BACKGROUND:During semi-knee arthroplasty,only the design and fabrication performed according to patient's injury can implement the good matching between prosthesis and joint surface,which is difficult to perform by conventional design and fabrication.OBJECTIVE:To develop a custom design and rapid fabrication method for artificial semi-knee joint based on computer aided design (CAD) and rapid prototyping (RP) techniques,and to evaluate the clinical application value of semi-knee arthroplasty and the role of CAD/RP in the design and fabrication of prosthesis.DESIGN,TIME AND SETTING:A custom design and fabrication of prosthesis and its clinical application was performed in the Xijing Hospital Affiliated to Fourth Military Medical University of Chinese PLA & Institute of Advanced Manufacturing Technology,Xi'an Jiaotong University & the State Key Laboratory of Materials and Mechanics,College of Mechanical Engineering,Xi' an Jiaotong University between January 2002 and December 2005.PARTICIPANTS:A 14-year-old male patient with osteosarcoma in the lower segment of the right femur was recruited into this study due to recurred osteosarcoma one year after surgery.Tumorectomy,large allogenic bone transplantation,and custom-made semi-knee arthroplasty were to be performed in this patient.A written informed consent was obtained from his relatives.METHODS:Clinical imageological data of the patient in terms of CT scanning and three-reconstruction were taken as data source.Data regarding joint shape were acquired by image processing technique.Joint contour was reconstructed by NRRBS algorithm using Surfacer software.Through the use of computer,the three-dimensional design of semi-knee joint prosthesis and its auxiliary devices was conducted.Subsequently,prosthetic prototype was fabricated by RP technique and prosthetic products were made by precise casting methods.Finally,the manufactured prosthesis was installed into the allogenic bone with the help of aiming device and was transplanted into the affected limb following distal locking.MAIN OUTCOME MEASURES:Error analysis of joint contour reconstructed using the Surfacer software; assembling of manufactured joint prosthesis and auxiliary devices; X-ray examination results,joint space status,and range of motion of joint in flexion and extension positions following prosthesis replacement.RESULTS:All procedures were conducted within 1 week.The maximum difference between CAD model-related data and original data was less than 1 mm.In the flexion,extension,and rotation positions,joint prosthesis well matched tibial joint surface,with evenly distributed stress.The prosthesis and auxiliary manufactured by RP and precise casting techniques met the requirements of design and could be installed into large segment of allogenic bone.Prosthesis was precisely placed into the affected knee and could well match contralateral tibial joint surface with normal joint space.No adverse reactions were found and the patient could implement functional exercise.One-year follow-up results revealed that the patient acquired satisfactory therapeutic effects without dislocation and chronic pain.CONCLUSION:Semi-knee joint individually fabricated by CAD and RP techniques provides some clinical application vilues in specific cases.

Objective A new type of bone graft material was constructed by combining calcium phosphate cement(CPC) with bone morphogenetic protein(BMP). In order to evaluate the feasibility to use this material to repair the segmental bone defect in clinic, the ability of CPC was compared with CPC/BMP in bone defects reconstruction by animal experiments. Methods The model of 15 mm bone defect was established in the middle shaft of the radius in 60 rabbits, of which 30 defects were implanted with CPC/BMP composites, 22 implanted with CPC, and the other 8 rabbits served as control group. The specimens were harvested separately at the end of 2, 4, 8, 16 and 24 weeks after operation. In order to observe the formation of new bone and the degradation process of the material, a series of examinations were carried out including of radiography, histomorphology, serum detection, energy dispersion analysis X-ray(EDAX), scanning electron microscope(SEM),bone density detection, mechanical measurement and inorganic substance detection. The results of CPC group and CPC/BMP group were compared on the same condition. Results All the animals survived after operation, and no reactions of toxicity were found. New bone formation was observed to be increasing significantly in CPC/BMP group with the time of implantation. Only little new bone formed in CPC group and no healing was found in the control group. By the end of 24 weeks, new bone had bridged the gap between the proximal and distal fragments in CPC/BMP group. In histomorphological detection, chondrocytes were found at the 2nd week, and woven bone at 4th week in CPC/BMP group. Remodeling of new lamellar bone and absorption of the composite material were observed at the 16th week, and the mechanical strength of the composite material reached almost to normal level at the 24th week. Calcification was significantly higher in CPC/BMP group than that in CPC group examined by EDAX, new bone density detection and measurement of inorganic substance in specimens. During the repairing process of bone defect, the material degraded while new bone formed, the speed of degradation of CPC/BMP was evidently higher than that of CPC group. Moreover, in the process of CPC degradation, the concentration of calcium in serum increased, and the concentration of phosphate in serum kept unchanged. Conclusion The CPC/BMP composite has great potential in bone defects repairing and could be used as a material for bone graft substitute in clinical patients.

