Objective To explore the clinical application of computer-assisted three-dimensional navigation system for thoracic pedicle screw placement. Methods From May 2003 to May 2004, the computer-assisted three-dimensional navigation system was used for thoracic pedicle screw placement in 80 screws of 15 cases, including 30 in the upper thoracic spine and 50 in the middle or lower thoracic spine. These fifteen patients included ten male and five female with a mean age of 47 years (range 13-76 years). In this series of 15 patients, thoracic spinal surgery was performed for tumor resection and reconstruction in 5, burst fracture in 4, ossification of thoracic ligamentum flavum in 2 and thoracic scoliosis in 4. The pedicle screw position was assessed with "C"-arm fluoroscopy during operation and with CT post-operation. The cost of time for pedicle screw installation and amount of bleeding were recorded. Results The cost of time averaged 15 minutes (range 10-20 min) for each pedicle screw placement. The amount of bleeding varied, it averaged 1200 ml in thoracic tumor resection and reconstruction, 800 ml in posterior fixation for burst fracture, 300 ml in resection of ossified ligamentum flavum, and 500 ml in surgery for scoliosis. The pedicle screw position was graded post-operatively with CT scanning into three groups: gradeⅠ, perfectly placed, grade Ⅱ, cortical perforation less or equal to 2 mm, and grade Ⅲ, perforation more than 2 mm. Of these 80 screws, 76 screws (96%) were found in gradeⅠ, 2 in gradeⅡ, and 2 in grade Ⅲ. All of the 4 screws in gradeⅡor Ⅲ were placed deviating to the lateral portion of pedicles, and no neurological deficit was resulted. Conclusion The computer-assisted three-dimensional navigation system is a valuable tool both for improving the accuracy of thoracic pedicle screw installation, and increasing the overall safety of the procedure during thoracic spine surgery.

Objective To investigate the consistency of M RI detecting posterior ligamentous complex (PLC) injury associated with thoracolumbar factures.Methods MRI data of 170 cases of thoracolumbar fractures were reviewed retrospectively.Each case underwent MRI around one week postinjury.MRI data were analyzed and compared by three physicians respectively to discuss the consistency in MRI detection of PLC injury and the severity of PLC injury.Results Kappa coefficient was 0.846 between observer 1 and 2,0.768 between observer 1 and 3,and 0.793 between observer 2 and 3.Interobserver reliability was high and overall Kappa coefficient was 0.803.Severity of PLC injury was interrelated with spinal cord nerve injury (P ＜ 0.05).Conclusions Accurate detection of PLC injury in thoracolumbar fractures is beneficial to clear the mechanical stability of the spine.MRI detection of PLC injury is of high consistency and hence deserves wide use.

Objective To evaluate the clinical efficacy of anterior C2-3 discectomy and fusion in treatment of type Ⅱ traumatic spondylolisthesis of the axis. Methods A total of 27 patients with type Ⅱ traumatic spondylolisthesis of the axis were treated with anterior C2-3 discectomy, fusion and plate fixa-tion. There were 19 males and 8 females, at average age of 38 years (22-67 years). The spinal cord function was at Fraukel D in four patients. Results Operation lasted for 75-95 minutes (mean 86 mi-nutes), with blood loss of 100-160 ml (mean 135 ml). Hospital stay was 9-12 days ( mean 10.8 days). Follow-up for 9-24 months (mean 14 months) showed that all patients achieved bony fusion within three months postoperatively, with no anterior displacement or kyphosis. The range of cervical movement was normal, with no chronic neck pain ocurred. Conclusions Anterior approach can minimize surgical trauma, shorten recovery time and hospital stay. Anterior C2-3 discectomy and fusion is a feasible and safe surgical technique and can get satisfactory therapeutic effect in treating type Ⅱ traumatic spondylolisthesis of the axis.

