Through consulting the domestic and foreign literatures,CO2 supercritical fluid technique is expounded including development overview,corresponding principle and characteristic.The CO2 supercritical fluid extraction is widely applied in many fields and the five application of chemical industry,food,medicine,biotechnology and tissue engineering are emphatically summarized,and meanwhile,the application prospect of the supercritical fluid technology is predicted.

The ideal treatment of osteonosus and bone tumor is individualized treatment with individualized implants on the basis of patient's geometrical anatomic condition.Traditional metal implants are lack of individual matching.The new individualized metal implant is based on reverse engineering and rapid prototyping technique,and has solved the problems of long period manufactural procedure in the traditional technique.New type of material is applied for rapid prototyping directly.It would be the developing tendency in orthopedic application.

To study the method and the optimal quantity of osteoblast transplantation to stimulate bone regeneration by transplanting 6～8 day old cultured osteoblasts and bFGF, together with osteoblast free calvaria of fetal rabbits into the defects of the rabbit radius. The fibroblasts were embedded in the type Ⅰcollagen in the concentrations of 10 7 ,10 6 ,10 5 , 10 4 /ml. Bone repair was evaluated by X ray, bone density,and scanning electron microscopy. Bone union ratio of the radius with transplantation of 10 7 ,10 6 ,10 5 , 10 4 /ml osteoblasts was 40%, 65%, 31 25%, 5 55% respectively at 4 weeks after transplantation, and 41 67%, 75%, 37 5%, 10% respectively at 8 weeks after transplantation. Bone density of radius defect with transplantation of 10 7 , 10 6 , 10 5 , 10 4 /ml osteoblasts was (0 112?0 018), (0 159?0 033), (0 122?0 039), (0 066?0 002) respectively at 6 weeks after transplantation and (0 150?0 059), (0 173?0 041), (0 145?0 023), (0 103?0 023) respectively at 8 weeks after transplantation, In 10 cases of bone non union, union was achieved by transplanting fetal osteoblast and basic fibroblast growth factor. This finding indicated that that transplantation of fetal osteoblasts could stimulate bone defect repair. The optimal concentration of osteoblasts implant was 10 6 cells /ml. It might be used in the treatment of bone non union.

Pre-graduation practice is an important part of teaching work for preventive medical science.The article is about investigation on the pre-graduation practice of 85 preventive medical students just graduated,and some suggestions for improvement.It is found that the overall teaching effect is good,but there are some problems,mainly on the construction of practice base,practice contents and time,and also graduation design.

BACKGROUND: The rudiment of tissue engineering is to obtain tissue from patients. The cells are expanded into a population through cellular culture, and seeded into scaffolds, which can accommodate and guide the growth and proliferation of new cells in the three-dimensional scaffolds. At last, the constructed tissue is transplanted in vivo to repair or replace damaged or diseased tissues. Afterward neovascularization of the graft, the scaffolds are absorbed gradually. Finally, the new tissue replaces completely the damaged or diseased tissuesOBJECTIVE: To evaluate the feasibility of designing and fabricating customized anatomical-shaped bone tissue-engineering scaffolds with reverse engineering and rapid prototyping (RP) techniques. To avoid the disadvantage of the conventional fabricated methods of the scaffolds.DESIGN: The method of fabricating customized anatomical-shaped bone tissue engineering scaffolds.SETTING: Computer-aided design (CAD) of the scaffold was conducted in CAD training center, Guangdong Machinery Research Institute. Rapid prototyping fabrication of the scaffold was conducted in Guangdong Longchuangyu Limited Cooperation. The scaffold was fabricated by sterophotocureable technology and was made of photosensitized resin.METHODS: This experiment was carried out at the Center of Department of Traumatic Orthopedics, General Hospital of Guangzhou Military Area Command of Chinese PLA from October 2004 and January 2005. According to reverse engineering, layered image information of skeleton of the patients was scanned with CT/MRI. Anatomical models of region of interesting were created by means of CT or MRI three-dimensional reconstruction and surface reconstruction. The internal construction of the scaffolds was designed with CAD software in the outline of the anatomical models to develop computer-aided model. The prototypes of the scaffolds were fabricated by RP process.MAIN OUTCOME MEASURES: ①CT/MRI scanning, three-dimensional reconstruction, anatomical modeling; ② computer-aided design of customized bone tissue engineering scaffolds; ③rapid prototyping fabrication of customized bone tissue engineering scaffold.RESULTS: ①Anatomical models of bone joint were established through CT/MRI three-dimensional reconstruction. ② The internal structure of the scaffold was designed to establish the entity model of bone tissue engineering scaffold successfully with computer-aided design software. ③ CAD model of bone tissue engineering scaffold guided prototypes to develop the customized anatomical-shaped bone tissue engineering scaffolds. The internal structure of bone tissue engineering scaffold was fine and had high degree of porosity-and pore interconnectivity.CONCLUSION: Customized anatomical-shaped bone tissue engineering scaffolds can be fabricated with reverse engineering and RP technology. Among all RP processes, stereophotocureable technology (SLA) is the best one with good precision, smooth surface and good shaping.

