BACKGROUND: It is often difficult to determine the cause of low back pain (LBP) in the patients with lumbar disc herniation. The herniated disc has long been thought to be an important cause of the patient's complaint about LBP and sciatica. Whether the adjacent degenerative disc results in LBP needs further confirmations. OBJECTIVE: This study sought to determine whether the degenerative disc adjacent to the herniated disc in patients with LBP and radicular pain can result in discogenic LBP, as assessed by provocative discography, and to report the outcomes of the residual LBP when adjacent symptomatic disc were treated with methylene blue after microendoscopic discectomy. METHODS: Twenty lumbar disc herniation patients complaint about LBP and radicular pain underwent provocative discography. There was one degenerative herniated disc with one or more adjacent degenerative discs in their MRI. Provocative discography was performed on all degenerative discs and at least one normal disc for control. The severity of LBP and leg pain of all patients was assessed using visual analog scale before discography. All patients underwent microendoscopic discectomy at herniated level, and intradiscal injection of methylene blue was given at painful adjacent level in five patients after microendoscopic discectomy. RESULTS AND CONCLUSION: Discographies were performed on 64 discs of 20 patients, from L2-3 to L5-S1. There were 11 discs satisfying the positive response criteria, including 6 in degenerative segment adjacent to the herniated disc and 5 in the herniated disc that induced corresponding radiculopathy. The leg pains were evidently improved in all patients, while LBP was partially improved after microendoscopic discectomy. Six patients with symptomatic adjacent degenerative disc still had evident LBP, influencing their daily living. Five of them received intradiscal injection of methylene blue treatment and the LBP was relived. One patient refusing to the treatment still complained the LBP. Results evidenced that accompanying LBP for many LDH patients may come from the degenerative levels adjacent to the herniated disc.

Objective To study the incidence and prognosis of avascular necrosis after talus fracture. Methods A retrospective survey was performed in 12 patients ( 13 feet) with talus fractures admitted into hospital from July 2004 to November 2009 to analyze necrosis rate, ankle function recovery and disability rate. According to Hawkin' s classification system, there were two patients with type Ⅰ feet, four with type Ⅱ feet, five with type Ⅲ feet and two with type Ⅳ feet. Results All patients were followed up for average period of 19.6 months (range 11-52 months). Avascular necrosis was detected in eight feet, of which one foot was treated with ankle fusion, one with subtalar arthrodesis and one with bone implantation. The other five feet had good ankle and subtalar function, with no collapse or osteoarthritis. According to Maryland foot score, the result was excellent in eight patients, good in two, fair in one and failure in two, with excellence rate of 77%. Conclusion The incidence of avascular necrosis after talus fracture is related to the location and energy of trauma. However, the function prognosis of the talus shows no correlation with necrosis.

Objective To analyze the causes of the complications of one-stage surgical management for spinal tuberculosis and its countermeasures.Methods From May 1997 to December 2008,116 patients with spinal tuberculosis underwent operations.Among them,6 were in cervical vertebra,3 in cervicothoracie vertebra,29 in thoracic vertebra,37 in thoracolumbar vertebra.29 in lumbar vertebra and 12 in hmbrosacrum vertebra.All cases underwent the anterior and/or radical debridement,decompression,autogenous bone grafting or radical debridement,decompression,autogenous bone grafting and internal fixation.The causes of the complications of surgical management and the countermeasures were analyzed.Results One hundred and ehven cases were followed upfor an average of(3.86±2.16)years(range 6 months to 12 years).The rate of complication was 13.5%(15/111).Recurrent spinal tuberculosis occarred in 5 cases,internal fixation loosened in 1 case,rupture of the external iliac vein occurred in 2 cases,lateral ventral syndrome in 1 case,venous embolism of the lower extremity in 1 csse,reactional psychosis in 2 cases,pneumatothorax in 2 cases and femoral nerve irritating syndrome in 1 case.Among the recurrent cages,2cases with anterior debridement and 2 cases with posterior debridement underwent anterior operation again andgot good results, 1 case with anterior debridement gave up the reoperafion.Other cases relieved after conservative therapy.Conclusions Standardized anti-tuberculosis thempy is fundamental for preventing the recurrence of tuberculosis.Correct approach for the operation and thorough radical debddement are the key points for preventing the recurrence of tuberculosis.Good and effective therapy surround the operation is helpful for preventing the recurrence of tuberculosis.

