Objective:To investigate the application effect of the comprehensive innovative teaching model with "3D printed model combined with visual surgical simulation" as the core in the clinical teaching of extremity bone defects.Methods:The physicians who participated in the clinical management of patients with extremity bone defects in Department of Orthopedics, Peking University Third Hospital, from March 2019 to December 2021 were selected as subjects and were divided into standardized training group with 52 physicians and refresher physician group with 58 physicians. Teaching and training was performed for the special disease of extremity bone defects, including basic knowledge teaching, dressing change for infected wounds, multidisciplinary discussion, digital surgical simulation, and practical surgical operation. The assessment indices for teaching quality included the assessment of theoretical knowledge and clinical skills, the objective evaluation of the clinical ability of patient management, and an investigation of the degree of satisfaction. SPSS 22.0 was used for the t-test and the chi-square test. Results:After training, both groups had significant increases in the assessment scores of theoretical knowledge [(32.4±6.7）and (42.2±3.8)] and clinical practice skills [(19.6±2.0), (20.8±2.2), (20.5±2.5), (21.5±2.3)]( P<0.05). After training, the standardized training group had significant increases in the scores of six objective evaluation indicators [(8.3±0.8) vs. (6.9±1.1), (7.4±0.7) vs. (6.3±1.5), (7.2±1.3) vs. (5.0±1.4), (7.9±1.2) vs. (4.0±1.5), (8.4±0.8) vs. (6.4±1.6), (40.3±2.6) vs. (28.6±2.4)]( P<0.01), while the refresher physician group had significant improvements in four aspects, i.e., the understanding of extremity bone defects [(8.1±0.9) vs. (7.2±1.1)], the self-confidence in facing complex extremity bone defects [(8.1±1.2) vs. (6.6±0.9)], spatial thinking ability in repair surgery for bone defects [(8.6±0.8) vs. (7.3±0.9)], and overall clinical performance in actual management of patients with bone defects [(41.4±2.3) vs. (37.3±1.8)] ( P<0.01). The satisfaction score for this comprehensive innovative teaching model was (95.3±3.2) points in the standardized training group and (94.8±2.8) points in the refresher physician group. Conclusions:The comprehensive innovative teaching model with "3D printed model combined with visual surgical simulation" as the core can significantly improve the basic knowledge and clinical skills of physicians in a short period of time and meet the needs for learning surgical techniques and advanced diagnosis and treatment concepts among refresher physicians.

Objective:To explore the clinical feasibility and effectiveness of using 3D printed porous titanium-alloy prosthesis to repair aseptic large bone defects in the limbs.Methods:A retrospective analysis was performed on 13 patients with aseptic bone defects of long limbs treated with 3D printed porous titanium alloy prosthesis from December 2017 to December 2022, including 7 males and 6 females, aged 52.6±11.5 years (range, 35-72 years). The bone defect locations included 2 humerus, 1 radius, 5 femur, and 6 tibia. One patient suffered both femoral and tibial defects. All 13 patients suffered from bone nonunion due to internal fixation surgery, including 5 cases of hypertrophic nonunion and 8 cases of atrophic nonunion. The interval between internal fixation surgery and this treatment was 20.1±3.6 months (range, 16.5-26.6 months). The clinical treatment effect was evaluated through parameters such as gross observation, imaging evaluation, disability of arm shoulder and hand (DASH), lower extremity functional scale (LEFS), and patient satisfaction evaluation.Results:The length of bone defect after debridement in 13 patients was 11.7±4.5 cm (range, 6.0-20.6 cm), and the length of implant was 12.9±5.3 cm (range, 6.1-22.9 cm). Partial or complete weight-bearing began at 14.8±6.5 days (range, 2-22 days) after surgery. All 13 cases were followed up for 18.3±12.5 months (range, 13-58 months). The X-ray images showed that the prosthesis and the internal fixation were stable, and the new bone gradually grew gradually from the bone defect section and formed stable bone integration with the prosthesis surface, and no prosthesis displacement or fracture occurred. At the last follow-up, the DASH scores of 3 patients with upper limb bone defect were 8.9, 10.5, and 11.2 points, respectively, and the LEFS scores of 10 patients with lower limb bone defect were 49.6±5.9 points (range, 38-56 points). No significant subsidence or loosening of all prosthetics was observed. Patient satisfaction was 9.8±0.1 points (range, 9.6-9.9).Conclusion:After the application of 3D printed porous titanium alloy prosthesis to repair the aseptic large bone defect of the limbs, the patients can carry weight and function exercise in the early stage, and the function of the affected limbs can recover significantly, and the patients have high satisfaction.

