BACKGROUND:Bioabsorbable polymer materials used in interbody fusion are currently a hot research, and there is stil no consensus.
OBJECTIVE:To summarize the basic research and clinical application of bioabsorbable polymer interbody fusion cages.
METHODS:A search of literatures in the database of Wanfang, VIP and PubMed databases from January 1989 to June 2012 was performed with the key words of“intervertebral fusion;bioabsorbable;spine;animal experiment;clinical research”in Chinese and English, respectively. Al the literatures concerning bioabsorbable polymer interbody fusion cage were extensively reviewed, and current developments in the basic research and the clinical application of bioabsorbable polymer interbody fusion cage were investigated.
RESULTS AND CONCLUSION:Basic researches show that bioabsorbable polymer cage can effectively promote interbody fusion, the main defect is the delayed inflammatory response and bulk erosion, and the degradation and fusion speed, mechanical strength and porosity need further studies. At present, the hybrid copolymer of polylactic acid and its derivatives is used in clinic and relevant research is being carried out. The main advantage of the material is that it is of flexibility to change parameters when used in fusion for different needs, but a good blood supply to tissues around the fusion cage and the osteogenesis effect are very important. Scaffold porosity and other key parameters can affect the mechanical properties of fusion cage to provide sufficient space to meet the requirement of cellmigration, angiogenesis, thereby promoting bone fusion, under the necessary pressure load. So, to find the optimal combination of parameters in the field of bone tissue engineering is stil a chal enge.

Objective A design of guide wire localization apparatus for the internal fixation of dens fractures. Methods From October 1999 to February 2000, 5 cases of dens fractures were treated by anterior internal fixation using cannulated compression screws; 4 cases were of Anderson typeⅡ and 1 case was typeⅢ . The guide wire localization apparatus was used for all of the patients during operations. Results The operating time was 2 to 2.5 hours, averaging 2 hours 15 minutes. The amount of bleeding was 20 to 100 ml, averaging 60 ml. The time of follow-up was 5 to 9 months, averaging 6.7 months. The locations of all the 5 cannulated compression screws were excellent, positioning in the center of the odontoid process without deviation. 4 cases healed normally and 1 had delayed bone healing. Conclusion The use of a guide wire location apparatus increased the accuracy of internal fixation of screws in dens fracture, decreased X-ray to radiation to the bodies, and reduced the possibility of pollution in operation.

Methoxyadiantifoline 10 mg/kg i.v. significantly increased the arrhythmia- inducing dose of aconitine in anaesthetized rats, and that of ouabain in anaesthetized guinea pigs. It markedly prevented ventr icular fibrillation induced by chloroform. Methoxyadiantifoline is also effective in preventing reperfusion-induced arrhythmias in anaesthetized rats. It was demonstrated that methoxyadiantifoline slowed heart rate significantly, and prolonged P-R and Q-Tc interval of ECG in rats.

Objective To study the method and ability of multi-slice CT isotropic scan and post-processing in displaying the anatomy of cervical vertebrae.Methods The normal cervical spines in 53 cases were scanned with isotropic parameters using 16-slice-helical CT.All the images were post-processed with the methods of MPR,MIP,SSD and VRT and each other were compared between them,then the best one was selected to compare with axial CT images and plain films.The abilities in displaying inter-vertebrae disc,spinal canal longtitude,vertebrae body,vertebral arch,zygapophyseal joint and inter-vertebrae foramen were compared among the 3D reconstruction,direct CT scan and X-ray plain film including post-anterior,lateral,left-anterior oblique and right-anterior position project.Results The quality of isotropic post-processing images had no remarkable differences with that of direct CT scan in showing inter-vertebrae disc,but it was better than X-ray plain film and conventional CT scan mode in showing other structures.Conclusion The multi-slice helical isotropic CT scan and post-processing images are of great value in the study of cervical spine.

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.

Objective To evaluate the safety and efficacy of one-level posterior lumbar interbody fusion(PLIF) combined with Prospace and facet fusion using local autograft. Methods Clinical and radiographic data of 76 patients treated by this technique was reviewed from May 2002 to December 2004. Of them, there were 52 males and 24 females, with an average age of 53.2 years (23-81 years), including 60 cases of degenerative disc disease, 9 cases of failed back surgery syndrome and 3 cases of spondylolysis. The disese courses were 1.2-8.7 years (mean 3.6 years). The levels of PLIF were: L2,3 in 2 cases, L3,4 in 7, L4,5 in 54, L5/S1 in 10, L4/S1 in 1 and L5,6 in 2. After decompression, Prospace was inserted into interbody space bilaterally,and located in disc space 4 mm beyond the rear edge of the vertebral body. Local laminectomy autograft was packed both laterally into and between 2 implants. Then the remanent local autograft was placed over facet bed. Pedicle screws were used after insertion of Prospace. Clinical results were evaluated by the JOA score. Disc height ratio and lumbar lordosis angles were measured on lateral radiographs. Fusion status was determined by evidence of bridge trabeculae across facet joint and interbody space on CT scan without mobility in lateral dynamic X-rays, and no radiolucent gap between Prospace and endplate. Paired t-test was used for statistical analysis. Results Mean blood loss and operative time was 384 ml and 178 minutes, respectively. The average JOA score at final follow-up (26.1 + 2.7) was significantly improved when compared with that of pre-operation (14.5 ± 4.0, P ＜ 0.05), with a mean recovery rate of JOA score 81.1% (37.5%-100.0%). The fusion rate was 97.4% (74/76). Mean disc height ratio and the involved segmental lordosis angle were increased from preoperative 0.27 ±0.07 and 5.8 + 2.2° to 0.33 + 0.06 and 11.3 + 2.0° respeetively at the final follow-up, and the differences were significant ( P ＜ 0.05). There were no device-related complications. Conclusion This surgical technique combined with Prospace interbody device is a safe and effective surgical option for patients with one-level lumbar disorders when PLIF is warranted.

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 analytical performance of homocysteine (Hcy) by circulating enzymatic method .Methods Re‐ferring to CLSI evaluation project and pertinent literature ,and by combining our actual works .we designed a verification procedure and experimental method .By using these above ,the precision ,accuracy ,analytical measurement range ,clinical reportable range of Hcy by circulating enzymatic method were evaluated .Results would be compared with the declaration of the manufacturer (NingBo Medical System Biotechnology Co .,Ltd) or desirable specifications derived from biologic variation .Results The results showed that the within‐run CV were 1 .26% and 0 .84% ,and the total CV were 1 .36% and 1 .32% ,less than 10% of the manufacturer′s statement .The relative bias between the results measured for calibrator at tow levels and target value was 3 .69% and 0 .69% ,less 10% .AMR was 3 .38-51 .81 μmol/L ,and the most suitable dilution rate was 1∶3 ,so the CRR was 3 .38-155 .43 μmol/L .Con‐clusion The analytical performance of Hcy analyzed by circulating enzymatic method is consistent with the standards which manu‐facturers has proclaimed ,so it is conform to the requirements of clinical .

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.

In surgical operation of the non-small cell lung cancer (NSCLC),the resection of lymph node involvement is highly correlated with the prognosis of NSCLC patients.The precise estimation of localized lymph node involved and the determination of relevant pattern of lymphadenectomy are the significant predictors for the prognosis and postoperative treatment in NSCLC patients.Therefore to identify the lymph node metastasis earlier has more important significance for tumor clinical staging and making therapeutic schedule.In recent years,the value of sentinel lymph node (SIN) has attracted more and more researchers attention in detecting the occult lymph node micrometastases and surgical staging.