Correlations between posterior longitudinal injury and parameters of vertebral body damage.

BACKGROUND: The posterior longitudinal ligament (PLL) is an important structure of spinal stability. The loss of vertebral body height, local kyphosis (LK), and canal compromise may lead to spinal instability. This study determined the correlations between injury of the PLL and the loss of vertebrae height, kyphosis, and canal compromise. MATERIALS AND METHODS: A retrospective review of a thoracolumbar burst fracture database was conducted from January 2009 to December 2011. Patients were divided into an intact group and a disrupted group according to the status of the PLL. The loss of vertebral height, mid-sagittal canal diameter, and LK was measured. The anterior, middle, and posterior vertebral compression ratios (AVBCR, MVBCR, and PVBCR) and mid-sagittal diameter compression ratio (MSDCR) were calculated. RESULTS: Forty-seven patients were included in the study, including 25 patients in the intact group and 22 patients in the disrupted group. There were significant differences in the AVBCR (t = -3.048, P = 0.004), MVBCR (t = -2.301, P = 0.048), PVBCR (t = -2.116, P = 0.040), and MSDCR (t = -4.095, P = 0.000) but no difference in the LK (t = 0.408, P = 0.686) between the two groups. There was a positive correlation between the injury of the PLL and the MSDCR (r = 0.428, P < 0.01), AVBCR (r = 0.372, P < 0.01), and PVBCR (r = 0.271, P < 0.05). There was no correlation between the injury of the PLL and the LK and MVBCR. CONCLUSIONS: The MVBCR and LK are not predictive of a PLL injury. The MSDCR, AVBCR, and PVBCR were associated with a PLL injury.

Study on different surgical approaches for acute Lumber disk protrusion combined with Cauda Equina Syndrome.

To compare the long and short term effectiveness and complications of different surgical approaches for Lumber disk protrusion combined with Cauda Equina Syndrome and find a better surgical method for the disease. In this study, follow up records of 144 patients received conventional laminectomy and minimally invasive decompression and fenestration 48 hours within acute injury of lumber disk protrusion combined with Cauda Equina Syndrome were analyzed. Surgical outcome immediately and 3, 6, 12, 36 months after the surgery were compared to evaluate the effectiveness two different approaches. The results indicated that there are no significant differences regarding age, sexual proportion, body mass index (BMI), visual analogue scale of pain (VAS) score as well as Frankel scores before the surgery, and significant differences VAS score as well as Frankel scores immediately after the surgery. In conclusion, minimally invasive decompression and fenestration can be of the same effectiveness and less complications comparing with the conventional laminectomy.

Association between osteoprotegerin genetic variants and bone mineral density in Chinese women.

Osteoprotegerin gene (OPG) is one of the most important candidate genes for osteoporosis. The aim of this study was to assess the association between the single nucleotide polymorphisms (SNPs) of OPG gene and bone mineral density (BMD). A total of 706 Chinese postmenopausal women were enrolled in this study. OPG gene variants were genotyped through created restriction site-polymerase chain reaction (CRS-PCR) and verified using DNA sequencing methods. The lumbar spine (L2-4), total hip and femoral neck were evaluated for BMD. Two genetic variants (g.18910G>A and g.27406C>T) were detected in this study. Our data indicated that the significant differences of spine BMD, neck hip BMD and total hip BMD were detected among different g.27406C>T genotype, subjects with the genotype CC were significantly higher than those of genotype CT and TT. However, the g.18910G>A polymorphism was not significantly associated with spine BMD, neck hip BMD and total hip BMD in the studied subjects. Results from this study indicated that OPG gene variants were associated with BMD in Chinese postmenopausal women. These findings will be useful to analyze the role of OPG gene in osteoporosis in the further studies.

Changes in compressed neurons from dogs with acute and severe cauda equina constrictions following intrathecal injection of brain-derived neurotrophic factor-conjugated polymer nanoparticles.

This study established a dog model of acute multiple cauda equina constriction by experimental constriction injury (48 hours) of the lumbosacral central processes in dorsal root ganglia neurons. The repair effect of intrathecal injection of brain-derived neurotrophic factor with 15 mg encapsulated biodegradable poly(lactide-co-glycolide) nanoparticles on this injury was then analyzed. Dorsal root ganglion cells (L7) of all experimental dogs were analyzed using hematoxylin-eosin staining and immunohistochemistry at 1, 2 and 4 weeks following model induction. Intrathecal injection of brain-derived neurotrophic factor can relieve degeneration and inflammation, and elevate the expression of brain-derived neurotrophic factor in sensory neurons of compressed dorsal root ganglion. Simultaneously, intrathecal injection of brain-derived neurotrophic factor obviously improved neurological function in the dog model of acute multiple cauda equina constriction. Results verified that sustained intraspinal delivery of brain-derived neurotrophic factor encapsulated in biodegradable nanoparticles promoted the repair of histomorphology and function of neurons within the dorsal root ganglia in dogs with acute and severe cauda equina syndrome.