Incidence and cost of vertebral fracture in urban China: a 5-year population-based cohort study

BACKGROUND

Osteoporotic vertebral fractures cause pain and disability, which result in a heavy socioeconomic burden. However, the incidence and cost of vertebral fractures in China are unknown. We aimed to assess the incidence and cost of clinically recognized vertebral fractures among people aged 50 years and older in China from 2013 to 2017.

MATERIALS AND METHODS

This population-based cohort study was conducted by using Urban Employee Basic Medical Insurance (UEBMI) and Urban Resident Basic Medical Insurance (URBMI) data in China from 2013 to 2017, which covered more than 95% of the Chinese population in urban areas. Vertebral fractures were identified by the primary diagnosis (i.e. International Classification of Diseases code or text of diagnosis) in UEBMI and URBMI. The incidence and medical cost of these clinically recognized vertebral fractures in urban China were calculated.

RESULTS

A total of 271 981 vertebral fractures (186 428, 68.5% females and 85 553, 31.5% males) were identified, with a mean age of 70.26 years. The incidence of vertebral fractures among patients aged 50 years and over in China increased ~1.79-fold during the 5 years, from 85.21 per 100 000 person-years in 2013 to 152.13 per 100 000 person-years in 2017. Medical costs for vertebral fractures increased from US$92.74 million in 2013 to US$505.3 million in 2017. Annual costs per vertebral fracture case increased from US$3.54 thousand in 2013 to US$5.35 thousand in 2017.

CONCLUSION

The dramatic increase in the incidence and cost of clinically recognized vertebral fractures among patients aged 50 and over in urban China implies that more attention should be given to the management of osteoporosis to prevent osteoporotic fractures.

Long-Term Follow-Up of Multilevel Thoracic Ossification of the Posterior Longitudinal Ligament Following Circumferential Decompression via Posterior Approach: A Retrospective Study

Objective

To examine the postoperative progression of multilevel thoracic posterior longitudinal ligament (OPLL) at circumferential decompression (CD) levels and evaluate the long‐term results after CD via the posterior approach.

Methods

Clinical data from 16 patients with thoracic myelopathy secondary to OPLL who underwent CD at a single center were evaluated retrospectively from 2007 to 2014 and were followed up for more than 60 months. Patients of all sexes and ages were included in the study. Thin‐slice computed tomography scans obtained at the time of surgery and the most recent follow‐up were analyzed. The ossified area was measured on the axial reconstructed scan of the most obvious protrusion of ossification at the CD level. The neurological outcomes were evaluated using modified Japanese Orthopaedic Association (JOA) scores and Hirabayashi recovery rates (HRRs). Continuous variables were presented as the mean ± standard deviation and were analyzed using the Student's t‐test, while categorical variables were tested using Fisher's exact test.

Results

Among all patients, the most predominant type was the mixed type (9/16, 56.3%), while the circumscribed type was only found in two patients (12.5%), and the continuous type was found in five patients (31.2%). Six cases were associated with ossification of the ligamentum flavum, and two cases were combined with cervical OPLL. The OPLL area at the CD level increased in all patients. The mean follow‐up period was 5.5 ± 0.92 years (range 5–8 years). The mean area of ossification increased from 35.63 ± 39.23 mm² at the time of surgery to 99.94 ± 65.39 mm² at the last follow‐up visit (P < 0.01). There was no internal fixation disorder on any computed tomography scan after the operation. The average JOA score of all patients improved from 4.2 ± 2.2 points before surgery to 8.4 ± 2.6 points at the final follow‐up (P < 0.01). The overall HRR was 61.8%. None of the patients exhibited any neurological deterioration due to OPLL progression. One patient developed a severe gait disturbance due to worsening lumbar canal stenosis, an unrelated cause, but the other 15 experienced gait disturbance improvements.

Conclusions

According to the long‐term follow‐up results, although OPLL progression did not decrease or stop after removing the OPLL mass, CD is a safe and effective procedure that can provide adequate reserve ventral space to cope with postoperative OPLL progression.

