External fixators have been widely u sed in treatment of war trauma due to t heir small size,light weight,easy application,and convenience in transport.There are several types of military external fixato r,such as FESSA(Fixateur Externe du Service de Sant?des Arm?es),CMC(Croatian Medical Corps),Synthes and Hoffman-Ⅱ.All of these have been used on the battlefields of Rwandese War,Croatia Wa r and the first Persian Gulf War.Most of military external fixators are unilateral connectable-joint.For temp orary fixation,one bar is enough;by adding another parallel bar,the fixation can be use d for long-time fixing.Facing with a great demand of war trauma treatment ,we should develop new types of military external fixator with more simplicity and less size or weight. [

Atlantoaxial dislocation with high spinal cord compression is a common disease, which endangers people's health and is difficult to treat. Transoropharyngeal surgery is a very important method for the treatment of this disease. The author briefly reviews various operations of decompression and internal fixation through anterior transoropharyngeal approach and some correlative treatments conducted over the past few years. Although transoropharyngeal surgery has not been widely adopted at present, with increasing understanding of physiology and anatomy of the cranio-cervical junction, and development of microsurgical technic, and improvement in pre-vention and treatment of amplications, it has rapidly become a more acceptable approach for the treatment of atlantoaxial dislocation with cord compression. And with the application of new techniques, its treatment result will be conspicuously improved.

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.

BACKGROUND:Many studies have shown that different nanostructures produce different influences on cellbioactivity, but the nanonetwork structure is not reported yet. OBJECTIVE:To study the influence of the nanonetwork topography on the bioactivity of bone marrow mesenchymal stem cels. METHODS:The nanonetwork topography was fabricated on biomedical titanium surface by alkali-heat treatment, and pure titanium served as control group. Bone marrow mesenchymal stem cels were co-cultured with the above two types of samples. cellmorphology and cytoskeleton were observed using scanning electron microscope and immunofluorescence method. The celladhesion, proliferation and osteogenic differentiation were detected by measurement of absorbance values at different culture time. RESULTS AND CONCLUSION: The nanonetwork topography had significant advantage on the number of adherent cels at 30, 60 and 120 minutes of co-culture. The cellproliferation was significantly accelerated by the nanonetwork topography at days 1, 3, 5 of co-culture, and the absorbance values in the nanonetwork group were significantly higher than those in the pure titanium group (P < 0.05). The alkaline phosphatase activity in the nanonetwork group was also significantly higher than that in the pure titanium group at 14 days of osteogenic induction (P < 0.05). The cellshape and cytoskeleton on the nanonetwork surface were better than those on the titanium surface. These findings indicate that the nanonetwork topography has better effects on cellbioactivity compared with pure titanium.

BACKGROUND:Autologous cartilage has a poor self-repair effect due to low chondrocyte density, low metabolism rate and no blood supply.
OBJECTIVE:To summarize the recent study about tissue engineering techniques and surgical treatment for cartilage injury.
METHODS:A computer-based online retrieval of PubMed database was performed by the first author for articles published between January 1992 and December 2013. The key words are“articular cartilage, injury, tissue engineering, repair”in English. According to the inclusion and exclusion criteria, 61 literatures were included into the final analysis.
RESULTS and CONCLUSION:The current clinical treatment of articular cartilage injury includes joint debridement, mosaicplasty, perichondrium transplantation and autologous chondrocyte implantation. However, their long-term result is unsatisfactory. One reason for limited clinical success is that new cartilage can be formed at the site of a defect, and the repaired tissue canot compare with the autologous cartilage in mechanical property. Tissue engineering technique is stil a hot topic in recent years, because it can potential y induce autologous cartilage formation. Through endogenous or ectogeneous seed cells and inducting factor and nutrient factors, tissue engineering technique can be applied to induce the self-repair of articular cartilage, thus regenerating into hyalinc cartilage with the similar even same biological property. How to simplify the treatment protocols and reduce treatment cost is the key to promote cartilage repair.

[Objective]To investigate the method of anterior transsternal approach for the patients with upper thoracic spine diseases and the clinic results.[Method]Six cases upper thoracic spinal diseases,1 case of C7/T1 grade V dislocation,1 case of T1、2 TB,2 cases of upper thoracic tumor,1 case of T2 fracture and 1 case of T2、3 disc prolapse,were treated with the anterior transsternal approach operation since Oct.2001.The lesions areas were exposed via partial or complete sternotomy.The relative articles were reviewed.[Result]The average follow-up was 12.4 months(range from 6 to 22 months,except the died one).The case of C7/T1 grade V dislocation died of respiratory tract obstruction and one case of malignant schwannoma recurred 6 months post-operation.Good results were obtained in the other 4 cases.No operative complication happened in all cases.[Conclusion]While the transthoracic lateral approach cannot expose the upper thoracic spine clearly,the anterior cervical approach cannot expose the T2、3 clearly also.The anterior transsternal approach can provide a safe access to the lesions located on the upper thoracic spine above T4.