[Objective]This study was designed to construct a recombinant adenovirus vector contains LMP-1 gene,and investigate the osteoinductive activity of MSC which were transfected recombinated adenoviral vector carrying LMP-1 gene.[Methods]Total RNA was extracted from mt osteoblast and the LMP-1 gene was acquired by RT-PCR,the LMP-1 gene and entry vector pENTR/D-TOPO were used to create the entry clone with the directional TOPO clone technology,then the entry clone and the expression vector were used to create the expression clone throush the LR recombination reaction.The adenovirus expression clone was linearized by PacI and transfected to the 293A cell line to harvest a high titer.Ad-LMP-1 was infected into the 3rd passage MSC,the expression of LMP-1 was detected by Western blot.The osteogenic activity of MSC was evaluated by the expression of collagen Ⅰ,ALP,osteocalcin and the formation of bone nodule.[Result]The LMP-1 gene was successfully acquired and confirmed,the entry clone and the expression clone were both verified by enzymes digestion,and the expression clone was further confirmed by sequenced.The expression of LMP-1 was detected successfully in MSC.The increasing expression of collagen Ⅰ,osteocalcin.ALP and bone nodule were observed by comparing to the control group.[Conclusion]Gateway technology not only make construction of the pAd-LMP-1 recombination adenovirus vector simple and fast,but also get a high transfection efficacy in MSC.LMP-1 gene can induce the osteoblast differention of MSCs,and improve its osteogenic activity.The adenovirus vector is reliable to be used in further gene therapy research.

Objective To explore the indications of anterior and posterior approach operations for unstable thoraco-lumbar fractures coupled with neurologic deficits and prevention of intraoperative and postoperative complications. Methods We investigated 107 consecutive eases of thoraco-lumbar fractures coupled with spinal cord injury who had been operated on from January 2000 to December 2006.Their average age was 37.8(range.17 to 78) years old. They were 71 males and 36 females. Anterior approach was selected for 46 cases and posterior approach for 61 cases according to their McCormack grades. By the Frankle system for neurologie deficits, 7 cases were graded as A,16 as B,39 as C and 45 as D. Fracture height vecoveries before and after surgery were analyzed statistically. Kyphotic deformity was assessed on lateraJ radiographs using the Cobb method. Results The mean follow-up of 97 cases was 2.8(range,0.5 to 6) years. In both groups. All the cases gained at least 1 grade improvement except those with Frankle grade A. The mean kyphotic angles before operation, after operation and at the latest follow-up were 23.7°,10.6°and13.1°respectively, with significant differences(P＜0.01),in the anterior approach group, while 16.3°,8.4°and 11.7°respectively, with significant differences(P＜0.01),in the posterior approach group. Some complications, such as deficit of cutaneous nerve of thigh, appeared in the 2 groups. Conclusions In treatment of unstable thoraco-lumbar fractures coupled with neurologic deficits, the anterior approach may be better than the posterior approach. The posterior approach can be applied for the cases with less than 7 points in McCormack index. Correct selection of operative approach, careful operation and good rehabilitation after operation are necessary for the prevention of complications.

[Objective]To study the stresses value and distribution of the facet joint of the normal L4、5 segment model and that of the denucleated lumbar segment model. [Method]A finite element model of the intact L4、5 segment was developed through Ansys software.The property of nucleus pulposus was changed to be negligible to model lumbar discectomy through anterior approach.Then the finite element model of the denucleated lumbar spine segment was created.The inferior end plate of L5 was fixed.Models were subjected to 6 Nm flexion,extension or right rotation moment in combination with 400 N axial compression preload.Forces were applied to the superior L4 end plate.Stresses value and distribution of the lumbar facet joint were analyzed under different loading conditions.[Result]Finite element models of the intact L4、5 segment and the denucleated lumbar spine segment were created.The facet joint was treated as a three dimensional contact,linear frictionless problem.The facet joint was composed of the inferior and superior facet surface and ligamentous structure.Both facet joints,especially the left of the intact model produced larger stresses in right rotation.Comparing with that of the intact model,stresses of the facet joint of the denucleated model increased in flexion,extension and right rotation.[Conclusion]The region of contact of each facet joint varies according to different loading conditions.So does the stresses value and distribution.The facet stresses of the lumbar segment increase in flexion,extension and rotation after discectomy.

[Objective]To study the intervertebral disc degeneration induced by bilateral zygopophysial joint resection in New Zealand rabbits.[Method]Forty-five New Zealand rabbits were randomly divided into 3 groups:group A,L_(4) and L_(5) inferior articular processes were en bloc excised,L_(5) and L_(6) superior articular processes were retained;its L_(6、7) and L_(3、4) as self-control group B;L_(3) to L_(7) paravertebral muscles were stripped and took L_(4、5),C_(5、6) as control group C.At one,two,four and eight months postoperatively,anterior-posterior and lateral X-ray film abnormal signs,including intervertebral space wedging,osteophyma formation at the edge of vertebral body and cartilage end plate celcification,were examined and counted.[Result]In the group C,cartilage end plate calcification,seldom intervertebral space narrowing,rare osteophyma formation at the edge of vertebral body and no lumbar spinal kyphosis were found in some rabbits.In the group A,cartilage end plate calcification began to found in the early stage on the L_(4、5) and L_(5、6),as time went on to the 8~(th) month postoperatively,almost all rabbits were found intervertebral space narrowing,osteophyma formation of vertebral space narrowing,osteophyma formation of vertebral body and cartilage end plate calcification.Conform kyphosis of L_(5、6) were also occurred at some rabbits.There was significant difference between group A and group C,but no difference with group B.[Conclusion]Radiological changes of L_(5、6) intervetevbral disc degeneration can be induced by excision of L_(5) and L_(6) zygopokhysial joint of rabbit.