Three-dimensional navigation (O-arm) versus fluoroscopy in the treatment of thoracic spinal stenosis with ultrasonic bone curette: A retrospective comparative study

Three-dimensional intraoperative navigation (O-arm) has been used for many years in spinal surgeries and has significantly improved its precision and safety. This retrospective study compared the efficacy and safety of spinal cord decompression surgeries performed with O-arm navigation and fluoroscopy. The clinical data of 56 patients with thoracic spinal stenosis treated from March 2015 to April 2017 were retrospectively analyzed. Spinal decompression was performed with O-arm navigation and ultrasonic bone curette in 29 patients, and with ultrasonic bone curette and fluoroscopy in 27 patients. Patients were followed-up at postoperative 1 month, 3 months, and the last clinic visit. The neurologic functions were assessed using the Japanese Orthopaedic Association (JOA) Back Pain Evaluation Questionnaire. The accuracy of screw placement was examined using three-dimensional computed tomography (CT) on postoperative day 5. There was no significant difference in the incidences of intraoperative dural tear, nerve root injury, and spinal cord injury between the two groups. The two groups showed no significant difference in postoperative JOA scores (P > .05). The O-arm navigation group had significantly higher screw placement accuracy than the fluoroscopy group (P < .05). O-arm navigation is superior to fluoroscopy in the treatment of thoracic spinal stenosis with ultrasonic bone curette in terms of screw placement accuracy. However, the two surgical modes have similar rates of intraoperative complications and postoperative neurologic functions.

Treatment for Thoracic Ossification of Posterior Longitudinal Ligament with Posterior Circumferential Decompression

OBJECTIVE

To report the results of the posterior approach for thoracic ossification of posterior longitudinal ligament (TOPLL) by using a special "L" osteotome.

METHODS

The present study enrolled 16 consecutive patients (9 men and 7 women) between May 2009 and September 2013. All patients underwent a posterior circumferential decompression osteotomy and segmental instrumentation with interbody fusion. The mean age at surgery was 57.3 years (range, 37-68 years). Patients' data, clinical manifestation, blood loss, length of surgery, complications, visual analog scale (VAS), Japanese Orthopedic Association (JOA), and Frankel grading system before and after surgery were collected and evaluated, retrospectively.

RESULTS

The average follow-up period was 30 ± 19 months (range, 12-50 months). All patients were successfully treated with posterior compression and segmental instrumentation with interbody fusion. The average operation time was 261.6 ± 51.3 min (range, 190-310 min). The mean blood loss was 980.3 ± 370.5 mL (range, 600-2100 mL). All patients had subjective improvement of motor power and gait. Average preoperative and postoperative JOA scores were 4.2 ± 1.7 and 7.8 ± 2.5 points, respectively. Differences in the overall JOA scores showed significant postoperative improvement. At the last follow-up, all patients improved either by one or two Frankel grades. There was a significant difference between preoperative VAS scores and those 3 months after surgery (P < 0.05). No significant difference was observed between the 3-month and 12-month results (P > 0.05). Cerebrospinal fluid (CSF) leakage occurred in 3 patients. Acute neurological deterioration was encountered postoperatively in 1 patient.

CONCLUSION

Treatment with posterior transpedicular osteotomy and circumferential decompression was found to be safe, effective, reliable, and technically feasible, and keeping the thoracic cavity intact avoids many shortcomings of anterior surgery and results in a satisfactory spinal decompression.

[A clinical study of the association between hepatic controlled attenuation parameter and metabolic syndrome]

