ObjectiveTo compare the biomechanical differences between the kidney-shaped nano-hydroxyapatite/polyamide 66 (n-HA/PA66) Cage and the bullet-shaped n-HA/PA66 Cage. MethodsL2-L5 spinal specimens were selected from 10 adult male pigs. L2, L3 and L4, L5 served as a motor unit respectively, 20 motor units altogether. They were divided into 4 groups (n=5):no treatment was given as control group (group A); nucleus pulposus resection was performed (group B); bullet-shaped Cage (group C), and kidney-shaped Cage (group D) were used in transforaminal lumbar interbody fusion (TLIF) through left intervertebral foramen and supplemented by posterior pedicle screw fixation. The intervertebral height (IH) and the position of Cages were observed on the X-ray films. The range of motion (ROM) was measured. ResultsThere was no significant difference in the preoperative IH among 4 groups (F=0.166, P=0.917). No significant change was found in IH between at pre- and post-operation in group B (P>0.05); it increased after operation in groups C and D, but difference was not statistically significant (P>0.05). There was no significant difference in the postoperative IH among groups B, C, and D (P>0.05). The distance from Cage to the left margin was (3.06±0.51) mm in group C (close to the left) and (5.68±0.69) mm in group D (close to the middle), showing significant difference (t=6.787, P=0.000). The ROM in all directions were significantly lower in groups C and D than in groups A and B (P<0.05), and in group A than in group B (P<0.05). The right bending and compression ROM of group C were significantly higher than those of group D (P<0.05), but no statistically significant difference was found in the other direction ROM (P>0.05). ConclusionThe bullet-shaped and kidney-shaped Cages have similar results in restoring IH and maintaining the stability of the spine assisted by internal fixation. Kidney-shaped Cage is more stable than bullet-shaped Cage in the axial compression and the bending load opposite implant, it can be placed in the middle and back of the vertebral body more ideally.
The present study is aimed to investigate the early clinical effects of nano-hydroxyapatite/polyamide 66 intervertebral fusion cage (n-HA/PA66 cage) for the treatment of lumbar degenerative diseases. We selected 27 patients with lumbar degenerative diseases who were managed by posterior decompression or reset operation combined with n-HA/PA66 cage intervertebral fusion and internal fixation from August 2010 to January 2012. The oswestry disability index (ODI), low back and leg pain visual analogue score (VAS), and intervertebral height (IH) were evaluated at preoperation, 1 week postoperation and the last follow-up period, respectively. Intervertebral bony fusion was evaluated at the last follow-up time. The patients were followed up for 12-24 months (averaged 19 months). The ODI, VAS and IH were significantly improved at 1 week postoperation and the last follow-up time compared with those at preoperative period (P<0.05). But there was no significant difference between 1 week postoperative and the last follow-up time (P<0.05). Brantigan's standard was used to evaluate fusion at the last follow-up time. There were 19 patients with grade 5 fusion, 8 with grade 4 fusion, with a fusion rate of 100%, and none with grade 1-3 fusions. There was no cage translocation and internal fixation breakage. These results suggested that n-HA/PA66 cage was an ideal biological material in the posterior lumbar interbody fusion and internal fixation operation for treatment of lumbar degenerative diseases. It can effectively maintain the intervertebral height and keep a high rate of bony fusion. The early clinical effect has been satisfactory.
