The early treatment principles of spinal cord injury (SCI) included early drug using, early surgery and early rehabilitation.The literatures on how to use drug early and how to control the time for SCI before surgery were reviewed.

Objective:To evaluate the feasibility and clinical efficacy of the treatment of lumbar spine steno-sis by modified unilateral approach for bilateral decompression under microendoscope.Method:217 cases with degenerative lumbar spine stenosis from September 2003 to December 2008 were treated by modified unilater-al approach for bilateral decompression of central spinal canal and nerve root canal under microendoscope.A-mong them laminectomy of one segment was done in 163 cases,two segments were done in 54 cases.After surgery,the routine radiograph were carried out and the Nakai criterion was used for assessment.Result:The mean operative time was 48±13min (range,25 to 95min),the average blood loss was 37±9ml (range,25 to 180ml),the average skin incision length was 2.2±0.2cm(1.8 to 2.4cm).2 cases had dural matter tearing,which healed after filling with gelatin foam and 2 weeks bed rest,after that no cerebrospinal fluid leakage was noted after surgery.Mislocation was noted in 1 case.No nerve inury and postoperative infection oceurred.Postoperative CT scan demonstrated complete decompression of the central spinal canal and nerve root canal.All patients were followed-up for an average of 14 months (range,3 months to 24 months).The Nakai criterion at final follow-up showed clinical excellent in 134 cases,good in 63 cases,fair in 16 cases and worse in 4 cases, with the excellent and good rate of 90.8%.No lumbar spine instability was noted.Conclusion:Treatment of de-generative lumbar spine stenosis by modified unilateral approach for bilateral decompression under mieroendo-scope has the merit of minimal invasive,less complications and reliable therapeutical effect.

Objective To evaluate the efficacy and safety of balloon kyphoplasty in the treatment of painful multi-vertebral osteoporotic compression fractures. Methods From October 2002 to April 2007, 42 patients (96 vertebrae) with painful multi-vertebral osteoporotic compression fractures underwent kyphoplasty. The group included 14 men and 28 women with an average age of 72.5 years (range 56-91 years). Each pro-cedure included insertion and insertion of balloon, fracture reduction and cement filling under "C"-arm monitoring. Preoperative and postoperative pain level, SF-36 score, vertebral height restoration, local kypho-sis correction and complications were recorded and analysed. Results All 42 patients tolerated the opera-tion well and were followed up for average 31.4 months (range 12-71 months). The mean VAS pain score decreased significantly from 7.1±2.4 preoperatively to 2.7±1.3 postoperatively, the mean height of anterior and medial vertebral body were (1.8±0.5) cm, (1.6±0.6) cm preoperatively and (2.3±0.6) cm, (2.2±0.7) cm postoperatively. No significant change of posterior vertebral height was recorded postoperatively.The mean correction of local kyphosis was 9.2°at each level. 6 of 8 subscahs measured by SF-36, including physical function, role function, bodily pain, vitality, role emotion, mental health, were significantly improved by the operation. Complications were found in 7 patients including 6 cases of cement leakage with no clinical symptoms (intradiscal cement leakage in two cases, paravertebral vessel leakage in two cases, paravertebral leakage in one case and cement leakage into canal in one case), and 1 case of pulmonary embelization with symptoms relieved after conservative treatment. Conclusion Kyphoplasty is effective and relatively safe for multi-vertebral osteoporotic compression fractures.

