BACKGROUND: Unstable cases of Hangman’s fracture or traumatic spondylilisthesis which are type II, IIa and III should be treated surgicaly. Retropharyngeal approach was employed in exposure of anterior upper cervical region. However, dissection and traction around important structures make the procedure complicated and increase the chance of nerve injury.
OBJECTIVE:To evaluate the clinical curative effect and safety of an innovative operative technique in which a polyetheretherketone cage was used to perform cervical spinal fusion for the treatment of Hangman’s fracture.
METHODS: Eight patients with type II or IIa Hangman’s fracture were enroled in this study and received cervical fusions at C2/3 levels. During folow-up postoperatively, they received X-ray examination. Fusion time and implant position were evaluated. The angle of deformity (α) and the displacement distance (β) were compared pre-operatively and 6-month post-operatively to measure reduction. The functional outcomes were also compared using the Post-Traumatic Neck Score (Mayo) pre-operatively and 6-month post-operatively, while neck pain was further investigated by Visual Analogue Scale score.
RESULTS AND CONCLUSION:Al eight patients were folowed-up successfuly, with an average folow-up of 13 months (range 6-26 months). Compared with pre-operatively, Clinical Post-Traumatic Neck Score (Mayo) was increased, Visual Analogue Scale score, angle deformity (α) and displacement distance (β) were reduced at 6-month post-operatively (P < 0.05). Neck activity was not limited in final folow-up. Bone fusion was found in al patients at 3 or 6 months post-operatively, and no complication was detected. Results confirm that polyetheretherketone cage for type II and IIa Hangman’s fracture could achieve good outcomes and safety.

AIM: To investigate the role of NF-κB in diabetic neuropathy.METHODS: The diabetic rats were induced by intraperitoneal injection of streptozocin ( STZ) .The pain behavior test was used to detect the mechanical and thermal withdraw threshold of the rats’ bilateral hind paws.The protein levels of p-NF-κB and t-NF-κB in the rats’ L4 and L5 dorsal root ganglions ( DRG) were determined by Western blotting.The expression of Nav1.7 in DRG of diabetic neuropathy rats with or without NF-κB inhibitor PDTC was detected by the method of immunohistochemistry.RESULTS:The mechanical and thermal withdraw threshold of bilateral hind paws in the diabetic rats was decreased from 4 weeks to 12 weeks after injection of STZ.The protein levels of p-NF-κB in L4 and L5 DRG were significantly increased in the rats with diabetic neuropathy.Intrathecal administration of NF-κB inhibitor PDTC attenuated the increase in p-NF-κB and Nav1.7 in L4 and L5 DRG.Pain behaviors were also alleviated by PDTC.CONCLUSION:The increase in p-NF-κB is closely rela-ted to the generation of diabetic neuropathy.Inhibition of NF-κB blocks pain behaviors and the over-expression of Nav1.7 in DRG.

BACKGROUND: With the understanding of pathology of cervical diseases, cervical curvature has become one of
the important indexes of long-term clinical outcome. To restore and maintain cervical curvature has a profound impact on cervical long-term stabilization and cervical biomechanical environment.
OBJECTIVE: To evaluate long-term influence of selective consecutive three-level appliance of intervertebral Solis cage on cervical curvature for spondylotic myelopathy.
METHODS: From June 2008 to December 2010, 22 spondylotic myelopathy patients were treated with
consecutive three-level anterior cervical Solis fusion. There were 14 males, 8 females, with an average age of
45.1 years (ranged from 26-73 years). There were two cases of C2/3/4/5, seven cases of C3/4/5/6, 12 cases of C4/5/6/7, and one case of C5/6/7/T1 , total y 66 intervertebral spaces. Al cases were fol owed up for 2 years.
RESULTS AND CONCLUSION: Average blood loss amount was 40 mL (20-80 mL). Average operation time was 121 minutes (100-175 minutes). After fol ow-up for 30.7 months, al segments were fused. There was no implant migration or vertebral body col apse. Pre-operative JOA score was 11.94±3.61, 15.56±1.13 at 6 months post-operation, and 15.21±1.85 at 2 years after implantation. Pre-operative cervical curvature was (1.86±3.24) mm,(4.83±1.78) mm at 6 months post-operation, and (4.44±3.36) mm at 2 years after implantation. There were significant differences between pre-operative and at 6 months post-operation, pre-operative and at 2 years post-operation (P < 0.05). There was no significant difference between 6-month and 2-year post-operation (P > 0.05). Results indicated that selective consecutive three-level appliance of intervertebral cage for spondylotic myelopathy could improve cervical curvature and have long-term favorable clinical outcomes.

