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BACKGROUND: It has been proved clinically that adhesion of fibrous scar with the dura mater or nerve root after lumbar operation is an important factor for postoperative symptoms, such as postoperative pain and numbness. OBJECTIVE: To verify the inhibitory effect of autologous ligamentum flavum on the formation of epidural fibrous scar after lumbar surgery and explore the possible molecular biological mechanism. METHODS: Forty-eight Japanese white rabbits (6-8 months old) were randomly divided into three groups: a ligamentum flavum preservation group, a ligamentum flavum non-preservation group, and an autologous fat reposition group. A lumbar laminectomy model was established in all the three groups of rabbits, and rabbit epidural tissues were collected at 3 and 6 weeks after modeling. Hematoxylin-eosin staining was used to observe histological changes and the number and density of fibroblasts, VG staining was used to observe the percentage of collagen fiber area, and immunohistochemistry was used to observe the expression of transforming growth factor β1 and Smad3 proteins. RESULTS AND CONCLUSION: Hematoxylin-eosin staining results revealed that fibroblasts in the ligamentum flavum preservation group were few and loosely arranged, while the cells in the ligamentum flavum non-preservation and autologous fat reposition groups were more numerous and closely arranged. The number density of fibroblasts in the ligamentum flavum preservation group was lower than that in the ligamentum flavum non-preservation and autologous fat reposition groups at 3 and 6 weeks after surgery (P < 0.05); however, there was no significant difference between the latter two groups. VG staining results showed that the collagen fibers in the ligamentum flavum preservation group were sparse and distributed unevenly, while a lot of red collagen fibers were gathered in the ligamentum flavum non-preservation and autologous fat reposition groups. The area percentage of collagen fibers in the ligamentum flavum preservation group was lower than that in the ligamentum flavum non-preservation and autologous fat reposition groups at 3 and 6 weeks after surgery (P < 0.05), but there was no significant difference between the latter two groups. The results of immunohistochemistry showed that the degree of positive staining of retained histone the ligamentum flavum preservation group was significantly lower than that of the other two groups. The absorbance value of transforming growth factor β1 and Smad3 in the ligamentum flavum preservation group was significantly lower than that in the other two groups at 3 and 6 weeks after surgery (P < 0.05), but there was no significant difference between the latter two groups. To conclude, there are different degrees of epidural fibrous scar formation after lumbar surgery. If the ligamentum flavum is preserved, it can help to reduce the number of epidural fibroblasts as well as the formation of collagen fibers, thus reducing the adhesion of the fibrous scar tissue to the dural sac and nerve root. The mechanism is not only a purely mechanical blockade, but also to reduce the formation of epidural fibrous scar by interfering with the transforming growth factor β1/Smad3 signaling pathway. [ABSTRACT FROM AUTHOR]

BACKGROUND: Needle-knife release of the ligamentum flavum can effectively improve symptoms in patients with lumbar degeneration, and ultrasound guidance can increase the precision of needle-knife release; however, the specific effects of needle-knife release of the ligamentum flavum on the degenerated intervertebral discs and the possible mechanisms remain to be clarified. OBJECTIVE: To investigate the effect of ultrasound-guided needle-knife release of the ligamentum flavum. METHODS: Twenty-four New Zealand rabbits were randomized into control (n=6) and model (n=18) groups. A rabbit model of lumbar disc degeneration model was established in the model group by cutting the supraspinous and interspinous ligaments of the L5/6 and L6/7 segments to maintain a standing posture and apply axial load to the lumbar spine. After successful modeling, the model rabbits were subdivided into a control group, a model group, an ultrasonic needleknife group, and a sham needle-knife group according to a random number table method, with six animals in each group. The ultrasonic