Objective To find the best sample collecting and template making methods. Methods The multiplex PCR results of three sample collecting methods and eight template making methods in malaria diagnosis were compared. Results Conserved blood sample collecting, and Na 3PO 4 template making were sensitive and simple. Conclusion Conserved blood of sample collecting and Na 3PO 4 in template making are the best methods in multiplex PCR diagnosis of malaria, and are worthy of wide use.

BACKGROUND: Bone morphogenetic protein-2 has been previously proved to not only stimulate and different bone tissue-derived cells, but also induce differentiation from cell strain into osteoblasts; however, direct application of bone morphogenetic protein has poor effects on repairing bone defects. OBJECTIVE: To study new bone formation in a rabbit model of avascular necrosis of the femoral head (ANFH) following recombinant human bone morphogenetic protein-2 (rhBMP-2)/fibrin sealant (FS) implantation combining with core decompression. DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Affiliated Hospital of Medical College of Chinese People’s Armed Police Force from January 2005 to December 2007. MATERIALS: Composite was made by rhBMP-2 and FS, and the final concentration of rhBMP-2 was 1 mg/L. METHODS: Animal models of ANFH were made by injecting hormone. The rabbits were randomly divided into three groups, including rhBMP-2/FS implantation group, rhBMP-2 implantation group, and core decompression alone group. MAIN OUTCOME MEASURES: Signal changes of femoral head and sclerotin were detected using MRI method; new bone formation was observed under optic microscopy; calcium content was measured using atomic absorrtion spectrophotometer. RESULTS: MRI indicated that new bone replaced primary bone defect channel at week 8 after rhBMP-2/FS implantation. A few of new bones were observed in the rhBMP-2 implantation group, and fiber tissue was still observed in the core decompression alone group. Morphology suggested that a great quantity of mature bone trabecula and plate-shaped bone replaced primary bone defect channel at week 8 after rhBMP-2/FS implantation. Bone defect was decreased in the rhBMP-2 implantation group, accompanying with a few of bone trabecula and blood capillary but a large quantity of fiber tissues. At week 8 after core decompression alone, bone defect was decreased, and a few of new bones were observed. Fiber tissue still existed in the center, and any bone tissue did not fill in it. Calcium content in the rhBMP-2/FS implantation group was greater than rhBMP-2 implantation group and core decompression alone group (P

Objective To investigate the chondrocyte proliferation and extracellular matrix biosynthesis of electrospun PCL scaffolds seeded with rabbit chondrocytes under flow perfusion culture in vitro.Methods Nonwoven PCL microfiber mats were fabricated,and contra-aperture cylindrical glass equipment as a perfusion bioreactor was designed and manufactured on our own.The experiment included peffusion culture group and static culture group.Primary chondrocytes were isolated from the knee joints of two-month-old New Zealand white rabbits and seeded into scaffolds.The scaffold-cell complexes were harvested at 3,7,and 14 days of culture for scanning electron micrograph (SEM) analysis,biochemical assay,real-time PCR and histology analysis.Results Electrospun PCL scaffolds were composed of microfibers with a diameter of 1.67±0.76 μm and pores with a diameter of 17.65±7.11 μm.SEM showed a better cell proliferation with typical morphology of chondrocytes under perfusion culture.At 7 days of culture,DNA content in perfusion culture group was higher than in static culture group.At 3,7 and 14 days of culture,compared with the static culture group,glycosaminoglycan (GAG) content and GAG/DNA ratio in perfusion culture group were higher,and the differences were statistically significant.At 14 days of culture,real-time PCR showed aggrecan and collagen type Ⅱ gene expression and collagen type Ⅱ to collagen type Ⅰ ratio were higher in perfusion culture group than in static culture group; HE and safranin O staining showed a significant cell proliferation,infiltration,as well as extracellular matrix biosynthesis in perfusion culture group.Conclusion Under flow perfusion culture,the electrospun PCL scaffolds seeded with rabbit chondrocytes can enhance chondrocyte proliferation and extracellular matrix biosynthesis,which is a promising method for cartilage tissue engineering.