Objective To investigate the causes and clinical significance of cement leakage into disc space during kyphoplasty. Methods Since 2002, 178 patients with osteoporotic vertebral compression fractures underwent kypboplasty and 15 of them were detected intradiscal cement leakage and followed up more than 2 years (mean 2 years and 8 months). The mean injection of cement in these patients was 4.2ml.The series comprised 10 females and 5 males, with an average of 71.2 years old ( range, 54～84 years old).Visual analog scale was used to score back pain pre- and postoperatively. The height and MRI index of the involved disc were recorded and compared. Results The discs involved were as following: T10-11 for 4 cases,T11-12 for 1, T12L1for 4, L1-2 for 2, L2-3 for 3, L3-4 for 1. Cement leakage was detected in the disc above the fractured vertebrae in 10 cases, and in the disc below the fractured vertebrae in 5 patients. The back pain significantly alleviated and the average visual analog scale (VAS) score was decreased from 8.5±2.1 preoper-atively to 3.3±1.4 postoperatively (P< 0.05). The anterior disc height was (5.1±2.1)mm preoperatively and (4.8±1.9) mm at the final follow-up, the middle disc height was (7.4±3.2) mm preoperatively and (7.3±2.9) mm at the final follow-up, the posterior disc height was (4.9±2.5) mm preoperatively and (5.0±1.8) mm at fi-nal follow-up, the heights of intervertebral space were well maintained. The signal intensity decreased and became inconsistent in some discs, and the preoperative MRI index significantly decreased from 25482.4± 3467.5 to 18927.6±2519.4 at the final follow-up (t=1.967,P< 0.05). Conclusion Pain relief is impressive in patients with intradiseal cement leakage during kyphoplasty. However, cement leakage into disc space may accellerate the process of disc degeneration.

Objective To investigate the anti-chronic stress effect of bone marrow mesenchymal stem cell (BMSCs) transplantation in rats with spinal cord injury.Methods Forty-eight adult SD rats were divided into control group,model group and treatment group according to the random number table,with 16 rats each.In model and treatment groups,lower thoracic (T10) spinal cord injury were constructed using the modified Allen's method.In control group,only laminectomy was performed.After 7 days,100 μl Hank's buffer suspension containing 1.0 × 106 BMSCs was injected into the subarachnoid space of L4-5 intervertebral space of rats in control group and treatment group.While in model group,only the equal volume of Hank's buffer was used.Basso-Beattie-Bresnahan (BBB) scale was performed to evaluate hindlimb motor function in rats.At postoperative 14 and 28 days,blood samples were collected to measure adrenocorticotropic hormone (ACTH),norepinephrine (NE),epinephrine (E) and corticosterone (CORT) using the ELISA method;brains were harvested for the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor proteins GluR1 and GluR2 immunohistochemical staining.Results After injury,BBB scores in model and treatment groups were similar,but both were lower than that in control group (P ＜ 0.05).After BMSCs transplantation,BBB score in treatment group [21 d:(9.85 ± 0.82)points and 28 d:(11.23 ±0.68)points] improved continuously compared to model group [21 d:(8.42 ± 0.39) points and 28 d:(8.84 ± 0.25) points],but all were lower than that in control group [(21.00 ±0.00)points,P ＜0.05].ACTH contents in model and treatment groups at 14d [(104.80±6.16) and (98.50 ± 4.07) pg/ml] and 28 d [(101.40±2.33) and (96.50± 2.28) pg/ml] were higher than those in control group [(90.40 ± 1 1.36) and (83.20 ± 5.22) pg/ml] (P ＜ 0.05).CORT contents in model and treatment groups [(44.40 ± 1.44) and (43.30 ± 1.17) ng/ml] was lower than that in control group [(48.20 ± 2.27) ng/ml] at 14 d,but were found to be elevated [(70.40 ± 1.90) and (61.40 ± 1.83) ng/ml] compared to control group [(46.40 ± 1.49) ng/ml] at 28 d (P ＜ 0.05).Meanwhile,the CORT content in treatment group was lower than that in model group (P ＜ 0.05).Changes in NE and E contents among the groups were similar with ACTH.Immunohistochemical staining suggested the amounts of GluR1 and GluR2 positive cells in treatment group lowered compared to control group (P ＜ 0.05),but increased in model group compared to control group (P ＜ 0.05).Conclusion BMSCs transplantation can improve the hindlimb motor function,contribute to reducing the secretion of stress-related hormones ACTH,CORT,NE and E,and down-regulate the expression of AMPA receptor proteins GluR1 and GluR2 in rats with spinal cord injury,suggesting a potential role in antichronic stress.