Objective: To investigate the association between hepatic controlled attenuation parameter (CAP) and metabolic syndrome (MetS) and the correlation of CAP and its changes with the incidence of MetS. Methods: A total of 2461 subjects who underwent physical examination from July 2013 to September 2015 were enrolled. Spearman correlation analysis was used to investigate the correlation of CAP with the number of MetS components and each MetS component, and the chi-square test was used to investigate the prevalence rates of MetS and each component under different CAP levels. Logistic regression analysis was used to analyze the odds ratio (95% confidence interval (CI)) of MetS under different CAP levels. A total of 230 subjects without baseline MetS were selected; in a prospective cohort study, these subjects were divided into groups according to the baseline CAP, change in CAP, and percent change in CAP, and the chi-square test was performed to compare the incidence of MetS. The Cox regression analysis was used to analyze the values of baseline CAP, change in CAP, and percent change in CAP in predicting MetS. Results: CAP was positively correlated with the number of MetS components (r = 0.309, P < 0.01) and significantly correlated with all components. There were significant differences in the prevalence rates of MetS and its components under different CAP levels (< 238 dB/m, 238-258 dB/m, 259-291 dB/m, and ≥292 dB/m) (P < 0.05). After the adjustment for sex and age, with < 238 dB/m as a reference, the odds ratios (95% CI) of MetS in patients with CAP levels of 238-258 dB/m, 259-291 dB/m, and ≥292 dB/m were 1.784 (1.369-2.325), 2.936 (2.292-3.760), and 4.363 (3.435-5.543), respectively (all P < 0.05). Follow-up data showed that 28 patients (12.2%) developed MetS. After the adjustment for related factors, the hazard ratios (95% CI) of MetS in patients with baseline CAP > 238 dB/m, change in CAP > 30 dB/m, and percent change in CAP > 25.0% were 3.337 (1.163-9.569), 7.732 (2.453-24.366), and 11.656 (3.329-40.813), respectively (all P < 0.05). Conclusion: CAP is closely associated with MetS and its components. CAP and its change can be used to predict the risk of MetS.

Intraosseous Injection of Simvastatin in Poloxamer 407 Hydrogel Improves Pedicle-Screw Fixation in Ovariectomized Minipigs

BACKGROUND

Osteoporosis leads to poor osseointegration and reduces implant stability. Statins have been found to stimulate bone formation, but the bioavailability from oral administration is low. Local application may be more effective at augmenting bone formation and enhancing implant stability. This study was performed to evaluate the efficacy of an intraosseous injection of simvastatin in thermosensitive poloxamer 407 hydrogel to enhance pedicle-screw fixation in calcium-restricted ovariectomized minipigs.

METHODS

Nine mature female Guangxi Bama minipigs underwent bilateral ovariectomy and were fed a calcium-restricted diet for 18 months. Simvastatin (0, 0.5, or 1 mg) in thermosensitive poloxamer 407 hydrogel was injected into the lumbar vertebrae (L4-L6), and titanium alloy pedicle screws were implanted. Bone mineral density (BMD) measurements of the lumbar vertebrae were determined by dual x-ray absorptiometry (DXA) before and 3 months after treatment. The lumbar vertebrae were harvested and analyzed with use of microcomputed tomography, biomechanical pull-out testing, histological analysis, and Western blot analysis for bone morphogenetic protein (BMP)-2 and vascular endothelial growth factor (VEGF) expression.

RESULTS

Evaluation over a 3-month study period demonstrated that the BMD of the vertebrae injected with 0.5 and 1.0 mg of simvastatin had increased by 31.25% and 31.09%, respectively, compared with vehicle-only injection (p ≤ 0.00014 for both) and increased by 32.12% and 28.16%, respectively, compared with the pre-treatment levels (p < 0.0001 for both). A single injection of simvastatin in poloxamer 407 increased trabecular volume fraction, thickness, and number and decreased trabecular separation (p ≤ 0.002). The bone formation and mineral apposition rates significantly increased (p ≤ 0.023). The percentage of osseointegration in the simvastatin 0.5 and 1-mg groups was 46.54% and 42.63% greater, respectively, than that in the vehicle-only group (p ≤ 0.006), and the maximum pull-out strength was 45.75% and 51.53% greater, respectively, than in the vehicle-only group (p ≤ 0.0005). BMP-2 and VEGF expressions were higher than for the vehicle-only injection.

CONCLUSIONS

A single intraosseous injection of simvastatin in thermosensitive poloxamer 407 hydrogel stimulated bone formation, increased BMD, improved bone microstructure, promoted osseointegration, and significantly enhanced the stability of pedicle screws in calcium-restricted ovariectomized minipigs.

CLINICAL RELEVANCE

These results provide rationale for evaluating intraosseous injection of simvastatin in poloxamer 407 to enhance implant fixation in patients with osteoporosis.