needle-knife group underwent ultrasound-guided needle-knife release of the right yellow ligament of L7/S1, once every week, for a total of four times. The needle-knife approach in the sham needle-knife group was the same as that in the ultrasound needle-knife group, but the ligamentum flavum was not released. At 30 days after the intervention, MRI was used to observe the changes in the signal intensity of the nucleus pulposus within the L7/S1 segment. Hematoxylin-eosin staining was used to observe the morphological changes of the L7/S1 segment. Immunohisto-chemical staining was used to detect the expression of type I and II collagen in the nucleus pulposus of the L7/S1 segment. RT-PCR and western blot were used to detect the expression of integrin α5 and β1, p38, and nuclear factor κB in the L7/S1 segment. RESULTS AND CONCLUSION: MRI findings indicated that the nucleus pulposus of the intervertebral disc of rabbits in the model group was gray-black in color, and the gray value of the nucleus pulposus was significantly lower than that of the control group (P < 0.01). The brightness of the nucleus pulposus of the intervertebral disc of the rabbits in the ultrasonic needle-knife group was elevated compared with that of the model group, and the gray value of the nucleus pulposus was higher than that of the model group (P < 0.01). Results from hematoxylin-eosin staining showed that in the model group, the shape of the nucleus pulposus was irregular, the number of nucleus pulposus cells was reduced, the extracellular matrix was compressed, the fibrous ring was ruptured, the structure and boundary of the end plate were unclear, and the chondrocytes were arranged disorderly. Compared with the model group, the ultrasonic needle-knife group showed an increase in the number of the nucleus pulposus, an improvement in the rupture of the fibrous ring, and more regular arrangement of cartilage endplate cells. Results from immunohisto-chemical staining showed an increase in positive expression of type I collagen (P < 0.01) and a decrease in positive expression of type II collagen in the nucleus pulposus of the model group compared with the control group as well as a decrease in positive expression of type I collagen and an increase in positive expression of type II collagen in the nucleus pulposus of the ultrasonic needle-knife group compared with the model group (P < 0.01). RT-PCR and western blot assays showed that the mRNA and protein expression of integrin α5, integrin β1, p38, and nuclear factor κB in the intervertebral discs of rabbits in the model group were increased compared with that in the control group (P < 0.01); the mRNA and protein expression of integrin α5, integrin β1, p38, and nuclear factor κB in the intervertebral discs of rabbits in the ultrasonic needle-knife group was decreased compared with that in the model group (P < 0.01). To conclude, ultrasound-guided needle-knife release of the ligamentum flavum can improve the degree of lumbar disc degeneration in rabbits, which may be related to the inhibition of p38 and nuclear factor-κB expression by modulating integrin α5 and β1 expression. [ABSTRACT FROM AUTHOR]

Objective To investigate effect of body position on ultrasonographic measurement of ligamentum flavum length in lumbar intervertebral space in the elderly patients. Methods 40 patients over 65 years of age who underwent spinal anesthesia were selected to examine the L3/4, L4/5 and L5 / S1 intervertebral spaces. Anterioredge length of the ligamentum flavum (ALL) and distance from skin to the ligamentum flavum (DSL) of L3/4, L4/5 and L5/S1 intervertebral spaces were measured by ultrasonic parasagittal oblique view in both sitting and left lateral decubitus position, and definition degree of each ultrasonic image were analyzed. Results Compared with the measurement in left lateral position, ALL at L5/S1 level in sitting position was longer, and longer than that at L3/4 in the same position (P < 0.05)；DSL at L5/S1 was lower than that at L3/4 in sitting position (P < 0.05). Compared with ultrasonic definition of L5/S1, the fine definition rate of the left and right sides of L3/4 and L4/5 in both positions was lower (P < 0.05). Conclusion The ALL ultrasonic measurement at L5/S1 level in sitting position was longer than that in left lateral decubitus position, and also longer than that at L3/4 and L4/5 in the same position, its depth and image were shallower and clearer than other spaces. It is recommended for elderly patients to use the paramidian puncture approach for lumbar anesthesia. The relatively shallow width of L5/ S1 should be selected under the sitting position, and the left and right sides are equivalent, especially under the guidance of ultrasound. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ligamentum flavum hypertrophy is considered to be the main cause of lumbar spinal stenosis. In recent years, it has been reported that hypertrophy of the ligamentum flavum is related to growth factors, microRNAs and key signaling pathways. OBJECTIVE: To make a systematic review on the molecular level and signaling pathway of hypertrophic fibrosis of the ligamentum flavum. METHODS: Chinese and foreign databases, including CNKI, VIP, WanFang, PubMed, Biosos Preview, and Web of Science, were searched for relevant articles, and the basic experiments of hypertrophic fibrosis of the ligamentum flavum were collected by hand. The search terms included “lumbar spinal stenosis; hypertrophy of ligamentum flavum; ligamentum flavum hyperplasia; fibrosis of ligamentum flavum; cell factor; protein; signal path; microRNA” in Chinese and English, respectively. The retrieval time limit was set as June 30, 2020. The retrieved articles were screened in strict accordance with the inclusion criteria, and finally 15 relevant basic experimental articles were reviewed. RESULTS AND CONCLUSION: In the process of hypertrophic fibrosis, the ligamentum flavum can be affected by a variety of growth factors, miRNAs and multiple signaling pathways. Therefore, it is rational to speculate that the proliferation and fibrosis of the ligamentum flavum is a consequence of multi-dimensional coordination by multiple biological processes. However, the degree of fibrosis has not been determined yet, and further basic research is still needed in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: The research on the pathogenesis and mechanism of thoracic ossification of the ligamentum flavum mainly focuses on the research of functional genome; however, less is reported on it from proteomics. OBJECTIVE: To investigate the differential proteins between ossified ligamentum flavum and normal ligamentum flavum in patients with thoracic ossification of the ligamentum flavum, and to search for disease-related target proteins. METHODS: Ossified ligamentum flavum and adjacent normal ligamentum flavum samples were collected from three patients with thoracic ossification of the ligamentum flavum, and detected through protein extraction, quantification, isotope labeling for relative and absolute quantitative technique-labeled peptides. Differentially expressed proteins were identified and screened by liquid chromatography-tandem mass spectrometry. RESULTS AND CONCLUSION: Totally 589 kinds of differentially expressed proteins were identified, including 532 up-regulated proteins and 57 down-regulated proteins. Further analysis identified 23 kinds of proteins related to inflammation, among which, the expression of CYBB, PODXL, S100A12, LXN, S100A10, GJA1, LIPA, FOLR2, CYBA, IFI16, ABCF1, HMGB1, RPS19, PRDX5, MAP2K3 was up-regulated, and the expression of KRT14, IL17D, IL1RAP, SLC7A2, RHOB, COMP, KRT6B was down-regulated. These inflammation-related proteins may be important diagnostic and therapeutic targets involved in the occurrence and development of thoracic ossification of the ligamentum flavum. [ABSTRACT FROM AUTHOR]

BACKGROUND: MRI has high sensitivity to thoracic myelopathy, which can assess the spinal cord injury by morphology and magnitude of cervical spinal cord compression. Additionally, it is a valuable tool for the prognosis evaluation of thoracic spinal stenosis. OBJECTIVE: To explore the value of quantitative MRI T2WI parameters in predicting surgical outcome of thoracic ossification of the ligamentum flavum, and to establish the prediction model of poor prognosis, so as to provide reference for prognosis evaluation. METHODS: From January 2010 to January 2019 at Cangzhou Central Hospital, clinical and imaging data of 87 cases of thoracic ossification of the ligamentum flavum treated by thoracic laminectomy were reviewed retrospectively. According to the JOA recovery rate at 6-month follow-up, the patients were divided into good recovery group (≥ 50%) and poor