ABSTRACT
Objective@#To analyze the correlations between intraoperative ultrasound and MRI metrics of the spinal cord in degenerative cervical myelopathy and identify novel potential predictive ultrasonic indicators of neurological recovery for degenerative cervical myelopathy. @*Materials and Methods@#Twenty-two patients who underwent French-door laminoplasty for multilevel degenerative cervical myelopathy were followed up for 12 months. The Japanese Orthopedic Association (JOA) scores were assessed preoperatively and 12 months postoperatively. Maximum spinal cord compression and compression rates were measured and calculated using both intraoperative ultrasound imaging and preoperative T2-weight (T2W) MRI. Signal change rates of the spinal cord on preoperative T2W MRI and gray value ratios of dorsal and ventral spinal cord hyperechogenicity on intraoperative ultrasound imaging were measured and calculated. Correlations between intraoperative ultrasound metrics, MRI metrics, and the recovery rate JOA scores were analyzed using Spearman correlation analysis. @*Results@#The postoperative JOA scores improved significantly, with a mean recovery rate of 65.0 ± 20.3% (p < 0.001). No significant correlations were found between the operative ultrasound metrics and MRI metrics. The gray value ratios of the spinal cord hyperechogenicity was negatively correlated with the recovery rate of JOA scores (ρ = -0.638, p = 0.001), while the ventral and dorsal gray value ratios of spinal cord hyperechogenicity were negatively correlated with the recovery rate of JOA-motor scores (ρ = -0.582, p = 0.004) and JOA-sensory scores (ρ = -0.452, p = 0.035), respectively. The dorsal gray value ratio was significantly higher than the ventral gray value ratio (p < 0.001), while the recovery rate of JOA-motor scores was better than that of JOA-sensory scores at 12 months post-surgery (p = 0.028). @*Conclusion@#For degenerative cervical myelopathy, the correlations between intraoperative ultrasound and preoperative T2W MRI metrics were not significant. Gray value ratios of the spinal cord hyperechogenicity and dorsal and ventral spinal cord hyperechogenicity were significantly correlated with neurological recovery at 12 months postoperatively.
ABSTRACT
Objective@#To analyze the correlations between intraoperative ultrasound and MRI metrics of the spinal cord in degenerative cervical myelopathy and identify novel potential predictive ultrasonic indicators of neurological recovery for degenerative cervical myelopathy. @*Materials and Methods@#Twenty-two patients who underwent French-door laminoplasty for multilevel degenerative cervical myelopathy were followed up for 12 months. The Japanese Orthopedic Association (JOA) scores were assessed preoperatively and 12 months postoperatively. Maximum spinal cord compression and compression rates were measured and calculated using both intraoperative ultrasound imaging and preoperative T2-weight (T2W) MRI. Signal change rates of the spinal cord on preoperative T2W MRI and gray value ratios of dorsal and ventral spinal cord hyperechogenicity on intraoperative ultrasound imaging were measured and calculated. Correlations between intraoperative ultrasound metrics, MRI metrics, and the recovery rate JOA scores were analyzed using Spearman correlation analysis. @*Results@#The postoperative JOA scores improved significantly, with a mean recovery rate of 65.0 ± 20.3% (p < 0.001). No significant correlations were found between the operative ultrasound metrics and MRI metrics. The gray value ratios of the spinal cord hyperechogenicity was negatively correlated with the recovery rate of JOA scores (ρ = -0.638, p = 0.001), while the ventral and dorsal gray value ratios of spinal cord hyperechogenicity were negatively correlated with the recovery rate of JOA-motor scores (ρ = -0.582, p = 0.004) and JOA-sensory scores (ρ = -0.452, p = 0.035), respectively. The dorsal gray value ratio was significantly higher than the ventral gray value ratio (p < 0.001), while the recovery rate of JOA-motor scores was better than that of JOA-sensory scores at 12 months post-surgery (p = 0.028). @*Conclusion@#For degenerative cervical myelopathy, the correlations between intraoperative ultrasound and preoperative T2W MRI metrics were not significant. Gray value ratios of the spinal cord hyperechogenicity and dorsal and ventral spinal cord hyperechogenicity were significantly correlated with neurological recovery at 12 months postoperatively.
