Objective:To explore the clinical value of extra-long subcutaneous tunnel ventricular drainage in patients with hydrocephalus.Methods:From March 2016 to March 2020, 33 patients who were not suitable for ventriculoperitoneal shunt, who would have expected time of external ventricular drainage longer than 7 d, who had external ventricular drainage reaching for 7 d and still could not expect for drainage tube drawing for the next 7 d, or who had hydrocephalus after external ventricular drainage were chosen in our study. These patients accepted extra-long subcutaneous tunnel ventricular drainage. The curative effects in the patients were analyzed retrospectively.Results:The drainage tube was kept for a maximum of 24 months and the shortest time was 13 d, with average of 69.3 d; 32 patients (97%) had drainage time longer than 14 d. There was no secondary infection after operation.Conclusion:Extra-long subcutaneous tunnel extraventricular drainage tube has a long duration of catheter placement, could avoid multiple drainage and secondary intracranial infection, so it is a safe and effective new technology for hydrocephalus.

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.

ObjectiveTo compare the clinical effect of posterior circumferential fusion with versus without intertransverse process fusion on lumbar instability in aged patients. MethodsThe elderly with lumbar instability were treated with the posterior instrumented circumferential fusion technique in 80 cases. Among 58 patients followed up for at least 2 years, 28 cases (group A)underwent posterior circumferential fusion with intertransverse process, while 30 cases (group B)without intertransverse process. X-ray examination was used before and 1, 3, 6, 12 and 24 months after operation to evaluate the fusion condition of the bone graft, and visul analogue scale (VAS) and Oswestry disability index (ODI) questionnaire were applied to assess the pain of center back and leg,and the conventional activity.ResultsThe operation time and blood loss were more in group A[(185.3±56.6) min and (376.3±92.9) m1] than in group B [(146.4±46.3) min and (234.3±64.5)ml (t=12.37, 37.49, P＜0.01)]. All the 58 cases were followed for at least 2 years. The 27 cases (96.4％) of group A and 28 cases (93.3％) of group B got bone fusion (x2 =0.004, P＞0.05).There were marked differences in the VAS of center back at 1 and 3 months after operation between the 2 groups (t=3.178, 2.158, both P＜0.05), while no difference at the other 3 time point. VAS about the leg pain and the ODI showed no differences between group A and B after operation (all P＞0.05). ConclusionsFor the lumbar instability in the elderly, the posterior circumferential fusion with or without intertransverse process fusion can achieve a similar high rate of fusion and satisfactory clinical results,andtheposteriorcircumferentialfusionwithoutintertranaverseprocess is recommended for less trauma.

ObjectiveTo establish a new biomechanical test for evaluating biomechanical properties of femoral metaphysis in ovariectomized rats.MethodsTwenty-five-month-old female Sprague-Dawley rats were randomly divided into ovariectomized (OVX) group and the sham-operated (Sham) group (n=10).Twelve weeks after operation,femur BMD and histomorphometry of distal femur were detected.Furthermore,femur biomechanical parameters were determined by diaphysis three-point bending test and a new designed metaphysis bending test.The relationships between the biomechanical parameters and BMD or bone histomorphometry were assessed with Pearson correlations.ResultsThe femur BMD,bone histomorphometrical indexes(％Th.Ar,Tb.N,Tb.Th),and biomechanical parameters(maximum load,yield load and stiffness) of OVX group significantly decreased compared with Sham group.In metaphysis bending test,the mean difference of the maximum load(Fmax),yield load(Fy) between group OVX and Sham were significant higher than that in diaphysis three-point bending test.Positive correlations between biomechanical parameters and femur BMD or bone histomorphometry indexes were observed in both the diaphysis bending and metaphysis bending test.The biomechanical parameters in the metaphysis bending test showed stronger correlations with BMD and bone.ConclusionFemur metaphysis bending test could be used to evaluate the biomechanical properties of osteoporosis.When compared with diaphysis bending test,femur metaphysis bending test is more sensitive in evaluating the change of biomechanical properties of femur in osteoporotic rats.