[The clinical analysis of instrumentation failure after corrective surgery for thoracolumbar focal kyphosis]

OBJECTIVE

To analyze the etiology of instrumentation failure after corrective surgery for thoracolumbar focal kyphosis, and make suggestion for treatment.

METHODS

Retrospective study for 8 patients with thoracolumbar focal kyphosis who underwent surgical treatment and suffered instrumentation failure from June 2005 to December 2011 was made. The surgical procedures included pedicle subtraction osteotomy (PSO), anterior opening-posterior closing osteotomy and correction (AOPC), and posterior vertebral column resection (VCR). The reasons of instrumentation failure were analyzed and revision surgeries were performed.

RESULTS

The incidence of instrumentation failure was 6.3%. The average occurrence time was 22.5 months after surgery. Except one had failure in 3 months after surgery, all cases happened after 1 year. In this series, there were 5 cases with post-tuberculosis, 2 cases with post-traumatic kyphosis and 1 case with congenital kyphosis. For the surgical procedure, 7 cases underwent VCR and 1 case AOPC. After the instrumentation failure, all cases had back pain, and 3 of them had combined neurological symptoms. The reasons or risk factors of instrumentation failure included non-fusion of bone graft, VCR procedure, sink of the titanium mesh, insufficiency of anchor sites, and more severe kyphosis. All the 8 cases were treated with revision surgery and got good results.

CONCLUSIONS

The instrumentation failure of thoracolumbar focal kyphosis is relatively late occurred, and can develop with various reasons. Positive revision surgery is suggested for the instrumentation failure, and good results can be expected.

[Clinical analysis of 67 cases of surgical site infection after spine surgery]

OBJECTIVE

To investigate the treatment of surgical site infection(SSI) after spine surgery.

METHODS

Sixty-seven patients (aged 20-77 years with mean age of 51 years) with etiologically-confirmed surgical site infection after spine surgery in Peking University Third Hospital between July 2004 and December 2012 were retrospectively analyzed. There were 39 male and 28 female patients; 47 lumbar infections, 4 thoracic infections, 7 lower cervical infections and 8 upper cervical infections; 64 early infections and 3 delayed infections; 23 superficial infections and 44 deep infections; 47 monomicrobial infections and 20 polymicrobial infections. Ninety-six strains of bacteria were identified from the bacterial culture of 67 patients. Sixty strains were gram-positive pathogenic bacteria (62.5%), and the top three species were Staphylococcus aureus, S. epidermidis and Enterococcus faecalis. The remaining 36 strains were gram-negative pathogenic bacteria (37.5%), and the 3 species most predominant were Escherichia coli, Enterobacter cloacae, and Acinetobacter baumannii. All the patients with SSI were administered antibiotics. Debridement and irrigation-suction was performed if little symptomatic improvement was achieved in two-to-three days of antibiotics treatment, patients underwent 1-5 times of debridements (mean 1.5 times).

RESULTS

One patient was dead of MRSA septicemia, whom manifested as high fever, alalia and incision swelling when the infection occurred. The patient underwent polymicrobial of pulmonary infection and urinary tract infection during the period of hospitalization, and finally died of multiple organ failure. Sixty-six cases had wound healed, and they were followed up for 25-117 months (average 70 months), no recurrence of infection was found at last follow-up. Among the 65 cases of internal fixation, 56 cases reserved the implants, while implants were removed in other 9 cases for controlling infection.

CONCLUSION

Reasonable antibiotics and irrigation-suction are effective methods for managing surgical site infections after spine surgery and prevent removal of implants.

Construction of a protein-protein interaction network of Wilms' tumor and pathway prediction of molecular complexes

Wilms' tumor (WT), or nephroblastoma, is the most common malignant renal cancer that affects the pediatric population. Great progress has been achieved in the treatment of WT, but it cannot be cured at present. Nonetheless, a protein-protein interaction network of WT should provide some new ideas and methods. The purpose of this study was to analyze the protein-protein interaction network of WT. We screened the confirmed disease-related genes using the Online Mendelian Inheritance in Man database, created a protein-protein interaction network based on biological function in the Cytoscape software, and detected molecular complexes and relevant pathways that may be included in the network. The results showed that the protein-protein interaction network of WT contains 654 nodes, 1544 edges, and 5 molecular complexes. Among them, complex 1 is predicted to be related to the Jak-STAT signaling pathway, regulation of hematopoiesis by cytokines, cytokine-cytokine receptor interaction, cytokine and inflammatory responses, and hematopoietic cell lineage pathways. Molecular complex 4 shows a correlation of WT with colorectal cancer and the ErbB signaling pathway. The proposed method can provide the bioinformatic foundation for further elucidation of the mechanisms of WT development.