BACKGROUND: Kyphoplasty-assisted bone cement augmentation can be used in lumbar pedicle screw fixation of osteoporotic patients.OBJECTIVE: To assess the fixation strengths of loosened sacral screws augmented with kyphoplasty-assisted and traditional bone cement techniques.METHODS: Fresh sacra were harvested from nine osteoporotic cadavers. After testing bilaterally placed unicortical and bicortical pedicle screws, two unicortical pedicle screws with the traditional and kyphoplasty-assisted cement augmentations were established on the same sacrum. Following 2000 cyclic compression loading to screw head on a MTS machine, their maximum pull-out forces were recorded and compared. RESULTS AND CONCLUSION: The bone mineral densities of nine specimens were ranged from 0.61 to 0.77 g/cm2 (0.71 g/cm2 in average). The mean maximum pull-out forces of unicortical and bicortical screws, and traditional and kyphoplasty-assisted cement screws were 203, 325, 437, and 565 N, respectively. The pull-out force was significantly higher in bicortical screw compared with unicortical (P < 0.05); however, these two fixations exhibited markedly lower pull-out strength compared with two cement augmentation techniques (P < 0.05). The pull-out strength was significantly higher in kyphoplasty-assisted cement augmentation group compared with traditional bone cement technique (P < 0.05). In addition, a significant positive correlation was exhibited between bone mineral density and pull-out force for the four fixations (P < 0.05). Results demonstrated that traditional and kyphoplasty-assisted cement augmentations can serve as the salvage technique for loosening sacral screw. However, kyphoplasty-assisted augmentation can provide higher stability.

Objective To evaluate the clinical outcome of mono-segment transpedicular fixation of type B thoracolumbar fracture.Methods A retrospective analysis was conducted on 40 cases suffering from type B thoracolumbar fracture treated with mono-segment transpedicular fixation from May 2003 to October 2012.According to the AO classification,13 cases were identified with type B1.1,11 type B1.2,11 type B2.2,2 type B3.1,2 type B3.2,and 1 type B3.3.Radiological results were evaluated by measuring compression rate of the fractured vertebra and Cobb' s angle of the vertebra adjacent to the fractured segment.Clinical results were assessed using Frankel classification for spinal cord injury and visual analogue scale (VAS) for pain.Results Mean operation time was 71 minutes and mean intrao perative blood loss was 105 ml.Mean period of follow-up was 47.5 months (range,24-82 months).Mean Cobb' s angle of the vertebra adjacent to the fractured segment and compression rate of the fractured vertebra revealed great correction at one week post-operation compared with preoperative ones (6.2° vs 20.1° and 10.1％ vs 38.9％ respectively,P ＜0.05) and there was no significant correction loss at the last follow-up (6.9° and 10.8％ respectively,P ＞ 0.05).Mean VAS was 8.6 points before operation,but mean VAS was 2.4 points at final follow-up (P ＜ 0.05).Neurological performance improved in 37 cases (93％).No cases experienced neurological deterioration.Conclusions Mono-segment transpedicular fixation has small incision,short operation time,few bleeding and decreased motor function loss.The procedure is indicated for most type B thoracolumbar fracture and clinical results are satisfactory.