recovery group (＜ 50%). Age, sex, duration of disease, JOA score, Sato type of ossification, maximum spinal cord compression, cross-sectional area, distribution of hyperintense signal, signal intensity ratio, intramedullary signal size, local kyphosis, kyphosis correction, number of decompressed levels and incidence of cerebrospinal fluid were compared between two groups. Univariate analysis was used to analyze indicators with significant differences. Receiver operating characteristic curve was plotted to analyze prognosis. Areas under the curve and cut-off values were recorded. The independent predictors of poor recovery were estimated through multivariate logistic regression analysis and the prediction model was established. RESULTS AND CONCLUSION: (1) The duration of disease, JOA score, maximum spinal cord compression, cross-sectional area, signal intensity ratio and intramedullary signal size showed significant difference between good recovery and poor recovery groups (P ＜ 0.05). (2) Receiver operating characteristic curve analysis showed that the area under the curve of the duration of disease, JOA score, maximum spinal cord compression, cross-sectional area, signal intensity ratio and intramedullary signal size was 0.670, 0.733, 0.647, 0.715, 0.753 and 0.765 respectively. The cut-off value was duration of 13 months, score 4, 29.8%, 0.25 cm², 1.593 and 13.64 mm respectively. The duration of disease and maximum spinal cord compression had low discrimination power (the area under the curve ＜ 0.7) in predicting poor recovery, whereas the JOA score, cross-sectional area, signal intensity ratio and intramedullary signal size had moderate discrimination power (the area under the curve 0.7-0.9). The area under the curve indicates good ability of signal intensity ratio and intramedullary signal size in combination (the area under the curve=0.791). (3) Logistic multivariate regression analysis showed that JOA score, cross-sectional area and combination of signal intensity ratio and intramedullary signal size were independent risk factors of poor recovery. A predicting model was built according to the result of the logistic regression analysis. It was shown that the area under the curve of this model was 0.890, which was significantly higher than that of the JOA score, cross-sectional area and combination of signal intensity ratio and intramedullary signal size (P ＜ 0.05). (4) Combination of signal intensity ratio and intramedullary signal size had higher predictive ability than other MRI parameters. JOA score, together with quantitative MRI T2WI parameters may have a better predictive value for the risk of poor recovery in patients with thoracic ossification of the ligamentum flavum. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pathological mechanism of ossification of the ligamentum flavum is unclear. There is no effective drug or non-surgical treatment in clinical practice. Current studies have found that osteopontin and autophagy play an important role in the process of osteogenesis, but their role in ossification of the ligamentum flavum has not been elucidated. OBJECTIVE: To seek for the potential target of drug therapy by exploring the mechanism of ossification of the ligamentum flavum. METHODS: (1) Surgical specimens of the ligamentum flavum were taken from patients with ossification of the ligamentum flavum, thoracic vertebrae or simple lumbar disc herniation undergoing posterior total laminectomy and decompression. These specimens were divided into two groups: an ossification group and a non-ossification group. Eight specimens from each group were collected. Osteopontin, osteocalcin and autophagy indexes Beclin-1, LC3 and P62 were stained by immunohistochemistry. (2) The ligamentum flavum cells were isolated and cultured by adherence method. The third generation cells were treated with osteopontin at different concentrations for different time to construct an in vitro model of ligamentum flavum ossification. (3) Autophagy inhibitor 3-methyladenine with different concentrations was used to intervene with non-ossified ligamentum flavum cells, followed by induction with 100 μg/L osteopontin. Western blot assay was used to detect the expression of alkaline phosphatase, osteocalcin. (4) Non-ossified ligamentum flavum cells were induced with 100 μg/L osteopontin, and the induction was terminated at 0, 15, 30, 