BACKGROUND:Percutaneous vertebroplasty has been extensively applied in treatment of osteoporotic vertebral compression fractures, and now it is also used in spinal metastatic tumor. OBJECTIVE:To evaluate the effectiveness of percutaneous vertebroplasty for metastatic tumor of thoracic lumbar vertebrae by bone cement perfusion at different times and temperature gradient. METHODS:A total of 24 cases (38 vertebrae) of metastatic tumor receiving percutaneous vertebroplasty and bone cement perfusion at different times and temperature gradient were reviewed retrospectively. Al patients were classified into group A (11 vertebrae in 9 cases) featured with apparent vertebral compression (≥ 1/4) and group B (27 vertebrae in 15 cases) of no obvious compression (<1/4). The percutaneous vertebroplasty was conducted with C-arm fluoroscopy positioning. Bone cement was injected by perfusion at different times and temperature gradient method. Visual Analogue Scales and Owestry Disability Index were recorded to assess pain al eviation and functional restoration before and after bone cement injection at different times and temperature gradient. The height of treated vertebrae was also analyzed. Fol ow-up was performed for 12 to 56 months. RESULTS AND CONCLUSION:Al 24 patients successful y underwent percutaneous vertebroplasty and bone cement perfusion at different times and temperature gradient. Bone cement (4±1) mL was averagely injected into each thoracic vertebra. Bone cement (5±1) mL was injected into each lumbar vertebra. Postoperative recheck radiographs revealed good bone cement distribution, no nerve root injury or spinal compression occurred. Vertebral height was significantly higher posttreatment compared with pretreatment in both groups (P<0.05). Visual Analogue Scales and Owestry Disability Index scores were significantly lower at 1 day, 1 month after treatment and during final fol ow-up compared with preoperation in al patients (P<0.05). No significant difference in Visual Analogue Scales and Owestry Disability Index scores was detected between two groups at the same time point. Results suggested that percutaneous vertebroplasty and bone cement perfusion at different times and temperature gradient for metastatic tumor of thoracic lumbar vertebrae could reduce the occurrence of bone cement leakage, and could ease the pain quickly for apparent and non-apparent compressed tumor metastatic vertebrae. It is an effective method to treat metastatic tumor of vertebrae.

Objective To evaluate biomeehanic characteristics of lumbar spondylolysis and spondylolisthesis single vertebrae reduction fixation system (LSRF), and discuss its mechanism of reduction. Method Twenty-four adult isthmus lumbar vertebrae specimen were disconnected and fixed with LSRF, Hefti, Salib's method respectively, and the biomechanic characteristics of the fixation devices were tested. Isthmus of L5 in 4 adult spine specimen was destroyed under loading to produce the spondylolisthesis model, and reduction by LSRF. Result The LSRF has a good ability for reduction and its strength for reduction is 1.6, 2.7 times as high compared with the Hefti, Salib's methods respectively. The mechanism of reduction is that the LSRF used contacted point of lamina by lamina hook as the fulcrum, through the pedicle screw to pull the spondylolisthetic vertebrae, and reduce the anterior displacement of vertebrae. Conclusion LSRF gives rigid fixation and good reduction, and provides a new and effective method for lumbar spondylolysis and isthmic spondylolisthesis.