Objective To investigate the changes of somatosensory-evoked potential(SEP)during an mild impact spinal cord injury in rats 80 as to evaluate its potential value in prevention of such iatrogenic damage. Methods Twenty-four SD rats weighing(340±28)g were randomly divided into two groups,ie,sham control group(only exposure without impact at C6)and injury group(mild impact spihal cord injury at C6).SEP wss recorded in both groups.The changes of SEP in waveform,amplitude and latency were observed and compared between groups and between operations.The gross dissection and histologic analysis were performed after surgery for comparative study. Results SEP waveforms,amplitude and latency showed no significant change in the sham control group.In contrast,the SEP waveform and amplitude animals showed significant changes in the injury group after impact spinal cord injury and the amplitude was decreased from pre-injury(1.3±0.7)μV to post-injury(0.5±0.4)μV(P<0.05),while the latency showed no significant difference between(11.1±2.1)ms pre-injury and(10.7±1.3)ms post-injury(P>0.05).However,this abnormal change appeared in a temporary period at(5.7±3.2)minutes after impact and lasted for about(7.1±3.3)minutes.Diffused hemorrhagic nidus could be seen in the injured cord,which was not found in the sham control group. Condusions Mild impact spinal cord injury may induce transient abnormalities of SEP in waveform and amplitude,which requires careful monitoring in clinical practice.The sudden change in SEP may be associated with impact and vibration damage to the spinal cord,suggesting timely use of protection measures for spinal cord.

Objective To evaluate of the efficacy of transcranial electrical stimulation motor evoked potential (TES-MEP)in combination with cortical somatosensory evoked potential (CSEP) monitoring during the anterior or posterior approach spinal surgery for cervical spondylitie myelopathy (CSM).Methods TES-MEP on the bilateral anterior tibial muscle and flexor hallucal brevis and thenar muscles and CSEP on the bilateral posterior tibial nerve and ulnar nerve were observed simultaneously in 135 patients during spinal surgery.Intravenous anesthesia was employed in all the patients.The results of TES-MEP,CSEP and combined monitoring were analyzed statistically.Pre-oporative and post-operative motor and sensory functions of the spinal cord were compared. Result Success rate of TES-MEP,CSEP and the combined monitoring was 87.4%.97.8%and 100%,respectively.Out of 135 patients,nine patients (6.7%) were detected with the positive evoked potentials due to surgical operation.The sensitivity of TES-MEP and CSEP in assessing the spinal cord motor function was 100%and 83.3%,respectively,while that in assessing the spinal cord sensory function was 77.8%and 100%,respectively.The sensitivity and specificity of the combined monitoring was both 100%. Conclusion The successful detection rate and accuracy of the combined monitoring for spinal cord function are apparently higher than that of simple TES-MEP or CSEP.The causes for operative maneuvers evoking a positive evoked potential include complete anterior decompression of the spinal canal,intervertebral bone graft,laminoplasty for OPLL and hematoma compression caused by a failed drainage in a posterior-anterior approach surgery.

Objective To analyze and evaluate the effect of posterior circumferential fusion for treatment of the mechanical instability of lumbar spine, and discuss the relative merits,indications and contraindications in this procedure. Methods Two hundred and two patients with mechanical instability of lumbar spine treated by the posterior instrumented circumferential fusion technique from January 2001 to January 2007. One hundred and thirty-two patients were selected who were treated with only one segment fusion and followed up for at least 1 year, of them 97 patients suffered lumbar spondylolisthesis, 35 patients suffered degenerative lumbar instability. X-ray was used to evaluate the fusion condition of the bone graft, and VAS and ODI questionnaire were applied to assess the pain of back and leg,and the conventional function. Results All patients were followed up for 12-84 months, averaged (43±23) months,125 patients got bone fusion, accounted for 94.7%(125/132). The VAS of low back pain was (6.71 ± 1.31) points before operation, while (3.20 ± 1.14) points after operation (P < 0.05) ,and the VAS of leg pain was (8.33 ± 1.78) points before operation,while (4.31 ± 1.15) points after operation (P< 0.05). The ODI was (68.6 ± 14.7) % before operation, while (13.6 ± 1.5) % after operation (P < 0.05). Conclusions Posterior circumferential fusion is a positive and excellent treatment for the mechanical instability of lumbar spine. With its merits, the high fusion rate and good clinical results can be received.

