Improved unilateral puncture PVP based on 3D printing technology for the treatment of osteoporotic vertebral compression fracture / 中国骨伤

OBJECTIVE@#To investigate the clinical effect of unilateral percutaneous vertebroplasty (PVP) combined with 3D printing technology for the treatment of thoracolumbar osteoporotic compression fracture.@*METHODS@#A total of 77 patients with thoracolumbar osteoporotic compression fractures from October 2020 to April 2022 were included in the study, all of which were vertebral body compression fractures caused by trauma. According to different treatment methods, they were divided into experimental group and control group. Thirty-two patients used 3D printing technology to improve unilateral transpedicle puncture vertebroplasty in the experimental group, there were 5 males and 27 females, aged from 63 to 91 years old with an average of (77.59±8.75) years old. Forty-five patients were treated with traditional bilateral pedicle puncture vertebroplasty, including 7 males and 38 females, aged from 60 to 88 years old with an average of(74.89±7.37) years old. Operation time, intraoperative C-arm X-ray times, anesthetic dosage, bone cement injection amount, bone cement diffusion good and good rate, complications, vertebral height, kyphotic angle (Cobb angle), visual analogue scale(VAS), Oswestry disability index (ODI) and other indicators were recorded before and after surgery, and statistically analyzed.@*RESULTS@#All patients were followed up for 6 to 23 months, with preoperative imaging studies, confirmed for thoracolumbar osteoporosis compression fractures, two groups of patients with postoperative complications, no special two groups of patients' age, gender, body mass index (BMI), time were injured, the injured vertebral distribution had no statistical difference(P>0.05), comparable data. Two groups of patients with bone cement injection, bone cement dispersion rate, preoperative and postoperative vertebral body height, protruding after spine angle(Cobb angle), VAS, ODI had no statistical difference(P>0.05). The operative time, intraoperative fluoroscopy times and anesthetic dosage were statistically different between the two groups(P<0.05). Compared with the traditional bilateral puncture group, the modified unilateral puncture group combined with 3D printing technology had shorter operation time, fewer intraoperative fluoroscopy times and less anesthetic dosage. The height of anterior vertebral edge, kyphosis angle (Cobb angle), VAS score and ODI of the affected vertebrae were statistically different between two groups at each time point after surgery(P<0.05).@*CONCLUSION@#In the treatment of thoracolumbar osteoporotic compression fractures, 3D printing technology is used to improve unilateral puncture PVP, which is convenient and simple, less trauma, short operation time, fewer fluoroscopy times, satisfactory distribution of bone cement, vertebral height recovery and kyphotic Angle correction, and good functional improvement.

Biological scaffold materials and printing technology for repairing bone defects / 中国组织工程研究

BACKGROUND:In recent years,with the development of biological scaffold materials and bioprinting technology,tissue-engineered bone has become a research hotspot in bone defect repair. OBJECTIVE:To summarize the current treatment methods for bone defects,summarize the biomaterials and bioprinting technology for preparing tissue-engineered bone scaffolds,and explore the application of biomaterials and printing technology in tissue engineering and the current challenges. METHODS:Search terms were"bone defect,tissue engineering,biomaterials,3D printing technology,4D printing technology,bioprinting,biological scaffold,bone repair"in Chinese and English.Relevant documents published from January 1,2009 to December 1,2022 were retrieved on CNKI,PubMed and Web of Science databases.After being screened by the first author,high-quality references were added.A total of 93 articles were included for review. RESULTS AND CONCLUSION:The main treatment methods for bone defects include bone transplantation,membrane-guided regeneration,gene therapy,bone tissue engineering,etc.The best treatment method is still uncertain.Bone tissue engineering technology is a new technology for the treatment of bone defects.It has become the focus of current research by constructing three-dimensional structures that can promote the proliferation and differentiation of osteoblasts and enhance the ability of bone formation.Biological scaffold materials are diverse,with their characteristics,advantages and disadvantages.A single biological material cannot meet the demand for tissue-engineered bone for the scaffold.Usually,multiple materials are combined to complement each other,which is to meet the demand for mechanical properties while taking into account the biological properties of the scaffold.Bioprinting technology can adjust the pore of the scaffold,build a complex spatial structure,and is more conducive to cell adhesion,proliferation and differentiation.The emerging 4D printing technology introduces"time"as the fourth dimension to make the prepared scaffold dynamic.With the synchronous development of smart materials,4D printing technology provides the possibility of efficient repair of bone defects in the future.

