Objective To analyze the influencing factors of extra uterine growth retardation (EUGR) in premature very low birth weight infants.Methods A total of 61 EUGR premature very low birth weight infants survived in intensive care unit of our hospital were enrolled into EUGR group,and at the same time another 50 non-EUGR premature very low birth weight infants were selected into non-EUGR group.The clinical related medical records in the two groups were compared and analyzed,and the influencing factors of EUGR was analyzed by Logistic regression analysis.Results The birth gestational age of EUGR group was (31.29±1.56)weeks,which was significantly lower than (33.98±1.35)weeks of the non-EUGR group (t=9.60,P<0.05).The birth weight of the EUGR group was (1 206.76±212.14)g,which was significantly lower than (1 341.55±103.26)g of the non-EUGR group (t=4.11,P<0.05).The hospital stay,return to birth weight time,start enteral nutrition time and total parenteral nutrition time in the EUGR group were (27.77±5.00)d,(15.36±5.91)d,(3.36±1.91)d,(16.93±4.02)d respectively,which were significantly longer than those in the non-EUGR group[22.69±3.97)d,(10.61±4.57)d,(2.61±1.37)d,(9.43±3.11)d](t=3.53,4.65,2.33,10.80,all P<0.05).The incidence rates of complications such as respiratory system,digestive system and metabolic disorder in the EUGR group were 26.23%,19.67% and 67.21%,respectively,which were significantly higher than those of the non-EUGR group(8.00%,6.00% and 40.00%)(x2=6.18,4.39,8.22,all P<0.05).Logistic regression analysis showed that low birth gestational age and birth weight,long hospital stay,later return to birth weight and total parenteral nutrition time,intrauterine growth retardation,and respiratory system,digestive system and metabolic disorder were independent risk factors for the occurrence of EUGR(all P<0.05).Conclusion The influencing factors of EUGR in very low birth weight infants were mainly low gestational age and birth weight,long hospital stay,later return to birth weight and total parenteral nutrition time,intrauterine growth retardation,and respiratory system,digestive system and metabolic disorder.Therefore,in order to prevent EUGR,active symptomatic measures should be given in clinic.

BACKGROUND:O-arm navigation integrates CT image quality and the flexible mobility of the C-arm. Surgery for severe spinal deformity is very difficult, with high incidence of nerve injury, so it is a chalenging surgery for spinal surgery. The role of O-arm in the correction of spinal deformity is particularly important. OBJECTIVE:To explore the effect and safety of pedicle screw placement in severe spinal deformity under the guidance of O-arm navigation system. METHODS:Clinical data of 25 patients with severe spinal deformity with the aid of O-arm navigation were retrospectively analyzed. We observed pedicle screw insertion, operation time, intraoperative blood loss, correction of scoliosis and correction of kyphosis, and assessed the safety of screw insertion. RESULTS AND CONCLUSION:(1) Totaly 326 pedicle screws were implanted in 25 patients. According to NEO classification, 280 pedicle screws (92%) belonged to grade 0 (no perforation of pedicle cortex). Grade 1: perforation of pedicle cortex, < 2 mm, including 44 screws (8%); grade 2: perforation of pedicle cortex, > 2 mm, < 4 mm, including 0 screw (0%); grade 3: perforation of pedicle cortex, > 4 mm, including 0 screw (0%). (2) Operation time was (272.3±17.3) minutes. Intraoperative blood loss was (1 710.0±229.1) mL. (3) Cobb angle of scoliosis was changed from (70.5±6.0)° preoperatively to (22.8±4.8)° postoperatively. Cobb angle of kyphosis was changed from (72.0±5.2)° preoperatively to (28.1±5.7)° postoperatively. Significant differences were detected (P< 0.05). (4) These findings verify that with the guide of the O-arm navigation system, the accuracy of screw insertion is high. The risk of intraoperative nerve injury was reduced. The scoliosis and kyphosis deformity were improved effectively.

Objective To evaluate the clinical outcomes of modified eggshell technique through posterior approach for the treatment of hard thoracic disc herniation. Methods From January 2006 to June 2009, 22 patients admitted for hard thoracic disc herniation were reviewed, including 13 males and 9 females, with an average age of 49.5 years (range, 33-69). The courses of disease were 11 months on the average (range, 3-18 ). The lesions located in T8-9 for 4 cases, T9-10 for 9, T10-11 for 7, T11-12 for 2. Each of the patients underwent X-ray, CT scanning and MRI examination before surgery. There were 16 cases of central type, and 6 cases of paracentral type. All patients were treated surgically by modified eggshell technique via posterior approach. Results The mean operative time was 210 min (range, 180-300 min), with a mean blood loss of 860 ml (range, 600-1200 ml). All surgeries were performed successfully without neurological symptoms aggravation. Surgical complications included dural laceration in 2 cases, both dural lacerations were repaired intraoperatively, epidural hematoma in 1 case with lower extremity neurological symptoms, full neurologic recovery was observed after surgical removal of the hematoma. All patients were followed up for average 27.5 months (range, 12-54). The mean JOA score increased from 3.36±1.79 before operation to 7.45±2.99 after the operation at 12 months follow up, and the mean improvement rate of neurological status was 58.3%±30.7%. There was significant difference in JOA score before and after surgery(t=10. 12,P＜0.01 ).The results of 14 cases were ranked as good, 6 as fair, 2 as unchanged, and none as worsened. All cases obtained bony fusion without instrument failure. Conclusion Modified eggshell technique enable ventral and dorsal spinal decompression from the posterior approach in cases of hard thoracic disc herniation, with reduction of the rate of postoperative paralysis.

