BACKGROUND:Swan-like memory connector (SMC) can form a three-dimensional fixation on long bone shaft,ensure the stability of fracture ends,and produce a continuous dynamic compressive stress on the fracture ends.Insulin-like growth factorⅠ (IGF-Ⅰ) regulates bone development and metabolism,cell differentiation,as well as mitosis.During the union process of fracture,IGF-I is effective to promote cellular proliferation,stimulate bone formation and result in chondrogenesis.OBJECTIVE:To quantitatively determine the effect of SMC and conventional dynamic compression plate (DCP) on the concentration of local IGF-Ⅰ in the union duration of rabbit humerus fracture.DESIGN,TIME AND SETTING:A controlled observational animal study was performed in the laboratory,Department of Orthopaedics,Changhai Hospital,the Second Military Medical University of Chinese PLA from January to May in 2007.MATERIALS:SMC was Ni-Ti alloy panel,comprising 50%-53% Ni,was customized by Lanzhou Seemine Shape Memory Alloy Co.,Ltd.The temperature of shape recovery was (33±2) ℃.METHODS:Thirty adult New Zealand rabbits were used in this study and were processed into osteotomy.The experiment sides of rabbit humerus were cut and fixed with SMC at random,serving as SMC group,and the other sides were cut at the same position and fixed with DCP,serving as DCP group.Each five animals were put to death at the time points of 2,3,4,6,8,and 12 weeks after internal fixation.Specimens were obtained from the areas that were 0.5 cm besides the fracture line.MAIN OUTCOME MEASURES:Following internal fixation,the contents of local IGF-Ⅰ in the specimens of different time points (2,3,4,6,8,and 12 weeks) were determined in both SMC group and DCP group.RESULTS:In the SMC-treated group,the contents of IGF-I increased 2 weeks after internal fixation,reached the maximum at 6 weeks,and then decreased at 8-12 weeks.In the DCP-treated group,the contents of IGF-Ⅰincreased 2 weeks after internal fixation,reached the maximum at 8 weeks,and then decreased at 12 weeks.No significant differences were found between the SMC group and the DCP group at 2,8,12 weeks after internal fixation (P ＞ 0.05).Compared with the DCP group,the SMC group had a remarkably higher content of IGF-Ⅰ at the time points of 3,4 and 6 weeks (P ＜ 0.05).The difference was the most statistically significant at 4 weeks.CONCLUSION:Compared with conventional DCP,the SMC could better promote the secretion of IGF-Ⅰin fracture and facilitate the fracture union due to the continuous dynamic compressive stress and three-dimensional fixation.

OBJECTIVE: To compare the clinical effect between Gamma nail and proximal femoral nail (PFN) on the treatment for femoral intertrochanteric fractures in the elderly.METHODS: A total of 131 cases (39 males and 92 females; aged 70?81 years, mean age of 76 years) with femoral intertrochanteric fractures were collected from the Department of Orthopaedics, the Affiliated Changhai Hospital of the Second Military Medical University of Chinese PLA from January 2005 to January 2008. Femoral intertrochanteric fractures were classified based on AO system, including type A1 (n=56) and type A2 (n=75). All cases were randomly divided into Gamma nail group (n=65) and PFN group (n=66). Pre- and post-operative blood loss, blood transfusion volume, operating time, and length of stay were recorded, while the complications were detected following nail implantation. Functional changes of injured limbs were detected after 9 months.RESULTS: At 9 months after following up, there was no significant difference in blood loss, blood transfusion volume, operating time, and length of stay between the two groups before and after implantation (P> 0.05). Furthermore, complications did not occur during or after implantation. Six cases in the PFN group had infection in which of them had diabetes mellitus. There were no complications such as cutting out of femoral head, femoral shaft fractures, breakage of internal device or pushing out phenomenon. All cases got bone union at the final follow-up of nine months and did not get nonunion, delayed union of fractures or shortening of injured extremity.CONCLUSION: Gamma nail and PFN have equal effect on the treatment of femoral intertrochanteric fractures in the elderly.

