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.

Objective: To study the effects of soluble multi-peptide agent,marked “Gu Kang Tai Ling”,derived from bone tissue on rat bone fracture healing.Methods 80 right tibia defects of rats were sawed.The “Gu Kang Tai Ling”were intramuscularly injected to the rats.The quality of the defect healing was investigated continuously and respectively by the defect bone histomorphometry,biomechanics,X-ray film,and bone mineral density(BMD).Results: Under the treatment of the agent,at early stage trabecular bone volume (TBV)ratio increased 24.7%,and osteoblast surface(OBS)26.7%,at late stage mean trabecular healing surface rate(MTHSR)was increased 38.8%,tibia anti-fracture strength 0.4527～1.4350N，and BMD 7.65% compared with the control group.Conclusion: “Gu Kang Tai Ling”can accelerate rat fracture healing and improve the quality of healing.

Objective: To evaluate the effects of PD145065(non-selective endothelin(ET)receptor antagonist)on injured spinal cord and explore mechanisms of how ET plays a role in secondary injury following spinal cord injury(SCI).Methods:Spinal cord of rat was traumatized by compression(50g,1min).PD145065 or vehicle was administered intrathecally 10 minutes before SCI.Alterations of spinal cord blood flow(SCBF),molondialdehyde(MDA),the total content of intracellular calcium(［Ca2+］i),Evans blue(EB),and water in spinal cord were inspected.Results:SCBF of injured area decreased obviously 5 minutes after SCI.SCBF was 75.23±9.21% of baseline 5 minutes after SCI,57.06±7.35% 2 hours.SCBF of adjacent area decreased lower.SCBF was 79.82±7.98% of baseline 30 minutes after SCI.SCBF of injured and adjacent areas did not recover 4 hours after SCI.The contents of MDA,［Ca2+］i,EB and water in traumatized spinal cord were significantly more than that of sham(P＜0.05)。PD145065 ameliorated SCBF of injured area obviously and abolished the decrease of SCBF of adjacent area.The contents of MDA,［Ca2+］i,EB and water in spinal cord of PD145065 treated group were significantly less than that of saline treated group(P＜0.05).Conclusion:PD145065 has protective effects on traumatized spinal cord in early phase.ET and its receptors may play a role in secondary injury following SCI by multiple pathways.ETA/ETB receptor antagonist may be useful in treatment of clinical SCI.

Objective To evaluate the biologic characteristics of a new type femoral stems either coated with gradient hydroxyapatite (HA) or additionally loaded with rhBMP-2. Methods Fifteen dogs were divided into 3 groups according to the implanted hip prosthesis. Each animal received hemiarthroplasty in the right hip with prosthesis made of pure Ti-6Al-4V femoral stem (Ti group), the new gradient HA-coated femoral stem (HA group) with 100 to 150 ?m hydroxyapatite coating, and the new gradient HA-coated femoral stem loaded with rhBMP-2 of 9 mg (BMP-HA group) respectively. The dogs were sacrificed at 12 weeks after operation, and labeled with tetracycline 3 of 30 mg/kg days prior to sacrifice, and then the histological changes of the tissue surrounding the prosthesis were evaluated. The radiographic examinations were taken before and after sacrifice. Results On radiographic examination, local radiolucent line around the prosthesis was observed only in one specimen in Ti group. The new bone formation was found both in HA group and BMP-HA group more obviously than in Ti group. Under microscopy, it was noted that this new gradient HA-coating was intact and no obvious biodegradation in most section, whereas a fibrous membrane was found in Ti group. The average rates of interface osteointergration in Ti group, HA group and BMP-HA group were 4.05%?7.66%, 71.04%?9.81% and 88.86%?6.56%, respectively, those of HA and BMP-HA group were significantly higher than that of Ti group (P