ObjectiveTo investigate the clinical efficacy of the 3-in-1 technique of Disc-FX system,namely:discectomy,radiofrequency ablation and annuloplasty for discogenic low back pain in the early stage.MethodsFrom February 2010 to February 2011,40 patients with the discogenic low back pain underwent discectomy,radiofrequency ablation and annuloplasty using Disc-FX system were retrospectively analyzed,including 22 males and 18 females with an average age of 38.7 years(range,32-58 years).The visual analogue scale (VAS) scoring was applied to evaluate the back and low limb pain at preoperative,postoperative 1week,3 months,6 months,and last follow-up.The Macnab score was also evaluated at last follow-up.Results All the patients were followed up for average 13.8 months (range,6-18 months).The operative time averaged 26 min(range,20-40 min).No surgical complication was found during the follow-up.The VAS of preoperative low back pain was 6.60±1.47,VAS score of low back pain at postoperative 1 week,3 months,6 months,and final follow-up were 1.05±0.68,1.15±0.70,1.00±0.62,0.95±0.63,respectively.The postoperative VAS of low back pain decreased significantly compared with that preoperative.The VAS of preoperative limb pain was 3.05±1.23,VAS score of limb pain at postoperative 1 week,3 months,6 months,and final follow-up after operation were 1.10±0.74,1.15±0.70,1.10±0.72,0.95±0.54,respectively.The postoperative VAS of limb pain decreased significantly compared with that preoperative.The evaluation of Macnab score were excellent in 20 patients,good in 17,fair in 2,and poor in 1,suggesting an effective rate of 92.5％ (37/40).Conclusion Disc-FX system,which combined three surgical technique in one procedure,provides a new choice for orthopedics to treat discogenic low back pain.It can give satisfactory clinical outcomes during a short-term followup,but the long term clinical outcomes remains unknown.

This study was aimed to establish the three-dimensional model of C_(3-7) segment of lower cervical spine after artificial disc implantation, to analyze the movement of lower cervical spine after artificial disc replacement. According to CT films of 1 patient at 6 months after artificial disc implantation, three-dimensional finite element model that included Bryan~(TM) artificial cervical disc prosthesis of the lower cervical spine was established using finite element method, then introduced into Ansys 9.0, the vertebral cortical bone, cancellous bone and intervertebral disc were meshed and analyzed by using under several states such as flexion/extension, lateral bending and rotation, thus understanding their motion characteristics. By comparison with previous research findings, test results nearly accorded with or exhibited identical trend with previous study. The results suggest that, cervical disc replacement can basically guarantee the stability of lower cervical spine movement.

BACKGROUND: Degenerative lumbar spinal stenosis could be treated by laminectomy internal fixation placement,unilateral or bilateral decompression,posterior laminectomy and so on.However,whether laminectomy internal fixation placement can be used remains unclear.OBJECTIVE: To evaluate the efficacy of interbody fusion cage implantation of pedicle screw fixation,in combination with posterior lumbar laminectomy,bilateral resection and decompression of the inferior articular process,autologous facet joint bone transplantation in the treatment of degenerative lumbar spinal stenosis.METHODS: A total of 41 patients of degenerative lumbar spinal stenosis,who failed after 3 months of conservative therapy,including 23 males and 18 females,at a mean of 60.3 years,Received posterior lumbar laminectomy,bilateral inferior articular process resection and decompression,autologous facet joint bone and cage interbody fusion implant pedicle fixation.They were followed up for 24 months,preoperative and postoperative Japanese Orthopedic Association(JOA)score evaluations were performed to assess the therapeutic efficacy of the patients,radiological examination was done to investigate the graft fusion and vertebral stability of surgical segments in patients.RESULTS AND CONCLUSION: During the follow-up,JOA score significantly increased compared with the preoperative score(P＜0.01)and clinical excellence rate was 90%; 40 cases obtained bony fusion,with a fusion rate of 98%,1 patient exhibited signs of lumbar instability.There was no loosening,fracture and other complications after internal fixation,but 2 cases appeared dural tear,1 case pedicle position deviation,1 case pseudoarticulation formation.The results suggest that the posterior lumbar laminectomy,bilateral inferior articular process resection and decompression,autogenous facet joint bone and cage interbody fusion implanted pedicle screw fixation show good clinical effects for the treatment of degenerative lumbar spinal stenosis.