Comparison and analysis of modeling heart valve bracket based on magnetic resonance imaging / 中国组织工程研究

BACKGROUND:Currently,artificial valves used in heart valve operations include biological valves and mechanical valves.The design and processing of the biological valve bracket determine the shape of the biological valves,which in turn determines their service life. OBJECTIVE:Various lobe and bracket models were created based on the spatial geometric equation.Through a comparison of the deformation and stress distribution of various lobe and bracket models,a more rational bracket model was derived.Subsequently,3D printing technology was utilized to produce a solid model. METHODS:According to the geometric and mathematical models of the heart valve leaf and valve bracket,parabolic and ellipsoidal heart valve bracket models were created.Three-dimensional modeling was used to design the heart valve bracket.Two-way fluid-structure coupling analysis was conducted to analyze the force and deformation of the valve bracket in the blood flow field.An appropriate printing method and materials were selected to achieve 3D printing of the heart valve bracket. RESULTS AND CONCLUSION:The distribution rules of deformation,maximum principal stress,and maximum shear stress of the parabolic bracket and ellipsoidal bracket are the same.The deformation and stress of the ellipsoidal bracket were greater than those of the parabolic bracket.The distribution law of maximum principal stress and maximum shear stress was mainly concentrated in the joint part of the lobe and bracket.The total deformation,maximum principal stress,and maximum shear stress of the bracket decrease with the increase of the bracket diameter.

3D printing precise positioning guided ulnar groove plasty for treatment of cubital tunnel syndrome / 中国组织工程研究

BACKGROUND:With the increase of patients with cubital tunnel syndrome,ulnar groove plasty does not affect the normal anatomical structure and distribution of the ulnar nerve,which is one of the main surgical procedures for the treatment of cubital tunnel syndrome.3D printing combined with ulnar groove plasty can more accurately position the expansion depth and width of the ulnar groove to avoid some surgical complications. OBJECTIVE:To investigate the effect of 3D printing technology combined with ulnar groove plasty on nerve electrophysiology and prognosis in patients with cubital tunnel syndrome. METHODS:A total of 70 patients with moderate and severe cubital tunnel syndrome who were treated in Cangzhou Integrated Traditional Chinese and Western Medicine Hospital from March 2020 to March 2022 were selected as the study subjects.They were divided into two groups,with 35 cases in each group.The control group underwent traditional ulnar groove plasty.The observation group underwent 3D printing technology combined with ulnar groove plasty.The patients were followed up for 3 months.The clinical efficacy,latency,amplitude of compound muscle action potential of abductor pollicis brevis of the affected limb and ulnar nerve motor conduction velocity,grip strength on the affected side,pinch strength of the middle and thumb fingers,S-W monofilament of the little finger,two-point discrimination of the little finger,and Disabilities of the Arm,Shoulder and Hand Questionnaire score were compared between the two groups. RESULTS AND CONCLUSION:(1)Compared with the control group(74%),the excellent and good rate was significantly higher in the observation group(91%)(P<0.05).(2)Compared with pre-treatment,the latency of compound muscle action potential of abductor pollicis brevis of affected limb was significantly shorter and the wave amplitude and ulnar nerve motor conduction velocity were significantly higher in the two groups after treatment.The latency was significantly shorter and the wave amplitude and ulnar nerve motor conduction velocity were significantly higher in the observation group than those in the control group(P<0.05).(3)Compared with pre-treatment,the grip strength,middle finger and thumb pinch strength of the affected side,S-W monofilament of the little finger and two-point discrimination of the little finger were significantly decreased in the two groups after treatment.The grip strength,middle finger and thumb pinch strength on the affected side were greater,S-W monofilament of the little finger and two-point discrimination of the little finger were significantly smaller in the observation group than those in the control group(P<0.05).(4)Compared with pre-treatment,the Disabilities of the Arm,Shoulder and Hand Questionnaire scores of the two groups were significantly reduced after treatment,and the Disabilities of the Arm,Shoulder and Hand Questionnaire scores of the observation group were significantly lower than those of the control group(P<0.05).(5)It is concluded that 3D printing technology combined with ulnar groove plasty in the treatment of cubital tunnel syndrome can effectively improve its clinical efficacy,promote the neurophysiological recovery of patients,and enhance the function of fingers and upper limbs,which has high clinical application value.

