Establishment of anin vivo rabbit model of intervertebral disc degeneration under tensile load and its significance / 中国组织工程研究

BACKGROUND:Abnormal stress is an important factor causing intervertebral disc degeneration. To establish an ideal in vivoanimal model of intervertebral disc degeneration is of great significance for in-depth study on the related pathogenesis. OBJECTIVE:To develop anin vivo rabbit intervertebral disc model and to investigate the relationship between continuous tensile load and intervertebral disc degeneration. METHODS:Twenty-five New Zealand white rabbits aged 6 months old were randomly divided into three groups: blank control (n=5), sham (n=10) and experimental (n=10) groups. The blank control group received no intervention, and the L4/5 segments were removed at the 1st day. The intervertebral disc assistor was used to fix the L4 and L5 vertebral bodies in the experimental and sham groups, the L4/5 segments in the experimental group were loaded 1 MPa axial tensile force, and the L4/5 segments in both two groups were then removed at 14 and 28 days. The changes of L4/5 intervetebral space height and surrounding bone substance were observed by X-ray examination, the morphological changes of the intervertebral disc were observed by hematoxylin-eosin staining, the cell survival was detected by nitro blue tetrazolium staining and mRNA expression levels of aggrecan, collagen type Ⅱ and SOX9 in the intervertebral disc tissues were assessed by RT-PCR at each time point. RESULTS AND CONCLUSION:The radiological manifestations, histological changes, cell survival and mRNA expression levels of aggrecan, collagen type Ⅱ and Sox9 showed no significant difference between the blank control and sham groups. Comparied with the blank control group, in the experimental group, the L4/5 intervertebral space was narrowed with time, the articular surface was coarse, and the upper and lower corpus vertebrae edge appeared to have lip-shaped hyperplasia; the intervertebral disc cells distributed irregularly; the nucleus pulposus was in dehydration and deflation, annulus fibrosus arranged irregularly, and the vacuoles in notochord cells tended to disappear; the expression levels of aggrecan, collagen type Ⅱ and SOX9 were markedly downregulated. These findings suggest that the in vivo rabbit model of intervertebral disc is successfully established, in which continuous mechanical tensile load is further proved to directly cause intervertebral disc degeneration.

Expression of AMP-activated protein kinase in subcultured rat endplate chondrocytes / 中国组织工程研究

BACKGROUND:Endplate cartilage degeneration initiates intervertebral disc degeneration. AMP-activated protein kinase (AMPK) regulates the formation and degradation of cartilage. OBJECTIVE:To explore the role of AMPK in an in vitro natural degeneration model of chondrocytes derived from endplate of rat intervertebral discs. METHODS:Morphology of in vitro subcultured endplate chondrocytes of rat intervertebral discs at passages 0, 2, and 5 were observed under an inverted microscope fol owing cytoskeleton staining. Chondrocyte phenotype, proliferation, and the cartilage marker genes (type II col agen, proteoglycan, SOX-9, matrix metal oproteinase-3 and-13), and AMPK phosphorylation were determined by toluidine blue staining, MTT assay, real-time PCR analysis, and western blot assay, respectively. RESULTS AND CONCLUSION:The altered morphology, decreased proliferation ability, and phenotype loss were observed in chondrocytes with increased passage number. Gene expression of type II col agen, proteoglycan, SOX-9 was significantly decreased;while gene expression of matrix metal oproteinase-3 and-13 was significantly increased in endplate chondrocytes at passage 5 compared with those at passages 0 and 2. AMPK phosphorylation in endplate chondrocytes at passage 5 was significantly decreased. These findings indicate that AMPK phosphorylation is involved in in vitro natural degeneration of chondrocytes derived from the endplate of rat intervertebral discs, and the degeneration of endplate chondrocytes and intervertebral discs can be inhibited through the regulation of AMPK activity.

Biocompatibility of rabbit annulus fibrosus-derived stem cells with genipin cross-linked decellularized annulus fibrosus matrix/chitosan hydrogels / 中国组织工程研究

