization were summarized.ResultsRebuilding or improving the blood supply of the femoral head is the key to the treatment of ONFH. Tissue engineering is a hot spot in current research. It mainly focuses on the three elements of seed cells, scaffold materials, and angiogenic growth factors, combined with three-dimensional printing technology and drug delivery systems to promote the revascularization of the femoral bone tissue.ConclusionThe strategy of revascularization of the femoral head can improve the local blood supply and delay or even reverse the progression of ONFH disease.
Objective To explore the feasibility and the effectiveness of the accurate placement of lumbar pedicle screws using three-dimensional (3D) printing navigational templates in Quadrant minimally invasive system. Methods The L1-5 spines of 12 adult cadavers were scanned using CT. The 3D models of the lumbar spines were established. The screw trajectory was designed to pass through the central axis of the pedicle by using Mimics software. The navigational template was designed and 3D-printed according to the bony surface where the soft tissues could be removed. The placed screws were scanned using CT to create the 3D model again after operation. The 3D models of the designed trajectory and the placed screws were registered to evaluate the placed screws coincidence rate. Between November 2014 and November 2015, 31 patients with lumbar instability accepted surgery assisted with 3D-printing navigation module under Quadrant minimally invasive system. There were 14 males and 17 females, aged from 42 to 60 years, with an average of 45.2 years. The disease duration was 6-13 months (mean, 8.8 months). Single segment was involved in 15 cases, two segments in 13 cases, and three segments in 3 cases. Preoperative visual analogue scale (VAS) was 7.59±1.04; Oswestry disability index (ODI) was 76.21±5.82; and the Japanese Orthopaedic Association (JOA) score was 9.21±1.64. Results A total of 120 screws were placed in 12 cadavers specimens. The coincidence rate of placed screw was 100%. A total of 162 screws were implanted in 31 patients. The operation time was 65-147 minutes (mean, 102.23 minutes); the intraoperative blood loss was 50-116 mL (mean, 78.20 mL); and the intraoperative radiation exposure time was 8-54 seconds (mean, 42 seconds). At 3-7 days after operation, CT showed that the coincidence rate of the placed screws was 98.15% (159/162). At 4 weeks after operation, VAS, ODI, and JOA score were 2.24±0.80, 29.17±2.50, and 23.43±1.14 respectively, showing significant differences when compared with preoperative ones (t=14.842,P=0.006;t=36.927,P=0.002;t=–36.031,P=0.001). Thirty-one patients were followed up 8-24 months (mean, 18.7 months). All incision healed by first intention, and no complication occurred. During the follow-up, X-ray film and CT showed that pedicle screw was accurately placed without loosening or breakage, and with good fusion of intervertebral bone graft. Conclusion 3D-printing navigational templates in Quadrant minimally invasive system can help lumbar surgery gain minimal invasion, less radiation, and accurate placement.
Three-dimensional (3D) printing, an emerging rapid prototyping technology, has been widely used in biomedical field. 3D printing was originally used to construct the visualization models and molds in medicine. With the development of 3D printing in biomedical field, the technology was gradually applied in complex tissue regeneration and organ reconstruction. Artificial tissues and organs obtained by 3D printing are expected to be used for organ transplantation, new drug development and drug toxicity evaluation in the field of medicine and health care research. This paper describes the individualized application of 3D printing technology in liver surgery and introduces the research progress of 3D bioprinting technology in liver transplantation, drug metabolism and hepatotoxicity evaluation, and prospects its future development trend to provide a reference for further study.
Objecitve To investigate the effectiveness of three-dimensional (3D) printing-assisted vascularized fibular graft for repairing metatarsal defects. Methods Between November 2021 and February 2024, 11 patients with varying degrees of metatarsal defects caused by trauma were treated. There were 10 males and 1 female, aged 22-67 years, with a mean age of 51.2 years. The defect locations were as follows: the first metatarsal in 4 cases, the fifth metatarsal in 2 cases, the first and the second metatarsals in 1 case, the first to third metatarsals in 1 case, the third and the fourth metatarsals in 1 case, the third to fifth metatarsals in 1 case, and the first to fifth metatarsals in 1 case. The preoperative American Orthopaedic Foot & Ankle Society (AOFAS) score was 67.0 (48.5, 72.5). Based on 3D-printed bilateral feet models and mirrored healthy-side foot arch angles for preoperative planning and design, the vascularized fibular graft was performed to repair the metatarsal defects. At last follow-up, the medial and lateral longitudinal arches of bilateral feet were measured on weight-bearing X-ray films, and functional assessment was conducted using the AOFAS score.Results All operations were successfully completed, with an operation time ranging from 180 to 465 minutes (mean, 246.8 minutes). All incisions healed by first intention, with no occurrence of osteomyelitis. All patients were followed up 6-22 months (mean, 10 months). X-ray film reviews showed bone graft healing in all cases, with a healing time of 3-6 months (mean, 5 months). All patients underwent internal fixator removal at 6-12 months after operation. At last follow-up, no significant difference was observed in the medial and lateral longitudinal arches between the healthy and affected feet (P>0.05). The AOFAS score of the affected foot was 78.0 (73.5, 84.0), showing a significant improvement compared to the preoperative score (P<0.05). The effectiveness was rated as excellent in 1 case, good in 7 cases, fair in 2 cases, and poor in 1 case. Linear scarring remained at the donor site, with no functional impairment in adjacent joint movement. Conclusion 3D printing-assisted vascularized fibular graft for repairing metatarsal defects can effectively restore the physiological angle of the foot arch, facilitate the recovery of weight-bearing alignment, promote good bone healing, and yield satisfactory clinical outcomes.
Objective To evaluate the effectiveness of combining three-dimensional printing (3DP) models with three-dimensional visualization (3DV) technology in the teaching of thoracoscopic sublobar resection. Methods From March 2024 to June 2025, 150 interns were randomly assigned by envelope method to the 3DV, 3DP, and combined (3DV+3DP) groups. Three theoretical tests and score changes were used to assess short- and long-term teaching outcomes, and a questionnaire survey was conducted to analyze learning experience. Results After teaching, scores improved significantly in all groups (P<0.001), with the greatest increase in the combined group (47.18±5.81), which was higher than the 3DV and 3DP groups (P<0.001 and P=0.002, respectively). At 1 month, scores declined in all groups (P=0.028), but the combined group showed the smallest decrease (?6.94 ± 6.05). The combined group also showed the most pronounced advantage in spatial cognition (38.0%). Conclusion Innovative 3DP+3DV instructional model improves sublobar lung resection teaching and shows better long-term retention and spatial cognition.