Preparation of venlafaxine hydrochloride and fluoxetine hydrochloride multilayer tablets by stereolithography 3D printing technology / 中国药房

OBJECTIVE To prepare venlafaxine hydrochloride and fluoxetine hydrochloride multiplayer tablets by stereolithography （SLA） 3D printing technology， and to conduct its quality evaluation and in vitro release investigation. METHODS Using venlafaxine hydrochloride/fluoxetine hydrochloride， photopolymerization monomer PEGDA 400， porogen PEG 300， photoinitiator TPO and light absorber citrine as formulation， SLA 3D printer technology was employed to prepare venlafaxine hydrochloride and fluoxetine hydrochloride multiplayer tablets， with outer diameter of 10 mm， inner diameter of 5 mm， and thickness of 6 mm. Moreover， the tablets’ appearance， three-dimensional dimensions， weight uniformity， drug content， internal structural characteristics and in vitro release characteristics were all investigated. RESULTS The multilayer tablets had good printing formability， smooth and round edges， and uniform size and thickness； the outer diameter， inner diameter and thickness were （10.06±0.26）， （4.94±0.06）， （5.80±0.12） mm （RSD＝2.58%， 1.21%， 2.07%，n＝20）， and the weight difference all met the requirements. The contents of venlafaxine hydrochloride and fluoxetine hydrochloride were （7.96±0.09） and （11.26±0.46） mg/tablet， respectively. The results of X-ray diffraction and scanning electron microscopy characterization showed that the two drug molecules in the multilayer film existed in an amorphous structure； after the dissolution of the venlafaxine hydrochloride layer， a clear pore structure was formed， while the fluoxetine hydrochloride layer did not show any pore structure. According to the release curve， 24 h accumulative release rates of venlafaxine hydrochloride layer and fluoxetine hydrochloride layer were（91.88±0.94）% and （106.25±1.28）%， which were in line with Rigter-Peppas release model. CONCLUSIONS This study successfully prepared venlafaxine hydrochloride and fluoxetine hydrochloride multilayer tablets using SLA 3D printing technology； the multilayer tablets have the advantages of excellent printing formability， which are in line with Rigter-Peppas release model.

Application of 3D printing in the preoperative evaluation of transcatheter aortic valve replacement for patients at risk of coronary artery obstruction:two case reports / 中国介入心脏病学杂志

Transcatheter aortic valve replacement(TAVR)is currently one of the main therapeutic strategies for aortic valve disease.Preoperative imaging assessment is crucial for operation project planning and prevention of procedure-associated complications.Different from planar image reconstruction,3D printing technology can accurately depict the anatomical structure of the aortic root.It enables further assessment of operative risk and therapeutic strategy through in vitro simulation,especially for assessing the risk of coronary artery obstruction and planning interventional procedures.Here,we report on two patients who underwent a 3D printing aortic root anatomical simulation model,followed an by in vitro balloon dilatation/valve implantation test,to evaluate the risk of coronary artery obstruction suggested by CT angiography planar image reconstruction before TAVR.

Curative effects of 3D printed microporous titanium (tantalum) prosthesis in reconstruction of large segmental bone defects caused by lower extremity osteomyelitis / 中华创伤骨科杂志

Objective:To evaluate the curative effects of 3D printed microporous titanium (tantalum) prosthesis in reconstruction of large segmental bone defects caused by lower extremity osteomyelitis.Methods:A retrospective study was conducted to analyze the clinical data of 18 patients who had been treated for large segmental bone defects caused by lower extremity osteomyelitis between January 2020 to May 2022 at Department of Orthopaedics, The 920th Hospital of Joint Logistics Support Force. There were 10 males and 8 females with an age of (45.3±14.1) years. The defects were at the left side in 13 cases and at the right side in 5 cases, at the femur in 11 cases and at the tibia in 7 cases. The duration of osteomyelitis was 1.0 (1.0, 3.5) years. The length of bone defects was 8.35 (6.50, 9.84) cm. Their bone defects were repaired by an individually 3D printed microporous titanium (tantalum) prosthesis after operative removal of osteomyelitis lesions. The wound healing was observed after surgery. The clinical efficacy was comprehensively evaluated by the Paley grading for bone defect healing, visual analog scale (VAS), lower extremity functional scale (LEFS), and imaging examination.Results:The postoperative follow-up period for the 18 patients was (12.2±0.3) months. Wound infection occurred 2 months after surgery in one patient who was treated with Ilizarov bone transfer after removal of the microporous titanium prosthesis. The remaining 17 patients had good postoperative wound healing. At the last follow-up, the 18 patients had a VAS pain score of 2.0(1.0, 4.0) points, significantly lower than the preoperative one [(6.1±2.3) points], and a LEFS score of 54.00(34.50, 69.25) points, significantly higher than the preoperative one [18.50(9.00, 26.50) points] ( P<0.05). At the last follow-up, according to the Paley grading, the bone union was rated as excellent in 16 patients, as good in 1 patient and as poor in 1 patient. The integration of femoral fractures with 3D printed microporous titanium prostheses was fine. Conclusion:In reconstruction of large segmental bone defects caused by lower extremity osteomyelitis, implantation of a 3D printed microporous titanium (tantalum) prosthesis is feasible and effective, not only reducing pain but also restoring the limb function.