ABSTRACT
BACKGROUND:Whether controling of post-injury inflammatory response combined with neural stem cel (NSC) transplantation can improve the curative efficacy for spinal cord injury stil remains unclear. OBJECTIVE:To investigate the repair of spinal cord tissue, myelin regeneration, axon regeneration, motor function recovery and the possible mechanism after early application of tumor necrosis factor α antagonist (Etanercept) combined with tyrosine kinase C (TrkC) gene-modified NSC transplantation. METHODS:TrkC-overexpressed NSCs (TrkC-NSCs) were constructed by lentiviral transfection technique. The rat models of spinal cord transection injury were prepared, and then subjected to Etanercept combined with TrkC-NSCs transplantation. The number of neurons and neuroregeneration after injury were measured by Nissl's staining, immunofluorescence and western blot. The rat motor function was detected by Basso Beattie Bresnahan score and evoked potential. The myelin regeneration was detected by electron microscopy and toluidine blue staining. RESULTS AND CONCLUSION:Compared with the other groups, the Etanercept combined with TrkC-NSCs transplantation group had more survived anterior horn motor neurons at 28 days after injury, more myelin-encapsulated axons, higher Basso Beattie Bresnahan score, greater amplitude of the evoked potentials, and relatively shorter latency (alP < 0.05). These findings indicate that early application of tumor necrosis factor-α antagonist combined with TrkC-NSCs transplantation after spinal cord injury in rats can effectively promote myelin regeneration, axon regeneration, and further promote motor function recovery.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
BACKGROUND:Antedor canulated screw has been considered an ideal method to treat odontoid fracture.OBJECTIVE:To compare the biomechanical properties of different anterior screws.DESIGN,TIME AND SETTING:A randomized contrast study was performed at the Biomechanics Laboratory of Southern Medical University from March to September 2006.MATERIALS:Double-thread canulated screws and single-thread canulated screws were made of titanium alloy and provided by Shuangyang Medical Apparatus Co.,Ltd.,Suzhou.METHODS:A total of head-neck complexes (C0-C3) which were collected from 20 corpses were maintained in formaldehyde for less than 3 months;thereafter,the muscles and ligaments were removed to obtain the axis specimens so as to make type Ⅱ odontoid fracture models.The fracture samples were individually treated with double-thread and single-thread canulated screws,with 10 samples for each group.MAIN OUTCOME MEASURES:The shear stiffness and the maximum resistance of the two kinds of screw were tested in this study.RESULTS:The shear stiffness of the double-thread screw group was significantly higher than the single-thread screw group (P＜0.01 );however,there was no significant different in the maximum resistance between the two groups (P＞0.05).CONCLUSION:Double-thread canulated screws have a strong biomechanical stability for treating odontoid fracture;therefore,the first choice of the internal fixation should be double-thread canuiated screws for patients with osteoporosis or those who are susceptible to expanded screw pathway during surgical procedures.