A single CT-guided percutaneous intraosseous injection of thermosensitive simvastatin/poloxamer 407 hydrogel enhances vertebral bone formation in ovariectomized minipigs

The ultimate goal of osteoporosis treatment is prevention of fragile fracture. Local treatment targeting specific bone may decrease the incidence of osteoporotic fractures. We developed an injectable, thermosensitive simvastatin/poloxamer 407 hydrogel; a single CT-guided percutaneous intraosseous injection augmented vertebrae in ovariectomized minipigs.

INTRODUCTION

The greatest hazard associated with osteoporosis is local fragility fractures. An adjunct, local treatment might be helpful to decrease the incidence of osteoporotic fracture. Studies have found that simvastatin stimulates bone formation, but the skeletal bioavailability of orally administered is low. Directly delivering simvastatin to the specific bone that is prone to fractures may reinforce the target bone and reduce the incidence of fragility fractures.

METHODS

We developed an injectable, thermosensitive simvastatin/poloxamer 407 hydrogel, conducted scanning electron microscopy, rheological, and drug release analyses to evaluate the delivery system; injected it into the lumbar vertebrae of ovariectomized minipigs via minimally invasive CT-guided percutaneous vertebral injection. Three months later, BMD, microstructures, mineral apposition rates, and strength were determined by DXA, micro-CT, histology, and biomechanical test; expression of VEGF, BMP2, and osteocalcin were analyzed by immunohistochemistry and Western blots.

RESULTS

Poloxamer 407 is an effective controlled delivery system for intraosseous-injected simvastatin. A single injection of the simvastatin/poloxamer 407 hydrogel significantly increased BMD, bone microstructure, and strength; the bone volume fraction and trabecular thickness increased nearly 150 %, bone strength almost doubled compared with controls (all P < 0.01); and induced higher expression of VEGF, BMP2, and osteocalcin.

CONCLUSIONS

CT-guided percutaneous vertebral injection of a single simvastatin/poloxamer 407 thermosensitive hydrogel promotes bone formation in ovariectomized minipigs. The underlying mechanism appears to involve the higher expression of VEGF and BMP-2.

Analysis of the gene-protein interaction network in glioma

Glioma is the most aggressive type of brain tumor. Great progress has been achieved in glioma treatment, but the protein-protein interaction networks underlining glioma are poorly understood. We identified the protein-protein interaction network for glioma based on gene expression and predicted biological pathways underlying the molecular complexes in the network. Genes involved in glioma were selected from the Online Mendelian Inheritance in Man (OMIM) database. A literature search was performed using the Agilent Literature Search plugin, and Cytoscape was used to establish a protein-protein interaction network. The molecular complexes in the network were detected using the Clusterviz plugin, and pathway enrichment of molecular complexes was performed using DAVID online. There were 378 glioma genes in the OMIM database. The protein-protein interaction network in glioma contained 1814 nodes, 6471 edges, and 8 molecular complexes. There were 17 pathways (false discovery rate <1), which were related to cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway, chemokine signaling pathway, oocyte meiosis, progesterone-mediated oocyte maturation, transmembrane transport of small molecules, metabolism of amino acids, and notch signaling pathway, among others. Our results provide a bioinformatic foundation for further studies of the mechanisms of glioma.

Recombinant human bone morphogenetic protein-2-induced ossification of the ligamentum flavum in rats and the associated global modification of histone H3

OBJECT

The primary object of this investigation was to study recombinant human bone morphogenetic protein-2 (rhBMP-2)-induced ossification of the ligamentum flavum and associated histone H3 modification in a rat model. In an additional set of studies the authors investigated spinal cord and behavioral changes in the same model.