Objective To observe the ultrastructure of the neurovascular Unit (NVU) in chronic compressive cervical myelopathy rat model at different stages.Methods From March, 2014 to March, 2015, 32 rats were divided into two groups: sham control group (n =8) and compressive spinal cord injury group (n =24).The model was established by inserting the compression sheet made of polyurethane at the level of C6.BBB and somatosensory evoked potentials (SEP) were used to evaluate the spinal cord function status of model rat.Transmission Electron Microscopy (TEM) examination of compressive cervical spinal cords was performed separately at the 14th, 21st, 28th and 42nd day after modeling.Results At the 14th, 21st, 28th and 42nd, the BBB score were 17.571 ± 0.870, 15.952 ± 0.870, 15.476 ± 0.602 and 16.190 ± 0.632 were significantly lower than those in the control group (the BBB score of 4 points were 19.600 ± 0.516, 19.500 ± 0.527, 19.600 ± 0.699 and 19.800 ± 0.6232 respectively) (P ＜ 0.05).Latency prolongation and amplitude reduction of somatosensory evoked potentials (SEP) were presented in the compressive spinal cord injury group.At the 14th day, edema around the capillaries was observed, the morphological structure of endothelial cells and basement membrane was normal, the tight junction between endothelial cell was intact, the mitochondria in the axons, oligodendrocytes and astrocyte foot processes were edematous.At the 21st day, extensive edema, even partial necrosis around the capillaries were found, the surrounding structure were arranged loosely, partial loss of endothelial cells and basement membrane, cavitation occurrence in endothelial cells, basal membrane density was significantly lower, mitochondria vacuoles and shrinkage in the cytoplasm, axon myelin loose or broken;at the 28th day, the edematous range surrounding capillaries narrowed, low density of basement membrane and endothelial cells, vacuoles in endothelial cells, loose axon myelin, while some mitochondrias backed to normal.At the 42nd day, capillary integrity, no abnormalities were found in endothelial cells, basement membrane, tight junction and mitochondria, double layers of endothelial cells and basement membrane could be seen, local broken and loose structure were presented in part of the axons;The TEM of the sham control group showed normal ultrastructure of NVU.Conclusion The ultrastructure of NVU in chronic cervical spinal cord compression presented various in the different periods, NVU disruption were found in the early stages (14th-28th days), and compensatory and repair process were developed incompletely later.

BACKGROUND: Posterior lumbar non-fusion devices have been developed to control vertebral column movement, change load pattern of instability segment, restrict abnormal action, as well as avoid adjacent segment degeneration.OBJECTIVE: To investigate the efficiency of Wallis dynamic stabilization system in the treatment of lumbar vertebrae instability.METHODS: Ten cases suffering from lumbar instability were selected, including 3 males and 7 females, aged 43-65 years. One patient sustained L_(1/2) and L_(4/5) segmental instability, one was L_(2/3) and another was L_(3/4), and the others were L_(4/5). Two patients complicated with lumbar disc herniation and 7 patients combined with lumbar spinal stenosis at the same affected segment, and 3 patients associated with lumbar spinal stenosis at adjacent segment. All unstable segments were treated with decompression, posterior implantation of Wallis dynamic stabilization system. Visual analogue scale (VAS) and Japanese Orthopedic Association (JOA) scores for low back pain and Oswestry disability index (ODI) were used to evaluate clinical outcomes. In addition, therange of motion (ROM) at the instrumented segment and adjacent segments and posterior disc height (PDH) in standing and extension position at L_(4/5) segment were also measured.RESULTS AND CONCLUSION: All the patients were followed-up for 2-13 months, mean 9.2 months. The mean operation duration was 128 minutes (90-185 minutes), with bleeding volume of 264 Ml (50-600 Ml). Sings and symptoms of all patients were improved significantly after operation, except one patient with recurrence of L_(4/5) lumbar spinal stenosis at 3 month after surgery, whose symptoms relieved by revision with fenestration and decompression. The postoperative VAS was dramatically decreased than that of preoperation (P=0.003); the JOA score was obviously increased (P=0.002), and the ODI score was decreased (p=0.008). The postoperative range of motion decreased significantly (P<0.05). However, there was no obviously difference between preoperative and postoperative L_(3/4), L_5/S_1 and posterior disc height (P>0.05). Good clinical results can be achieved by surgical intervention with Wallis dynamic stabilization system in treating lumbar vertebrae instability.

Objective To investigate the feasibility of mono-segment pedicle instrumentation (MSPI)in management of thoracolumbar fracture (AO classification,A1 and A3) by being compared with short-segment(two-segment) pedicle instrumentation(SSPI).Methods Overall 141 patients with tape A1 or A3 thoracolumbar fractures,aged from 20 to 60 years (average,40.5 years),were enrolled in this prospective study.According to a simple randomized method,35 patients with type A1 fracture and 41 patients with type A3fracture were treated with MSPI,while 26 with type A1 fracture and 39 with type A3 fracture were treated with SSPI.Low back outcome score (LBOS) and ASIA2000 were used to evaluate clinical outcome.Eighteenth month postoperatively was assigned as the last follow up period.Wedge index (WI) and sagittal index (SI) of the affected vertebrae on radiography were measured and compared preoperatively,one week postoperatively and at the final follow-up.Results All patients were followed up successfully.The blood loss and duration of operation of MSPI group were significantly less than that of SSPI group,respectively.However,there were no significant differences of clinical outcome between two groups.For type A1 fracture,correction rate and correction loss of WI in MSPI group were better than those in SSPI group.For type A3 fracture,there were no significant differences of correction rate and correction loss of WI and SI between MSPI group and SSPI group; however,the failure rate of MSPI group was significantly higher than that of SSPI group.Conclusion For type A1 and partial type A3 thoracolumbar fractures,MSPI can provide the same or better fixation with less blood loss and operative duration than SSPI.Since MSPI for type A3.2 thoracolumbar fracture has a higher failure rate,the surgical indication should be strictly controlled.