Objective:To analyze and summarize the clinical effects of 3D printed porous titanium-alloy prosthesis implantation in the treatment of long bone defects of lower extremities.Methods:We retrospectively studied the clinical cases with lower extremity bone defect treated by 3D printed porous titanium prostheses from December 2017 to November 2021. 18 patients who were followed up for more than 12 months were included in this study. The enrolled patients included 12 males and 6 females, with an average of 48.9±22.5 years (range, 13-79 years), and an average body mass index of 23.1±4.3 kg/m 2 (range, 17.2-27.1 kg/m 2). There were 14 osteomyelitis-derived bone defects and 4 nonunion-derived bone defects. The bone defect locations included 10 cases of femur and 8 cases of tibia. The average bone defect distance was 13.9±9.7 cm (range, 5.8-31.2 cm), and the proportion of the defect length to the long bone (femur of tibia) was average 33.7%±16.8% (range, 15.0%-63.0%). The clinical efficacy was comprehensively evaluated through gross observation, imaging evaluation, changes in the total length of lower extremities and long bones, femorotibial angle (FTA) measurement, lower extremity functional scale (LEFS), satisfaction, complications and other indicators, focusing on the stabilization mechanism of the prosthesis and the regeneration of new bone. Results:All 18 patients were followed up for 12-35 months, with an average of 16.3 months. Postoperative X-rays at 1, 3, 12 and 24 months showed that new bone could gradually creep along the prosthesis surface. The preoperative bone defect length of long bone and total length of lower limb were respectively 39.4±4.0 cm and 80.5±5.7 cm, which were different from those of the healthy side by 1.6±1.0 cm and 1.5±1.1 cm. One week after implantation, the length of long bone and lower limb was 39.9±3.5 cm and 80.9±6.2 cm, respectively, and the average difference was 1.0±0.6 cm and 0.9±1.1 cm compared with the healthy side. At the last follow-up, the length of long bone and lower limb was 39.7±3.6 cm and 80.9±7.8 cm, with an average difference of 1.8±1.1 cm and 1.0±0.7 cm from the healthy side. There were no significant differences in the length of long bone and lower limbs at the three time points before surgery, one week after surgery and the last follow-up ( F=0.12, 0.04; P>0.05). The average FTA of the affected limb was 174.7° (173.9°, 175.5°), 175.2°(173.5°, 176.4°), and 175.0°(173.5°, 176.3°) at three time nodes, before surgery, one week after surgery and the last follow-up, respectively, and there was no significant statistical difference in pairwise comparison ( Z=0.01, P>0.05). Patients had a mean LEFS score of 50 (46, 51) at the last follow-up, significantly higher than the preoperative score of 20 (17, 21) ( Z=-5.56, P<0.001). The mean satisfaction score of the 18 patients at the last follow-up was 9.7. Two patients (11.1%) had screw fractures but all 3D printed porous titanium alloy prostheses remained stable without significant loosening or displacement. Two patients (11.1%) had nail channel infection of external fixator, all patients with channel infection were cured by intravenous antibiotics combined with local disinfection and dressing change. Conclusion:The implantation of 3D printed porous titanium-alloy prosthesis could efficiently and safely repair the long bone defects of the lower extremities. The prosthesis could maintain stable in the early and middle postoperative period. The length of the long bones and lower limbs did not change significantly with the weight-bearing and functional exercise of the limbs. The new bone could gradually crawl and grow from both ends of the defect, and the patient's limb function recovered significantly, and the patient's satisfaction was high.