METHODS

The authors report on 2 separate sets of studies. A total of 90 rats were used for the 2 sets of studies (45 each); in each study, a lyophilized rhBMP-2 and collagen mixture (20 μg rhBMP-2 and 200 μl collagen) was implanted in the lumbar extradural space in 18 rats; another 18 animals were used for a sham-operation control group and underwent implantation of lyophilized collagen without rhBMP-2 at the same level; an additional 9 animals were used as untreated controls. Lumbar spinal samples were harvested from the rhBMP-2 groups and the shamoperation control groups at 1 week, 3 weeks, and 9 weeks after the operation. Samples were also obtained from untreated controls at the same time points. All samples were scanned using micro-CT and then made into paraffinembedded sections. The sections from the first set of 45 rats were stained using elastica van Gieson and toluidine blue, and the expression of histone modifications (H3K9ac, H3K18ac, H3K4me3, and H3K36me3) and osteogenic transcription factors (osterix, Runx2) was detected by immunohistochemistry. In the second set of studies, hindlimb motor function was assessed at 1 week, 3 weeks, and 9 weeks after surgery. After behavioral evaluation, samples were harvested, scanned using micro-CT, and then made into paraffin-embedded sections. The sections were stained using Luxol fast blue. The expression of NeuN was also detected using immunohistochemistry.

RESULTS

Ossification was seen in the rhBMP-2 group from 1 week after insertion, and the volume of ossified mass increased at 3 and 9 weeks. There was no ossification seen in the sham-surgery and normal controls. The pathological changes of ossification involved ligament degeneration, cartilage formation, and, finally, bone replacement. Spinal cord evaluation showed a significant decrease in white matter content and number of neurons at 9 weeks after operation in the rhBMP-2-treated group (compared with findings in the sham-surgery and control groups as well as findings at the earlier time points in the rhBMP-2 group). Using immunohistochemical staining, histone modifications (H3K9ac, H3K18ac, H3K4me3, and H3K36me3) and osteogenic transcription factors (osterix, Runx2) all were found to be expressed in the fibrocartilage area of the rat ossified ligamentum flavum samples (rhBMP2 group).

CONCLUSIONS

This rhBMP-2-induced OLF is a typical endochondral ossification, which is similar to clinical OLF. The compressed spinal cord around the ossification site showed signs of a chronic degenerative process. Histone H3 modifications (H3K9ac, H3K18ac, H3K4me3, and H3K36me3) may play an important role in OLF.

Circumspinal decompression through a single posterior incision to treat thoracolumbar disc herniation

BACKGROUND

Various surgical approaches have been successfully used in the treatment of thoracolumbar disc herniation (TLDH). Although the anterior transthoracic approach has a reputation for better visualization than the posterolateral and lateral approaches, it involves the manipulation of the thoracic and pulmonary structures. Thus, this approach is technically demanding and prone to compromising the respiratory system. An ideal approach would involve adequate visualization and be accomplished through the posterior midline approach that is familiar to spine surgeons. The objective of this retrospective preliminary clinical study was to introduce a new surgical procedure, circumspinal decompression through a single posterior incision, for the treatment of TLDH (T10/11-L1/2) and to evaluate the surgical outcome of this procedure by comparing it to the conventional anterior transthoracic approach.

METHODS

In this study, 15 patients (10 males, 5 females; mean age 51 years) with symptomatic TLDH underwent the circumspinal decompression through a single posterior incision procedure between January 2008 and December 2009. Altogether, 17 herniated discs were excised, with 2 discs at T10/11, 4 discs at T11/12, 5 discs at T12/L1 and 6 discs at L1/2. Of these patients, 13 were followed up with a mean follow-up period of 23.5 months. Clinical outcomes, including operative time, blood loss, perioperative complications, postoperative time of hospitalization, neurologic status improvement, back pain and correction of local kyphosis, were investigated by comparing these data with the results from patients who underwent the anterior transthoracic approach for TLDH during the same period. The patients' neurologic status was evaluated by a modified Japanese Orthopedic Association (JOA) scoring system of 11 points. Neurologic status improvement after the surgery was assessed by calculating the recovery rate, which was equal to the (postoperative JOA score-preoperative JOA score)/(11-preoperative JOA score)×100%. The rates of patients who improved at the final follow-up were also assessed.