Application of improved 3D digital guide plate-assisted guided puncture in microballoon compression for primary trigeminal neuralgia / 口腔疾病防治

Objective @#To investigate the clinical efficacy and application value of an improved 3D-printed guide plate for the treatment of primary trigeminal neuralgia (PTN) by percutaneous microballoon compression (PMC). @*Methods @# This prospective study included 42 patients with primary trigeminal neuralgia treated at the Department of Stomatology, Xuzhou Central Hospital, from September 2019 to January 2022. The group was divided by the random number table method into the experimental group (adopting 3D printing technology to make guide plates to guide the puncture, 22 cases) and the control group (adopting the traditional Hartel anterior approach to position the puncture, 20 cases). The intraoperative success rate of the first puncture, puncture time, operative time, radiation exposure of patients and postoperative complications were compared between the two groups. Postoperative Barrow Neurological Institute Scale (BNI) scores, facial numbness, diminished corneal reflexes and chewing weakness were recorded. The t-test, rank-sum test and chi-square test were used for statistical analysis, with P<0.05 indicating a statistically significant difference. @*Results @#The experimental group was significantly better than the control group in terms of the success rate of the first puncture (χ2 = 21.51, P<0.001), puncture time (Z = -5.51, P<0.001), operative time (t = 9.37, P<0.001), and the number of C-arm scans (Z = -4.59, P<0.001). Postoperative BNI scores of the experimental group included 21 cases of grade Ⅰ (91.5%) and 1 case of grade Ⅱ, while the control group included 17 cases of grade Ⅰ (85.0%), 2 cases of grade Ⅱ (10.0%) and 1 case of grade Ⅲ (5.0%), with no statistical significance (P>0.05). In the experimental group, 16 patients had postoperative masseter weakness, 1 had keratitis and 10 had perilabial herpes, while in the control group, 18 patients had postoperative masseter weakness, 2 had keratitis, 11 had perilabial herpes and 1 had monocular blindness. There was no significant difference in postoperative complications between the two groups (P>0.05). At 12 months of follow-up, there was no recurrence in either the experimental or control group. @* Conclusions @#3D digital guide plate-guided percutaneous microballoon compression for primary trigeminal neuralgia can improve the accuracy and safety of puncture to a certain extent, obviously shorten the operation time, reduce radiation exposure of the patients, improve the success rate of the operation, meaning it has a high clinical application value.

Application of CBL combined with 3D printing teaching in clinical teaching of sacral tumors / 中华医学教育探索杂志

Objective:To explore the application effect of case-based learning (CBL), teaching mode combined with 3D printing in clinical teaching of sacral tumors.Methods:A total of 108 undergraduate interns and standardized residency training students who studied in our hospital from 2017 to 2018 were divided into the CBL teaching group ( n = 53) and the CBL combined with 3D printing teaching group ( n = 55) according to their study time. The combined teaching group used computer tomography (CT) data to reconstruct and print out a 3D model of sacral tumors based on CBL, and performed preoperative teaching on the invasion of the surrounding tissues of the tumor. The scores of the students in the two groups were evaluated respectively, and the students were surveyed by self-identification questionnaire (learning interest, self-learning ability, teamwork ability, comprehensive analysis ability and clinical thinking ability). The t-test (one-sided) was used for comparison between groups using stata 14.0. Results:The score of CBL teaching group (75.90±6.70) was lower than that of CBL combined with 3D printing teaching group (83.60±7.40). In terms of critical thinking ability evaluation, self-learning ability, learning interest, comprehensive analysis ability and clinical thinking ability, the CBL combined 3D printing teaching group was superior to the CBL teaching group, and the difference was statistically significant ( P<0.001). In terms of teamwork ability, there was no statistical difference between the two groups. Conclusion:The CBL teaching mode combined with 3D printing can improve academic performance, students' learning interest and clinical thinking ability of sacral tumors in the teaching of undergraduate interns and standardized residency training students.

Fixation with a 3D printed individualized custom-made plate for elderly patients with periprosthetic femoral fracture: an analysis of short-term efficacy / 中华创伤骨科杂志

