Objective To investigate pathophysiological changes in the multifidus muscles of patients with lumbar disc herniation.Methods Thirty-six patients with unilateral symptoms caused by lumbar disc herniation were enrolled.They were divided into a symptomatic side group and a contralateral side group according to whether their symptomatic (algetic) or contralateral side would be studied.The percentage area of pimelosis and the mean gross signal intensity of each multifidus were measured with magnetic resonance imaging (MRI)_ The amplitude and duration of motor unit potentials of each multifidus were recorded using electromyography (EMG) when the patients were performing isometric contraction.Results The bilateral multifidus muscles of 36 patients displayed various degrees of pimelosis on magnetic resonance images.The percentage of pimelosis cross-sectional area in the symptomatic side group was significantly higher than in the contralateral side group.[(44.20 ± 15.14)％ versus(37.31 ± 13.85)％,P ＜ 0.05] The mean value of the gross signal intensity was also significantly higher.Both the amplitudes and duration of the motor unit potentials recroded from the multifidus had increased and widened,but significantly more in the symptomatic side group than in the contralateral side group.Conclusions Both the imaging and electrophysiological data showed more significant changes on the symptomatic side in patients with unilateral symptoms caused by lumbar disc herniation.

Objective To discuss the effect of the sustained releasing agent FK506 on the ultrastructure of the regenerative nerve fibers.Methods The new fusiform-shaped double channel nerve conduit was used for bridge the sciatic nerve defects for 10 mm in 32 Sprague-Dawley rats.The rats were divided into Group A(100μl chitin for both channels)and Group B(chitin plus FK506 for B1 and chitin plus normal saline for B2)according to different addition of the drugs.At 8 and 12 week after operation,the middle line of the regenerated nerve was observed under the transmission electron microscope.In the meantime,an analysis was done on the area of the regenerated nerve fibers(myelinated and unmyelinated),diameter and myelin thickness of the myelinated fiber axon at 8 and 16 months.Results There was not significant difference in aspects of type and number of the regenerative nerve fibers between two channels in Group A.However,the myelinated and unmyelinated fibers of the regenerative nerves were increased in Group B1,with larger area than Group B2(P ＜ 0.05).Conclusion FK506 can significantly promote the regeneration of both the myelinated and unmyelinated fibers.

Objective To investigate the effect of caffeine and cisplatin induced apoptosis of osteosarcoma cell line(OS-732), and to explore the potential mechanism of caffeine enhancing cytotoxic effect of cisplatin in osteosarcoma cell line. Methods The OS-732 cell line was cultured for 72 hours; treated with caffeine, cisplatin and caffeine combined with cisplatin for 72 hours respectively, the apoptosis rates of OS-732 cell line were analysed by flow cytometry. Mitochondrial transmembranous potentials were measured by cellular rhodamine 123 stain on flow cytometry. Apoptosis was assessed by electron microscope at 80 kV. Results The OS-732 cell line was cultured for 72 hours; treated with caffeine (5.0 mmol/L ), cisplatin (10.0 ?g/ml ) and caffeine (5.0 mmol/L ) combined with cisplatin (10.0 ?g/ml) for 72 hours respectively. The apoptosis rates were 2.50%, 10.62%, 31.62% and 57.44% respectively. The percentage of decline of mitochondrial transmembranous potentials were 8.12%, 26.45%, 17.82% and 38.26% respectively. Electron microscope revealed the characteristic apoptosis alterations,such as shrinking cellular chromatin condensation, crescent nucleus, cytoplasmic vacuoles and so on. Conclusion Caffeine and cisplatin can induce apoptosis of osteosarcoma cell line(OS-732), while the cell line treated with caffeine and cisplatin simultaneously, the apoptosis rate was increased obviously. The induction of apoptosis of osteosarcoma cell line by caffeine may be one of potential mechanism enhancing cytotoxic effect of cisplatin in osteosarcoma cell line.

