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ABSTRACT: The activation of a delayed secondary cascade of unsatisfactory cellular and molecular responses after a primary mechanical insult to the spinal cord causes the progressive degeneration of this structure. Disturbance of ionic homeostasis is part of the secondary injury process and plays an integral role in the early stage of spinal cord injury (SCI). The secondary pathology of SCI is complex and involves disturbance of the homeostasis of K(+) , Na(+) , and Ca(2+) . The effect of ion channel blockers on chronic SCI has also been proved. In this Mini-Review, we provide a comprehensive summary of the effects of ion channel blockers on the natural responses after SCI. Combination therapy is based on the roles of ions and disturbance of their homeostasis in SCI. The effects of ion channel blockers suggest that they have potential in the treatment of SCI, although the complexity of their effects shows that further knowledge is needed before they can be applied clinically.
Journal of Neuroscience Research 03/2011; 89(6):791-801. · 2.74 Impact Factor
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ABSTRACT: A prospective study to compare the effects of injection of various doses of phosphate-buffered saline (PBS) solution into the intervertebral disc.
To evaluate the effect of injection volume on disc degeneration in a rat tail-disc model.
There are many studies on disc degeneration models induced by needle injection. Recently, novel treatments for disc degeneration have been developed that are administered by injection. However, it is unknown whether injection volume affects disc degeneration.
A total of 180 Sprague Dawley rats were randomized into five groups and injected with 0(control), 1.0, 2.0, 2.5, or 3.0 μL of PBS solution. Discs were harvested at weeks 1, 2, and 4 after injection and were evaluated using radiography, histology, and biochemistry (glycosaminoglycan, hydroxyproline, and water content).
No significant differences in radiography, biochemistry, or histology were observed at any of the three sampling times between the 1.0, 2.0 μL groups and the control. The 2.5 and 3.0 μL groups exhibited significant decrease in radiographic disc height index and water content since week 2. The glycosaminoglycan content of 2.5 μL group decreased significantly by week 4 and that of 3.0 μL group decreased at weeks 2 and 4. Significant hydroxyproline content decrease was only observed for 3.0 μL group during week 4. Significantly higher histologic score was observed in 3.0 μL group since week 1 and 2.5 μL group since week 2. The three parameters of 3.0 μL group indicated more severe disc degeneration than those of 2.5 μL group, particularly during week 4.
When the volume of PBS injected into the rat tail-disc exceeded a threshold, it rapidly exhibited degenerative changes according to radiographic, biochemical, and histologic analysis. The degenerative changes were dose-dependent and increased as the dose increased.
Spine 02/2011; 36(16):E1062-9. · 2.08 Impact Factor
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ABSTRACT: The intravertebral vacuum phenomenon (VP) is usually associated with degenerative disc disease, which could be related to the low back pain. Various theories related to the pathogenesis of VP have been proposed, but these theories have not been critically examined and remain hypothetical. In this article, we review the possible role of endplate degeneration in the pathogenesis of VP, and discuss several pathways possibly linked to them. Due to the endplate calcification and activated cytokines, the transport pathway of the nutrition for the intervertebral disc was blocked, resulting in the metabolic unbalance and decrease of the synthesis of matrix structural proteins. It could promote the matrix decomposition, causing the decrease of the quantity of matrix and the changes of stress distribution in intervertebral disc. As a result, the structure of intervertebral discs became increasingly unstable. While compression happened, the intravertebral cleft could occur and be gradually filled with gas, which may cause low back pain and aggravate the intervertebral discs degeneration. As outlined above, we hypothesize that endplate degeneration might be the origination of the vacuum phenomenon.