Objective:To evaluate the curative effects of Masquelet technique and 3D printing in repair of Cierny-Mader type Ⅳ long bone osteomyelitis.Methods:A retrospective study was conducted of the 8 patients who had been treated at Department of Orthopaedics, The Third Affiliated Hospital to Peking University for Cierny-Mader type Ⅳ osteomyelitis of the lower extremity from June 2017 to December 2019. They were 6 males and 2 females, aged from 27 to 79 years (average, 54.6 years). The defects involved femoral shaft in 5 cases, femoral metaphysis in one, tibia shaft in one, and tibial metaphysis in one. The defect lengths ranged from 7.7 to 15.5 cm, averaging 10.2 cm. Stage one was local infection control and temporary stability reconstruction using Masquelet technique, stage two design and 3D printing of the prosthesis and stable pattern design, and stage three prosthesis implantation and rehabilitation. The ranges of motion of the knee and ankle were recoded postoperatively and the functions evaluated using the Johner-Wruhs scores.Results:The average follow-up time for the 8 patients was 12.6 months (from 6 to 18 months). The total treatment time from the first admission to the last discharge ranged from 62 to 125 days (average, 91.0 days), the time for stage one from 13 to 57 days (average, 28.7 days), that for stage two from 30 to 87 days(average, 48.3 d), and that for stage three from 28 to 84 days (average, 63.0 days). The infection was controlled and there was no recurrence, implant loosening or breakage. Seven patients were capable of full weight-bearing at 14.7 days (from 4 to 42 days) after surgery. One patient recovered full weight-bearing 6 months after surgery due to severe osteoporosis. Fine functional recovery was achieved in the 8 patients, with a range of motion from 0° to 100° for the knee and a range from 35° dorsal flexion to 40° toe flexion for the ankle. The Johner-Wruhs scores at the last follow-up showed 2 excellent, 5 good and one moderate cases.Conclusion:In repair of Cierny-Mader type Ⅳ long bone osteomyelitis, Masquelet technique and 3D printing can shorten the treatment process and allow for early recovery.

Treatment of extremity bone defects,especially large segmental ones,is a difficult problem encountered by orthopedic surgeons in the clinic.Despite a variety of treatment techniques available,lack of uniform protocols causes patients to suffer enormous physical and psychological pain during their medical treatment.Now that new materials and new techniques are constantly evolving and patients' requirements for functional and morphological recovery of the injured limb become more demanding,it has become a great challenge for orthopedic surgeons to provide an optimal individualized treatment protocol for each patient.This review intends to help surgeons with brief update information on the research progress in the treatment of extremity bone defects.

Objective: By comparing different repairing effects of different methods on articular cartilage defects in rabbit model, the ability of a new bioactive glass scaffold to repair cartilage defect was studied. Methods: We prepared the PSC/CS bone cement by mixing the bioactive glass (BG) powder composed of 10.8%P₂O₅-54.2%SiO₂-35%CaO (PSC), chitosan solution (CS) and calcium sulfate hemihydrate (CSH), then the bone cement was sized by a mold to form cylindrical scaffold. In vivo experiment, 18 male rabbits were divided into three groups randomly, including blank group, BG group and TGF-β1 group, which was added TGF-β1 into BG scaffold. Both knees of each rabbit were made cartilage defect for the same group, and no intervention was applied in B group, then implanted scaffolds into defects in both experimental groups. At 6 and 12 weeks after surgery, observed the macroscopic growth, histologic staining and collagen II immunohistochemistry (IHC), and the International Cartilage Repair Society (ICRS) and Wakitani score were used to analyze the experimental results quantitatively. Results: At 6 weeks after surgery, there was no obvious difference between blank group and BG groups, but the macroscopic result of TGF-β1 group was better than the other two groups and its ICRS score 4.67±0.52 points was statistically higher than BG group 2.83±0.75 points (t=-2.817, P=0.015). As to the comparison of histologic staining and Wakitani socre among three groups, no statistical difference was observed (blank group=13.67±0.52, BG group=13.83±0.41, TGF-β1 group=13.33±1.03). At 12 weeks after surgery, there was still no obvious difference between blank and BG groups, while the results of macroscopic observation and ICRS score in TGF-β1 group were significantly higher than them 9.01±0.63 points (blank group vs TGF-β1 group: t=-2.289, P=0.022; BG group vs TGF-β1 group: t=-2.326, P=0.020). More importantly, much deeper positive staining were observed in TGF-β1 group, and the Wakitani score was higher than the other two groups (blank group=9.83±1.33, BG group=9.51±1.05, TGF-β1 group=6.50±1.38, blank group vs TGF-β1 group: t=-2.771, P=0.007; BG group vs TGF-β1 group: t=-2.756, P=0.006). By comparing the degree of histologic staining and Col II expression with normal cartilage, the regenerated tissue in TGF-β1 group was similar. Conclusion Single PSC/CS scaffold doesn’t possess excellent ability to repair cartilage defect. When TGF-β1 was added into PSC/CS bioactive glass, the scaffold was able to promote cartilage defect repair, and the regenerated tissue was similar to normal cartilage.

