Objective To evaluate the efficacy of combined anterior and posterior approaches in treatment of severely unstable lower lumbar burst fractures.Methods A retrospective case series study was made on clinical data of 14 patients with lower lumbar burst fractures collected from August 2009 to August 2014.There were 12 males and 2 females,with a mean age of 39 years.Seven fractures occurred at L3,five at L4,and two at L5.Nine patients were associated with injury to the posterior ligament complex (PLC).According to the American Spinal Injury Association (ASIA) classification,the spinal injuries were rated as grade B in two patients,grade C in four,grade D in five and grade E in three.All patients underwent posterior pedicle screw fixation combined with anterior spinal canal decompression and titanium mesh or iliac bone grafting.Lumbar lordosis angle,vertebral height,spinal canal decompression,ASIA grade and complications were evaluated after operation.Results Two patients experienced cerebrospinal fluid leakage postoperatively,which were healed after 2 weeks' local pressure treatment.Three patients experienced recurrent lumbar pain postoperatively,which were relieved after the removal of internal fixation 18 months after operation.All patients were followed up for 12-36 months (mean,18 months).Compared to the detection before operation,final follow-up showed improved lumbar lordosis [(30.2 ± 7.3) ° vs.(41.3 ± 6.5) °],decreased loss of the anterior vertebral height [(62.3 ± 21.5) ％ vs.(11.8 ± 7.8) ％] and reduced canal compromise [(65.7 ± 30.5) ％ vs.(21.9 ± 12.7)％] (all P ＜ 0.05).ASIA grade was significantly improved at the final follow-up,including grade C in one patient,grade D in three and grade E in ten (P ＜ 0.05).Follow-up showed no apparent graft loosening,pseudarthrosis,implant breakage and severe kyphosis.Conclusion Combined anterior and posterior approaches to treat severely unstable lower lumbar burst fractures can effectively reconstruct the height and stability of the vertebral body,restore the spinal canal volume,and attain satisfactory clinical outcome.

BACKGROUND:Hair fol icle stem cel s derived from skin and hair have the most readily available sources, and cannot lead to serious complications and immunogenicity after col ection, which can be used for autologous transplantation. OBJECTIVE:To provide effective experiment basis for hair fol icle stem cel s in the repair of skin wound through reviewing the role of hair fol icle stem cel s in promote the repair of skin wound. METHODS:Articles related to hair fol icle stem cel s for the repair of skin wound were retrieved in CNKI and PubMed databases (1999-01/2014-12). The key words were“hair fol icle stem cel , skin repairing, regenerative medicine, tissue engineering”in Chinese and English, respectively. A total of 45 articles based on inclusion criteria and exclusion criteria were obtained for the review. RESULTS AND CONCLUSION:Hair fol icle stem cel s belong to adult stem cel s, which are easy to access, have a significant number, and possess differentiation potential and safety. Hair fol icle stem cel s can promote the repair of skin wound and provides good seed cel s for regenerative medicine and tissue engineering research through early vascularization of the skin, epidermal and appendage regeneration, signaling pathways, and transcription factors.

Objective To investigate the effect of three-dimensional gelatin-chondroitin sulfatehyaluronic acid (Gel-C6S-HA) composite scaffold seeded with genetically modified hair follicle stem cells (HFSCs) on tissue engineering skin angiogenesis.Methods Three-dimensional scaffolds composed of Gel-C6S-HA were fabricated by freeze-lyophilizing.VEGF165 modified HFSCs were seeded on those scaffolds and cellular morphology and adhesion were observed using scanning electron microscope.Eighteen rats were subjected to the full-thickness skin defects with dimensions of 1.2 cm × 1.2 cm on the bilateral sides of the back and covered with VEGF165 transduced HFSCs/Gel-C6S-HA scaffold (Group A),empty-vector transduced HFSCs/Gel-C6S-HA scaffold (Group B),Gel-C6S-HA scaffold (Group C),and vaseline gauze (Group D) respectively according to the random number table.At days 7,14,and 21 after surgery,wound healing was observed,HE staining and immunohistochemistry of CD31 and alpha smooth muscle actin (α-SMA) were performed,and microvessel density (MVD) was used to measure new blood vessel growth.Results Electron microscopy exhibited three-dimensional spongy structure of the scaffold with round or polygon apertures connecting mutually and the scaffold pore size of (133.2 ± 43.4) μm.Cells seeded on the scaffolds spread thoroughly out and anchored firmly after being cultured for 7 days.There were no obvious inflammation reactions on the wounds for all groups at day 7 after operation.Wound healing and scaffold degradation were faster in Group A than in other groups at days 14 and 21 after operation.Histological and immunological detections showed microvasculariztion of the scaffold in Groups A and B with fluffy three-dimensional structure and evenly distributed cells,but scaffolds remained sharp at the edge and there were small cells aggregating at subcutaneous tissue junction area in Group C.At 14 and 21 days after operation,new blood vessels were large and rich in Group A; scaffolds in Groups A and group B were filled with cells,partial of which gathered in the epidermal layer and the scaffold materials were assimilated differentially,whereas a few subcutaneous tissue cells migrated to scaffolds in Group C.MVD was significantly higher in Group A than in Groups B and C at each time point (P ＜ 0.05).Conclusion VEGF165 modified HFSCs compounded with Gel-C6S-HA composite scaffold can facilitate the growth of blood vessels and promote the angiogenesis in wound healing and hence is a promising skin substitute in clinical applications.