Medical Hypotheses 08/2010; 75(2):169-71. · 1.39 Impact Factor
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ABSTRACT: Early diagnosis of septic sacroiliitis is difficult because symptoms are nonspecific, especially during pregnancy and the postpartum period. We describe a female patient with left buttock pain radiating down the thigh after an uncomplicated induction delivery. She was afebrile and had no apparent abnormality on pelvic x-ray or computed tomography scan. A sensory deficit in the lateral portion of her left lower limb was found, and electromyography showed neurogenic abnormalities in the left lower limb. She was initially misdiagnosed as sciatic neuropathy. As her symptoms worsened, septic sacroiliitis is considered. Bone scintigraphy showed increased Tc-methylene diphosphonate uptake in the left sacroiliac joint, and magnetic resonance imaging scan showed a signal abnormality in the left sacroiliac joint. The diagnosis of septic sacroiliitis was then confirmed by the rapid efficacy of antibiotic therapy. This report suggests that irritation and injury of spinal nerves can be the presenting signs in septic sacroiliitis.
The American Journal of the Medical Sciences 03/2010; 339(3):292-5. · 1.39 Impact Factor
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ABSTRACT: Schmorl's nodes (SNs) are common abnormalities in the human spine, which represent herniation of the nucleus pulposus of the intervertebral disc into the adjacent cartilaginous endplate of the vertebra. However, the principle mechanism of SNs is still not fully understood. And the relationship of SNs in the spine and their clinical significance as a source of low back pain in the general population remains unknown. It is therefore important to get better understanding of this. Here, we review the clinical and experiment evidence on inducing of the SNs and correlative back pain, and propose a possible mechanism. Studies showed that once the nucleus pulposus enters into vascular tissue, the immune system could recognize it as a foreign body, and induces the immunological reaction. Then, there would be osteoimmunology action, a crosstalk between the immune system and bone, leading to bone loss by dysregulating T-lymphocyte function, and resulting to the bone absorption. Furthermore, the cytokines are involved in the development of immunological reactions and could be responsible for the significant pathology of symptomatic SNs. Given the above background, we hypothesize that immune system could be a key role in SNs and result in the pain.
Medical Hypotheses 10/2009; 74(3):552-4. · 1.39 Impact Factor
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ABSTRACT: To determine whether spinal cord decompression plays a role in neural cell apoptosis after spinal cord injury.
We used an animal model of compressive spinal cord injury with incomplete paraparesis to evaluate neural cell apoptosis after decompression. Apoptosis and cellular damage were assessed by staining with terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) and immunostaining for caspase-3, Bcl-2 and Bax.
Experiments were conducted in male Sprague-Dawley rats (n=78) weighing 300-400 g. The spinal cord was compressed posteriorly at T10 level using a custom-made screw for 6 h, 24 h or continuously, followed by decompression by removal of the screw. The rats were sacrificed on Day 1 or 3 or in Week 1 or 4 post-decompression. The spinal cord was removed en bloc and examined at lesion site, rostral site and caudal site (7.5 mm away from the lesion).
The numbers of TUNEL-positive cells were significantly lower at the site of decompression on Day 1, and also at the rostral and caudal sites between Day 3 and Week 4 post-decompression, compared with the persistently compressed group. The numbers of cells between Day 1 and Week 4 were immunoreactive to caspase-3 and B-cell lymphoma-2 (Bcl-2)-associated X-protein (Bax), but not to Bcl-2, correlated with those of TUNEL-positive cells.
Our results suggest that decompression reduces neural cell apoptosis following spinal cord injury.
Journal of Zhejiang University SCIENCE B 04/2009; 10(3):180-7. · 1.10 Impact Factor
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ABSTRACT: : We evaluated the degenerative changes to rat tail vertebral discs induced by percutaneous needle puncture, and we compared 2 puncture styles for the depth of needle puncture and the rate of disc degeneration.
: To develop a simple animal model of disc degeneration.
: The study of biologically based treatments for degenerative disc disease depends largely on animal models. Annulus needle puncture in the lumbar spine inducing disc degeneration in rabbits has proven successful, but a similar method has not been evaluated in the tail discs of rats, even though it might produce a desirable model for disc repair studies.