Objective To compare the outcome of adult-to-adult single kidney transplantation from donation after drain death and cardiac death. Methods The outcome of adult-to-adult single kidney transplantation from October 2012 to September 2015 in kidney transplantation center of Zhujiang Hospital was retrospectively analyzed. 53 recipients received donation from donors after brain death (DBD group) and 28 from cardiac death (DCD group). The deadline of follow-up is May 2016. Results During the period of observation, the mean follow-up was (17.26±10.85) months and patient's survival rate was 100%. When compared graft survival rate with the two groups, survival rate is 93.7% in DBD group and 92% in DCD group (χ2= 0.184,P = 0.668). There was no statistically significant difference (P > 0.05), the overall incidence of DGF was 28.4%. General DGF incidence is 28.4%, and DGF incidence between groups is χ2= 4.402,P = 0.036. Infection rate within 1 year is χ2= 4.507,P = 0.034, and the difference is significant (P < 0.05). There were no statistically significant difference (P > 0.05) in AR, eGFR of 1 month, proteinuria of 1 month after, transplantation and surgical complications. Conclusions Adult-to-adult single kidney transplantation from donation after cardiac death (DCD) has a higher rate of incidence of DGF, and the postoperative infection rate within 1 year. Renal transplantation from donation after cardiac death could have a good outcome.

BACKGROUND: Acetabular malignant tumor reconstruction is to obtain pelvic stability and lower limb walking function to excise the tumor at safe margin.Excision range has been evaluated by MRI,CT,X-ray,which are subjective and lack preoperative design.Computer-aided three-dimensional reconstruction can evaluate tumor erosion range from all planes to accurately excise the tumor.OBJECTIVE: To evaluate the value of computer aided design in the treatment of acetabular malignant tumor.METHODS: One case with acetabular hemangiosarcoma was checked with lamellar CT scanning,which acquired some two-dimensional data in disease area.The three-dimensional reconstruction of anatomical model,design of cutting bone extent,design of individual prosthesis and sham operation were made by computer.Based on computer aided design proposal,acetabular tumor was resected,pelvic ring and right hip articulation were reconstructed with allogeneic semi-pelvis and individual total hip replacement.RESULTS AND CONCLUSION: The patient began to non-weight bearing walk with double crutches 2 months after operation.At6 months,the patient walked normally.The right hip joint motion was good with no pain.Postoperative X-ray film displayed individual prosthesis matched to pelvis.The patient fell a little numbness of skin in the lateral of right hip.No phlebothrombosis,prosthesis loosening or dislocation was found.Computer aided design has a good perspective of application in the treatment of acetabular malignant tumor.Individualized treatment can improve operation accuracy,reliability,convenience and curative effect.

In order to simplify the distal femoral comminuted fracture surgery and improve the accuracy of the parts to be reset, a kind of surgery orienting model for the surgery operation was designed according to the scanning data of computer tomography and the three-dimensional reconstruction image. With the use of DiMetal-280 selective laser melting rapid prototyping system, the surgery orienting model of 316L stainless steel was made through orthogonal experiment for processing parameter optimization. The technology of direct manufacturing of surgery orienting model by selective laser melting was noted to have obvious superiority with high speed, precise profile and good accuracy in size when compared with the conventional one. The model was applied in a real surgical operation for thighbone replacement; it worked well. The successful development of the model provides a new method for the automatic manufacture of customized surgery model, thus building a foundation for more clinical applications in the future.
Computer-Aided Design ; Femoral Fractures ; surgery ; Fractures, Comminuted ; surgery ; Humans ; Lasers ; Models, Anatomic ; Surgery, Computer-Assisted ; instrumentation

Objective To evaluate the correction rate,accuracy of pedicle screw fixation and overall clinical efficacy of intravertebral osteotomy and internal fixation surgery with the assistance of 3D printing guide plates in treatment of severe kyphosis.Methods A single-center nonrandomized clinical pilot study was conducted on 19 patients(8 males and 11 females)with severe kyphosis undergoing intravertebral osteotomy between December 2018 and June 2023.Seven of them(CAD group)had preoperative planning with computer-aided design(CAD)and intraoperative guidance of individualized 3D printing guide plates.And another 12 patients(control group)were corrected with conventional pedicle screw placement.Postoperative evaluation included assessment of posterior Cobb angle,spinal angular correction rate,accuracy of pedicle screw placement and Oswestry Dysfunction Index(ODI)questionnaire.Results The 19 patients were at a mean age of 48.0 years,and followed up for 26.4(9～54)months.All of them achieved relatively satisfactory corrective results,with those of the CAD group having a correction rate of 96.83％and those of the control group of 86.61％.There were no statistical differences in average intraoperative blood loss(857 vs 1 045 mL)and average operative time(344 vs 402 min),but significant difference was observed in average length of hospital stay(11 vs 18 d,P＜0.05)between the 2 groups.A total of 278 nails were placed in this study,including 70 guide-assisted pedicle screws,97.1％of which were grade A or B.In the control group,208 pedicle screws were placed,93.8％of which were grade A or B.Postoperative CT/X-ray scanning displayed that both groups achieved certain correction for kyphosis.No obvious difference was found in the average spinal angular correction(43.37° vs 36.10°),and significantly higher correction rate was seen in the CAD group than the control group(96.83％vs 86.61％,P＜0.01).The ODI value was notably lower in the CAD group than the control group(P＜0.05).Conclusion CAD-assisted preoperative planning,surgical simulation and individualized 3D printing guide plates can promote surgical correction and accuracy of pedicle screw placement and improves the quality of life of patients with severe kyphotic deformity.