Objective To observe the research of the biologically performance,interface micro-structure and nano-indentation situation when polymethyl methacrylate bone cement-PMMA injected into rabbit in the near future and far future individually.Methods New Zealand white rabbits were used ovariectomy plus dcxamethasone intramuscular injection to establish osteoporosis animal model.All animal models were divided into 3 groups with 35 in each osteoporosis group,testing group,and normal group.Execute the lumbar centrum of New Zealand rabbit as osteoporosis bone defect model,injected bone cement,with the help of material dynamo experiment machine to do the axial compression tests,three point bending test,and torsion test in order to observe the biological dynamic changes.Optical microscope,fluorescence microscope and scanning electron microscope were used to observe the changes of micro bone cement and the changes of bone looseness.Nano-indentation testing was applied by the triboindenter to study the critical load.Results PMMA can rapidly establish the strong support with stable function in the near future.Biomechanical experiments showed that biomechanical properties of bone cement group was significantly higher than those in the other two groups.Biomechanical properties of bone cement group may decline with the time,but which were still better than those of OP in the control group.Histo-morphological observation result shows that under osteoporosis state the bone grows slower,bone's rebuilding time also extended.And in the later period,main bone's continuous osteoporosis had some impact on the interface.Nano-indentation testing showed that the young modulus and stiffness of the interface among bone,material and interface were significantly differences.Bone cement had showen the best nano indentation hardness,then was interface and bone tissue.Conclusion The polymethyl methacrylate bone cement llⅢ has a good effect in filling,on account of it has great plasticity and liquidity and can penetrate into the minuteness aperture between trabecula,then after solidifying,it will combine firmly with the host bone.PMMA can rapidly establish the strong support with stable function after operation.The performance is decreasing in the far future but still with satisfaction.

This article sorts out and analyzes recent years’ literature about experimental studies on Huatuo jiaji (Ex-B2) point acupuncture treatment for spinal cord injury (SCI), discusses the mechanism of Huatuo jiaji point acupuncture treatment for spinal cord injury from three aspects:improving microenvironment for nerve repair, inhibiting apoptosis and promoting nerve repair and tries to explore the possible direction of its future development.

Objective To investigate the effect of minitype titanium plate fixation through transoral approach in the treatment of unstable atlas fractures.Methods A retrospective case series study was made on 21 patients with unstable atlas fractures treated by minitype titanium plate fixation through transoral approach from June 2008 to June 2014.There were 15 males and 6 females,at age of (40.9 ± 10.6)years (range,21 to 57 years).Anterior 1/2 Jefferson fractures were seen in 12 patients and 1/2 ring Jefferson fractures in 9 patients.Preoperative visual analogue score (VAS) was 4-9 points [(7.6 ± 1.3) points].Before operation,degree of mobility of the cervical vertebra was (15.4 ± 3.9) °in bending,(10.8 ± 2.5) °in extending,(18.3 ± 3.1) ° in left-bending,(18.9 ± 2.7) ° in right-bending,(21.8 ± 5.8) °in left-rotation and (22.4 ± 4.6) ° in right-rotation.Operation time,intraoperative blood loss,VAS,cervical mobility and bone healing were detected after operation.Results Operation time was (86.3 ±25.3)m in,and intraoperative blood loss was (120.5 ± 33.3)ml.VAS was improved to 0-2 points [(1.6 ± 0.4) points] at postoperative 3 days (P ＜ 0.05).All patients were followed up for 12 to 48 months[(23.7 ±5.9) months].VAS was improved to 0-2 points[(0.6 ± 0.1) points] at postoperative 3 months (P ＜ 0.05).Degree of mobility of the cervical vertebra was improved significantly at postoperative 3 months,with the bending of(38.6 ± 4.5) °,extending of (39.3 ± 4.0) °,left-bending of (39.2 ± 4.0) °,right-bending of (39.2 ± 2.9) °,left-rotation of (66.8 ± 8.8) ° and right-rotation of (66.3 ± 9.2) ° (P ＜ 0.05).Postoperatively,there were no surgical wound incision infections and vertebral artery or spinal injuries,Bone union was found in all patients,without the occurrence of implant loosening or breakage and the dysfunction of the cervical vertebra.Conclusion Minitype titanium plate fixation through transoral approach is associated with less trauma,high healing rate and preservation of the activity of cervical vertebra in the treatment of unstable atlas fractures.