Objective To research the biomechanical characteristics and clinical applicant of posterior transarticular screws (Magerl technique) with bene graft in atlantoaxial instability.Methods 30 fresh cadaver human cervical spine specimens were obtained and randomized subdivided into 5 groups:intact group,atlantoaxial destabilized group,atlantoaxial destabilized and fixed with pedicle screws group,fixed with Magerl screws group and fixed with Maged screws combined with Brooks way group.ROM(range of motion)and NZ(neutral zone)of extend,flex,right and left lateral bend,right and left rotation of each specimen in 5 groups were measured.Transarticular screws were placed in 23 patients with atlantoaxial instability from 2000 Feb.to 2005 Jan.,with 16 males and 7 females,age from 17 to 62 years.20 of them were traumatic dislocation and 3 were congenital instable.Results Biomechanical study indicated that stability of all 6 degrees were Magerl+Brooks＞Magerl screws＞Pedicle screws＞Intact＞Destabilized.23 patient were fixed with 46 Maged screws in total,none were suffered from vertebral artery injury and neurological deterioration.All patients were followed-up from 4 to 36 months.2 of them complained that difficult in rotation of head.Conclusion Single use of Magerl screw can provide enough biomechanical stable for adantoaxial instability,and is an effective,low-risky way combined with intra-spinal-process bone graft.

Objective To investigate the correlation between intra-operative estimated blood loss (EBL) and bone mineral density (BMD) during minimally invasive posterior lumbar interbody fusio,n (PLIF).Methods In this retrospective case control study,61 consecutive patients suffering from mono-segment low back disorders were treated by minimally invasive PLIF from 2005 to 2010.The patients' parameters including age,gender,operation time (OT),BMD,EBL,prothrombin time were collected.According to BMD of the lumbar spine,all the patients were divided into two groups: the normal group and the osteopenia group.The differences of the EBL and other parameters between the two groups were analyzed by student's t test and Pearson's Chi-square test.Besides,the correlation between intra-operative EBL and each of the other parameters except for gender were analyzed among all the patients.To detect the relationship between intra-operative EBL and gender,patients were divided by gender and the intra-operative EBL of two groups were examined by student's t test.Finally,a probable model about intra-operative EBL and the other parameters was proposed using stepwise linear regression analysis.Results The average intra-operative EBL of the normal group and the osteopenia group were (346.41±199.53) ml and (552.62±300.21) ml,respectively.The difference was significant.However,the other parameters including post-operative EBL had no significant differences between two groups.A negative correlation between intra-operative EBL and BMD (r=-0.37,P=0.035)and a positive correlation between intra-operative EBL and OT (r=0.34,P=0.008) were found.But none of the other parameters was correlated with intra-operative EBL.The similar result was observed by the stepwise linear regression analysis.Intra-operative EBL was influenced by BMD and OT under the control of this research,and the relationship might be formulated with the equation,EBL=-0.63×BMD+1.46×OT.Conclusion BMD should be considered an important predictor of intra-operative EBL in PLIF.

With the aging of population, the incidence of osteoporosis and intervertebral disc degeneration increased remarkably.As a consisting part of spine, vertebrae play important roles in spinal diseases.The microstructure of vertebrae is closely associated with not only its biomechanical properties, but also its adjacent intervertebral discs.A detailed understanding of vertebrae's microstructure can help us understand the initial mechanism, progression and prognosis of vertebrae and its adjacent discs' diseases.On the other hand, traditional examinations are less effective in detecting vertebrae's microstructure.Being a noninvasive, high-resolution and bony-sensitive neo-technology, Micro-CT has obvious advantages in detecting vertebrae's microstructure.Many researches have reported the usage of Micro-CT in reveling microstructures while they also raised problems.Thus, herein we searched the related information of vertebrae's microstructure scanning with Micro-CT, explained its basic mechanism, reviewed its progress in technology and arithmetic, and concluded the latest developments.Depending on the microstructure revealed by Micro-CT, achievements in biomechanical properties of vertebrae and intervertebral disc degeneration have been made,and related problems have been summarized.Also, new applications of Micro-CT in spinal diseases are discussed for acquiring reasonable clinical data in the future.

Objective To investigate the morphological characteristics of the intervertebral foramina and their alterations in the process of disc height loss in low lumbar spine in order to provide basic data for the diagnosis and treatment of foraminal stenosis. Methods Eight fresh cadaveric lumbar spines of L3 to S1 were obtained for study, which were cleaned off their surrounding muscles and kept the ligaments, annulus fibrous and nerve roots attached. The morphological characteristics of foramina of L4,5 and L5S1 and their anatomic relationships with the nerve roots were observed with and without nucleus pulposus in situ under different loading conditions (0, 300, 500 N). The foraminal dimensions including heights, maximal widths and minimal widths were measured, and the disc heights were measured on lateral radiograph under above loading conditions as well. Results Without any loading, the foramina were inverted teardrop shaped, the foramina of L4,5 were similar to that of L5S1. The nerve roots were located in the upper part of the foramina, and passed across the foramina obliquely. With 500 N loading, the shapes of the foramina and the relationships with the nerve roots were found to be changed little. After removal of nucleus pulposus and more loading was applied, the foramina became stenotic gradually and the nerve roots were pushed against the superior pedicle. The foraminal heights, maximal widths and the anterior, posterior disc heights became narrower, and were significantly different from those under no loading condition (P