Objective:To explore the short-term efficacy of fixation with a 3D printed individualized custom-made plate in the treatment of elderly patients with periprosthetic femoral fracture.Methods:Retrospectively analyzed were the 5 elderly patients with periprosthetic femoral fracture who had been treated by fixation with a 3D printed individualized custom-made plate from January 2022 to July 2022 at Department of Orthopaedics and Traumatology, Beijing Jishuitan Hospital. There were 3 males and 2 females, aged 81, 86, 77, 91 and 87 years, respectively. One left and 4 right limbs were affected. Vancouver classification: type B1 ( n=3), type B2 ( n=1), and type C ( n=1). The time from operation to injury was 5, 6, 10, 5 and 7 days, respectively. Preoperatively, the femur affected, prosthesis and individualized plate with a greater trochanteric hook, loop cable channel and bone-like trabecular microporous structure were custom-made by 3D printing according to 1:1 models. Virtual operations were simulated to formulate surgical protocols. The operation time, length of surgical incision, intraoperative blood loss and transfusion, hospital stay, hip function and complications at the last follow-up were recorded. Results:The 5 patients were followed up for 12, 7, 10, 3 and 6 months, respectively. There were no events of superficial incision or deep prosthesis infection. Respectively, the operation time was 1.8, 1.7, 2.3, 2.0 and 3.3 h; the length of surgical incision 31, 30, 38, 27 and 30 cm; the intraoperative bleeding volume 400, 300, 300, 500 and 600 mL; the length of hospital stay 8, 9, 15, 14 and 11 d. Four patients received intraoperative blood transfusion of 300, 900, 150 and 1, 050 mL, respectively. One patient died of a heart attack 3 months after discharge; another patient developed dyskinesia at the contralateral limb 3 months after discharge due to cerebral infarction and died of recurrent cerebral infarction 7 months after discharge. At the last follow-up, the Harris hip scores of 3 patients were 86, 77 and 69 points, respectively. None of the patients had complications like breakage or loosening of implants.Conclusion:In the treatment of elderly patients with periprosthetic femoral fracture, fixation with a 3D printed individualized custom-made plate may lead to fine limb function and good short-term curative efficacy.

3D-printing-assisted surgery versus conventional surgery for treatment of Schatzker VI tibial plateau fractures: a multi-center clinical study / 中华创伤骨科杂志

Objective:To compare 3D-printing-assisted surgery and conventional surgery in the treatment of Schazker type Ⅵ tibial plateau fractures.Methods:A retrospective study was conducted to analyze the clinical data of 50 patients with type Ⅵ tibial plateau fracture who had been treated from January 2019 to December 2021 at the 5 Departments of Orthopedics in The First Affiliated Hospital of Nanchang University, The First People's Hospital of Jiujiang, Pingkuang General Hospital, Ganzhou People's Hospital, and Nanchang Hongdu Hospital of Traditional Chinese Medicine. The patients were divided into 2 groups according to their different treatment methods. In the 3D printing group of 25 cases treated by 3D-printing-assisted surgery, there were 14 males and 11 females, with an age of (42.5±9.1) years; in the conventional group of 25 cases treated by conventional surgery, there were 13 males and 12 females with an age of (42.2±9.3) years. The 2 groups were compared in terms of operation time, intraoperative blood loss, intraoperative fluoroscopy frequency, fracture healing time, postoperative complications, the Rasmussen radiological scores and the American Hospital for Special Surgery (HSS) knee function scores at 6 and 12 months after operation.Results:There was no significant difference in the preoperative general data between the 2 groups, indicating comparability ( P>0.05). The operation time [(125.4±10.6) min], intraoperative blood loss [(206.2±16.3) mL], intraoperative fluoroscopy frequency [(9.2±2.7) times] and fracture healing time [(3.0±0.7) months] in the 3D printing group were all significantly less than those in the conventional group [(168.2±14.1) min, (303.2±20.4) mL, (15.5±3.5) times and (4.1±0.8) months] while the Rasmussen radiological scores (17.6±1.2 and 17.9±0.6) and HSS knee scores (90.8±6.4 and 91.5±5.6) at 6 and 12 months after operation in the 3D printing group were all significantly higher than those in the conventional group (16.2±2.6 and 16.7±2.2; 84.5±9.2 and 87.6±8.0) (all P<0.05). In the 3D printing group, there were 1 case of wound infection and 1 case of wound dehiscence after operation. In the conventional group, there were 2 cases of wound skin necrosis, 3 cases of wound dehiscence, 1 case of traumatic arthritis, 2 cases of wound infection, and 1 case of screw loosening. The incidence of complications in the 3D printing group (8.0%, 2/28) was significantly lower than that in the conventional group (36.0%, 9/25) ( P<0.05). Conclusion:In the treatment of Schatzker type VI tibial plateau fractures, compared with conventional surgery, 3D-printing-assisted surgery can lead to better curative outcomes, because it is conducive to lowering surgical difficulty, reducing postoperative complications, and promoting fracture union and functional recovery of the knee.

Current situation and prospect of 3D printing technology in pharmaceutical preparations / 中国药科大学学报

@#With the rapid advancement of science and technology, the application of 3D printing technology for personalized drug manufacturing is becoming increasingly sophisticated.Compared to traditional manufacturing technology, 3D printing can easily customize preparations with specific sizes, shapes and release behaviors for personalized drug use.This review summarizes the principles of several 3D printing technologies commonly used in drug manufacturing, lists the unique advantages and application examples of 3D printing technology for pharmaceutical preparation, analyses the current research status and development trends of the global industry of drug 3D printing, and summarizes the current problems and challenges facing drug 3D printing, aiming to provide some guidance for researchers of 3D printed drugs.

