Objective To prepare recombinant human bone morphogenetic protein-2(rhBMP-2)loaded chitosan nanospheres and to evaluate their ectopic bone formation activity in vivo. Methods The rhBMP-2 loaded chitosan nanospheres were prepaid using the ionic crosslinking method with TPP as a crosslinking agent.The morphological properties and particle size distribution were evaluated by transmission electron microcopy(TEM) and particle size analyzer.An intramuscular ectopic bone formation test was carried out to compare the ectopic bone formation activity in 24 SD rabbits that were randomized into 4 even groups.rhBMP-2 loaded chitosan nanospheres (1 mg),rhBMP-2 (1 mg),chitosan nanospheres and nothing were implanted into the muscle pouch at the left thigh,respectively,in groups A,B,C and D. Results The rhBMP-2 loaded chitosan nanospheres were well distributed and spherical in shape.The average particle diameter was 230.0 nm,the entrapment efficiency was 66.87％ ± 4.58％,and the loading rate was 33.44 ± 2.29 μg/mg.The mean ALP activity was respectively 1.94 ± 0.35 kat/g,1.48 ± 0.56 kat/g,0.20 ±0.07 kat/g and 0.18 ±0.06 kat/g in groups A,B,C and D,with a significant difference between the 4 groups( F =42.959,P =0.000).The mean Ca2 + content was respectively 5.20 ± 1.42 μg/mg,3.80 ± 1.40 μg/mg,0.19 ± 0.08 μg/mgand 0.20 ± 0.08 μg/mg in groups A,B,C and D,with a significant difference between the 4 groups ( F =39.242,P =0.000).Groups A and B were obviously higher than groups C and D and group A was obviously higher than group B in terms of ALP activity and Ca2+ content. Conclusion The rhBMP-2 loaded chitosan nanospheres prepared by ionic crosslinking method show a good property and obvious ectopic bone formation activity.

Objective To provide anatomical profile of the cranio-cervical region for the surgical treatment of ventral atlantoaxial lesions through transoropharyngeal approach.Methods Ten fresh specimens of craniocervical region were dissected layer by layer with microsurgical technic in accordance with the transoropharyngeal approach for the surgical treatment of atlantoaxial lesion, with special attention to anatomical stratification of pharyngeal posterior wall, the course of the vertebral artery, anatomical relation between the atlas and the axis, and anatomical parameters pertaining to internal fixation for the atlantoaxial joint. Results Pharyngeal posterior wall consisted of two layers (mucosa and prevertebral fascia) and two spaces (posterior interspace of pharynx and anterior interspace of vertebrae). Through anterior transoropharyngeal approach, the region between the anterior rim of the foramen magnum down to C 3 could be exposed. The distance between the vertebral artery and midline of the atlar and axis was 25.2?2.3mm(20.4-29.7mm) and 18.4?2.6mm(13.1-23.0mm) respectively. The exposed areas of the atlas and axis were 39.4?2.2mm(36.2-42.7mm) and midline was 39.0?2.1mm(35.8-42.3mm), respectively. The distance(a) between the two screw inserting points on the atlas (middle point of C 1 lateral mass) was 31.4?3.3mm(25.4-36.6mm). The vertical distance(b) between the connecting line of two screw inserting points on the atlas and that of two screw inserting points on the axis (3-4mm lateral to the midline of C 2 vertebra) was 18.7?2.7mm(14.9-23.2mm). The odds of a/b ranged from 1.5 to 1.7. Conclusion Atlantoaxial surgery through transoropharygeal approach is safe and feasible. The approach is suitable for internal fixation of anterior atlantoaxial joint, and the design of the plate should be based on the above data.