Objective To evaluate the primary outcomes of minimally invasive lumbar microdiscectomy. Methods There were 34 cases with single lumbar disc herniation treatment of tubular retractor access with METRx system and microdiscectomy(MMD group)and same cases with treatment of conventional discectomy(CD group).Operating time,blood loss,time of leaving the bed and length of hospital stay were compared in two groups.The postoperative wound pain was measured using a visual analog scale(VAS).The modified MacNab criteria were used to evaluate the outcomes. ResuIts The mean operating time was 65 min in MMD group,63 min in CD group.The mean blood loss was 34 ml in MMD group,85 ml in CD group.To compare in two groups,there was significant difference(P＜0.05).The mean time of leaving the bed after operation was 3.2 d in MMD group.5.8 d in CD group.The mean length of hospital stay was 5.8 d in MMD group.9.6 d in CD group.The mean VAS of the postoperative wound pain was 3.2 scores in MMD group,5.6 scores in CD group.To compare in two groups,there was significant difference(P＜0.05).There was one complication in MMD group,4 in CD group.Thirty-three cases got follow-up mean 8.5 months in MMD group.The success rate was 93.9%. Conclusion The minimally invasive lumbar microdiscectomy has the advantages on less trauma,safety,quickly postoperative recovery,and satisfactory outcomes.

BACKGROUND: There have been many methods of fixation between lumbar-sacral spine and pelvis. However, a safe, firm, and ideal method of internal fixation has not been found.OBJECTIVE: This study was designed to investigate the stability of the fixation between lumbar-sacral spine and pelvis with the connectible skills using iliac screw and lumbar-sacral spine pedicle screw.DESIGN, TIME AND SETTING: This study, a control experiment, was performed at the Institute of Biomechanics, Sun Yat-sen University, Guangzhou, Guangdong Province, China between January 2006 and December 2007.MATERIALS: The lumbar-sacral spine and pelvis specimens were collected from six freshly cryo-preserved male adult corpses caused by trauma. Iliac screw (8.5mm×100mm), L5 pedicle screw (6.5mm×45mm), and S1 pedicle screw (6.5mm×35mm) were provided by Sofamor Company, USA. MTS 858 Bionix Material Testing System (USA) was also used.METHODS: The lumbar and iliac vertebrae, pelvis from six fresh frozen cadaveric specimens were operated in three different ways of fixation respectively: iliac ala lag screw, L5-S1 pedicle screw rod system, iliac screw and L5 pedicle screw connecting system. Three ways of fixation as mentioned above were compared with the intact group in biomechanical stability.MAIN OUTCOME MEASURES: The mobility of whirl, lateral bending, proneness, and backward stretching among groups.RESULTS: Using iliac screw for the fixation between lumbar-sacral spine and pelvis turned out to be the best in stability. The range of motion (ROM) decreased obviously in each situation. The three-dimensional mobility in the 6.4Nm moment of force was (1.07±0.86)° for whirl, (0.95±0.47)° for lateral bending, (1.22±0.67)° for proneness, and (1.80±0.73)° for backward stretching. There was significant difference between the intact group and the group carried out by iliac screw and L5 pedicle screw for the fixation between lumbar-sacral spine and pelvis (P<0.01).CONCLUSION: The connectible skills using iliac screw and the lumbar-sacral spine pedicle screw possesses the biomechanical advantages of maintaining the stability between lumbar-sacral spine and pelvis.

[Objective]To report the initial outcomes of occipitocervical fixation using plate-rod-polyaxial screw system and investigate whether this new system offers any advantage over other existing methods of fixation.[Method]Fourteen cases(male 9,female 5)accepted cervicooccipital fixation with plate-rod-polyaxial screw system.There were 3 cases of odontoid dysplasia with dislocation;spinal canal tumor in 3;2 cases of metastatic carcinoma with pathologic fracture of C_1 and C_2,rheumatoid arthritis with cervicooccipital instability,and fasilar impression;burst fracture of C_1 with oecipital-atlantal-axial instability in 1.Twelve cases had neck pain.Thirteen cases had neurological deficits in different degrees.JOA score was 12.4 on average.[Result]The positions of all screws were good.There was no complication related to inserting screws.All neck pain released.Fourteen-months follow-up was obtained on average in 13 patients.Cervicooccipital nonunion was in one case and its occipital screws were pulled out.Twelve patients had satisfactory fixation and got firm fusion.Ameliotate rate of JOA score of the neurological function was 63.0%.[Conclusion]These initial data indicate that posterior occipitocervical fixation using plate-rod-polyaxial screw system is safe and reliable,and satisfactory clinical outcome can be obtained.The system appears to offer some advantages over other existing methods of fixation.