Objective To research on the new technique and method of bone grafting for nonunion of four limbs. Methods A new method of bone grafting was developed to take advantage of Nitinol Shape Memory Connector. It included splinting mode, padding mode and seeding mode. 148 cases of bone nonunion in 134 patients were treated with the modified method. Results The patients were followed up for 5.5 months to 6 years, with an average period of 2.25 years. On the average, the nonunion healed with lamellar bone 3.5 months after the operation. The healing rate was 99.3% . Conclusion The author s modified bone grafting provides a new and efficacious method for treatment of the limb nonunion.

Objective To explore the effect of minimally invasive pedicle screw fixation for the treatment of thoracolumbar spine fracture.Methods Totally 80 patients with thoracolumbar spinal fracture accepted pedicle screw internal fixation in our hospital from January 2012 to December 2015 were selected as the observation object.According to the operation mode,they were equally divided into minimally invasive surgery group and open surgery group.The operation effect,quality of life and the incidence of complications of the two groups were compared.Results The operation time of the two groups had no significant difference.The amount of blood loss and postoperative drainage volume in minimally invasive surgery group were less than those in open surgery group(P ＜ 0.05).The anterior and posterior Cobb's angles of the two groups had no significant difference.The anterior and posterior Cobb's angles of the two groups both decreased 3 months after operation,and it decreased more significantly in the minimally invasive surgery group compared with the open surgery group with statistically significant difference(P ＜0.05).The VAS and ODI scores between the two groups had no significant difference before operation.And the scores of the two groups all decreased 3 months after operation,but the reduction in the minimally invasive surgery group was more significant (P ＜ 0.05).The incidence rate of complications of the two groups had no significant difference (P ＞ 0.05).The quality of life of the two groups had no difference before surgery,and it increased 3 months after the operation both in the two groups,and the minimally invasive surgery group increased more significantly (P ＜ 0.05).Conclusion The minimally invasive pedicle screw internal fixation for thoracolumbar spine fracture has a better therapeutic effect,which can significantly improve the patients clinical symptoms,signs,and their quality of life.

BACKGROUND:Intravertebral bone graft to rebuild anterior and middle column structure and to recover vertebral morphology has been re-understood, and a suitable bone graft material can promote bone healing and be conducive to rebuild the long-term stability of the spine. OBJECTIVE:To discuss the differences in clinical efficacy of three kinds of bone graft materials through unilateral pedicle to treat thoracolumbar burst fractures. METHODS:Total y 102 thoracolumbar burst fracture patients were randomized into three groups:autologous bone, autologous bone combined with al ogeneic bone and al ogeneic bone were implanted via the unilateral pedicle, respectively, in the three groups. We measured the percentage of height of the anterior edge of vertebral body and Cobb angle by X-Ray before and after bone grafting, and used CT to observe bone graft healing, and used Mimics to measure the defect area of vertebral body at the last fol ow-up. RESULTS AND CONCLUSION:Al the 102 patients were fol owed-up for 24-36 months. The percentage of height of the anterior edge of vertebral body and Cobb angle of three groups were restored after bone grafting (P<0.05), but there was no difference in the percentage of height of the anterior edge of vertebral body of three groups at different time point after bone grafting. The Cobb angle in the al ogeneic bone group was bigger than that in the autologous bone group and autologous bone combined with al ogeneic bone group at 9, 12 and 24 months after bone grafting (P<0.05). The fracture healing rate of the al ogeneic bone group at different time points was lower than that of the autologous bone group and autologous bone combined with al ogeneic bone group (P<0.05), and the area of bone defect was bigger than that in the autologous bone group and autologous bone combined with al ogeneic bone group (P<0.05). These findings indicate that these three bone graft materials can rebuild the vertebral body via the unilateral pedicle to treat thoracolumbar burst fracture, reduce the loss of vertebral height and Cobb angle, and decrease defect area of the vertebral body. The clinical efficacy of autologous bone combined with al ogeneic bone to heal bone graft and reduce bone defect is similar to autologous bone, both of which are better than al ogeneic bone alone.