BACKGROUND: Surgery is the common therapy for pterygium, and there are several surgical management techniques.OBJECTIVE: To clinically assess the effect of pterygium retro-resection followed by the transposition of conjunctival autograft rich in stem cells.DESIGN: Follow-up of the cases.SETTING: Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University.PARTICIPANTS: Fifty patients (60 eyes) with pterygium, who were treated in the Fourth Affiliated Hospital of China Medical University from May 2003 to May 2006, were selected. All patients agreed to receive the treatment and participate in the follow-up. The trial was permitted by the Hospital Ethics Committee.METHODS: The head of pterygium was separated from cornea, including the conjunctiva and the underlying proliferating tissue towards lacrimal caruncle until plica semilunaris. The pterygium was totally removed. The adjacent healthy conjunctiva harboring stem cells was transposed to cover the naked sclera. The patients were evaluated following the operation.MAIN OUTCOME MEASURES: ①Epithelization of cornea and conjunctiva; ②reoccurrence of pterygium.RESULTS: ①The epithelium of cornea and conjunctiva in all cases (60 eyes) healed within 1-2 days after the operation. ②The patients were followed for 8-16 months after the sutures were removed. Out of the total of 60 eyes, 26 were followed for 8-12 months and 34 for 13-16 months. The average length of observation was 12 months. Fifty-eight eyes healed completely, and reoccurrence took place in 2 cases.CONCLUSION: Pterygium resection followed by the transposition of adjacent conjunctival autograft harboring stem cells is easy to perform and effective to reduce the recurrence of the lesion.

ObjectiveTo explore the effect of osteoarthritis (OA) chondrocytes and normal chondrocytes on the chondrogenesis of bone marrow mesenchymal stem cells(BMSCs) in self designed co-culture system. MethodsRabbit BMSCs and chondrocytes were isolated and expanded in vitro. OA chondrocytes were harvested from the rabbit of established osteoarthritis model. We made a BMSCs-low melting agarose constructs, then put it onto the self-made 6 well plates lattice assembly for co-culture with chondrocytes. The groups were divided into Normal P0-BMSCs, Normal P3-BMSCs, OA PO-BMSCs, OA P3-BMSCs and BMSCs (control) group. At 3, 7, 14 day culture, cultured cells in all groups were collected for real-time PCR, glycosaminoglycan (GAG) content, cytoactive detection, and histological observation. ResultsType Ⅱ collagen gene expression was up-regulated in group Normal PO-BMSCs, which showed 5.1-, 7.2-, 11.2-fold increase over that of control group at 3, 7, 14 days, respectively. Type Ⅰ, Ⅱ collagen and aggrecan gene expressions were not obviously up-regulated. In group OA P3-BMSCs, type Ⅰ collagen gene expression level lower than the control group in 3, 7, 14 day. In normal PO-BMSCs, GAG content showed 2.59-fold increase over that of the control group. GAG content of group OA PO-BMSCs and control group showed no significant differences.Others groups showed significant differences in comparison with the control group(P＜0.05). Alcian stain showed positive in all groups. The normal PO-BMSCs group showed the darkest blue-stained. Conclusion Rabbit normal PO chondrocytes and rabbit OA P0 chondrocytes significantly enhanced chondrogenic differentiation of rabbit BMSCs. The secreted morphogens of the rabbit normal P3 chondrocytes and rabbit OA P3 chondrocytes do not have a significant effect on chondrogenic differentiation of rabbit BMSCs.

Objective To systematically evaluate the efficacy and safety of posterior short segment and long segment pedicle screw internal fixation in the treatment of thoracolumbar burst fracture. Methods By searching the database, including PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, a comprehensive study was carried out to make a comparison between the posterior short segment and the long segment pedicle screws internal fixation in treatment of thoracolumbar burst fracture, and Meta analysis was performed. Results A total of 14 related studies and 658 patients were enrolled in the study, including 320 patients in short segment group and 338 cases in long segment group, and Meta analysis was performed. The results suggested that there was no significant difference between the short segment group and the long segment group in terms of the deformity angle of the injured vertebra measured after operation and at the last follow?up, and sagittal index at the last follow?up ( MD=-0. 22,95%CI -2. 73,2. 28,P=0. 86;MD=-0. 28,95%CI -2. 23,1. 67, P=0. 78;MD=0. 47, 95%CI -3. 45, 4. 39, P=0. 81 ) . Besides, both groups had no statistical difference in post?operative COBB angle,anterior vertebral height and compression rate of injured vertebrae ( MD=0. 21,95%CI -0. 65,1. 06,P=0. 64; MD=-0. 46,95%CI -1. 40,0. 49,P=0. 34; MD=0. 47,95%CI -2. 28, 3. 21, P= 0. 74 ) , while the differences in COBB angle, anterior vertebral height, compression rate, correction loss were statistically significant at the last follow?up (MD=5. 11,95%CI 2. 81,7. 40,P<0. 0001;MD=-11. 89,95%CI-15. 28,-8. 50,P<0. 00001;MD=6. 46,95%CI 3. 85,9. 07,P<0. 00001) . There was no significant difference in VAS scores and the ODI scores between the two groups at the last follow?up ( MD =0. 01,95%CI -0. 15,0. 17,P=0. 9; MD=-0. 47,95%CI -2. 68,1. 74,P=0. 86),while the two groups showed statistically significant difference in fixation failure ( RR = 0. 08, 95%CI 0. 01, 0. 15, P = 0. 02 ) . Conclusion Posterior long segment pedicle screw internal fixation is more effective in treating thoracolumbar burst fracture than short segment surgery. It can reduce the COBB angle,restore the anterior height of the injured vertebra,and decrease the anterior vertebral pressure.