Objective To report the preliminary experiences in the treatment of old unstable thoracolumbar vertebral fractures by using anterior decompression, bone graft or titanium mesh and internal fixation with Z-plate system. Methods There were 23 cases (18 males and 5 females) with age range of 25-66 years (mean 41.7 years) as well as thoracolumbar vertebral fracture history for 1.2-28 years (mean 5.6 years). All cases complained of severe lower back pain, 17 of whom had slight neurological deficits (Frankel Grade D). Preoperative radiographic evaluation showed that all 23 cases had various degrees of kyphosis (25?-40?, averaged 34?), spinal cord compression and vertebral instability. Of 23 cases, 15 were treated with anterior decompression, full-thickness iliac crest autograft and internal fixation with Z-plate and the other 8 with titanium mesh instead of full-thickness iliac crest autograft. Results No severe complications happened during and after operation. The lower back pain and neurological deficits were improved or disappeared 2-3 months postoperatively. The average kyphotic correction degrees ranged from preoperative 34? to postoperative 12?. No patients' symptoms worsened during follow-up. In three cases with preoperative Frankel Grade D, the myodynamia recovered slightly but the Frankel Grade remained unchanged. The postoperative MRI examinations showed that vertebral canals were well decompressed. Conclusions Anterior decompression, autograft or titanium mesh and internal fixation with Z-plate are proved to be safe and effective techniques for clinical management of old thoracolumbar fractures, for they have advantages in effective decompression of neural structures, high healing rate of autograft and correction of kyphotic deformity.

Objective To evaluate the clinical results of self-designed anterior cervical low-profile plate system (ACLPS). Methods The anterior cervical plate system, composed of one plate, two locking caps and two types of screws. The system was made of medical titanium alloy possessing the following characteristics: low profile, instant locking, versatile use and unicortical screw fixation. 37 patients with cervical disorders were fixed with ACLPS after anterior spinal decompression and interbody fusion. The diagnosis included spondylosis in 8 cases, cervical intervertebral disk protrusion in 12, fracture and /or dislocation with paralysis in 14 and metastatic tumor in 3. The fusion were performed with autologous iliac crest bone graft for 29 patients while the others with cages. The fixed levels ranged from C3 to T1. Results 37 cases were followed-up for an average of 9.6 months, ranging from 6 to 12 months. Postoperatively all patients felt comfortable in neck without any foreign body sensation. No obvious complications such as wound infection, hematoma, asphyxia, nerve injury, laceration of spinal cord dura, leakage of cerebrospinal fluid, bleeding and nonhealing of the wound were observed. Solid interbody fusion were achieved in all cases. According to JOA scores, the total effective rate was 94.6% while the good rate was 83.8%. The radiograph confirmed that there was no dislocation or subsidence of graft, no obvious loss of intervertebral height, no loosening or failure of implant. Conclusion In regard to the high rigidity, good bony purchasing and easy handling, ACLPS is able to provide sufficient biomechanical stability and is an optional choice for clinical use.

Objective To determine the correlation between the Modic degeneration of lumbar endplate on MRI and the pain provocation or degeneration of lumbar intervertebral discs observed on CT discography. Methods One hundred and twenty lumbar intervertebral discs (40 L3-4, 40 L4-5, 40 L5S1 intervertebral discs) of 40 patients among 45 patients were examined. 120 intervertebral discs underwent discography guided by CT scan, according to Dallas Discography Description system, degeneration of lumbar intervertebral disc were divided into 0-3 grade, and pain provocation were graded into negative, indifferent and positive. On the basis of Modic classification system of the lumbar endplate changes and Pearce classification system of the degeneration of lumbar intervertebral disc, the lumbar endplate changes were divided into 0-3 grade, the degeneration of lumbar intervertebral disc were graded into Ⅰ-Ⅴ. All the results were analysed by Chi-Square test for the correlations. Results There was positive correlation between pain provocation test and the lumbar endplate Modic degeneration; There was a positive correlation between the Modic degeneration of lumbar endplate and the degeneration of lumbar intervertebral disc and so is the relation between the CT discography and MRI on discs. Conclusion There is positive correlation between pain provocation test and the Modic degeneration of lumbar endplate, it suggest the endplate might be one of the sources of low back pain. There is a positive correlation between the Modic degeneration of lumbar endplate and the degeneration of lumbar intervertebral disc.