Objective To analyze the long term results of thoracolumbar burst fractures treated with short segment pedicle instrumentation. Methods Sixty eight cases of thoracolumbar burst fractures fixed with short segment pedicle instrumentation were followed up for at least 5 years (5-13 years, average 8 years). All of them were checked with radiography pre and post operation and before implant removal. At final follow up assessment, all were examined with radiography, 18 cases were checked with CT scan as well. Results 1) Neurological status improved at least 1 Frankel grade in 90.3% of the patients who had preoperative incomplete paraplegia, while no improvement was obtained in those who had preoperative complete paraplegia. Low back pain was evaluated according to Denis Pain Scale, the results showed P1 41 cases (60.3%), P2 24 cases (35.3%), P3 3 cases (4.4%). 2) The shortest distances between the upper and lower pedicle screws tips shortened for 0-6.5 mm (average 2.5 mm) before removal in contrast to that at post operative immediately. Of the 68 cases, nuts loosened in 1 case, pedicle screws loosened in 1 case, bent in 2 cases and broken in 5 cases. Of the 8 cases whose implants were not removed timely, screw broke in 2 cases, and seepage occurred through incision in 2 cases. 3) At final follow up, the correction of anterior vertebral body height averaged 30.5%, and Cobb angle 5.8?, despite a mean correction loss of Cobb angle 12.1?. Correction loss was most evident at the above disc spaces, then the below disc spaces. Correction loss of vertebral body height averaged 1.9% in the anterior, and 6.0% in the middle part. 4) The collapse of vertebral body was most serious in the middle part. The deformity of "codfish vertebrae" occurred in the superior part of vertebrae body in 21 cases, among them the upper adjacent vertebral body sank into the injured body in 5 cases, 3 of whom engendered kyphoses greater than 25?. Evident intra corporeal gaps were found in 16 of 18 patients who were checked with CT, and the gaps communicated with the above disc space. The fractured body could have a deformity of the "cup" after reduction. 5) Degeneration and narrowing of the disc spaces next to fractured vertebrae were very common, and the above space disappeared in 27 cases, while the lower space disappeared in 14 cases. The upper disc space adjacent to fixation levels degenerated in 1 of 8 cases whose implants were not removed timely. Five patients had Cobb angle greater than 20?, three of them had low back pain, and one had mild symptom of nerve compromise. Low back pain was not correlated with degeneration of discs. Conclusion Short segment pedicle instrumentation provides satisfying stability for thoracolumbar burst fractures. It helps physiologic postural contour restoration and facilitates neural recovery, but is associated with relatively high rates of implant failure and correction loss which is most evident at adjacent discs spaces. Deficiency of bone grafting and delayed implant removal are the most probable causes for correction loss.

[Objective]To study the prophylactic effects of high dose methylprednisolone(MP) for perioperative surgical treatment of thoracic spinal stenosis.[Method]From July 2003 to December 2007,a retrospective study of 40 patients who underwent simply posterior thoracic vertebral canal decompression was made.The patients were divided into 2 groups according to the application of MP or none-MP at perioperation.Twenty-one patients in MP group were treated with MP stoss(30 mg/kg,iv 15 min) 30 min prior to the decompression and then 45 min later MP(5.4 mg/kg/h) was continuted for 23 hours.Nineteen patients in the control group were treated with dexamethasone(DX) 15 mg 30 min prior to the decompression and then DX(10 mg/d,iv) was given for 3 days after operation.Neurological function improvement rates were evaluated according to the JOA scores(postoperative JOA scores-preoperative JOA scores /17﹣preoperative JOA scores)?100% at 3d,7d,3d and 12 months after operation.Complication were observed.[Result]Neurological function recovery rates were 33.54?10.01% in MP group and 28.29?8.73% in the control group at 3 days after operation.The difference was found to be significant(P0.05).Neurological deficit was found in 5 in control group,while no one in the MP group.[Conclusion]High dose of MP used perioperatively for thoracic stenosis can protect spinal cord and improve operative security,while it does not increase serious adverse complications.

Objective To investigate the effect of metformin on the osteogenic differentiation of human mesenchymal stem cells exposed to PMMA particles. Methods Human placental mesenchymal stem cells were iso-lated and cultured in vitro. The effect of metformin with different concentrations on cell viability was determined by CCK8 assay. The effect of metformin on the mRNA expression of osteogenic genes was detected by using real-time RT-PCR. Calcified nodules were stained by alizarin S. The effect of metformin on the expression of eNOS was also detected by using real-time RT-PCR. Results PMMA particles could inhibit the viability of mesenchymal stem cells. Metformin(0.05 mmol/L)could promote the viability of mesenchymal stem cells exposed to PMMA particles. Metformin(0.05 mmol/L)could increase the expression of osteogenic genes,including OCN,RNUX2,and ALP, in human mesenchymal stem cells exposed to PMMA particles. The calcium deposit was also increased after metfor-min treatment. Results of real-time RT-PCR showed that metformin could increase the expression of eNOS in human mesenchymal stem cells exposed to PMMA particles. Conclusions Metformin can increase the osteogenic differentiation of human mesenchymal stem cells exposed to PMMA particles,partially by inducing eNOS expression.