RESULTS

The mean operative time was 183 minutes, the mean blood loss was 1067 ml, and the mean postoperative hospitalization time was 8.4 days. Three patients suffered perioperative complications, but none of these complications involved the respiratory system. Local kyphotic angles at the fusion levels were reduced. Of the 13 patients that were followed up, 12 improved at the final follow-up, with a mean recovery rate of 52.8%. Patients who underwent the circumspinal decompression procedure showed a higher percentage of improvement at the final follow-up, a higher degree of local kyphosis correction and a lower percentage of complications (especially respiratory complications) compared to patients who underwent the anterior transthoracic decompression procedure.

CONCLUSIONS

The circumspinal decompression through a single posterior incision procedure is an effective and safe technique that is comparable to anterior tranthoracic approach for the surgical treatment of TLDH patients. It could be an attractive choice in certain circumstances.

Diagnosis and treatment of ossification of the ligamentum flavum associated with dural ossification

Object

In this paper, the authors aimed to summarize the clinical characteristics of ossification of the ligamentum flavum (OLF) associated with dural ossification (DO) and to identify improved methods for preoperative diagnosis.

Methods

Thirty-six patients who had undergone OLF surgery between February 2005 and September 2009 were included in this retrospective study. The patients were divided into 2 groups: one that included patients with intraoperative evidence of DO and a second group that included patients without DO. The clinical features of DO were summarized and the neurological status of the patients was evaluated pre- and postoperatively.

Results

The incidence rate of DO associated with OLF was 39% (14/36). The sensitivity and specificity of the tram track sign were found to be 93% and 59%, respectively. Dural ossification was found among 86% of the patients with tuberous type Sato classification. The postoperative neurological status of patients was generally improved relative to that observed prior to surgery, although neurological recovery did not differ between the 2 groups. Cerebrospinal fluid leakage was the main complication, occurring predominantly in the patients with DO, and all leaks resolved in all patients after comprehensive treatments.

Conclusions

The tram track sign and Sato classification were found to be useful for preoperative diagnosis of DO and for determining the surgical procedure to be performed. Dural ossification had no effect on postoperative neurological recovery.

[The impact of thoracic and thoracolumbar angular kyphosis on pelvic shape and sagittal alignment]

OBJECTIVE

To analyze the impact of thoracic and thoracolumbar angular kyphosis on pelvic shape and sagittal alignment.

METHODS

From May 2002 to June 2010, the sagittal spino-pelvic parameters were analyzed in lateral standing radiographs of 32 patients (mean age 29.6 years) with thoracolumbar angular kyphosis. The parameters included Cobb angle of kyphosis, lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), pelvic tilt (PT) and sagittal vertical axis (SVA). All pelvic parameters in the patients were compared with those reported in historical normal subjects. All patients were treated by using kyphotic correction and fusion. The preoperative and postoperative parameters were compared. The pelvic parameters were also compared between the patients with kyphotic apex located at T(1-8) and those located at T(9-12) and thoracolumbar junction. The linear regression analysis was used to investigate the independent factors of PI.

RESULTS

The mean kyphosis was 90.1° (31° - 138°). The mean age of kyphosis occurrence was 6.1 years. The mean PI, SS and PT were 34.8°, 35.8° and -0.7° respectively. The PI and PT were significantly smaller (P < 0.001) in the patients than those in normal subjects while the SS was similar. The kyphosis was improved to 27.9° post-operatively. There was no difference in PI values between pre-operation and postoperation (P > 0.05). The PI and SS in patients whose kyphosis located at thoracic spine (T(1-8)) were significantly higher than those at T(9)-L(2). Instead of patients' age and LL, the preoperative Cobb angle of kyphosis and the levels where kyphosis located were two independent impact factors of PI.