: Two consecutive rat tail vertebral discs, proximal and distal to the eighth coccygeal vertebra, were randomized for injury and control. The disc selected for injury was punctured percutaneously using a 20-gauge needle with either full penetration or half penetration. The discs were harvested 1, 2, and 4 weeks later. Measurements included disc height on molybdenum target digital radiographs, biochemistry (water content, glycosaminoglycans, and hydroxyproline), and histology.
: Needle punctures with full or half penetration caused significant disc space narrowing and progressive histologic changes of degeneration as early as 1 and 2 weeks after injury, respectively. Significant decrease in glycosaminoglycan content was observed at 4 weeks in the half-penetration puncture discs and at 2 and 4 weeks in discs punctured penetratively. Penetrative puncture resulted in a faster decrease in disc height, lower glycosaminoglycan content, and higher grades of histologic degeneration. The water and hydroxyproline content of the discs did not change appreciably.
: Tail disc percutaneous needle puncture is a simple method for inducing disc degeneration and the rate of degeneration is positively related to the depth of needle puncture. This model still has some limitations that should be taken into consideration when results of disc regeneration research in this model are interpreted and extrapolated to human.
Spine 09/2008; 33(18):1925-34. · 2.08 Impact Factor
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ABSTRACT: To explore the effects of intervertebral disc degeneration on the biomechanical behavior of the lumbar motion segment.
A three-dimensional nonlinear finite element model of L4-L5 segment was established using CAD technique based on CT images. A normal disc model and three degenerative disc models were established by changing the parameters such as disc material properties and disc height. The effects of disc degeneration on the biomechanical properties, including stiffness, nucleus pressure, maximum von Mises stress in the annulus, and force of posterior structure were studied under two moment loads (flexion and extension) and for three different direct forces (compression, and anterior and posterior shear forces), and the stress distribution of vertebral body and end- plate was also analyzed.
The stiffness of the lightly degenerative disc model was decreased compared with that of the normal disc, while it was increased in the moderately and severely degenerative disc models when compared with the normal disc. The force of posterior structure in the lightly degenerative disc model was increased while the values of force of posterior structure in the moderately and severely degenerative disc models were decreased gradually. The maximum von Mises stress in the annulus increased, and the nucleus pressure decreased as the disc degeneration progressed. Moreover, the stress of intervertebral disc, vertebral body, and end-plate was distributed more peripherally.
Light degeneration of intervertebral disc leads to instability of lumbar spine, while the stability restores with further degeneration of disc. There is a negative correlation between the force of posterior structure and the load on the intervertebral disc. With the disc degeneration progressing, the intervertebral disc load pattern changes, the stress of intervertebral disc, vertebral body, and end-plate is concentrated peripherally.
Zhonghua yi xue za zhi 07/2008; 88(23):1634-8.
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ABSTRACT: To explore the method of implanting upper-middle thoracic pedicle screws under monitoring by X-ray and evaluate accuracy and safety.
(1) Six normal adult thoracic spine samples (T1-T8) were selected, from which single spine units were separated. A surgical probe went in along the pedicle axis. By C-shaped arm X-ray, the four probe positions were recorded: at the entering point, the front end of the probe in the middle of the pedicle, at the pack of the spine, and under the cortex of the front of the spine. The position of the front end of the probe at the entering point, and the front end of the probe at different depth at central-side perspective position were analyzed. The related positions and their corresponding changing rules were also analyzed. (2) Based on the changing rules mentioned above, different steps were adopted under the guidance of the C-shaped arm X-ray, to safely implant upper-middle thoracic pedicle screws. First, six T1-T8 spine samples were used, and under the guidance of the C-shaped arm device, 96 pedicle screws were implanted. After the operation,the sping samples were scanned through CT, and the positions of the screws were determined.
According to the result of the CT scanning, the result were excellent (the screw was safely inside the pedicle) in 90 screws; Medium (the screw penetrated a little of the inside or outside bone cortex, within 2 mm) in 6; No one was had (the screw penetrated a lot, more than 2 mm).