ABSTRACT
BACKGROUND:Hydroxyapatite (HA) artificial bone,as bone grafting substitute,would not cause inflammatory reaction or immunological rejection and possesses good biocompatibility after transplantation into human body.It is a novel implant material with bone conduction ability.OBJECTIVE:To investigate the efficacy of HA artificial bone in bilateral open-door posterior cervical expansive laminoplasty and to make a comparison with autogenous bone.DESIGN,TIME AND SETFING:A retrospective case analysis was performed at the Department of Spine Surgery,Hungpuyuan Branch,the First Affiliated Hospital of Sun Yat-sen University from March 2001 to December 2008.PARTICIPANTS:Seventy patients with cervical spondylosis complicated by compression in 3 or more segments or by cervical stenosis and additional fifteen patients with cervical stenosis complicated by cervical trauma were included in this study.METHODS:A bilateral open-door posterior cervical expansive laminoplasty was performed,in which,23 patients received autogenous bone transplantation (autogenous bone group) and 62 patients underwent HA artificial bone transplantation (HA group).MAIN OUTCOME MEASURES:① Japanese Orthopaedic Association (JOA) score pdor to and after surgery,surgery time,and intraoperative bleeding.② HA artificial bone-host biocompatibility.RESULTS:All eighty-five patients were followed up for more than 3 months.There was no significant difference in JOA scores no matter prior to or after surgery between the autogenous bone and HA groups (P＞0.05).The surgery time averaged 85.2 minutes (range 65-110 minutes) in the HA group and averaged 116.4 minutes (range 75-150 minutes) in the autogenous bone group.The intraoperative bleeding averaged 210 mL (range 130-400 mL) in the HA group and averaged 260 mL (range 170-500 mL) in the autogenous bone group.There were no material-host response and other severe complications found in each group,except HA artificial bone fragmentation in 3 patients from the HA group.CONCLUSION:HA artificial bone yields good efficacy and causes fewer complications in bilateral open-door posterior cervical expansive laminoplasty;in addition,it requires less time for surgery and causes less bleeding.
ABSTRACT
Objective To evaluate the clinical efficacy of monosegmental pedicle instrumentation in management of thoracolumbar burst fractures. Methods A total of 67 patients with traumatic thora-columbar burst fractures (type A3.1 and A3.2) were treated with monosegmental pedicle instrumentation in our department from October 2003 to February 2008. Imageologic effect was observed by measuring sagittal index and wedge index via X-ray and clinical outcomes evaluated by using low back outcome score. Results All operations were performed successfully, with average operation duration of 93 mi-nutes and average intraoperative blood loss of 157 ml. Of all, 65 patients were followed up for 4-27 months (average 19.8 months), which showed that all the patients achieved bony fusion, with no implant failure except for one with screw loosening. The sagittal index and wedge index were 13.06°and 42.9% preoperatively and 4.47° and 21.78% postoperatively, with statistical difference (P <0.01). The final follow-up showed no significant correction loss except for two patients (P < 0.05). The low back outcome scores of all patients at follow-up were improved significantly (P < 0.05). Conclusions Monoseg-mental pedicle instrumentation has advantages of minimal invasion, short operative duration, less blood loss and less vertebral motion segment loss and hence is an effective and reliable operative technique for thoracolumbar burst fractures.
ABSTRACT
Objective To compare the biomechanical properties of mono-segTnent pedicle instru-mentation and its combination with bone cement fixation in treatment of thoracolumbar fractures. Meth-ods Eight fresh specimens of calf spines ( T11 -L3 ) were used for development of incomplete burst frac-ture models at the vertebral body of L1. Mono-segment pedicle instrumentation and its combination with vertebroplasty were respectively applied in each specimen subsequently to restore spinal stability. A cyclic loading with pure moment of 4 Nm was applied to specimens, with load frequency of 0.5 Hz for 2 000 cy-cles. Range of motion (ROM) at flexion/extension, left/right lateral bending and left/right axial rotation of the fixated segment at different status of intact, injury, fixation and cyclic loading was determined by spinal three-dimensional instability test system. Results ROM after treatment with two fixation tech-niques and that at different directions after cyclic loading were distinctly smaller than that of intact and fractured models (P <0.05 ). Under mono-segment pedicle instrumentation combined with bone cement fixation, ROM at flexion, extension, lateral bending and axial rotation was 0.40°, 0. 53°, 0.86° and 0.55° respectively and that after cyclic loading was 0.10°, 0.07°, 0.19° and 0.08°respectively, which were all lower than those of monosegmental fixation, especially at flexion and axial rotation, with statisti-cal difference (P <0.05 ). Conclusions Both fixation techniques can provide instant stabihty of the fractured spine and have good fatigue resistance effect. However, mono-segment pedicle instrumentation is inferior to mono-segment pedicle instrumentation plus bone cement fixation in treatment of fractured verte-bral body at flexion and axial rotation.