[Objective]To discuss the surgical extension and clinical effects of CAD custom-made hemipelvic for treating malignant pelvic tumors.[Method]The pelvis model was generated with its CT data by rapid prototyping.Simulated bone resection and prosthesis design were performed on the models.Surgical extension and made hemi-pelvic were designed.Nine patients received resection of pelvic tumor and reconstruction by individualized hemi-pelvic from June 2003 to June 2007.The series comprised three males and six females,four were diagnosed having giant cell tumor,two having chordoma,two having chondrosarcoma and one having osteosarcoma.According to Enneking's division,region Ⅱ(n=3),the region Ⅱ and Ⅲ(n=5),involved region Ⅰ,Ⅱand Ⅲ(n=1).[Result]The resection of tumor the implantation of prosthesis was easily accessible.The amount of bleeding was 5700 ml on an average.One patient suffered from infection and recovered after debridement.All patients began non-weight bearing walk with double crutches 4～6 weeks after operation and gradually abandoned crutches in 4 months.Three patients had local relapse,one osteosarcoma patient died of lung metastasis at 18 months after operation,one chondrosarcoma patient relapsed locally at 13 months after operation and died at 17 months after operation.One chordoma patient relapsed locally at 6 months operation and received the second operation.It was relapsed again at 6 months after the second operation and died at 3 months.Bolt was loosened in one patient,but the patient can walk with one crutch.No loosening was found in the 5 patients.The position of bilateral hips was symmetric.[Conclusion]The surgical extension of tumor designed by computer aided technical makes thorough resection possible.The custom-made hemi-pelvic is highly similar to the pelvis of patient in appearance,which makes the operation easy and produces good clinic results.The custom-made hemi-pelvic offers a good promise for the reconstruction of pelvic malignant tumors.

Objective To evaluate the clinical effect and application value of internal fixation of Magerl combined with Brooks technique for atlantoaxial instability. Methods A total of 18 patients with atlantoaxial instability, reducible atlantoaxial dislocation with reduction after traction and irreducible atlantoaxial dislocation with traction reduction after anterior laxation were treated with internal fixation of Magerl combined with Brooks technique using autologous bone grafts. Results The patients were followed up for an average 18 months (6-36 months). Screw was probably cut into the vertebral artery in one case. The guide needle was cut into the pharynx due to incorrectly penetrating the C 1 anterior arch of atlas for 3.5 cm in one case but no early complications such as spinal cord injury and local infection occurred. The spinal cord function improvement was marked in 3 cases, good in 9, mild in 4 but unchanged in 2. No case got worse. There were no loosening or break of the screw and cable. Conclusions Combined fixation of Magerl and Brooks techniques reaches three-point fixation and improves the reduction effect. It is necessary to use the combined fixation with best biomechanical stability for atlantoaxial dislocation patient with reduction or near reduction if the structure of the posterior arch of C 1,2 is intact.

Objective To study the relevant position of atlas pedicle to axis lateral mass, set up a technique of C1 pedicle screw placement with the lateral mass of axis as an anatomic landmark, and evaluate the reliability of the present screw placement technique by clinical practice. Methods 50 paired atlas and axis specimens were used to measure the distance from the sagittal midline to the medial border, the midpoint (the middle point of the mediolateral border) and the lateral border of C1 pedicle and C2 lateral mass. Furthermore, the distance between the medial border of C1 pedicle and that of C2 lateral mass, the distance between the midpoint of C1 pedicle and that of C2 lateral mass and the distance between the lateral border of C1 pedicle and that of C2 lateral were calculated respectively. The technique of C1 pedicle screw fixation was established. Using the present landmark technique, C1 pedicle screws were placed in 6 patients of atlantoaxial instability, including 5 males and 1 female averaged 41 years old, with os odontoideum in 1, odontoid hypoplasia in 3, and old odontoid fractures in 2. Results The medial border, the midpoint and lateral border of C1 pedicle was averaged (1.37?0.51) mm, (1.60?0.61) mm and (2.15?0.60) mm medial to C2 lateral mass, respectively. The entry point of C1 pedicle screw in present technique was defined as the method of making a vertical line through the midpoint of C2 lateral mass, and the entry point was 3 mm under the cross point of the superior rim of C1 posterior arch with the vertical line. 12 C1 pedicle screws were placed exactly in all 6 patients, and no neural or vascular injury was observed. The postoperative radiographs and CT scans verified all of C1 screws with a good position. Conclusion There is a steady anatomic relation between C1 pedicle and C2 lateral mass, the C2 lateral mass could be as a convenient anatomic landmark to determine the location of C1 pedicle and the position of C1 pedicle screw entry point.

BACKGROUND:Scholars have made certain progress in the basic and clinical studies regarding antibacterial bone graft materials. OBJECTIVE: To investigate the mechanical property of antimicrobial silver-loaded coral hydroxyapatite bone usingin vitro mechanical experiments and to explore its ability to repair large segmental contaminative bone defects. METHODS:Compression test and three-point bending test were used to evaluate the mechanical properties of silver-load coraline hydroxyapatite, coraline hydroxyapatite and coral. Thirty-six New Zealand white rabbits were selected and randomly divided into four groups to establish right-side large segment of contaminative radial bone defect models. Rabbits in three groups were implanted silver-load coraline hydroxyapatite, coraline hydroxyapatite andin situ autologous bone, and rabbits in the other group were not implanted any material (as control). At 2, 6 and 10 weeks post-operation, the rabbits were sacrificed to take specimens. The repair of bone defects in each group was observed and compared by gross observation, radiographic examination and histological examination. The antimicrobial condition in each group was evaluated by bacteriological examination. RESULTS AND CONCLUSION:There was no significant difference between the mechanical properties of silver-load coraline hydroxyapatite, coraline hydroxyapatite and coral. At the 10th week post-operation, X-ray and histological observation showed mature bone tissues in the silver-load coraline hydroxyapatite bone group. A large number of lacunae and mature bone cels were visible in bone tissues. Haversian system was visible. Most of the materials were degraded, and there was only a smal amount of residual material. Partial recanalization was visible in bone marrow cavity. The repair effect of silver-load coraline hydroxyapatite bone group was similar with the autologous bone group, and better than the coraline hydroxyapatite group and the control group. Bacteriological examination showed that the silver-load coraline hydroxyapatite had good antibacterial ability. These results demonstrate that the silver-load coraline hydroxyapatite has good mechanical properties and antibacterial properties, which can be used to repair large segmental contaminative bone defects.