60, and 120 minutes, respectively. The phosphorylation of ERK1/2, JNK and P38, which are important molecules in the MAPK signaling pathway, was detected by western blot. (5) Finally, after inhibition by ERK1/2 phosphorylation blocker U0126, the expression of alkaline phosphatase and osteocalcin was detected by western blot after induction with 100 μg/L steopontin. RESULTS AND CONCLUSION: (1) Immunohistochemical staining of osteopontin and osteocalcin in ossified and non-ossified ligamentum flavum was positive. In the ossified ligamentum flavum, Beclin-1 was positive, but LC3 and P62 were not. Beclin-1, LC3 and P62 were all positive in the non-ossified ligamentum flavum. (2) The expression of alkaline phosphatase and osteocalcin in the ossified ligamentum flavum cells was higher than that in the non-ossified ligamentum flavum cells. Osteopontin could induce ossification of the ligamentum flavum in a concentration- and time-dependent manner. (3) The degree of ossification was negatively correlated with the degree of autophagy, that is, the more obvious autophagy was, the weaker ossification was. (4) Osteopontin could phosphorylate the MAPK signaling pathway in a time-dependent manner. After inhibiting the phosphorylation of MAPK, osteopontin could still induce the ossification of ligamentum flavum cells. To conclude, in the process of ligamentum flavum ossification, the upstream and downstream relationships of ERK1/2, osteopontin, alkaline phosphatase and osteocalcin molecules in signaling pathway are ERK1/2→osteopontin→osteocalcin /alkaline phosphatase. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lumbar spinal stenosis is one of the key causes of gait disorder and low back pain in the older adults. Hypertrophy of the ligamentum flavum is the main pathological mechanism leading to lumbar spinal stenosis. Although there are numerous imaging and pathological studies on the ligamentum flavum, little is reported on cell apoptosis. OBJECTIVE: To detect the apoptotic rate and the expression of caspase-3, fas and p53 in the hypertrophic ligamentum flavum, providing experimental evidence for understanding the mechanism underlying degeneration of the ligamentum flavum. METHODS: In experimental group, 50 hypertrophic ligamentum flavum specimens (L2-S1) confirmed by MRI and postoperative measurement were obtained from 50 patients with lumbar spinal stenosis who underwent posterior decompression surgery. There were 22 males and 28 females, aged from 32 to 74 years old, with an average of 54.46 years old. In control group, 30 non-hypertrophic ligamentum flavum specimens (L2-S1) confirmed by MRI and postoperative measurement were obtained from 30 patients with lumbar disc herniation undergoing surgery and lumbar burst fractures. There were 19 males and 11 females, aged 19-67 years, with an average of 47.27 years old. The apoptotic rate in the ligamentum flavum was detected by TUNEL staining, and the expression of caspase-3, fas and p53 was detected by SP immunohistochemistry. The study protocol was approved by the Ethics Committee of the Sixth Affiliated Hospital of Xinjiang Medical University, with approval No. LFYLLSJ2016007. RESULTS AND CONCLUSION: TUNEL results showed that the average apoptotic rate of the experimental group was (37.80±3.04)%, which was significantly higher than that of the control group [(13.18±1.34)%; t=41.83, P < 0.001]. The immunohistochemical staining of SP revealed that the positive expression percentages of caspase-3, fas and p53 in the ligamentum flavum were all 100% in the experimental group, while the positive percentages were 13.3%, 16.7%, and 10% in the control group, respectively. There was a significant difference between the two groups (P < 0.001). These findings indicate that cell apoptosis in the hypertrophic ligamentum flavum is increased and has a certain correlation with the up-regulation of caspase-3, fas and p53. [ABSTRACT FROM AUTHOR]