Research on Digital Manufacturing Technology of Key Components of Artificial Knee Joint / 中国医疗器械杂志

The surface of the artificial knee joint manufactured by 3D printing technology is rough. This study uses advanced multi-axis machining technology to study how to improve the manufacturing accuracy of the artificial knee joint surface, and uses five-axis machining CAM software to analyze the process of three-dimensional model of the artificial knee joint and to compile tool path, create a five-axis special post-processor, convert the tool path point file into the NC program for machine tool processing. In order to ensure the safety and efficiency of the processing procedure, a Mikron HEM-500U machine tool simulation platform was built in the VERICUT simulation system for simulation processing verification, and then the blank prototype obtained by 3D printing was processed in a five-axis machine tool to meet medical clinical use requirements.

Accuracy of infra-acetabular screw implantation assisted by a 3D-printed personalized screw guide in vitro / 中华创伤骨科杂志

Objective:To investigate the accuracy of infra-acetabular screw implantation assisted by a 3D-printed personalized screw guide in vitro. Methods:The imaging data were collected of the 10 patients with acetabular fracture involving the anterior column who had been treated at Department of Orthopaedics, The Fourth Hospital of Wuhan from June 2015 to October 2021. There were 8 males and 2 females, with an average age of (42.6±2.1) years. According to the Letournel-Judet classification, there were 2 anterior column fractures, 4 anterior column + posterior semi-transverse fractures, 3 double column fractures, and 1 T-shaped fracture. The thin-slice CT scan data of the patients’ pelves were imported into the E3D software to generate digital 3D fracture models in which fracture reduction and post-reduction were simulated and personalized screw guides for infra-acetabular screw implantation were generated. After the above models were printed by a 3D printer, the fracture models were reduced in vitro and the infra-acetabular screws were implanted assisted by the personalized guide on the affected and healthy acetabulum models. After operation, the printed models were scanned by CT again, and the CT data were imported into the E3D software again to generate the postoperative digital 3D models. The position relationships were observed between the screws and the cortex around the corridor on the postoperative CT scan images. The consistency of the position parameters was compared between pre- and post-operation for each screw in the digital models. Results:Ten personalized screw guides were generalized respectively for the affected and healthy sides of the 10 patients in this group. Anatomical reduction was achieved in vitro in all the 3D printed fracture models. A total of 20 infra-acetabular screws were implanted with the assistance by the screw guide. According to the Andrew's CT grading for pedicle screw positions, 19 infra-acetabular screws were rated as grade Ⅰ and 1 was rated as grade Ⅱ. The linear distance from the midpoint of the pubic symphysis to the point of insertion, and the angles between the axis of the screw and the horizontal, sagittal and coronal planes on the health side before operation were respectively (60.65±5.55) mm, 23.96°±5.59°),2.88 °±1.25°, and 65.06°±5.48°, showing insignificant differences from the postoperative values [(60.91±5.73) mm, 24.00°±6.15°, 3.20°±1.13°, and 65.74°±5.57°] ( P>0.05); the above screw position parameters on the affected side before operation were respectively (60.76±4.41) mm, 24.77°±2.97°, 3.06° (2.66°, 3.68°), and 63.70° (62.70°, 65.60°), showing insignificant differences from the postoperative values [(60.71±4.56) mm, 24.67°±2.73°, 3.04° (2.64°, 3.51°), and 64.40°(63.20°, 65.90°)] ( P>0.05). Conclusion:In the models in vitro, implantation of infra-acetabular screws assisted by a 3D printed personalized screw guide can be highly accurate, owing to insignificant differences in all the position parameters between the simulated operations and the operations in vitro.

Application of canal-shaped implant template in brachytherapy for cervical cancer / 中华放射肿瘤学杂志