Objective To observe the inhibition of vascular endotheilal growth factor (VEGF) gene transcribition and translation with antisense VEGF165 adenovirus vector transfection. Method To transfect the synovial cells with antisense VEGF165 adenovirus and detect the gene translation level with northern-blot method. Result The Northern-blot showed that: the transcription of VEGF gene were inhibited markedly after the antisense VEGF165 gene transfection for 3 days and the inhibition efficiency was obivious in 4th day. In the 5th day, the VEGF translation signal was hardly detected. Conclusion The antisense VEGF165 adenovirus gene transfection can inhibite not only the transcription but the translation of VEGF gene in synovial cells. Thus it can inhibit the secretion of VEGF in synovial cells with high efficiency.

Vascular endothelial growth factor(VEGF) is a kind of protein facilitating the angiogenesis,which can combine with its special receptor. The 2 major functions of VEGF are:(1) accelerate the proliferation of endothelial cells,leading to the formation of new vessels;(2) up regulation of the vessels permeability.The activity of the VEGF is regulated by various factors at different levels,such as: hypoxia, oncogene,the cytokine, the intercellular matrix, etc .The biological character and role of VEGF were summarized in this article with special emphasis on VEGF function and regulation.

Objective To introduce extreme lateral interbody fusion (XLIF) as a new minimally inva-sire spinal surgery with established correction and fusion methods to assess its clinic use for degenerative scoliosis. It is emphasized the value and highlight of this technique in spinal surgery. Methods Surgical treatment of 8 patients with degenerative scoliosis were performed with XLIF between March 2006 and April 2008. In this group of patients, 5 cases provided an anterior cage in every disc space, and another 3 supplemented with vertebrae screw fixation. Blood loss was 50 ml every procedure. To observe the low back pain, corrective rate, achieving a balanced and complications. Results The low back pain have been relieved in all patienta after operations, the disc height can be restored, allowing more room at the foraminal level for nerve roots, and lumber lordosis can be maintained. Corrective rate was 64%, there wasn't neurologic and vascular injury, 2 case had correction loss a little postoperation 6-30 month. Conclusion The potential benefits of XLIF include safe, effective, less approach-related blood loss, improved cosmetic result with smaller incisions, and reduced hospital stay for degenerative scoliosis.

Objective To discuss the TARP (transoral pharyngeal atlanto axioal reduction plate,TARP) stress distribution under the condition of atlantoaxial dislocation treatment with the TARP system and explore the possible suggestion for the further innovation of the TARP system.Methods A fixed Finite Element model was constructed for transoral atlantoaxial reduction plate system based on the CT digital data of the China Digital Human NO.1.The internal structure changes and the stress distribution of TARP system under different loads were imitated and analyzed.Results The results showed that,after the fixation of the TARP system,different parts of the atlantoaxial had different stress under anteflexion,extension,lateral bending and rotation,the internal fixation parts located mainly at the mid-part of the TARP(0.159 × 108 ～0.732 × 108 Pa) and the root of the screw(0.214 × 109 ～0.958 × 109 Pa).Beside that,when using anteflexion,the stress mainly focused on the articular surface of the atlantoaxial(0.512 × 107 Pa).As for extension,the stress mainly focused on the part between the lateral mass and anterior arch (0.582 × 107 Pa).While lateral bending or rotation,the stress mainly focused on the axial screw nailing path (0.287 × 109 Pa and 0.241 × 109 Pa).Conclusions Although different parts of the TARP plate have different stress,its maximum stress lied in the root of the screw.The stress of plate mainly focused on the mid - part,no matter in what state of motion,therefore,the root of the screw and the mid-part of the plate bore the biggest stress,their strength decided the fatigue property of the TARP system.