BACKGROUND:To improve the mechanical properties and uncontrolability of degradation of decelularized matrix, wemanufactured genipin cross-linked decelularized annulus fibrosus matrix/chitosan hydrogels as annulus fibrosus tissue-engineereds caffold. OBJECTIVE:To observe the biocompati bility of annulus fibrosus-derived stem cels with genipin cross-linked decelularized annulus fibrosus matrix/chitosan hydrogels, and the degradation of hydrogels in vivo. METHODS:Genipin cross-linked decelularized annulus fibrosus matrix/chitosan hydrogels caffoldswere prepared, and the internal structure and hydrophilic property of hydrogels was detected by scanning electron microscopy and contact angle meter, respectively. Afterwards, passage 1 rabbit annulus fibrosus-derived stem cels were seeded on thescaffoldsfor 3 days, cel morphology was observed by inverted immun of luorescence microscopy and scanning electron microscopy after cytoskeleton staining, andadditionaly, curve of cel growth was obtained. In the meanwhile, thescafflodswere transplanted into theintermuscular space of New Zealand white rabbits, and the degradation and inflammatory reaction of the hydrogels were observedafter4 weeks. RESULTS AND CONCLUSION:The prepared hydrogelsc affoldshowed porous and network structure and the contact angle was (39.94±1.61)°; annulus fibrosus-derived stem cels adhered wel on thescaffold surfacewithafaster growth rate. Furthermore, at 4 weeks after trans plantation, the hydrogelin vivowas degraded, and inflammatory cels appeared. These findings indicate that genipin cross-linked decelularized annulus fibrosus matrix/chitosan hydrogels have good biocompati bility.

A comparison of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion for lumbar degenerative diseases / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Bilateral transpedicular screw fixation in conjunction with interbody fusion is widely used to treat lumbar degenerative diseases; however, there are some disadvantages of using this fixation system. This study comparatively analyzes the results of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion (TLIF) for one-level lumbar degenerative diseases.</p><p><b>METHODS</b>Sixty-six cases with one-level lumbar degenerative diseases were studied. The patients were divided according to surgical approach into a unilateral group (Group A) and a bilateral group (Group B). The patients were evaluated for pain by visual analog scale (VAS) and Oswestry Disability Index (ODI). Operating time, blood loss, duration of hospitalization, and complication rate were also evaluated. Patients were examined at 1, 3, 6, and 12 months postoperatively and every year thereafter.</p><p><b>RESULTS</b>Group A patients' average preoperative VAS and ODI scores were 7.03 ± 0.98 and (64.22 ± 6.38)%, respectively, significantly decreased to 2.91 ± 0.88 and (14.42±2.08)%, respectively, at the last follow-up (P = 0.000). In Group B, the average preoperative VAS and ODI scores were 6.79 ± 0.86 and (63.22 ± 4.70)%, respectively, significantly decreased to 3.12 ± 0.96 and (14.62 ± 2.08)%, respectively, at the last follow-up (P = 0.000). No significant difference in the duration of hospitalization was found between groups. Operating time and blood loss of (125.9 ± 13.0) minutes and (211.4 ± 28.3) ml, respectively, in Group A were significantly less than (165.2 ± 15.3) minutes and (258.6 ± 18.3) ml, respectively, in Group B (P = 0.000). All patients achieved good bone union and had no pseudarthrosis at the last follow-up.</p><p><b>CONCLUSIONS</b>There are no clinical differences between unilateral and bilateral pedicle screw fixation combined with TLIF for one-level lumbar degenerative diseases. Unilateral fixation reduces operating time, bleeding, and cost of hospitalization.</p>

Morphologic differences of vascular buds in vertebral cartilage endplate in age-specific rabbits / 中华骨科杂志

Objective To observe the morphologic changes of of vascular buds in vertebral cartilage endplate in age-specific rabbits and also to investigate the correlation between the changes of vascular buds and interverbral disc degeneration. Methods There were 15 New Zealand white rabbits in our study,which include three groups, 2-week-old rabbits, 1-year-old rabbits and 3-year-old rabbits, and each groups had five rabbits. The X-ray radiograph, histology and scanning electron microscope were used to observe the changes of vertebral cartilage endplate. According to Miyamoto standard, the interverbral disc was graded 1-5, and scored 1-5 respectively. Results The changes of micro-vascular structure of vertebral cartilage endplate were observed during aging. Under the scanning electron microscope, the vascular structure degenerated gradually, and disappeared in the end. The blood vessels in the central region of the vertebral cartilage endplate reduced more obviously than those in periphery region. The severe degeneration was found in vertebral endplate, compared with intervertebral disc. The changes of vascular buds in rabbits vertebral cartilage endplate had positive correlation with the vertebral endplate calcification and the interbertebral disc degeneration. Conclusion Changes of vascular buds in vertebral endplate may accelerate intervertebral disc degeneration.

