BACKGROUND:The factors to affect spinal fusion are suitable bone graft location,good graft bed,enough bone grafts,strict fixation measure and enough fixation time. However,it is unclear which method should be used between intervertebral bone grafting and intertransverse bone grafting,as well as which material should be used between autogenous iliac bone and autogenous spinous process and vertebral lamina of resection. OBJECTIVE:To compare the fusion rate and improvement of clinical symptoms among different bone graft materials and methods which used in bone fusion for lumbar spondylolisthesis. DESIGN:A control observational experiment. PARTICIP ANTS:A total of 92 patients with lumbar spondylolisthesis who received bone fusion treatment. According to Meyerding classificantion,there were 50 cases of degree Ⅰ,40 cases of degree Ⅱ,1 case of degree Ⅲ,and 1 case of degree Ⅳ. There were 1 case in L3,58 cases in L4,and 33 cases in L5. METHODS:All patients received spinal canal decompression. After reduction and fixation was performed by spondylolisthesis reduction system(SRS) ,bone grafting fusion was performed in all patients. They were divided into four groups:autogenous spinous process and vertebral lamina graft placed between transverse processes group(n=21) ,autogenous spinous process and vertebral lamina graft placed between the vertebral bodies group(n=27) ,autogenous iliac bone graft placed between transverse processes group(n=21) ,autogenous iliac bone graft placed between the vertebral bodies group(n=23) . MAIN OUTCOME MEASURES:The fusion rate and the improvement of clinical symptoms were evaluated according to the X-ray pre and post operative,as well as the JOA score. RESULTS:At 6 months after operation,the fusion rate in the autogenous iliac bone graft placed between the vertebral bodies group were significantly higher than that in the other three groups(P 0.05) . According to the JOA score,at 6,9,and 12 months after operation,there were no differences in the score among the four groups. CONCLUSION:Posterior bone graft fusion of the vertebral body or transverse process using the vertebral lamina,spinous process,or iliac bone as autograft along with internal fixation for lumbar spondylolisthesis are effective. However the use of the iliac bone as autograft contributes to a higher fusion rate in the same method at 6 months. Further using the same material as autograft,the fusion rate of the autograft placed between vertebral bodies is better than that of the autograft placed between transverse processes at 6 months.

Objectives: To verify the feasibility and safety of the anterior transpedicular screw(ATPS) fixation of the upper thoracic spine (T1-T4) through the radiological anatomy study on the cadaveric specimens. Methods: The upper thoracic spine thin-section CT data of 40 cases were collected from the radiology de-partment′s database(20 males and 20 females, aged from 18 to 68 years, the mean age was 39.7 years). The data of OPW(outer pedicle width), OPH(outer pedicle height), PAL(pedicle axis length), TPA(transverse section angle), SPA(sagittal section angle), DTIP(distance of transverse intersection point) and DSIP(distance of sagittal intersection point) of each pedicle were measured on the transverse and sagittal sections through the axis of each pedicle. The data were recorded and statistically analyzed. 10 upper thoracic spine(C7-T6) specimens of adults(5 males and 5 females, with unknown ages), with no damage to their appearance, the costovertebral joints and paravertebral soft tissue were completely retained. Then simulate surgical operations were done on the cadaveric specimens based on the obtained data. Screws were implanted anteriorly by free hand. After that, the specimens accepted X-ray fluoroscopy and CT scan. At last, the screws were removed, the speci-mens were sawed along the transaction and sagittal section of the screw channel. Then the success rate of the screw placement was evaluated according to Rao′s worn out classification standard of pedicle screws. Results: From T1 to T4, the OPW decreased from 8.14mm to 3.47mm; the OPH increased from 6.89mm to 10.29mm; the TPA decreased from 32.96° to 11.64°; the DTIP increased from 1.80mm to 5.50mm; the SPA increased from 104.95° to 115.74°; the DSIP increased from 5.95 to 8.76mm; the PAL changed irregularly, from 32.95 to 35.96mm. The pedicle diameters of T3 and T4 were too small to implant ATPS, but the ARTPS can be implanted successfully. The diameter of ATPS was about 4.0mm; the length of ATPS was about 35mm. The diameter of ARTPS was about 5.0mm; the length of ARTPS was about 35mm. 80 pedicle screws were implanted anteriorly, according to Rao′s worn out classification standard of pedicle screws, the fine rate was 90%. The internal walls of 7 pedicles were broken by screws of less than 2mm and no compression to the spinal cord. The internal walls of 5 pedicles were broken of 2 to 4mm, 1 at T1, 1 at T3 and 3 at T4, with varying degrees of spinal cord compression. The internal walls of 2 pedicles were broken of greater than 4mm, 1 at T2 and 1 at T4, with serious spinal cord compression. The external wall of 1 pedicle was broken at T2. Conclusions: The ATPS techniques at T1, T2 and the ARTPS techniques at T3, T4 are feasible, but the safety and clinical practice and further research is needed.