Objective To evaluate the potential use of a probe melting analysis (PMA) assay in detecting the embB mutations which confer resistance against ethambutol in Mycobacterium tuberculosis. Methods The analysis sensitivity and specificity of PMA were investigated by detecting a serially diluted H37 Rv DNA and a reference panel from National Institute for the Control of Pharmaceutical and Biological Product. Six hundred and thirteen sputum samples were collected from the Xiamen Center for Disease Control and Prevention, Xiamen First Hospital and Center for Zhangzhou Disease Control and Prevention from September 2009 to April 2010. The PMA assay was then evaluated by detecting 613 clinical isolates and the results were compared with the sequencing results. Results The PMA assay could specifically detect Mycobacterium tuberculosis and had a limit of detection of 3 copies per reaction. The assay results with 613 clinical isolates showed that PMA gave a 100% concordance with sequencing in the 583 qualified samples, among which 34 were mutations at embB 306,23 at embB 378-380, 3 at embB 406 and 3 at embB 497. Conclusions PMA assay is a sensitive and specific method enabling efficient detection of common embB mutations causing ethambutol-resistance. The rapidness of this method together with its reliability would facilitate its use in routine testing.

BACKGROUND:Spinal canal decompression is needed in posterior pedicle screw fixation surgery for thoracolumbar burst fractures combine with spinal cord injury. The structure of posterior spine is often damaged. The posterolateral bone fusion in al fixed segment is stil the main surgery. In order to further reduce fusion segment and maintain motor unit, it is necessary to perform selective segmental bone graft fusion during fixation and decompression.
OBJECTIVE: To discuss the advantages of selective posterolateral vertebral fusion for thoracolumbar fracture with spinal injury through comparing with posterolateral vertebral fusion.
METHODS: Data of 83 thoracolumbar burst fracture cases, who received posterior lumbar decompression and short segment fixation with pedicle screws and bone graft through injured vertebra from January 2006 to July 2013, were analyzed retrospectively. According to fusion segments, above patients were divided into selective posterolateral vertebral fusion group (n=42) and the whole posterolateral vertebral fusion group (n=41). Perioperative index, internal fixation, vertebral height loss rate, Cobb angle, spinal nerve recovery and Oswestry Disability Index were compared between the two groups.
RESULTS AND CONCLUSION:(1) Al cases were folowed up for 25-32 months. (2) There was no statistical significance in operation time, intraoperative blood loss and ambulation time between the two groups (P > 0.05). Postoperative drainage volume was less in the selective posterolateral vertebral fusion group than in the whole posterolateral vertebral fusion group (P < 0.05). Before removal of fixator, there was no loosened fixator or breakage of screw or stick. (3) There were improvements in the rate of vertebral front height loss and Cobb angle in both groups at various time points after operation (P < 0.05). There was no statistical significance in the rate of vertebral front height loss and Cobb angle in both groups (P > 0.05). (4) There was no significant difference in fusion rate at 6 months after treatment between the two groups (P > 0.05). Fusion was achieved in both groups before removal of the fixator. (5) Spinal nerve recovery was found after treatment in both groups. No significant difference in Oswestry Disability Index was detected in final folow-up (P > 0.05). (6) Results verified that compared with the whole posterolateral vertebral fusion, selective posterolateral vertebral fusion can obtain a good vertebral height and prevent Cobb angle loss again, reduce the internal fixation loosening and breakage. After removal of the fixator, selective posterolateral vertebral fusion can reduce spinal motion unit lost, and decrease the adjacent vertebral degeneration.

Objective To investigate the genotype and epidemiology of plasmid‐mediated AmpC β‐lactamases produced by the clinical strains of Escherichia coli and Klebsiella pneumoniae .Methods A total of 176 clinical nonrepetitive cefoxitin non‐sensitivity isolates of Escherichia coli and Klebsiella pneumoniae was collected from July 2011 to August 2012 .Polymerase chain reaction (PCR) for AmpC enzyme gene amplification and DNA sequencing were carried out for genotype of AmpC beta‐lactamases .Results The results of PCR showed that the positive rate of ampC of the 176 strains of Escherichia coli and Klebsiella pneumoniae AmpC was 18 .2% ,mainly DHA type ,counting for 59 .4% ,CIT counting for 37 .5% ,EBC counting for 3 .1% .The positive rate of ampC of Escherichia coli was 11 .4% ,mainly CIT type ,counting for 77 .8% ,the positive rates of DHA type and EBC type both were 11 .1% .The positive rate of ampC of Klebsiella pneumoniae were 23 .7% ,mainly DHA type ,counting for 78 .3% ,CIT type count‐ing for 21 .7% .The results of DNA sequencing showed that there were 18 strains DHA‐1 type and 1 strain ampC gene type of Morganella morganii in DHA type strains ,the concordance rate was 97 .0% ,10 CIT type strains was CMY‐2 type ,1 strain was CMY‐42 ,one strain was CMY‐4 type ,EBC type was ampC gene type of Enterobacter cloacae ,the concordance rate was 99 .0% .A total of 32 strains of gene sequencing were registered as KJ127248 - KJ127279 in GenBank .Conclusion The main genotypes of plasmid‐mediated ampC enzyme produced by Escherichia coli and Klebsiella pneumoniae were CMY‐2 and DHA‐1 respectively .