Diagnosis and treatment of cervical disc calcification in children / 中华外科杂志

<p><b>OBJECTIVES</b>To investigate the diagnosis and treatment cervical disc calcification in children.</p><p><b>METHODS</b>13 children with cervical disc calcification were analysed retrospectively. Cervical pain was observed after influenza in 5 children, suddenly cervical pain in 3, sudden wryneck in 3 cases. Two children with this disease were accidentally found after injury.</p><p><b>RESULTS</b>14 calcifications of cervical disks were found in 13 children. Clinical symptoms disappeared after symptomatic management. Calcification disappeared in 5 months.</p><p><b>CONCLUSIONS</b>Cervical disc calcification in children is a kind of benign self-limited disease. Correst understanding of pathophysiologic course of this disease helps to avoid unnecessary surgery.</p>

Surgical treatment of metastatic spinal tumor / 中国医学科学杂志(英文版)

<p><b>OBJECTIVES</b>To evaluate the effect of surgical treatment on metastatic spinal tumor.</p><p><b>METHODS</b>The results of surgical intervention for metastatic spinal tumor of 31 consecutive patients since October 1985 were reviewed.</p><p><b>RESULTS</b>The average survival time was 17.6 months (range from 3 months to 9 years), and 4 patients are still alive with an average survival time of 24.6 months (range, 14 to approximately 84 months). No postoperative complication was noted. The preoperative symptoms were partially relieved and neurological functions were improved after surgery.</p><p><b>CONCLUSION</b>Surgical treatment for metastatic spinal tumor could improve the life quality, but should be adopted cautiously. The surgical procedures such as decompression and internal fixation should be involved only when neurological deficits occurred. The surgery with postoperative complementary therapy may not only improve the life quality, but also extend the patients' life span.</p>

Surgical treatment of lumbar spinal stenosis associated with unstable degenerative spondylolisthesis / 中华外科杂志

<p><b>OBJECTIVES</b>To assess surgical treatment of lumbar spinal stenosis associated with unstable degenerative spondylolisthesis.</p><p><b>METHODS</b>In 86 patients with lumbar spinal stenosis associated with unstable degenerative spondylolisthesis. (30 men and 56 women, aged from 30 to 77 years), 63 patients complained of lower back pain with both lower extremity pain, 10 patients pain in one leg, and 13 patients only lower back pain. Seventy-two of these patients complained of intermittent claudication, with a walking distance ranging from 10 to 1 000 m. Thirty-two patients had some changes in sensation, motion and reflexes of the foot. According to White' critera, all patients showed dynamic instability of the lesion. Meyerding criteria showed degree 1 in 79 patients, and degree 2 in 7. CT scan was made in 56 patients, MRI in 24 and MRM in 6 before operation. Myelography was performed in 61 patients, and CTM in 6. Stenosis and spondylolisthesis located between L(4) and L(5) in 49 patients, between L(3) and L(4) in 6, between L(5) and S(1) in 25, between L(3) and L(4) and between L(4) and L(5) in 2, and from L(3) to S(1) in 4. The patients with pathological spondylolisthesis were excluded. Lateral recess stenosis of one leg was observed in 10 patients, lateral recess of both legs in 22, and central canal stenosis in 54, of whom 12 patients were associated with protrusion of the lumbar disc. Decompression and autograft with iliac bone and various internal fixation were performed in all patients.</p><p><b>RESULTS</b>The patients were followed up from 8 months to 13 years, longer than 1 year (average 5.6 years) in 81 patients. According to Amundsen et al, excellent results were obtained in 78 patients, good in 5, and fair in 3. Spondylolisthesis was completely reduced in 70 patients of degree 1 (89.9%), and in 6 patients of degree 2 (85.7%). No patient showed slippage aggravated. 74 patients gained bone graft fusion within 3 months and 10 patients within 6 months. Two patients showed pseudoarthrosis during the follow-up. Complications included internal fixation breakage in 1 patient, and delayed infection in 1.</p><p><b>CONCLUSIONS</b>Complete decompression and bone graft fusion are the key to treatment. Decompression and internal fixation improve the symptoms of patients with lumbar spinal stenosis associated with spondylolisthesis. Transpedicle instrumentation can reduce spondylolisthesis and maintain the physical curve of the lumbar.</p>