CONCLUSIONS

The kyphosis occurred at childhood may influence pelvic shape and alignment significantly. The lower kyphotic apex located and the bigger kyphosis, the greater impact on the pelvic morphology. The surgery can improve the kyphosis, but can not change the sagittal pelvic morphology. Early treatment of thoracolumbar angular kyphosis is beneficial not only to reconstruction of spine alignment but also to the formation of sagittal pelvic morphology.

[Combined segmental resection osteotomy with dual axial rotation correction, fixation and fusion for the treatment of severe angular kyphosis]

OBJECTIVE

To design a new surgical correction and fixation technique for the treatment of severe angular kyphosis, observe the feasibility, safety and effectiveness of the technique.

METHODS

From May 2004 to February 2007, 16 cases with severe kyphosis (average 90.8 degrees, range 50 degrees-130 degrees) were treated with segmental resection osteotomy, section distraction, dual axial rotation correction and instrumentation fusion technique. The patients were inspected by local and total spine anteroposterior and lateral radiography pre-and postoperatively. The kyphotic Cobb angle was measured and 7 cases combined scoliosis Cobb angle was also measured. The Frankel Grading for neurological function, Oswestry Disability Index (ODI) and Patients Satisfactory Index (PSI) were evaluated preoperatively, postoperatively and at follow-up. The back pain relief was also observed.

RESULTS

The average surgical duration was 6.9 hours. The average blood loss was 4000 ml. The complications include 1 shifting of artificial vertebrae, 3 nerve root injury, 3 dural tear and 1 transitory dysfunction of lower extremity. All of these complications were relieved greatly after feasible treatment. The average follow-up time was 25 months. The average kyphotic angle was 90.8 degrees preoperatively, which was improved to 26.9 degrees immediately after surgery, and got an average correction rate of 72.5%. At follow-up, the average kyphotic angle was 28.9 degrees, and correction rate was 70.1%. The 7 cases who combined with scoliosis had an average Cobb angle of 35.9 degrees preoperatively, which decreased to 4.4 degrees immediately after surgery, and the correction rate was 87.2%. The correction rate was kept until follow-up (78.6%). Some patients got an improved neurological function. The Frankel Grading were E in 5 cases, D in 5 cases, C in 5 cases, and B in 1 case preoperatively. There were 10 cases of E grade, 3 cases of D grade, and 3 cases of C grade at follow-up. Except 3 cases who had no symptoms before surgery, the average ODI was 18.9 preoperatively, and 10.8 postoperatively. The average improvement of ODI was 52.7%. The PSI result showed a satisfied rate of 93.8%. The back pain of 3 cases were totally relieved after surgery.

CONCLUSIONS

Segmental resection osteotomy with dual axial rotation correction and fusion technique is an effective way to treat severe angular kyphosis. It is a safe technique and has high correction rate. The long-term results is acceptable.

[Mechanism of effect of intraventricular administration of histamine H1-receptor agonists on gastric acid secretion in rats]

The present experiment is undertaken to study the mechanism of the inhibitory effect of 2-pyridylethylamine (PEA, i.c.v.) on the gastric acid secretion. Gastric acid was continuously washed out with 37 degrees C saline by means of a perfusion pump in Wistar rats weighing 200-300 g. Drugs were injected into the third ventricle to examine the effect on pentagastrin-induced (160 micrograms/kg, s.c.) gastric acid secretion. The results were as follows: (1) Pretreatment with naloxone (2.5 micrograms, i.c.v.) blocked the inhibitory effect of PEA (10 micrograms, i.c.v.) on gastric acid secretion. (2) The inhibitory effect of PEA (5-20 micrograms, i.c.v.) was turned into an excitatory effect after subdiaphragmatic vagotomy in a dose-dependent manner, but not changed by bilateral adrenalectomy. (3) In vagotomized rats, pretreatment with CRF-antiserum (1:20,000, 2.5 microliters, i.c.v.) or bilateral adrenalectomy abolished the excitatory effect of PEA (10 micrograms, i.c.v.). (4) PEA (10 micrograms, i.c.v.) did not change the basal gastric acid secretion in vagotomized rats. These results suggest that histamine H1-receptor in brain may be involved in both the inhibitory and excitatory regulation of gastric acid secretion mediated by vagus nerve and the hypothalamus-pituitary-adrenal axis.