Objective To design a new method of posterior wall reconstruction for severely corn-minuted and obsolete fracture of the posterior wall of the aeetabulum. Methods (1) Biomechanical study (from two perspectives: the stability and the stress distribution on the femoral head and the acetabu-lure) : six fresh adult' s pelvis and femur specimens were collected and divided into experimental group ( consisted of the left sides) and control group ( consisted of the right sides). After the defects of the pos-terior wall were made, the defects were anatomically reconstructed with the harvested ilium by acetabular tridimentional memory fixation system (ATMFS) in the experimental group, whereas the acetabular frag-ments were repositioned to the defect sites and fixated by the plates and screws in the control group. Lon-gitudinal and latitudinal displacement, stability of the anatomically reconstructed posterior wall of the ace-tabulum, the fitness of femoral head to the acetabulum after anatomical reconstruction and mean and maxi-mum pressure of anterior wall, posterior and cupuh of the acetabuhm were analysed and compared. (2) Cinical study: The posterior wall defect on the harvested ilium piece was repaired with 3-directional loc-king of ATMFS in 10 male patients (at age of 16-50 years, mean 36.4 years) from January 2000 to June 2002. There were seven patients with flesh acetabular fractures and three with old acetabular fractures.The period from fracture to reconstruction for the patients with old fractures was 58-251 days ( 137.7 days an average). The patients were foUowed up for 5.8 years (average 5.2-7.1 years). Results (1) Biomechanical study showed no statistical difference upon stability and fitness of femoral head to acetabu-lum after reconstruction in experimental and control groups. (2) Clinical study: postoperative X-ray film showed no repeated displacement of the fracture and the patients began out-of-bed movement with weight bearing after 1.6 months (1.2-2.1 months). Heterotopic ossification was found in two patients, with no influence on the joint function. According to the elinieal ranking standard of Modified d' Aubigne and Postal, the excellence rate was 93%. Conclusions Anatomical reconstruction of posterior wall of the acetabulum by using serf ilium with ATMS has good stability and stress distribution of the femoral head and the reconstructed acetabulum in clinical application and offers a new method for treatment of severely comminuted and obsolete fracture of posterior wall of acetabulum.

Objective To discuss the therapy for acetabular comminuted fractur e combined with compressive defects. Methods From July 1997 to February 2005, 43 cases of comminuted acetabular fracture combined with compressive defect were t reated. 25 cases were obsolete, 16 fresh, and 2 malformed (90 days after injury) . 34 cases were complicated fractures with defects, and 9 simple fractures with defects. The defect volumes ranged from 3 to 9 cm3, averaging 4.5 cm3. They were treated with ATMFS (acetabular tridimensional memory fixation system) to fixate the comminuted bone fragments tridimensionally. The modified acetabular approac h, reduction of acetabular comminuted articular face, anatomical reconstruction of posterior wall of acetabulum with autogenous ilium, autogenous and artificial bone implantation and bone wax isolation were used. The follow-ups lasted from 5 to 86 months, averaging 15.7 months. Results 31 cases achieved anatomical red uction by filling up the compressive defects. 12 cases were treated by anatomica l reconstruction of posterior wall. On average, 5.3 months after operation, the injured hip joint was as good as the healthy one in 40 cases. Ischemia necrosis of femoral head occurred in 1 case, and 2 cases experienced heterotopic ossifica tion with ischemia necrosis of femoral head which led to osseous fusion of hip j oint. Conclusion The new methods for treatment of acetabular fractures with comp ressive defects elevate the reduction rate of acetabulum and femoral head, and a re effective for the functional recovery of hip joint.