BACKGROUND: Formation of scar tissue and the consequent formation of adhesions with dura and nerve root is an important factor for postoperative outcomes of laminectomy. How to reduce or prevent the adhesion or scar formation has been paid much attention in the clinic. OBJECTIVE: To explore the effect of preserving the ligamentum flavum on preventing dural adhesions after laminectomy in lumbar surgery. METHODS: Forty New Zealand white rabbits were randomly divided into ligamentum flavum resection group and ligamentum flavum preservation group (n=20 per group). All animals underwent L4-5 laminectomy, simulating nucleus pulpotomy. Postoperative dural adhesion was assessed according to Rydell-balazs and Nuss-baum criteria. RESULTS AND CONCLUSION: The operations were successfully completed, and there was visible scar in the operation area in the ligamentum flavum preservation group, the dura adhesion was easy to be separated bluntly from surrounding tissue. In the ligamentum flavum resection group, the scar tissue around the dura was very dense and the dural adhesions were serious, even osteoid was observed. The Rydell-balazs and Nuss-baum scores in the ligamentum flavum preservation group were significantly lower than those in the ligamentum flavum resection group (P < 0.05). To conclude, retaining the ligamentum flavum can reduce epidural scarring and adhesion of the dura to the surrounding tissue. [ABSTRACT FROM AUTHOR]

BACKGROUND: The pathogenesis of hypertrophy of lumbar ligamentum flavum is complex, and whether it is related to the sagittal spinopelvic balance remains unclear. OBJECTIVE: To investigate the relationship between hypertrophy of lumbar ligamentum flavum and sagittal spinopelvic balance parameters. METHODS: A retrospective analysis of the clinical data of 38 patients with lumbar degenerative diseases admitted to hospital from January 2015 to December 2017 was conducted. The sagittal spinopelvic balance parameters, including thoracic kyphosis, lumbar lordosis, sacral slope, pelvic incidence, pelvic tilt, sagittal vertical axis, were measured on the full-length radiographs in standing position. The thickness of lumbar ligamentum at L1-2, L2-3, L3-4, L4-5, L5-S1 was measured on the axial T2-weighed MR images at the facet joint level. In order to analyze the relationship between hypertrophy of lumbar ligamentum flavum and sagittal spinopelvic balance parameters, patients were divided into normal group (thickness of ligamentum ≤ 3 mm) and hypertrophy group (thickness of ligamentum > 3 mm) RESULTS AND CONCLUSION: (1) There was no significant difference in the sex and body mass index between two groups at each segment (P > 0.05), but age showed significant difference (P < 0.05). (2) There was significant difference in the thoracic kyphosis at L1-2 between groups (P < 0.05). There were significant differences in the thoracic kyphosis and pelvic tilt at L2-3 between groups (P < 0.05). There was no significant difference in the thoracic kyphosis at L3-4 between groups (P=0.054). There was significant difference in the lumbar lordosis at L4-5 (P < 0.05). The parameters at L5-S1 showed no significant difference between groups. (3) There was a negative correlation between L5-S1 thickness and sagittal vertical axis (r=-0.33, P < 0.05). (4) To conclude, hypertrophy of ligamentum flavum is closely related to the sagittal spinopelvic balance parameters. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ligamentum flavum hypertrophy is one important cause of spinal stenosis. Ligamentum flavum thickness of more than 4 mm measured on computed tomography (CT) and magnetic resonance imaging is considered hypertrophy, but causes of hypertrophy and distribution characteristics remain poorly understood. Previous studies showed that the ligamentum flavum thickness at the segments L2/3, L3/4, L4/5 and L5/S1 was positively correlated with age. It remains unclear whether ligamentum flavum thickness is associated with nationality, sex and obesity. OBJECTIVE: To retrospectively analyze the risk factors for ligamentum flavum hypertrophy in lumbar spinal stenosis patients from the Xinjiang Uygur Autonomous Region, China. METHODS: We conducted a retrospective, single-center, case analysis at the Sixth Affiliated Hospital, Xinjiang Medical University, China. We collected lumbar CT imaging data of 104 patients diagnosed with lumbar spinal stenosis in the Sixth Affiliated Hospital, Xinjiang Medical University from May 2012 to May 2016. The primary outcome was the ligamentum flavum thickness of patients with different nationalities, sexes, heights, ages, and weights. The secondary outcomes were the morphology of lumbar vertebrae in patients with different nationalities, sexes, heights, ages, and weights; the correlation of nationality, sex, height, age, and weight with ligamentum