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Objective To evaluate our noval rod-screw construct in anterior single-segmental decompression and fixation for the treatment of Denis type B burst fractures.Methods From February 2007 through May 2010,we treated 28 patients with Denis type B burst fracture.They were aged from 18 to 52 years (average,37.4 years).The fractures were located at T1 1 in 3 cases,at T12 in 10,L1 in 12,and L2 in 3.Of them,7 were complicated with unilateral pedicle fracture and 3 with bilateral pedicle fractures.According to the American Spinal Injury Association (ASIA) scale,the neurological deficits were rated as grade B in 11 cases,as grade C in 9,and grade B in 8.All the patients received anterior single-segmental decompression,titanium mesh and autogenous bone graft,and fixation with our noval rod-screw construct.The therapeutic efficacy was evaluated in terms of visual analogue scale (VAS),cobb angle,and spinal canal encroachment.Results The mean follow-up time was 26 months (range,from 17 to 33 months).The average length of surgery was 144 minutes(range,from 90 to 176 min);the mean blood loss was 580 mL (range,from 300 to 1 100 mL).The mean VAS score,cobb angle and spinal canal encroachment were improved from 8.2 ± 1.5,17.4° ± 4.3° and 53％ ± 16％ preoperatively to 2.7 ± 2.4,9.4° ± 5.8° and 4％ ±2％ at the final follow-up,respectively(P ＜ 0.05).None of the patients exhibited neurological deterioration.Conclusion Our noval rod-screw construct is a safe and effective device that can be used in the anterior single-segmental decompression and fixation for the treatment of Denis type B burst fractures.
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AIM:To observe the expression of nuclear factor-kappa B ( NF-κB) , N-methyl-D-aspartic acid re-ceptor 2B (NR2B) and inducible nitric oxide synthase (iNOS) in the spinal cord in a rat model of chronic constriction in-jury (CCI) of the sciatic nerve.METHODS:Fifty-six adult male Sprague-Dawley rats weighing 180~220 g were random-ly divided into sham group (n=8) and CCI group (n=48).The mechanical withdrawal threshold (MWT) and paw with-drawal latency (PWL) of the hind paws were measured 1 d before CCI and 1 d, 4 d, 7 d, 14 d and 21 d after surgery.The L4~L6 segment of the spinal cord was taken for determining the expression of NF-κB, NR2B and iNOS by RT-PCR and Western blotting.RESULTS:At 1 d, 4 d, 7 d, 14 d and 21 d after surgery, the MWT and PWL in CCI group were obviously lower than those in sham group .The expression of NF-κB, NR2B and iNOS at mRNA and protein levels in-creased significantly.Positive correlations were found between the mRNA expression of NF-κB and iNOS (r=0.842, P<0.05), and between the mRNA expression of NR2B and iNOS (r=0.833, P<0.05).CONCLUSION:The generation and maintenance of hyperalgesia in sciatic nerve injury rats may attribute to the activation of NF -κB and NR2B and concom-itant increase in iNOS .
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Objective To evaluate the safety and efficacy of the newly combined anterior platerod system in treatment of acute thoracolumbar burst fracture combined with neurologic deficit.Methods A retrospective study was carried out on 84 consecutive patients with acute thoracolumbar burst fracture combined with neurologic deficits treated by anterior surgery,bone fusion,and internal fixation with the new plate-rod system.There were 61 males and 23 females with a mean age of 31.4 years (range,19-53 years).Primary pathogenesis was high falls in 67 patients,traffic accidents in 13 patients and others in 4 patients.Fractured segments included T11 in 19 patients,T12 in 22,L1 in 25,and L2 in 18.Visual analogue scale (VAS),spinal canal encroachment,and loss of kyphosis correction were measured for all patients to evaluate radiologic and neurological outcomes.Results Bony union occurred in all patients at the 3-5 months of follow-up.There was no pseudarthrosis or vascular complications related to the fixation device.Percentage of canal encroachment decreased from preoperative 70％ to postoperative 2％.Mean segmental kyphotic angle measured 27.9 ° before operation and 7.4 ° after operation,with a mean correction of 20.5°.All patients demonstrated at least one grade of neurological improvement at final follow-up.Mean VAS was improved significantly from preoperative 7.3 points to postoperative 2.9 points.Conclusion The new anterior plate-rod system is safe and effective in treatment of acute thoracolumbar burst fracture combined with neurologic deficit.