Objective:To explore the method of developing a canal-shaped implant template using a combined automatic pre-planning and 3D printing technology, and assess its impact on dose and efficacy improvement.Methods:Retrospective analysis of 15 patients with advanced cervical cancer admitted to the Affiliated Cancer Hospital of Guangxi Medical University from September 2020 to September 2022 was performed. Patients had characteristics such as vaginal stump recurrence, tumor eccentric growth, and previous hysterotomy, etc. Three-dimensional images were obtained by CT scan after automatic pre-planning. The PMT 3D software was used to analyze digital imaging and communications in medicine (DICOM) radiotherapy data, capture the coordinates of the pre-planned stay points to establish the implant channel, and generate the size and shape of the canal-shaped implant template based on patients' physiological structure. Dosimetric parameters, such as conformity index (CI), were evaluated. The changes of tumor size before and after treatment were analyzed by paired t-test. Results:Fifteen patients were treated with the canal-shaped implant template. The CI was 0.74±0.26, the total radiation dose (HR-CTV) D 90% (EQD 2, α/β=10) was (85.5±6.8) Gy, and the D 2 cm3 (EQD 2, α/β=3)for bladder, rectum, small intestine, and colon were (72.2±4.2), (65.8±6.1), (65.2±4.4), and (69.8±3.7) Gy, respectively, meeting clinical needs. After the treatment, the tumor volume was significantly decreased. The template had a good fit with the vaginal cavity, and a small amount of air gap on the sidewall did not affect the dose. Non-parallel needle insertion increased the utilization of the cavity space and implant needles. Conclusion:The method of developing the canal-shaped implant template using automatic pre-planning and 3D printing technology is efficient and effective, meets the requirements of modern precise radiotherapy, and has practical clinical value.

Clinical implications of 3D printing technology in preoperative evaluation of partial nephrectomy / 中南大学学报(医学版)

OBJECTIVES@#Renal cancer is a common malignancy of the urinary system, and the partial nephrectomy is a common surgical modality for early renal cancer. 3D printing technology can create a visual three-dimensional model by using 3D digital models of the patient's imaging data. With this model, surgeons can perform preoperative assessment to clarify the location, depth, and blood supply of the tumor, which helps to develop preoperative plans and achieve better surgical outcomes. In this study, the R.E.N.A.L scoring system was used to stratify patients with renal tumors and to explore the clinical application value of 3D printing technology in laparoscopic partial nephrectomy.@*METHODS@#A total of 114 renal cancer patients who received laparoscopic partial nephrectomy in Xiangya Hospital from June 2019 to December 2020 were enrolled. The patients were assigned into an experimental group (n=52) and a control group (n=62) according to whether 3D printing technology was performed, and the differences in perioperative parameters between the 2 groups were compared. Thirty-nine patients were assigned into a low-complexity group (4-6 points), 32 into a moderate-complexity group (7-9 points), and 43 into a high-complexity group (10-12 points) according to R.E.N.A.L score, and the differences in perioperative parameters between the experimental group and the control group in each score group were compared.@*RESULTS@#The experimental group had shorter operative time, renal ischemia time, and postoperative hospital stay (all P<0.05), less intraoperative blood loss (P=0.047), and smaller postoperative blood creatinine change (P=0.032) compared with the control group. In the low-complexity group, there were no statistically significant differences between the experimental group and the control group in operation time, renal ischemia time, intraoperative blood loss, postoperative blood creatinine changes, and postoperative hospital stay (all P>0.05). In the moderate- and high- complexity groups, the experimental group had shorter operative time, renal ischemia time, and postoperative hospital stay (P<0.05 or P<0.001), less intraoperative blood loss (P=0.022 and P<0.001, respectively), and smaller postoperative blood creatinine changes (P<0.05 and P<0.001, respectively) compared with the control group.@*CONCLUSIONS@#Compared with renal tumor patients with R.E.N.A.L score<7, renal cancer patients with R.E.N.A.L score≥7 may benefit more from 3D printing assessment before undergoing partial nephrectomy.

Close reduction and internal fixation assisted by a 3D printed guide plate for Sanders type Ⅱ calcaneal fracture / 中华创伤骨科杂志

Objective:To compare minimally invasive treatment with versus without a 3D printed guide plate for Sanders type Ⅱ calcaneal fractures.Methods:A retrospective analysis was done of the 74 patients with Sanders type Ⅱ displaced intra-articular calcaneal fracture who had been treated at Foot and Ankle Surgery Center, Beijing Tongren Hospital Affiliated to Capital Medical University from January 2018 to January 2020. They were divided into 2 groups according to whether a 3D printed guide plate was used or not. In the 3D printing group of 38 patients treated by minimally invasive surgery assisted by a 3D printed guide plate, there were 22 males and 16 females with an age of (41.5±3.5) years; in the control group of 36 patients treated by traditional minimally invasive surgery, there were 24 males and 12 females with an age of (40.3±7.2) years. The 2 groups were compared in terms of operation time, intraoperative fluoroscopy, American Orthopaedic Foot and Ankle Society (AOFAS) score, visual analog scale (VAS), Short Form 36 (SF-36), B?hler angle, Gissane angle, calcaneal length, width and height and postoperative complications.Results:There was no significant difference in the preoperative demographic data between the 2 groups, indicating comparability between groups ( P>0.05). All patients were available for a follow-up of (12.6±3.6) months (from 6 to 24 months) after surgery. The operation time [(55.3±7.1) min] and intraoperative fluoroscopy [(8.1±2.6) times] in the 3D printing group were significantly less than those in the control group [(71.2±8.7) min and (21.2±8.7) times] ( P<0.01) while the AOFAS score in the former group (81.4±6.3) was significantly higher than that in the latter (77.9±6.2) ( P<0.01). There were no statistically significant differences between the 2 groups in VAS, SF-36, B?hler angle, Gissane angle, calcaneal length, calcaneal width or calcaneus height ( P>0.05). In the control group, 4 screws were found to be too long with possible impingement on the medial structures of the foot, and 3 screws to penetrate the subtalar joint; in the 3D printing group, there were no too long or off-target screws in the sustentaculum tali. Conclusion:The minimally invasive treatment of Sanders type Ⅱ calcaneal fractures assisted by a 3D printing guide plate can reduce operation time, intraoperative fluoroscopy and potential complications, improving the clinical efficacy.