Objective To compare the outcomes of percutaneous pedicle instrumentation combined with vertebral augmentation or vertebra pedicle instrumentation for treatment of osteoporotic thoracolumbar fractures (OVCF) in elderly patients.Methods A retrospective case cohort study was conducted on 62 patients with OVCF manifesting non-neurological symptoms treated from January 2009 to January 2012.There were 22 males and 30 females,with a mean age of 61.3 years (range,55 to 70 years).Fracture level was T11 in 8 patients,T12in 20,L1 in 22 and L2 in 12.Treatments included percutaneous pedicle instrumentation combined with vertebral fracture fixation in 36 patients (Group A) and percutaneous pedicle instrumentation combined with vertebral augmentation in 26 patients (Group B).Operation time,intraoperative blood loss,anterior vertebral body height,sagittal Cobb angle and visual analogue score (VAS) were compared between the two groups.Results All patients were followed up for average 46.5 months (range,36 to 58 months).Operation time in Group A [(82.6 ±16.2) min] was shorter than that in Group B [(96.8 ± 20.6) min] (P ＜ 0.05).Blood loss in Group B [(40.5 ± 10.2) ml] was less than that in Group A [(52.2 ± 15.5) ml] (P ＜ 0.05).Before operation and 3 days and 1 year after operation,the anterior vertebral body height and sagittal Cobb angle in Group A showed no significant differences compared to Group B (all P ＞ 0.05).At the final follow-up,the ratio of anterior vertebral height and Cobb angle in Group B [(87.8 ± 2.5) ％,(7.8 ± 3.5) °] were better than these in Group A [(82.6 ±3.2)％,(9.1 ± 1.8)°] (P＜0.05).VAS showed no statistical significance between the two groups before and after operation (P ＞ 0.05).Bone cement leakage was seen in four patients in Group B.During the perioperative period,there were 3 patients with lung infection in Group A and 1 patient with lower limb deep vein thrombosis in Group B.No implant failure occurred in both groups.Conclusion Both procedures are effective in treating elderly patients with OVCF,but percutaneous pedicle instrumentation combined with vertebral augmentation is associated with better results in maintaining vertebral height and preventing kyphosis.

AIM: To evaluate the immunogenicity of a novel orthopedics materials (graded zirconia-hydroxyapatite composite) in vitro by using peripheral blood mononuclear cells (PBMCs) from healthy young people, and simple zirconia-hydroxyapatite composited material was used as control materials. METHODS: Proliferation of PBMCs cultured in different liquid after 5 days was measured by MTT methods. ELISA was used to detect TNF-? and IL-6 concentration in the supernatant of PBMCs cultured in the extracts after 24 hours. Flow cytometery was used to measure CD69 and CD25 in activated PBMCs cultured in the extracts of the two kinds of materials after 24 hours. RESULTS: The proliferation rate of the simple composite group was significantly lower than that in negative group (P

A total of 33 non-neurological symptoms patients with thoracolumbar fractures underwent unilateral pedicle screw fixation plus short segment pedicle screw through para-vertebral muscles. Preoperative computed tomography ( CT) scan showed one side pedicle was complete.The average follow-up period was 22 (12-40) months.There was no internal fixation failure.The posterior paraspinal approach for unstable thoracolumbar fractures , retaining posterior ligament complex and fixation by unilateral pedicle screw fixation through the pedicle of fractured vertebra , is both safe and effective for thoracolumbar fractures.

BACKGROUND:Porous gradient hydroxyapatite/zirconia composite, which can adhere to a variety of cel s, such as osteoblasts, bone marrow mesenchymal stem cel s and chondrocytes, can induce and promote fracture healing or replace bone defects. OBJECTIVE:To review the development and application of porous gradient hydroxyapatite/zirconia composite in bone tissue engineering. METHODS:Articles related to porous gradient hydroxyapatite/zirconia composite in bone tissue engineering were retrieved in CNKI and PubMed databases (1971-01/2014-12). The key words were“porous bioceramic, bone tissue engineering, bone morphogenetic protein-2, induced pluripotent stem cel s”in Chinese and English, respectively. A total of 54 articles based on inclusion criteria and exclusion criteria were obtained for the review. RESULTS AND CONCLUSION:Porous gradient hydroxyapatite/zirconia composite can provide a scaffold to induce natural y forming bone growing to fil the three-dimensional pores, thus realizing the perfect integration of tissue-engineered bone material and host-bone tissue. As zirconia functions as an enhancer of hydroxyapatite, high-quality artificial bone materials, which have elastic modulus, fracture toughness and structure similar to human bone, can be prepared by adjusting the proportion and porosity of materials. Additional y, the new hydroxyapatite/zirconia foamed ceramics as tissue-engineered bone carrying bone morphogenetic protein-2/chitosan gel sustained release system and bone marrow mesenchymal stem cel s derived from induced pluripotent stem cel s wil be expected to increase bone formation and bone fusion rates significantly in the future.