Objective To explore the application value of self-made directional arcuate bone drill during vertebroplasty by observing its operative effects for osteoporosis in vitro . Methods EDTA-Na2 was used to soak the prepared vituline osteoporotic vertebral bodies in vitro .A total of 40 osteoporotic vertebral bodies were randomly divided into Group A and B , with each group having 20 vertebral bodies for vertebroplasty .The Group A underwent a puncture by routine straight bone drill , while the Group B received a puncture by self-made directional arcuate bone drill with the arc directing toward the contralateral , which terminated when the drill reached the first 1/3 of vertebral body .Finally, statistical analysis was conducted on the distance between the bone drill bit and exterior margin of contralateral vertebral body , as well as whether bone cement reached or went over the vertebral sagittal midline . Results The osteoporotic vertebral bodies were successfully prepared in vitro by using EDTA-Na2 immersion decalcifying for 9 days. In the Group A, the drill bit was (2.50 ±0.32) cm away from contralateral exterior margin of vertebral bodies , which was significantly different from that in the Group B (0.90 ±0.26) cm (t=17.354, P=0.000).The bone cement reached or went over the vertebral sagittal midline in 11 vertebral bodies in the Group A and in 19 vertebral bodies in the Group B , with statistical difference ( Fisher’ s test,P=0.004).The intraspinal bone cement leakage occurred in 9 vertebral bodies in the Group A and 4 in the Group B, without significant difference between the two groups (Fisher’s test,P=0.176). Conclusion The self-made directional arcuate bone drill can build an osseous channel that reach or go over the vertebral sagittal midline and guide bone cement distributed to contralateral puncture , which avoids the disadvantages of bilateral vertebral pedicular puncture .The result shows that the self-made directional arcuate bone drill has more adventages in vertebroplasty than that of traditional straight bone drill but doesn ’ t have significant advantages in preventing bone cement leakage .

Objective To evaluate the role of brain-derived neurotrophic factor (BDNF) in inflammatory pain in rats. Methods Sixty female SD rats weighing 150-180 g in which intrathecal (IT) catheters were successfully placed without complication were randomly divided into 5 groups (n= 12 each): group Ⅰ sham operation; group Ⅱ sham operation + IT anti-BDNF antibody; group Ⅲ inflammatory pain; group Ⅳinflammatory pain + IT control IgG and group Ⅴ inflammatory pain + IT anti-BDNF antibody. Inflammatory pain was induced by injecting complete Freund's adjuvant (CFA) into ankle joint cavity of left hindpaw, while in sham operation group equal volume of normal saline was injected instead of CFA. Anti-BDNF antibody or control IgG 15 μg/10 μl was injected IT once a day for 3 days after inflammatory pain was induced. Paw withdrawal latency to thermal stimuli (PWTL) was measured one day before and at 3, 5, 7, 10 and 14 d after inflammatory pain was induced. The rat was sacrificed on 3 rd day of IT anti-BDNF antibody or control IgG injection. The lumbar segment L4-6 of the spinal cord was removed for detection of the expression of BDNF and p-ERK1/2 by immunohistochemistory and Western blot. Results Intra-articular CFA injection significantly increased the expression of BDNF and p-ERK1/2 in the spinal cord in group Ⅲ as compared with sham-operated animals in group Ⅰ . IT antiBDNF antibody injection significantly suppressed the expression of BDNF and p-ERK1/2. PWTL was significantly shortened after intra-articular CFA injection in group Ⅲ as compared with group Ⅰ . IT anti-BDNF antibody reversed the inflammation-induced thermal hyperalgesia in group Ⅴ but IT control IgG did not. Conclusion BDNF in the spinal cord may be involved in inflammatory pain through p-ERK1/2 signal transduction pathway.