The implantation of upper-middle thoracic pedicle screw under the guidance of the C-shaped arm X-ray perspective is a simple and feasible method, and improve the accuracy and safety.
Zhongguo gu shang = China journal of orthopaedics and traumatology 03/2008; 21(2):106-8.
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ABSTRACT: To explore the operative approach and method of internal fixation for the treatment of type-C thoracolumbar fractures.
T wenty-eight patients (male 20, female 8, ranging in age from 20 to 54 years, with an average of 38.5 years) with type-C thoracolumbar fractures were invovled in the study. Distributed segments involved T11 in 2 patients, T12 in 3 patients, L1 in 11 patients, L2 in 8 patient, L3 in 3 patients and L4 in 1 patient. Twenty-six patients were followed up (range from 12 to 20 months). According to the analysis of X-ray and CT image,height of vertebral body, Cobb angle on sagittal and coronal plane and the percentage of occupancy of vertebral canal were measured. The recovery of nerve, happening of back pain and the failure of internal fixation were observed.
The preoperative averaging height-loss decreased from 37.4% to 6.8% and the deformation of coronal plane was completely rectified. The preoperative averaging Cobb angle on sagittal plane recovered from 22.3 degrees to 5.6 degrees and the preoperative occupancy of vertebral canal averaging recovered from 33.7% to 5.9%. The difference was statistically significant (P < 0.05). Moreover, after 1 year follow-up, the changes of the above-mentioned index was no statistically significant (P > 0.05). Except for 8 patients with complete nerve damage losing the possibility of recovery, the others with incomplete nerve damage obtained 1 to 3 degree's improvement. The ratio of back pain occurrence was 19.2%. There was no failure of internal fixation.
The treatment of thoracolumbar type-C fractures with simple posterior long-segment internal fixation or posterior long-segmental fixation added by anterior autograft fusion is a reliable and effective method. The short-term therapeutic effect is satisfactory and the long-term therapeutic effect is to be further observed.
Zhongguo gu shang = China journal of orthopaedics and traumatology 01/2008; 21(1):13-5.
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ABSTRACT: To investigate the mechanism, clinical features and treatment of odontoid fracture combined with lower cervical spinal injury.
From January 1999 to December 2004, 57 cases of type II or shallow type III odontoid fractures were studied retrospectively. Six cases were found combined with lower cervical injury, the mean age was 54 years, and 4 of the 6 cases were complicated with cervical spondylarthrosis or ankylosing spondylitis. For the lower cervical injury, fracture-dislocation was found in 2 cases, the disruption of disc and ligament was found in 4 cases among which 2 cases were suffered from incomplete spinal cord injury; Both were caused by lower cervical spinal injury. All of the 6 cases were performed with surgery in odontoid fracture and lower cervical spinal injury simultaneously; Lower cervical spinal injuries were stabilized firstly in 2 cases, which responsible for neurological involvement; For the other 4 cases without neurological involvement, stabilization was performed in odontoid fracture firstly in 2 cases, due to inability to achieve reduction of odontoid fracture preoperatively, however, for the another 2 cases with anatomic reduction of the odontoid fracture preoperatively, lower cervical injuries were stabilized firstly.
After an average follow-up of 10 months, all cases were obtained solid fusion both in odontoid fracture and lower cervical spinal injury, and without the complications associated with operation and prolonged bed rest. Two cases with neurological defect improved 1 scale in Frankel score.
The incidence of odontoid fracture combined with lower cervical spinal injury is about 10.5% of the odontoid fracture, and it is vulnerable in the elderly patient with cervical spondylarthrosis. MRI should be used routinely for accurate diagnosis. Surgical stabilization is the choice of treatment due to facilitating early rehabilitation and reducing the complications. The surgical schedule is planned according to the fact of neurological involvement and the extent of stability between the odontoid fracture and lower cervical spinal injury.
Zhonghua wai ke za zhi [Chinese journal of surgery] 11/2006; 44(20):1395-8.