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Objective To evaluate the possibility and curative effect of total en bloc spondylectomy (TES) for the treatment of primary tumors of the lumbar spine. MethodsBetween June 2005 and July 2009,nine cases of primary tumor of the lumbar spine were treated with total en bloc spondylectomy through a single posterior approach performed in seven cases(L1 giant cell tumor, L1 osteosarcoma, L2 giant cell tumor,L2 solitary plasmacytoma, L2 chondrosarcoma, L2 chordoma, and L3 histiocytic sarcoma), and two cases through a single stage anterior and posterior combined approach (L4 giant cell tumor with paraspinal mass and L4 fibrosarcoma). They were performed a single stage reconstruction after removing tumors of vertebra. Neurofunction was evaluated perioperatively and recurrence of tumor was tracked for all cases.ResultsThe follow up was obtained for 3-49 months (averaging 19 months). All patients attained significant clinical improvement after surgery without any severe complications. There was no local recurrence and distal metastasis in shortterm follow-up. ConclusionThe treatment by TES to remove tumors and reconstruction of spine are reliable for primary tumors of the lumbar spine. The curative effect of short-term follow-up is satisfactory. However, the long-term curative effect remain to be further follow-up.
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Objective To investigate the effects of a novel |3 titanium fixation with high strength and low elastic modulus on bone healing of osteoporotic fracture and its effects on stress shielding.Methods Forty female Sprague-Dawley rats were oophorectomized before establishment of femur fracture model.The fracture of left femur was stabilized by titanium alloy pin with high elastic modulus (110 Gpa,high elasticity modulus group) and the fracture of right femur by titanium alloy pin with low elastic modu-lus (30 Gpa, low elasticity modulus group).Six and 12 weeks later, the bone volume (BV) , total vol-ume (TV) and bone volume fraction (BVF) were detected by Micro-CT, and the maximum load was de-tected by biomechanical test.The effects of two titanium alloy pins on formation of bony calluses and me-chanical properties of bones were compared.Results Compared with the low elasticity modulus group, more collagen and bony callus, thicker bone trabeculae and more regular lamellar bone were found in the high elasticity modulus group.In low elasticity modulus group, TV (ROI1) was increased obvious-ly at week 6, with no statistical differences in BV (ROI 1), BV (ROI 2) and maximum load between two groups (P < 0.05).TV and BV in region ROI 1 in the low elasticity modulus group were significantly higher than that in high elasticity modulus group (P < 0.05) , while BV in region ROI 2 in low elasticity modulus group was significantly higher than that in high elasticity modulus group at week 12 postoperative-ly (P<0.05).Biomechnical test indicated that the maximum load in low elasticity modulus group was higher than that in high elasticity modulus group.Conclusions The novel B titanium alloy with high strength and low elastic modulus helps reduce effects of stress shielding, diminish bone resorption, in-crease the fibrous callus formation at the initial phase and improve the quality of bone healing at the later phase.
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This study was undertaken to assess the effect of different surface microtopograph of Ti-Nb-Zr-Sn alloy on the biological behavior and soft tissue integration of rabbits' lacertus fibroblast. The lacertus fibroblasts of Achilles tendon of rabbits were cultured and inoculated on the surface of smooth Ti-flake (control group), and on the surface of sand blast, microgrooves, thread Ti-flakes respectively (3 treatment groups). The cell's growth ratio and attaching status were examined by MTT test and scanning electron microscopy (SEM). The rabbits' lacertus fibroblasts proliferated regularly on the surface of Ti-flakes, and most results of their inter-group comparison showed statistically significant difference (P<0.05), thus indicating the different effects of different surface microtopographs on cell's proliferation; By SEM, the cells were noted to have no obvious directivity on smooth surface; they attached irregularly on the sand blast surface. But in the other two groups, they were oriented regularly along the texture. The cells were almost shuttle-like on the four kinds of surface except for a part of irregular cells on the sand blast surface, and there were plentiful cell-cell junctions. Under high power lens, we found cells with limpid microvilli in the experiment samples. Owing to the cell's fast proliferation and regular attachment in the experiment, we concluded that the regular microgrooved surface was more suitable for meeting the requirement of the soft tissues' physiological function.