ObjectiveTo explore the effectiveness of posterior unilateral transpedicular debridement, bone graft fusion, and pedicle screw fixation for thoracolumbar tuberculosis. MethodsBetween January 2009 and January 2013, 97 patients with thoracolumbar tuberculosis were treated with posterior unilateral transpedicular debridement, bone graft fusion, and pedicle screw fixation in 53 cases (group A), and with traditional posterior operation in 44 cases (group B). There was no significant difference in age, sex, disease duration, affected segments, Frankel grade, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), sagittal Cobb angle, visual analogue scale (VAS), and Oswestry disability index (ODI) between 2 groups (P>0.05). The surgery and follow-up results were compared between 2 groups. ResultsThe patients were followed up 24-60 months. All patients achieved intervertebral bone fusion after operation. The bone graft fusion time of groups A and B was (6.79±1.68) months and (6.89±2.00) months respectively, showing no significant difference (t=-0.251, P=0.802). There was no significant difference in operation time, intraoperation blood loss, and postoperative hospitalization time between 2 groups (P>0.05); the postoperative drainage volume of group A was significantly less than that of group B (P<0.05). The CRP and ESR at 1 year and the VAS score at last follow-up were significantly decreased when compared with preoperative values in 2 groups (P<0.05), but no significant difference was found between 2 groups (P>0.05). The Cobb angle at 1 week and at last follow-up and ODI at 3 months and at last followup were significantly improved in 2 groups (P<0.05), but there was no significant difference between the time points after operation (P>0.05). At 3 months after operation, the ODI of group A was significantly lower than that of group B (t=-2.185, P=0.027), but no significant difference was found in Cobb angle, Cobb angle loss, and ODI at other time points between 2 groups (P>0.05). At last follow-up, the Frankel classification of nerve function was improved 1-2 grades in 2 groups, showing no significant difference between 2 groups (Z=-0.180, P=0.857). No complication of internal fixation breakage or loosening was observed. ConclusionThe effectiveness of posterior unilateral transpedicular debridement, bone graft fusion, and pedicle screw fixation in the treatment of thoracolumbar tuberculosis is satisfactory, with the advantages of less trauma, strong spinal stability, and fast function recovery.
Objective To explore the effect of pyropheophorbide-a methyl ester-mediated photodynamic therapy (MPPa-PDT) on the apoptosis in human osteosarcoma cell line MG63 and the underlying mechanism. Methods Human osteosarcoma MG63 cells in logarithmic growth phase were divided into 4 groups: blank control group (control group), the MPPa treatment group (MPPa group), the light irradiation group (LED group), and MPPa-PDT treatment group (MPPa-PDT group). MPPa-PDT group and MPPa group were incubated with MPPa (0.75 μmol/ L) for 20 hours in dark condition; control group and LED group were incubated with equal volume of fresh medium for 20 hours in the same condition. After washing with PBS and replacement with fresh culture medium, LED group and MPPa-PDT group cells were exposed to light (4.8 J/cm2) for 120 seconds. After light exposure, all groups were cultured in dark condition again. Then cellular morphology changes were observed by an inverted phase contrast microscopy, endoplasmic reticulum morphology changes were observed by transmission electron microscopy, cellular apoptosis was detected by Hoechst33258 nuclear staining, cell apoptotic rate and the levels of Ca in cells were analyzed by flow cytometry, the expression of p-PERK, C/EBP homologous protein (CHOP), cleaved-Caspase-12 were assayed by Western blot. Results In MPPa-PDT group, the retracted and round cells were observed; Hoechst33258 nuclear staining showed nuclear condensation, fragmentation, and other typical apoptotic morphological changes; the cell apoptotic rate (48.76%±3.54%) was significantly higher than that of control group (5.04%±0.41%), MPPa group (5.33%±0.38%), and LED group (6.48%±0.46%) (P < 0.05); the levels of Ca2+ in cells (485.29±58.77) was also significantly higher than that of control group (97.24±4.77), MPPa group (97.95±6.30), and LED group (101.17±5.26) (P < 0.05); swelling endoplasmic reticulum was observed under transmission electron microscope; the expressions of p-PERK, CHOP, and cleaved-Caspase-12 gradually increased at 1, 3, and 6 hours after treatment respectively, which were significantly higher than those of the other groups (P < 0.05). There was no typical apoptotic morphological changes and endoplasmic reticulum morphological changes in control group, MPPa group, and LED group, and there was no significant difference in the above indexes among 3 groups (P > 0.05). Conclusion MPPa-PDT can significantly induce apoptosis in MG63 cells. The endoplasmic reticulum stress pathway is involved in the MPPa-PDT induced apoptosis.