Experimental analysis of clinical applicability of individualized customized materials / 中国辐射卫生

@#<b>Objective</b> To study the feasibility of clinical application of an individualized customized material. <b>Methods</b> Five batches of individualized customized materials were randomly selected, from which 10 cm × 11 cm samples were intercepted for experimental analysis. Among them, 10 cm × 10 cm materials were selected to perform dosimetric analysis and HU change analysis before and after irradiation with a radiotherapy dose for breast cancer of 50 Gy as the irradiation basis. The center Point 1 on the lower surface of the individualized material and the center Point 2 of the solid water volume were selected for dosimetric analysis before and after the sample is irradiated. After reaching a sufficient amount of irradiation, the 1 cm × 10 cm materials intercepted in the center position and the remaining 1 cm × 10 cm materials after the first sampling were sent to the material science laboratory for analysis of physical properties of density, viscosity, hardness, and tear strength. <b>Results</b> In the comparative analysis of HU values before and after exposure, after receiving 50 Gy dose irradiation, the difference rate of HU value was 5.252%, which was close to the expected 5% difference rate in clinical medicine. In the dosimetric analysis of Point 1 and Point 2, the dose in the irradiated samples was significantly higher than that in the unirradiated samples; the dose in Point 1 increased by 3.742%, and the dose in Point 2 increased by 2.039%. Before and after irradiation, except for the physical density which showed a significant difference, there was no significant difference in viscosity, hardness, and tear strength. <b>Conclusion</b> The individualized customized material can meet the requirements of routine clinical medicine.

Progress in application of digital medical technology assisted fibular flap transfer in repair of mandibular defects / 中华显微外科杂志

Free vascularised fibular flap has many advantages in repair of mandibular defects, and it has become the main method in the mandibular reconstruction. However, the traditional free fibular flap used to repair the mandibular defect is lack of individualised design and precise surgical guidance, and it is difficult to achieve accurate repair and the effect of reconstruction. The concept of personalised and accurate functional reconstruction and the clinically application of digital medical technology provides a new approach to solve the problems. The application of digital medical technology in the repair of mandibular defects with fibular flap is one of the hotspots of current research. This article introduces the application characteristics of digital medical technology, such as 3-dimensional reconstruction technology, virtual surgery planning (VSP) technology and 3D printing technology, in the repair of mandibular defects with fibular flap transfer.

Preliminary exploration of the domestic balloon-expandable valve in the treatment of degenerated tricuspid bioprosthetic valve via transcatheter "valve-in-valve" technology / 中国胸心血管外科临床杂志

@#Objective    To discuss the operation skill and clinical effects of using domestic balloon-expandable Prizvalve® transcatheter "valve-in-valve" to treat the degenerated bioprosthesis in the tricuspid position. Methods    All the admitted surgical tricuspid valve bioprosthetic valve replacement patients were evaluated by computerized tomography angiography (CTA), ultrasound, and 3D printing technology, and 2 patients with a degenerated bioprosthesis were selected for tricuspid valve "valve-in-valve" operation. Under general anesthesia, the retro-preset Prizvalve® system was implanted into degenerated tricuspid bioprosthesis via the femoral vein approach under the guidance of transesophageal echocardiographic and fluoroscopic guidance. Results    Transcatheter tricuspid valve implantation was successfully performed in both high-risk patients, and tricuspid regurgitation disappeared immediately. The operation time was 1.25 h and 2.43 h, respectively. There was no serious complication in both patients, and they were discharged from the hospital 7 days after the operation. Conclusion    The clinical effect of the degenerated tricuspid bioprosthetic valve implantation with domestic balloon-expandable valve via femoral vein approach "valve-in-valve" is good. Multimodality imaging and 3D printing technology can safely and effectively guide the implementation of this innovative technique.