Objective To study the surgical indications and effectiveness of short segment pedicle screw fixation plus pecutaneous vertebroplasty (PVP) for single thoracolumbar fracture combined with Kümmell disease.Methods Between June 2012 and June 2014,a prospective case series analysis was made on the clinical data of 15 selected cases of single thoracolumbar fracture patients who were combined with Kümmell disease.There were three males and 12 females,with an average age of 62.5 years (range,48-80 years).The iujured vertebrae were located at T11 in 3 cases,at T12in 4,at L1 in 5 and at L2 in 3.All the patients were treated by short segment fixation plus PVP.Operative time,surgery-related complications and adjacent vertebral fracture during follow-up were recorded.The effectiveness of the treatment was appraised by visual analogue scale (VAS),Oswestry Disability Index (ODI),Cobb angle of operative segment,which were recorded preoperatively,one week post-operatively and at final follow-up.One-way ANOVA (Analysis of Variance) was employed for statistical analysis.Results The operative time was 0.8-2 hours (mean,1.35 hour).There was no observation of incision infection,nerve injury,cement leakage or other related operative complications.A total of 15 patients were followed up for 16-36 months (mean,22.4 months),which showed solid fusion and bone bridges in all patients,with no fracture of adjacent vertebra observed.VAS was improved from preoperative (5.93 ± 0.62) points to (1.80±0.64) points one week postoperatively and (2.60 ± 0.53) points at final follow-up.ODI was improved from preoperative 61.53 ± 4.30 to 19.93 ±3.26 one week postoperatively and 23.07 ± 4.06 at final follow-up.Cobb angle of operative segment was improved from preoperative (17.40 ± 6.73) ° to (9.53 ± 3.12) o one week postoperatively and (11.00 ± 3.20) ° at final follow-up.There was significant difference of all the indexes namely,VAS,ODI and Cobb angle,between preoperative and one week postoperative status as well as between preoperative and final follow-up (P ＜ 0.05 or 0.01).However,there was no significant difference between ODI and Cobb angle in one week postoperatively and at last follow-up (P ＞ 0.05).Conclusion For single thoracolumbar fracture with Kümmell disease,short segment fixation plus PVP can shorten the surgery time,reduce the rate of complications,relieve pain,recover the function and avoid loss of kyphosis correction,as is worthy of clinical recommendation.

Background: Lumbar disc herniation (LDH) is a common cause of radicular pain, but the mechanism is not clear. In this study, we investigated the engagement of toll-like receptor 4 (TLR4) and the nuclear factor-kappa B (NF-κB) in radicular pain and its possible mechanisms. Methods: An LDH model was induced by autologous nucleus pulposus (NP) implantation, which was obtained from coccygeal vertebra, then relocated in the lumbar 4/5 spinal nerve roots of rats. Mechanical and thermal pain behaviors were assessed by using von Frey filaments and hotplate test respectively. The protein level of TLR4 and phosphorylated-p65 (p-p65) was evaluated by western blotting analysis and immunofluorescence staining. Spinal microglia activation was evaluated by immunofluorescence staining of specific relevant markers. The expression of proand anti-inflammatory cytokines in the spinal dorsal horn was measured by enzyme linked immunosorbent assay. Results: Spinal expression of TLR4 and p-NF-κB (p-p65) was significantly increased after NP implantation, lasting up to 14 days. TLR4 was mainly expressed in spinal microglia, but not astrocytes or neurons. TLR4 antagonist TAK242 decreased spinal expression of p-p65. TAK242 or NF-κB inhibitor pyrrolidinedithiocarbamic acid alleviated mechanical and thermal pain behaviors, inhibited spinal microglia activation, moderated spinal inflammatory response manifested by decreasing interleukin (IL)-1β, IL-6, tumor necrosis factor-α expression and increasing IL-10 expression in the spinal dorsal horn. Conclusions The study revealed that TLR4/NF-κB pathway participated in radicular pain by encouraging spinal microglia activation and inflammatory response.