OBJECTIVETo establish a mouse model of spinal metastasis of human prostate cancer using fluorescence-labeled PC-3 cells to allow direct observation by in vivo imaging.

METHODSPC-3 cells were infected with a lentivirus carrying green fluorescence protein (GFP) gene. The GFP-positive cell clone was expanded and prepared into cell suspension for injection into the inferior vena cava of nude mice. The tumor growth and metastasis in the mice was directly observed using an in vivo fluorescence imaging system. The tumor-bearing mice were sacrificed after 3 months for histological examination with HE staining.

RESULTSThe labeled cells showed stable GFP expression both in vitro and in vivo. One week after cell injection, green fluorescence signals were detected by the in vivo fluorescence imaging system in the lower back of the mice, and at 4 weeks, the fluorescent tumor mass increased with a bone metastasis rate of 19% (3/16). Dissection of the mice at 3 months revealed lumbar tumor infiltration in 3 mice, showing a consistent result with in vivo fluorescence imaging.

CONCLUSIONThe nude mouse model of spinal bone metastasis of human prostate cancer established using GFP-labeled PC-3 cells facilitates further study of bone metastasis of prostate cancer.

Animals ; Cell Line, Tumor ; Disease Models, Animal ; Green Fluorescent Proteins ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Metastasis ; Prostatic Neoplasms ; pathology ; Spinal Neoplasms ; secondary

Objective To compare the rigidity at upper thoracic spine among the anterior transpedicular screw-plate system (ATPSPS),posterior transpedicle screw-rod system (PTPSRS) and anterior vertebral body screw-plate system (AVBSPS).Methods Twelve embalmed cadaver specimens were divided into three groups.The specimens in each group were randomly allocated to use the above 3 different internal fixation devices for conducting fixation.The stiffness of each specimen on the directions of axial compression,flexion and extension,and left and right lateral bending was detected under original status.All specimens conducted the simulated corpectomy of T2 (damage status).Then the rigidity on various directions was re-detected on the damage status.The corresponding internal fixation system was selected for conducting the install and fixation according to the grouping results.The intra-group and inter-group rigiditieson different directions were compared amongoriginal status,damage status and after internal fixation.Results The rigidities on different directions under original and damage statushad no statistical difference among various groups (P＜0.05).After conducting fixation in each group,the rigidity after fixation on different directions had statistically significant difference among groups(P＜0.05).The stiffness of anterior flexion in the ATPSPS group was greater than that in the other two groups (P＜0.05).The rigidity of axial compression and extension in the PTPSRS group was greater than that in the other two groups,the difference among groups was statistically significant (P＜0.05).The stiffness of lateral bending in the AVBSPS group was smaller than that in the other two groups,the difference was significant (P＜0.05),but the difference between the other two groups had no statistical significance (P＞0.05).Conclusion The rigidity of ATPSPS in all directions is higher than that of AVBSPS.The anterior flexion rigidity is greater than PTPSRS,and the axial compression and extension rigidity are less than PTPSRS,but the lateral bending rigidity is equivalent to PTPSRS.

Some primary bone tumors are prone to hematogenous metastasis and after that, the therapeutic effect is not that good and prognosis is poor. Circulating tumor cells (CTC) shed from the tumor cells of primary or metastatic focus and then enter into blood circulation. CTC may appear in the early stage of the tumor, which can implant in distant organs to form metastatic sites and self-implant in the primary sites leading to the tumor recurrence; CTC are closely related with the prognosis of patients with tumors. In most primary bone tumors, CTC are heterogeneous compared with primary tumor cells. Studying CTC from various aspects can provide a basis for the early diagnosis and treatment of primary bone tumors. This review summarizes the current researches of CTC in common primary bone tumors, and expects the future of research direction and application practice in clinic.