The surgical treatment of scoliosis in neurofibromatosis Ⅰ / 中华骨科杂志

Objective To investigate the surgical management of scoliosis in neurofibromatosis Ⅰ type. Methods Since 1983, the results of surgical intervention of 31 consecutive patients for scoliosis in neurofibromatosis were reviewed. There were 19 males and 12 females. The mean age of the patients was 15.4 years (range, 5 to 25 years). The type of curve in scoliosis included thoracic curve in 23 patients, lumbar curve in 3 and thoracolumbar curve in 5. There were 6 cases of thoracic curves associated with kyphosis. The mean Cobb angle of scoliosis was 85.9? ranging from 45? to 145?, and the mean Cobb angle of kyphosis was 81.3? ranging from 43? to 120? before operation. The surgical methods included posterior operation in 17 patients, anterior operation in 2, and combination of anterior and posterior in 12. The instrumentation used for internal fixation included Harrington rod in 7 patients,Luque rod in 3, combination of Harrington and Luque rod in 5 patients, CD in 4 patients, CDH in 3 patients,TSRH in 7, and PRSS in 2, 10 cases of whom only single rod fixation were used. Results The patients were followed up for an average of 9.4 years (range, 1-18 years). The correction rate of Cobb angle in scoliosis was 33.4% in scoliosis, and 39.6% in kyphosis postoperatively. The complications of the group consisted of Luque rod breakage in 1 patient, Harrington rod breakage in 1, Harrington rod and Luque wire breakage in 1,nonunion of bone graft and pseudarthrosis in 4, curve aggravation in 1. One patient underwent revision for three times because of recurrent hook dislodgement. Conclusion Scoliosis in neurofibromatosis should be operated early, sufficient bone graft and the solid instrumentation for internal fixation are required.

Causes and strategies on decompensation after operation for adolescent idiopathic scoliosis / 中华骨科杂志

Objective The study was to probe into the causes and strategies of decompensation after operation in adolescent idiopathic scoliosis in order to reduce the operative mistakes and be aware of pitfalls in scoliosis surgery.Methods From July1997to December2001,174patients underwent the operation of three-dimensional correction of adolescent idiopathic scoliosis,ten of them developed postoperative decom-pensation.Other four patients with postoperative decompensation were referred to our hospital,who received the primary operation for idiopathic scoliosis at the local hospital.In all,fourteen patients with decompensa-tion were retrospectively reviewed including3male and11female cases aging from12to23years(range,15.7years).The criteria of postoperative decompensation was defined as trunk shift more than2mm,shoul-der tilting,aggravated distal lumbar rotation in coronal plane,the plumb line of center of C 7 deviating the from the posterior edge of S 1 and kyphosis of thoracic-lumbar junction more than10degree in sagittal plane.Results The analysis was made depending on preoperative and postoperative X-ray films,the causes of de-compensation after surgery included classification error,inappropriate fusion level,over correction for tho-racic curve and insufficient knowledge of lumbosacral hemicurve in this group.According to the patientssubjective symptoms and decompensation conditions,ten of the patients were treated surgically,which in-cluded re-fusion and fixation for3patients,fusion level extension for6patients and fusion of the upper tho-racic curve after removing major thoracic curve instrumentation for one patient.The other four patients re-ceived conservative therapy with brace.The patients were followed up from1to3years(average,18.9months),except one case followed up to6months.Twelve patients regained spinal balance;two patients re-mained more than20mm trunk shift.Conclusion Although operative treatment is frequently used for idio-pathic scoliosis,it is important to recognize the necessity for operative intervention,indication for surgery.The adolescent idiopathic scoliosis should be operated according to the curve type and flexibility,the appro-priate fusion level and operative procedures can contribute to lessen the postoperative decompensation.If postoperative decompensation occurs,therapeutic decision should be made according to subjective symptoms and the decompensation type of the patients.

The changes of core protein of proteoglycan and cytokines in the vertebral cartilage endplate of adolescent idiopathic scoliosis / 中华骨科杂志

Objective To observe the expression of the transforming growth factor beta 1, the basic fibroblast growth factor and the core protein of proteoglycan on the convex and concave sides of apex and end vertebral cartilagnous endplate in adolescent idiopathic scoliosis. Methods There were 12 cases in the study group. There were 4 males and 8 females. The age of patients at the surgery ranged from 12 to 20 years(with an average of 14.9 years). The Cobb angle ranged 43? to 102? (mean, 65.1?) preoperatively. The diagnosis of idiopathic scolisis was made based on radiography, CTM and/or MRI to rule out congenital, neuromyeputhic and other scolisis. All patients underwent anterior correction procedures. The sections of the convex and concave side of the resected apex and end vertebral cartilage endplate were examined with S-P immunohistochemistry and the results were analyzed with image analysis system. Results The transforming growth factor beta 1, the basic fibroblast growth factor and the core protein of proteoglycan were all expressed in the cytoplasm of chondrocytes in the cartilaginous endplate. With non-parameter Wilcoxon rank test, the area density and quantity density of the transforming growth factor beta 1, the basic fibroblast growth factor on the concave curve of the apex and end vertebrae are expressed in a significantly higher level than those of the convex curve at the apex and end vertebrae(P0.05). Conclusion There was a significantly higher expression of TGF?1 and bFGF, while a lower expression of the core protein on the concave side, which suggest a possible aetiological factor or a secondary change in the development of AIS.