flavum thickness; results of multiple linear regression analysis of relevant factors for ligamentum flavum hypertrophy. This trial has been registered at clinical Trials.gov (indentifier: NCT03057353). This protocol has been approved by the Medical Ethics Committee of Xinjiang Medical University and will be performed in accordance with the guidelines of the Declaration of Helsinki, formulated by the World Medical Association. Signed informed consent regarding trial procedure and treatment will be obtained from each participant. DISCUSSION: This study will determine the variations in the ligamentum flavum thickness of lumbar spinal stenosis patients of different nationalities, sexes, heights, ages, and weights in the Xinjiang Uygur Autonomous Region by measuring the ligamentum flavum thickness using CT, and analyzing risk factors for ligamentum flavum hypertrophy; the findings will provide quantitative reference data for preventing lumbar spinal stenosis induced by ligamentum flavum hypertrophy in the Xinjiang Uygur Autonomous Region. [ABSTRACT FROM AUTHOR]

BACKGROUND: The pathogenesis of ligamentum flavum hypertrophy remains poorly understood, and the expression of transforming growth factor beta1 (TGF-β1) is increased notably. Reactive oxygen species (ROS) accumulation is associated with tissue degeneration, which may accelerate the progression of ligamentum flavum hypertrophy by upregulating TGF-β1 expression. OBJECTIVE: To clarify the effect and significance of ROS H2O2-mediated up-regulation of TGF-β1 and collagen type I in the progress of ligamentum flavum hypertrophy. METHODS: Ligamentum flavum was removed from a case of acquired lumbar disc herniation with normal ligamentum flavum during lumbar posterior decompression surgery, and then separated and cultured in vitro to the 4-6 generations, followed by exposure to H2O2 at various concentrations (0, 50, 100, 150, 200 μmol/L) for 72 hours. The mRNA and protein expression levels of TGF-β1 and collagen type I were detected by real-time PCR and western blot assay, respectively. RESULTS AND CONCLUSION: Real-time quantitative PCR showed that the mRNA expression level of TGF-β1 was significantly increased in the 150 and 200 μmol/L groups (P < 0.05). The mRNA expression level of collagen type I was significantly higher in the experimental groups than that in the control group, especially in the 200 μmol/L group (P < 0.05). Western blot assay revealed that the protein expression levels of TGF-β1 and collagen type I were significantly increased in a dose-dependent manner (P < 0.05). These findings indicate that H2O2 may accelerate the progression of ligamentum flavum hypertrophy by up-regulating the expression levels of TGF-β1 and collagen type I. [ABSTRACT FROM AUTHOR]

Objective To summarize the outcome of treatment for thoracic vertebra ossification of ligamentum flavum (OLF) with en-bloc removal of the spinal canal's posterior wall termed as the "thinned cap uncovering" technique. Methods From 2003 to 2013, 56 patients with OLF were treated with thinned cap uncovering technique. In this group, there were 40 male patients and 16 female ones, with the average age of 45 years (range of 30-65 years) and the average history of 3 years. The 56 patients were followed up for an average duration of 2 years and 7 months (1-5 years). Results According to WANG's evaluation, 45 cases (about 80%) had excellent results, 9 cases (about 16%) had good results, and 3 cases had improved symptoms, the excellence to good rates being 96%. Conclusion Removal of the posterior wall of the spinal canal via "thinned cap uncovering" technique is a reliable and effective treatment for thoracic OLF. The strategy for successful operation is to use high speed drill to cut bone accurately, which allows discectomy for thoracic vertebra and to diminish faults and complications during the surgical procedure. [ABSTRACT FROM AUTHOR]