0. 001 ). Comparedwith the TAA negative group, much higher cytolytic activity was observed in the positive group (P

BACKGROUND: Lateral collateral ligaments play an important role in maintaining knee stability.Motion reduction of knee joint can be realized and the changes laws of medial and lateral collateral ligaments' length after anterior cruciate ligament(ACL)injury during weight-bearing flexion can be obtained via 2D/3D image registration technique.OBJECTIVE: To study in vivo stability of length changes of the medial and lateral collateral ligaments of ACL injury knee during weight-bearing flexion.METHODS: Eight volunteers with unilateral ACL rupture and contralateral normal knees,was captured CT images and 2orthogonal images of the knee at 0,15°,30°,60°,and 90° of weight-bearing flexion.These orthogonal images were used to recreate the in vivo knee positions at each of the targeted flexion angles by the method of 2D/3D image registration.Through the bone insertion of medial and lateral collateral ligaments,the elongation changes of medial and lateral collateral ligaments were obtained.RESULTS AND CONCLUSION: At 0°,15° and 30°,the length of medial collateral ligament of ACL injury knees was longer than normal knees,but the lateral collateral ligaments length of ACL injury knee was shorter than that of normal knees.All the differences have statistical significances(P < 0.05).The findings demonstrated that,at 0°,15° and 30°,the medial collateral ligament length of ACL injury knees was longer than normal knees,but lateral collateral ligaments length of ACL injury knees was shorter than normal knees.

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.

BACKGROUND: With the rapid development of digital orthopaedics, navigational template has been widely used in the field of orthopaedics, but the research status of the technique in China based on bibliometric analysis is never reported. OBJECTIVE: To investigate the application status of navigational template in the orthopaedic field and to explore its tendency and hot spot based on bibliometric analysis, thereby providing reference for the development of digital orthopaedics in China.METHODS: A computer-based retrieval of CBMdisc, CNKI, CSPD, CMCI databases was conducted for articles published before December 1, 2016 using the keywords of navigational template and subject heading orthopaedics and the core orthopaedic journals published in 2016 were searched by manual. The articles were screened according to inclusion and exclusion criteria, and finally were analyzed by bibilometric study.RESULTS AND CONCLUSION: (1) In China, the first paper reporting navigational template was issued in 2008. A total of 199 articles were published in the past 9 years, with more than 10 papers yearly from 2009 to 2014, while there was a rapid increase tendency during 2015 and 2016. (2) The articles were mainly published in the orthopaedic journals and some professional journals closely related to digital orthopaedics, such as biomedical engineering, basic medicine and digital medicine. About 86.9% papers belong to Chinese core journals, including Chinese Journal of Orthopaedic Trauma,Chinese Journal of Orthopaedics, and Chinese Journal of Tissue Engineering Research. (3) There is a 99.5% cooperation rate and 6.15 degree of cooperation. Zhang Yuan-zhi, Ding Huan-wen, Lu Sheng, Chen Yu-bing, Hu Yong,Huang Xuan and Zheng Peng-fei are most productive authors, and core authors contribute to 53.8%, indicating that the group of core authors is being formed. First authors are all from hospitals and universities, mostly from Kunming General Hospital of Chengdu Military Command of PLA, General Hospital of Guangzhou Military Command of PLA, the Affiliated Hospital of Inner Mongolia Medical University and South China University of Technology. The cooperation rate of more than two institutes occupies 54.8%, indicating that the study holds a promising future with the strong support of research institutes in universities. About 59.3% articles are sponsored by funding, the national and provincial foundations accounting for 64.0% in 239 projects, and 57.6% articles were supported by more than two foundations, revealing the high research levels and academic values of this technique. (4) The articles are cited by 763 times; Lu Sheng,Chen Yu-bing, and Zhang Yuan-zhi are the highly cited authors; Kunming General Hospital of Chengdu Military Command of PLA, General Hospital of Guangzhou Military Command of PLA and Nanfang Hospital of Southern Medical University are the highly cited institutes, and Chinese Journal of Orthopaedic Trauma is the highly cited journal. (5) To conclude, based on product design, manufacture and cadaver studies of the navigational template, it has been extensively applied in the spine surgery (especially cervical surgery), orthopaedic traumatology, bone and joint surgery,bone tumor and pediatric orthopaedics, and has obtained satisfactory clinical outcomes in assisting screw placement,osteotomy and precise resection and functional reconstruction. However, there is still a lack of a large-sample,multicenter, and long-term randomized trial.