Objective To analyze the factors that influence screw penetration after plating for proximal humerus fractures of Neer two-or three-part.Methods We reviewed the patients with proximal humerus fracture of Neer types Ⅱ & Ⅲ who had been treated from January 2006 to June 2017.The data were documented regarding gender,age,Neer classification,osteoporosis,surgical procedure,cephalic screw number,type of medial support and screw penetration.They were divided into 2 groups according to the presence or absence of screw penetration.x2 test and independent samples t test were used with software IBM SPSS 22.0.The multivariate logistic regression was used to identify the independent risk factors when there were two or more statistically significant factors.The two-side test was used and significance was set to P ＜ 0.05.Results Altogether 78 patients were included in our analysis,including 27 males (34.62％) and 51 females (65.38％) with an average age of 57.41 years (from 18 to 85 years).Their average follow-up time was 7.7 months (from 3 to 24 months).There were 54 Neer two-part fractures (69.23％) and 24 Neer three-part ones (30.77％).Screw penetration was observed in 18 patients (23.08％) but not in the other 60 ones (76.92％).The x2 test and independent samples t test revealed that screw penetration was significantly associated with gender (P =0.003),osteoporosis (P =0.003) and cephalic screw number (P =0.003) but not with age (P =0.256),Neer classification(P =0.754),surgical procedure((P =0.308) or type of medial support (P =0.186).The multivariate logistic regression revealed that osteoporosis (P =0.027) and cephalic screw number (P =0.026) were independent risk factors for screw penetration.Conclusions After plating for proximal humerus fractures of Neer two-or three-part,the patients with osteoporosis and those receiving more than 5 cephalic screws may face a higher risk of screw penetration than those without osteoporosis and those receiving 4 cephalic screws.

Objective To investigate the factors influencing the image quality of prostate magnetic resonance spectroscopy (MRS),and to put forward quality control measures to improve MRS in success ratio and image quality.Methods Totally 1 255 patients with prostate diseases confirmed pathologically from October 2009 to December 2015 had their MRS data analyzed retrospectively.MRS was executed with multi-voxel 3D chemical shift imaging technique,and special-purpose software was involved in for post processing.Re-scanning would be performed in case of baseline clutter,low SNR and etc.Results There were 1 218 patients had MRS executed well in preparedness,positioning,parameters setup,post processing,baseline and chemical shift,one patient underwent unsuccessful MRS due to incorrect bed mode,9 ones due to unstable baseline resulting from unsatisfactory preparedness,26 ones due to unstable baseline resulting from bad shimming and 1 case due to non-standard post processing.Conclusion Prostate SRS depends on patient preparedness,positioning,parameters setup,shimming and post processing.

Objective To explore the predictive value of serum N-terminal pro-brain natriuretic peptide (NT-proBNP) level in anthracycline-based chemotherapy-related cardiotoxicity of breast cancers.Methods A total of 135 breast cancer patients was analyzed if NT-proBNP was associated with chemotherapy-related cardiotoxicity.The level of NT-proBNP in the diagnosis of cardiotoxicity was assessed.Results A total of 22 patients (16.29％) had subsequent claims for cardiotoxicity events.NT-proBNP in cardiotoxicity group was significantly higher than that non-cardiotoxicity group (P ＜ 0.05).According to receiver operating characteristic (ROC) curve, the cut-off value of NT-proBNP was set at 350 pg/ml, specificity and sensitivity were 70.32％ and 82.58％ , respectively.Positive and negative predictive values were 78.12％ and 65.45％, respectively.Conclusions The present study is to confirm excellent clinical value of NTproBNP on cardiotoxicity.The level of NT-proBNP for early detection of cardiotoxicity has good prospects for high risk patients.

BACKGROUND:Currently, neural stem celltransplantation can be performed through three main approaches:local lesions, blood circulation, and cerebrospinal fluid.
OBJECTIVE:To review the transplantation of neural stem cells or neural precursor cells via the cerebrospinal fluid in the treatment of central nervous system diseases.
METHODS:A computer-based search of PubMed and CHKD databases was performed to retrieve articles concerning transplantation of neural stem cells via the cerebrospinal fluid, and its application and therapeutic mechanism in the treatment of central nervous system diseases in both animal experiment and clinic study published from 2000 to 2009.
RESULTS AND CONCLUSION:It is suitable for neural stem cellsurvival, proliferation, and differentiation in the cerebrospinal fluid. Transplantation of neural stem cells via the cerebrospinal fluid is effective and feasible to treat central nervous system diseases. However, some problems have not been solved, such as the source of neural stem cells, the optimal time window and celldose, the safety and the long-term effect. Further studies are needed to pave the way for the intrathecal injection of neural stem cells in the treatment of central nervous system diseases.