[Objective]To study whether intervertebral disk degeneration can be induced by destroying bilateral zygapophysial joints of New-Zealand rabbit.[Method]Thirty male New-Zealand rabbits were randomly divided into operation group on the bone and operation group on the soft tissue.In operation group on the bone,L4 and L5 inferior articular processes were en bloc excised,L5 and L6 superior articular processes were retained.In the operation group on the soft-tissue,Only L3 to L7 paravertebral muscles were stripped.In operation group on the bone,L4、5 and L5、6 intervertebral disks acted as experimental group;L3、4 and L6、7 acted as self-control group.In the operation on the soft tissue,L4、5 and L5、6 acted as experimental control group.One,two,four and eight months post-operation,histological and ultrastructure organizations of intervertebral disks of New-Zealand rabbits were performed.[Result]The normal rabbit discs formed a very complex system,with an outer anulus fibrosus surrounding a central nucleus pulposus in which collagen fibers aligned parallelly and intervertebral disk cells distributed evenly.Collagen fibers derangly aligned and intervertebral disk ceils declined with time post-operation.At the end of four months post-operation,many degenerative cells were found in the study group,which features as irregular cell contours,swelling chondrosome,rough endoplasmic reticulum,and condense nucleus located in the cellular nucleus.Eight months after operation,many dead cells were found.Cytolysosomes increased,cellular nucleus became twisted,rough endoplasmic reticulums swelled,and chondrosome became vacuolization.Dead intervertebral disk cells were located in nidi which were made of multilayer degenerative collagen fibers.[Conclusion]Histological changes of intervertebral disk degeneration can be induced by destroying L4、5 and L5、6 zygapophysial joints of New-Zealand rabbit.

[Objective]To establish a reproducible rat model of disc degeneration by puncturing the annulus with needles of defined gauges.[Method]Twenty skeletally mature male Sprague-Dawley rats were used to determine the depth of puncture by measuring anular thickness of lumbar disc.Twelve rats were carried out transperitoneal ventral surgery and anular stab was performed using a 21-gauge needle to make a full-thickness or partial-thickness stab incision in the L3、4,L4、5 and L5、6 anteriorlateral disc.The L6S1 level was used as a control.Magnetic resonance images scans of the stabbed discs and control discs were performed at 4,8-week time point and after MRI histological analysis were performed.[Result]The depth of puncture was respectively partial-thickness 1.5 mm and full-thickness 2.3 mm.The stabbed discs exhibited a decrease signal intensity from T2-weighted images starting at 4-week time point in full-thickness stab incision and 8-week in partial-thickness.Histological analysis revealed disc degeneration in both stab incision groups at 4-week time point and full-thickness stab incision displayed more severe degenerative changes compared with that of partial-thickness.[Conclusion]Full-thickness or partial-thickness anulus stab incision with needles of defined gauges is reliable,effective and reproducible to establish a rat model of intervertebral disc degeneration.

[Objective]To study the MRI changes in rabbit lumbar intervertebral disk degeneration induced by spinal intervertebral instability through destroying L4、5 and L5、6 zygapophysial joints.[Method]Thirty male New-Zealand rabbits were randomly divided into operation group on the bone and operation group on the soft tissue.In operation group on the bone,L4 and L5 inferior articular processes were en bloc excised,L5 and L6 superior articular processes were retained.In the operation group on the soft-tissue,Only L3 to L7 paravertebral muscles were stripped.In operation group on the bone,L4、5 and L5、6 intervertebral disks were acted as experimental group;L3、4 and L6、7 acted as self-control group.In the operation on the soft tissue,L4、5 and L5、6 were acted as experimental control group.One,two,four and eight months post-operation,lumbar spine MRI of New-Zealand rabbits were performed.The area fractions of high T2 signal zone of the nucleus pulposus were calculated according to the reference reports.[Result]On the T2 sagittal image,the nucleus pulposus showed uniform high signal intensity.On the axial image,high signal area of the nucleus pulposus located at the center of the intervertebral disk,and the areal fraction was 50%.High sagittal T2 signal and area fraction of high axis T2 signal of the nucleus pulposus not obviously declined in the normal rabbit with time.There was no statistical difference by t test.However,MRI showed the most significantly decreased the axial T2 high-signal area fraction in the experimental group,and the smallest declined in the experiment-control group.At the end of eight months after operation,L4、5 and L5、6 appeared the dark discs in the experiment group.[Conclusion]Disc degeneration may be caused by spine instability.The decline of the axial T2 high-signal area fraction of the nucleus pulposus is a earlier and common sign of intervertebral disk degeneration.