AIM: To investigate the synergistic induction of apoptosis in rhabdomyosarcoma cells by the combination of TRAIL or TRAIL gene with cisplatin. METHODS: Rhabdomyosarcoma cells were treated with TRAIL, (Ad/GT)-TRAIL, cisplatin, respectively or the combination for 3 days. The cytotoxicity was observed by MTT assay. The apoptotic rates and the expression rates of Fas protein were measured by flow cytometry (FCM). The expression of cFLIP mRNA was determined by RT-PCR. RESULTS: Rhabdomyosarcoma cells were treated with Ad/ GT-TRAIL and TRAIL (100.0 ?g/L), the cytotoxicity index were 52.5% and 43.5%, the percentage of apoptotic cells were 12.95% and 10.26%, respectively. Combined with cisplatin, the cytotoxicity index and the percentage of apoptotic cells were increased significantly (P

Objective To study the diagnosis and treatment for distractive extension injuries of the cervical vertebrae.Method From 2000 to 2005.the clinical and image data of fifty-six patients in the Second Affiliated Hospital of Zhejiang University College of Medicine with distractive extension injuries of the cervical vertebrae were studied and treated with anterior discectomy or subtotal vertebrectomy in the second affiliated Hospital of zhejiang university collegeof medicine,bone grafting and internal fixation with plate.Results The follow-up period was six to seventeen months in fourty-eight patients.The neurological recovery was found after operation in five of nine case with complete spinal cord injuries and thirteen patient had complete recovery.Neck pain completely disappeared in 6 patients with oboslete injury and neurological recovery was improved in 4 patients.Condusions MRI examination is the essential approach to diagnoze distractive extension injuries of the cervical vertebran,and early operation,including anterior discectomy,bone graftillg and internal fixiation with plate,is a best choice of surgical interrention to achieve cervical stabilization and neurological improvement.

Objective To compare the safety and efficacy of posterolateral lumbar fusion (PLF) and transforaminal lumbar interbody fusion (TLIF) in the treatment of degenerative lumbar scoliosis (DLS).Methods Forty DLS patients with Cobb angles of 20 to 60 degrees were divided randomly into PLF and TLIF groups.Operative time,intraoperative blood loss,imaging results,and clinical outcomes were compared.Results Complete information was available in 37 patients,including 18 patients in the PLF group and 19 in the TLIF group.There were significant differences between two groups with regard to the operative time (P=0.002) and the intraoperative blood loss (P=0.048).The incidence of early complications in the 2 groups was 11.1％ and 26.3％.There was no significant difference in the recovery rates of the Cobb angle and the spinal coronal balance between two groups.However,the recovery rates of the lumbar lordotic angle and spinal sagittal balance were significantly different between two groups (36.7％ vs.62.5％ and 44.8％ vs.64.1％,respectively).In various domains of SRS-22,the scores for pain and satisfaction with treatment in TLIF was better that those in PLF groups.There was no significant difference in ODI score between two groups.Conclusion TLIF helps to improve lumbar lordosis and sagittal balance,which leads to better clinical outcomes.For patients without significant loss of lumbar lordosis and with good spinal sagittal balance preoperatively,PLF is still an option.

Objective To analyze the perioperative complications of posterior transpedicular osteotomy (wedge osteotomy and total vertebral osteotomy) for patients with spinal deformity.Methods From January 2007 to December 2011,73 patients with spinal deformity underwent posterior transpedicular spinal osteotomy (wedge osteotomy and total vertebral osteotomy).Among them,30 patients,including 8 males and 22females,aged from 8 to 68 years (average,40.7 years),presented with at least one perioperative complication.There were 10 cases of scoliosis,9 cases of kyphoscoliosis and 11 cases of kyphosis.Twenty two patients underwent total vertebral osteotomy,and 8 patients underwent wedge osteotomy.A retrospective analysis on perioperative complications of 30 patients was performed.Results Except 1 patient dying of hemorrhagic shock after operation,29 patients were followed up for 6 to 61 months (average,17.2 months).The total perioperative complication rate was 41.1％.Neurological complications occurred in 16 patients (21.9％),bleeding complications in 2 patients (2.7％),dural injury in 6 patients (8.2％),postoperative cerebrospinal fluid leakage in 4 patients (5.5％),wound infection in 4 patients (5.5％) and pleural effusion in 4 patients (5.5％).Conclusion Posterior transpedicular osteotomy is an effective surgical technique for spinal deformity.However,perioperative complications are common,including nerve injury,bleeding,dural injury,wound infection and so on.Among them,nerve injury and bleeding are most common.