Objective Investigating transplanted time of periosteal mesenchymal stem cell (PMSC) Methods Rat PMSCs were allografted into rat tibia defects made in different time of granulation Then the quantity of formatted bone,i.e.,trabecular volumm rate (TVR),in the defects were measured in histology and bone histomorphometry by 2,3,4 and 8 weeks respectively after transplantation The long bone draft fracture defects of patients were allografted with PMSC of youth children after 2 week of fracture Results TVR was higher and the defects healed more fast in those rats transplanted PMSCs within 2 weeks after the defect were made However there was insignificant difference between the groups of PMSC transplantation was carried out after two weeks of the defect The fractured defects were healed in 15 cases (57 7%) and were not healed in 11 cases (42 3) after 9 months of transplantation Conclusion That rat bone defects were transplanted PMSC within 2 weeks showed expected bone formed effect and insignificant effect on accelerating defect healing by PMSC transplantation in rats or patients after 2 weeks.

[Objective]To investigate the diagnosis and treatment of lumbosacral nerve roots anomalies. [Method]Etiological factors,typing,diagnosis and treatment of lumbosacral nerve roots anomalies confirmed by operation were analyzed.Operative treatment included wide laminectomy(n=8),hemilaminectomy(n=8) and enlargement fenestration(n=9).[Result]The presenting symptoms of lumbosacral nerve roots anomalies often resulted from lumbar disc herniation or spinal canal stenosis.The typs of lumbosacral nerve roots anomalies included conjoined nerve roots(n=10),closely adjacent roots(n=8),thickening of nerve roots(n=2),caudal origin roots(n=2),division of nerve roots(n=1),double nerve roots(n=1),and anastomosis of nerve roots(n=1).The levels of nerve roots anomalies were L4 in 1,L5 in 14,and S1 in 10.Only 5 cases were diagnosed preoperatively by myelography,CT or MRI.The others were found at operation.All patients were followed up for more than 2 years.Postoperatively,the results were rated as excellent in 12,good in 8,and fair in 4.One patient had residual radiating pain in the lower lims and weakness in dorsiflexion of the foot. [Conclusion] Radicular symptoms of lumbosacral nerve roots anomalies are changeable.The preoperative diagnosis is difficult to establish by myelography,CT or MRI(axial and sagittal plane).It is necessary to heighten the sensitivity of diagnostic modalities.It may improve the surgical outcomes to expose sufficiently,to explore the nerve roots carefully and to decompress thoroughly.

Objective To investigate the clinical application of transcranial magnetic stimulation motor evoked potentials (TMS-MEP) of rectus abdominis in the diagnosis of thoracic spinal cord injury. Methods The innervation of rectus abdominis and dermatomal distribution were studied in 5 adult cadavers. MEP of bilateral rectus abdominis in different segments was measured and recorded in 25 normal subjects for reference and in 23 patients with T4-T12 spinal cord injury. Results The anatomic study showed that rectus abdominis was innervated by 7 pairs of intercostal nerve from T6 to T12, useful to determine the MEP recording points in the body surface. In all normal subjects, T6-T12 MEP of bilateral rectus abdominis were recorded successfully and the referential range of normal MEP was established. The MEP peak latencies of each level were significantly different each with other. Among 23 patients suffering from thoracic spinal cord injury, 12 cases with complete paralysis had no MEP record below the injured level and no neurological recovery during the follow-up; while in 11 cases with incomplete paralysis, abnormal MEP were recorded in all but one with T4 fracture, the MEP of this patient disappeared below T6. The change of MEP of rectus abdominis was consistent with the level of fracture except in 1 case. During follow-up, 9 cases with incomplete paralysis patients showed recovery to different extent. Conclusion According to neuroanatomy, segmental MEP of rectus abdominis can be evoked and recorded in all normal subjects. The MEP peak latencies are significantly different in each level. MEP of rectus abdominis is proved to have the localizing and characteristic diagnostic value in the evaluation of the thoracic spinal cord injury.

[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.

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.

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.