Objective To report the clinical efficacy of Kirschner wire combined with external fixator in the treatment of open comminuted distal tibiofibular fractures according to the concept of damage control orthopaedics.Methods A case series study was done on the clinical data of 15 open comminuted distal tibiofibular fractures which had been treated with kirschner wire combined with external fixation from January 2015 to August 2018 at Department of Orthopedics,Affiliated Hospital to Logistics College of Chinese People's Armed Police.They were 12 men and 3 women,aged from 27 to 62 years (mean,46.5 years).By the Gustilo classification,there were one case of type Ⅰ,4 cases of type Ⅱ,7 cases of type Ⅲ A,2 cases of type ⅢB and one case of type ⅢC.All the patients were treated with emergency debridement,tibial fixation using external fixator and fibular fixation using kirschner wire,followed by vacuum sealing drainage(VSD).Effective anti-inflammatory and other comprehensive treatments were given postoperatively.Regular follow-up was conducted to observe fracture healing and complications like osteomyelitis and bone disconnection.At the final follow-up,the American Orthopaedic Foot Ankle Society (AOFAS) ankle-hindfoot scale was used to evaluate the ankle function.Results All the patients were followed up for 12 to 18 months (mean,12.8 months).Primary bone union was achieved in 13 cases (86.7％),delayed healing observed in one case (6.7％) and bone nonunion in one case (6.7％).No osteomyelitis occurred.By the AOFAS ankle-hindfoot scale,the ankle function was rated as excellent in 9 cases,as good in 4,as fair in one and as poor in one.Conclusions For patients with open comminuted distal tibiofibular fracture,treatment should be conducted according to the concept of damage control orthopaedics.After early thorough debridement,the tibia should be fixated using external fixator and the fibula using kirschner wire,followed by VSD,leading to economical cost and satisfactory clinical efficacy.

OBJECTIVESTo construct new type of bone graft material by combining calcium phosphate cement (CPC) with bone morphogenetic protein (BMP), and then to detect its osteogenic activity.

METHODSThe surface of CPC and CPC/BMP composite were observed by scanning electron microscope (SEM). CPC and CPC/BMP pellets were separately implanted into the thigh muscle pouches of mice. Samples obtained at different times were tested by histological analysis, SEM, organic substance detection, and alkaline phosphatase (ALP) measurement to observe the induced ectopic bone formation.

RESULTSUnder SEM, the CPC and CPC/BMP composite was found to consist primarily of platy crystals, granular crystals and some small rod-like crystals with micropores about 10-50 microm in size. BMP about 1-5 microm in size was seen like micro globules distributing evenly in the micropores. Newly formed cartilage or bone was not found in the CPC group. In the CPC/BMP group, mesenchymal cells were proliferated and abundant cartilage was found in one week. Woven bone appeared at 2 weeks. New bone formation increased with bone marrow at 4 weeks. At 8 weeks, the implanted CPC/BMP became heterogeneous and a lot of collapsed granules were observed. At the end of 16 weeks, mature lamellar bone appeared and the volume of the implanted CPC/BMP became smaller. One week after implantation, the ALP increased evidently in the CPC/BMP groups and reached the highest level at the 4th week, which was about 168 U/L. The content of organic substance in specimens increased from 22% to 39% by the end of the 16th week, showing the continuous calcification and formation of new bone. SEM also showed that the CPC/BMP composite had good potentiality of ectopic bone induction, and the new bone formed accompanied by the slow degradation of the material.

CONCLUSIONThe results of this study suggested that the CPC/BMP composite could be used as material for bone graft substitute.

Animals ; Bone Cements ; Bone Morphogenetic Proteins ; pharmacology ; Bone Substitutes ; chemical synthesis ; pharmacology ; Calcium Phosphates ; Male ; Materials Testing ; Mice ; Mice, Inbred Strains ; Osteogenesis ; drug effects ; Prosthesis Implantation