Objective To evaluate the effectiveness of rehabilitative treatment after extended open-doorlaminoplasty of the cervical spine for cervical spondylotic myelopathy.Methods Sixty patients(mean age 61.7 ±12 years)who had undergone extended open-door laminoplasty of the cervical spine for cervical spondylotic myelopa-thy were studied for an average of 40.7 months.They are divided into a rehabilitation group and a control group with 30 patients in each.The patients in the rehabilitation group received systematic rehabilitation therapy pre-and post-operation.In both groups,the neurological recovery rate,the cross-sectional areas of the cervical posterior muscles,and the incidence of axial symptoms and post-operative complications were recorded and compared. Results The wounds of patients in the rehabilitation treatment group healed with no complicating infections,but the wounds of three patients in the control group became infected.There was no statistically significant difference in neurological recovery between the two groups.In the rehabilitation treatment group,the rate of atrophy and the cross-sectional areas of the cervical posterior muscles were significantly lower than in the control group.At the same time,the rate of neck axial symptoms was 23% in the rehabilitation group but 60%in the control group.a difference which was statistically significant. Conclusions Although rehabilitation treatment pre-and post-operation may not speed up neurological recovery,it may prevent postoperative atrophy of the cervical extensors and lower the incidence of neck axial symptoms.

Objective To investigate the appropriate surgical approach in the management of cervical cord injury following ossification of the posterior longitudinal ligament. Methods The clinical data of 25 patients with cervical cord injury following ossification of the posterior longitudinal ligament who received surgical treatment were retrospectively analyzed. According to Frankel grades, two patients were at grade A, three at grade B, 14 at grade C and six at grade D. The surgical procedures consisted of anterior decompression (12 patients), posterior decompression (8 patients) and combined posteroanterior decompression (5 patients). Results No iatrogenic injury of great vessels, trachea, esophagus or spinal cord occurred. All the patients were followed up for 15-86 months (mean 38.3 months). All segments with anterior fixation attained solid fusion, without implants loosening or breakage. No reelosed open-door was found in patients who received posterior laminoplasty. The spinal function got improved in 21 patients, and a relief of pain or numb of the upper limb was attained in four patients whose spinal cord injury was not cured. Conclusions The surgical outcome of cervical cord injury following ossification of the posterior longitudinal ligament is satisfactory. It is important to select a suitable surgical approach according to the imaging manifestations associated with the general conditions of the patients.

Objective To investigate the efficacy and safety of the resection of cervical posterior longitudinal ligament (PLL) in Bryan cervical disc arthroplasty. Methods Thirty-one patients underwent Bryan cervical disc implantation only in one level from August 2006 to January 2009 were investigated in this study. Cervical PLL was preserved in 14 patients, but not in other 17 patients. The clinical (JOA score,VAS score for neck and arm pain) and radiographic parameters (the FSU angle, ROM and diameter of the spinal cord) were compared between the two groups. Results No differences were found in terms of age, affected segment, gender, follow-up period, operation time and blood loss between the two groups. Patients underwent removal of cervical PLL were significantly superior to those underwent reservation of cervical PLL in term of clinical outcomes. There were no differences between the two groups with regard to the increase of FSU angle and ROM. However, the diameter of the spinal cord had a significant increase in patients underwent removal of cervical PLL. No severe complication was found in the two groups. Conclusion Removal of the cervical PLL is beneficial for the clinical outcomes and does not have an impact on the angle and ROM of the affected segment. The procedure is safe and feasible.

Objective To evaluate the effectiveness of rehabilitative treatment for severe cervical spondylotic myeiopathy after combined posterior-anterior surgery. Methods Fifty-four patients (mean age, 59.5) who had undergone combined posterlor-anterior surgery of the cervical spine due to severe cervical spondylotic myelopathy were studied with an average follow-up of 38.7 months. All the patients were allocated into either a rehabilitation treatment group (28 patients) or a control group (26 patients). Neurological function in the two groups was assessed using the Japanese Orthopedic Association (JOA) grading system. In addition, the status of axial symptoms, wound healing and post-operative complications were also evaluated. Results The bone grafts completely fused in both groups. All of the wounds in the rehabilitation treatment group healed without any infection. Three wounds were infected in the control group, but were cured by prompt treatment. Two patients in the rehabilitation group and 9 in the control group suffered laryngeal edema. There was no significant difference between the two groups before the operation with regard to their JOA scores, which significantly increased postoperation in both groups. In the rehabilitation treatment group, the postoperation JOA scores were significantly higher than in the control group. At the same time, there were significantly fewer patients with neck axial symptoms in the rehabilitation treatment group than that in the control group (25.0% versus 69.2% , P < 0.01 ). Conclusions Systematic rehabilitation treatment pro-and post-operation of patients with severe cervical spondylotie myelopathy can accelerate neurological recovery and help prevent postoperative complications and neck axial symptoms.