Objective To compare the surgical outcomes between microsurgery lumbar discectomy and microendoscopic discectomy for lumbar disc herniation. Methods A prospective study was conducted on the surgical procedures for lumbar disc herniation.The target of our study was a group of 33 patients who underwent surgery by microsurgery lumbar discectomy(MSLD group)and 36 patients who underwent surgery by microendoscopic discectomy(MED group).The items investigated were the operation time,amount of bleeding,duration of hospitalization,pre-and postoperative scores based on judgment criteria for treatment of lumbar spine disorders established by the Japanese Orthopaedic Association score,visual analog scales (VAS,0 to 10) for lumbago and sciatica before surgery and at discharge,perioperative complications.Results The mean duration of follow-up was 2 years and 2 months (11 months to 4 years).There were no significant differences between the 2 surgical procedures in the frequency of the pre-and postoperative Japanese Orthopaedic Association scores or postoperative VAS for lumbar pain and sciatica,operation time and duration of hospitalization. Statistically significant differences were observed in amount of bleeding and operation time,but the differences were not large, and may not have been clinically significant.Conclusion Both microsurgery lumbar discectomy and microendoscopic discectomy are appropriate for lumbar disc herniation.

Objective To investigate different surgical procedures for treatment of thoracic ossification of ligamentum flavum.Methods From January 1994 to June 2008,56 cases of thoracic ossification of ligamentum flavum underwent different surgical procedures.There were 40 males and 16 females,aged from 43 to 76 years(average 58.1 years).The courses of disease were 3 months to 5 years,average 13.4 months.CT and MRI examinations were used to observe ossification involving levels,distributions,ossification nest shapes,spinal canal stenosis and spinal cord compression and so on.All patients were treated with en bloc or dissolved laminectomy combining with posterolateral fusion.Japanese Orthopaedic Association(JOA)score was used to evaluate postoperative outcomes.Results The patients were followed up for 18 to 70 months,with an average of 25 months.The mean JOA score increased from 6.25±2.47 preoperatively to 7.53±3.20 at the final follow-up.According to CT scans,the ossifications were divided into lateral type in 6 cases,diffuse type in 17 and thickened nodular type in 33 cases.Patients of lateral type was treated with en bloc laminectomy,and the excellent and good rate was 83.3%.In the patients of diffuse type,11 were treated with en bloc laminectomy and 6 with dissolved laminectomy,and the excellent and good rate was and 81.8% and 83.3% respectively.For patients of thickened nodular type,4 were treated with en bloc laminectomy and 29 with dissolved laminectomy,the excellent and good rate was 50% and 82.8% respectively,and 2 cases presented spinal cord injury aggravation.Conclusion En bloc laminectomy combining with lateral fusion is ideal surgical procedure for lateral type and diffuse type,dissolved laminectomy combining with laeral fusion is suitable for thickened nodular type.

Objective To investigate the damage sequence of posterior ligamentous complex (PLC) and its clinical significance in thoracolumbar fracture.Methods Data of 132 patients with spinal fracture evaluated with X-rays,CT and short-tau inversion-recovery (STIR) sequences in MRI were collected prospectively.Fracture morphology was classified using the AO classification.PLC components including interspinous ligament (ISL),supraspinous ligament (SSL),ligamentum flavum (LF) and facet capsules (FC) were assessed and classified as intact,edema,or tear.ISL edema was further subdivided depending on the extension (＞ 50％ or ≤50％).Correlation between MRI signal and AO progressive scale of morphological damage was analyzed.Results AO type A1/A2 fracture associated with only FC distraction.AO type A3 fracture showed additional ISL tear,usually less than 50％,with neither LF nor SSL tear.AO type B1 fracture showed FC distraction,ISL edema or disruption,and low rate of SSL/LF tear,but B2 fracture increased the rate of SSL/LF tear.AO type C fracture showed facet fracture or dislocation and ISL,SSL as well as LF tear.High correlation was found between AO progressive scale and MRI signal (P ＜ 0.01).Conclusions MRI study can well display the PLC damage and damage sequence.MRI correlates with AO progressive scale of morphological damage,which shows a progressive orderly rupture sequence among different PLC components as traumatic forces increase.