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 evaluate the diagnostic value of the nerve root sedimentation sign for lumbar spinal stenosis and improve morphological classification.Methods This is a retrospective radiologic study.From November 2012 to November 2013,511 patients who carried out MR examination due to backache together with intermittent claudication were selected.Cross-section MRI images at the narrowest layer of canalis spinalis were chosen.The patients were further divided into 7 groups,A1,A2,A3,A4,B,C,and D based on Schizas.The dural sac cross-sectional area (DSCA) of each group was measured.The groups without difference were merged.A new method to grade nerve root sedimentation was developed.Then,the correlation and consistency of nerve root sedimentation dichotomy,Schizas classification,new nerve root sedimentation classification and DSCA classification were compared.The differences of patients' Oswestry disability index (ODI) which adopted new classification method were compared.Results Results show there are no statistical significance between groups A1 and A2,groups A4 and B,or groups C and D in DSCA.After the merger,new nerve root sedimentation classification includes negative,a,b,and c.The correlation between nerve root sedimentation dichotomy and DSCA method is rs=0.579,and the consistency is κ=0.254.The correlation between new nerve root sedimentation classification method and DSCA method is rs=0.722,and the consistency is κ=0.381.The scores improve compared with the first two classification methods.ODI score difference of each group which adopted new nerve root sedimentation classification method has statistical signiftcance (F=17.972,P=0.000).Pairwise comparison shows only group c differs significantly from other groups (P＜0.05).Conclusion The new nerve root sedimentation classification method is more effective than nerve root sedimentation dichotomy and Schizas grading.It reflects the severity degree of patients'clinical symptoms to some extent.

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.

Objective To evaluate the special roles of modified procedure of instrumented posterior lumbar interbody fusion (PLIF) for the treatment of the isthmic lumbar spondylolisthesis. Methods Surgical procedure was modified. The definitive reduction of the spondylolisthesis using pedicle screw instrumentation was followed by primary reduction using intervertebral disc space distraction and interbody fusion with insert cages and local morselized bone after decompressive laminectomy. A prospective, single-cohort, observational study of the clinical outcomes and radiological data, was assessed in a series of 46 patients with isthmic spondylolisthesis who underwent surgery from January 1999 to February 2004. The clinical outcomes were evaluated according to Oswestry disability questionnaire, and the radiographic data included slipping degree, slipping angle and posterior height of intervertebral disc. Thin-section helical computed tomography (CT) scanning was used in 5 cases post-operatively to assess the interbody fusion. Results Post-operatively, the slipping degree reduced, the posterior heights of intervertebral space increased and slipping angle decreased. The radiographic data had no obvious loss in mean follow-up time of 36 months (range, 12-73 months). Thin-section helical CT study clearly demonstrated the radiographic presence or absence of bridging bone, and solid bony fusion could be obtained at least one year after operation. The objective clinical outcomes of the Oswestry disability questionnaire were in average 33.6?6.4 before operation and 17.6?5.5 after operation. Conclusion The modified procedure as described offers advantages for isthmic spondylolisthesis, not only in substantial deformity correction, but also in suitable interbody cages choosen and normal sagital plane alignment restoration.

Objective To investigate therapeutical methods on lumbar disc herniation with posterior edge separation of the vertebral body. Methods Different methods were applied to 31 patients, including 24 males and 7 females whose ages ranged from 18 to 61 years. Except that 2 patients with mild lumbar pain were treated with conservative therapy, the other 29 patients were treated with operation. The operations were made according to the relationship between compressive hernia and vertebral canal. For instance, for cases that the herniated mixtures were lateral, decompression with fenestration or amplified fenestration was applied to the trouble side; for cases that mixtures were central or paracentral, the same treatment was applied to both sides; and posterior lumbar interbody fusion(PLIF) or transforaminal lumbar interbody fusion (TLIF) was applied to those that the mixtures occupied most part of the front canal. Results The follow-up studies were made for all the patients for 1 to 4 years with an average period of 2.6 years. For the two patients treated with conservative therapy, one was fully recovered and the other, who took no effect from former therapy, was finally recruited after decompression with fenestration on the trouble side. Among the patients who were treated with operation, those with lateral herniated mixtures received significant effect, while only 60% of those with central or paracentral mixtures recovered (the unrecovered or even worsened patients after operation finally recruited by PLIF), and for those with mixtures occupying most part of the front canal, satisfactory effect were achieved. Conclusion Operation treatment should be applied to patients as early as possible when conservative therapy has no obvious effect. Different operation methods should be taken according to the relationship between compressive hernia and vertebral canal: 1) Decompression with fenestration or amplified fenestration on the trouble side be applied to those with lateral herniated mixtures; 2) Decompression with fenestration on both sides be applied to those with paracentral mixtures but no lateral crypt narrowness, and PLIF or TLIF to those with central mixtures or lateral crypt narrowness; 3) PLIF or TLIF be applied to those with mixtures occupying most part of the front canal.

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.