Objective: To investigate the mechanism of p38 mitogen activated protein kinase (MAPK) signaling pathway in regulating the hyperplasia and hypertrophy of human lumbar ligamentum flavum via transforming growth factor β 1 (TGF-β 1 )/connective tissue growth factor (CTGF)., Methods: The lumbar ligamentum flavum tissue taken from patient with lumbar intervertebral disc herniation was isolated by collagenase-predigested explant cultures. The ligamentum flavum cells were treated with the extracellular regulated protein kinase pathway blocker PD98059, c-Jun N-terminal kinase pathway blocker SP600125, and p38 pathway blocker SB203580, and then the mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ were detected by real-time fluorescence quantitative PCR (qRT-PCR). The ligamentum flavum cells were divided into 4 groups, and transfected with small interfering RNA (siRNA), p38 siRNA, siRNA+3 ng/mL TGF-β 1 , and p38 siRNA+3 ng/mL TGF-β 1 in groups A, B, C, and D, respectively. After 24 hours of transfection, immunofluorescence staining was performed to observe the expressions of p38 and phosphorylation p38 (p-p38); the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ in each group were detected by qRT-PCR; the protein expression of CTGF in each group was detected by Western blot., Results: p38 pathway blocker SB203580 could significantly reduce the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ ( P <0.05). After 24 hours of transfection, immunofluorescence staining showed positive staining with p38 and p-p38 expressions in groups A, C, and D and negative staining in group B. Compared with group A, the relative mRNA expressions of CTGF, collagen type Ⅰ, and collagen type Ⅲ and relative protein expression of CTGF in group B decreased significantly ( P <0.05), while those in groups C and D increased significantly ( P <0.05); and those indicators significantly increased in group C than in group D ( P <0.05)., Conclusion: TGF-β 1 /CTGF based on the p38 MAPK signaling pathway play an important role in the occurance and development of hypertrophy of human lumbar ligamentum flavum.

Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose.

Objective: To evaluate the effectiveness of posterior cervical decompressive laminectomy and lateral mass screw fixation combined with foraminotomy for treating cervical radiculo-myelopathy., Methods: Between January 2010 and January 2012, 58 patients with cervical radiculo-myelopathy were treated by posterior cervical decompressive laminectomy and lateral mass screw fixation combined with foraminotomy. There were 31 males and 27 females, with an average age of 52.7 years (range, 41-72 years). The mean disease course was 5.4 years (range, 3-15 years). The preoperative Japanese Orthopaedic Association (JOA) score was 7.8±1.3, and visual analogue scale (VAS) score was 6.8±1.7. There were 37 cases of inter-vertebral disc herniation and ligamentum flavum hypertrophy, 11 cases of vertebral osteophyte formation with the osteophyte spinal canal occupational ratio of 51.7%±18.1%, and 10 cases of inter-vertebral disc herination with cervical instability. Preoperative cervical curvature was (-5.5±12.5)°. The fixed segments included C 3-7 in 29 cases, C 4-7 in 19 cases, and C 3-6 in 10 cases. Foraminotomy was performed in 135 nerve foramina (mean, 2.33 foramina)., Results: The mean operation time was 204 minutes (range, 167-260 minutes), and the mean blood loss was 273 mL (range, 210-378 mL). No injury of vertebral artery or nerve root occurred during operation. Postoperative subcutaneous hematoma and cervical axial pain occurred in 1 case and 8 cases, respectively; and no nerve root palsy was observed. The patients were followed up 2.1-4.3 years (mean, 3.4 years). The postoperative JOA score was significantly increased to 14.1±1.7 ( t =-27.672, P =0.000), with an improvement rate of 68.5%±21.9%. Postoperative VAS score was significantly decreased to 2.1±1.1 ( t =15.168, P =0.000). The imaging examination showed adjacent segmental degeneration in 1 patient, who had no clinical symptom. There was no screw loosening or pseudoarthrosis formation during follow-up. The cervical curvature was (13.6±5.1)° at 5 days and was (13.2±4.8)° at 2 years, showing significant difference when compared with preoperative one ( P <0.05). The osteophyte spinal canal occupational ratio was 36.5%±10.4% at 2 years, showing significant difference when compared with preoperative one ( t =6.921, P =0.000)., Conclusions: The procedure of posterior cervical decompressive laminectomy and lateral mass screw fixation combined with foraminotomy is effect in treating cervical radiculo-myelopathy. The spinal cord and nerve root can be adequately decompressed by laminectomy and foraminotomy. The lateral mass screw fixation can correct the cervical curvature and further reduce the tension to spinal cord.