Predictive signs of discogenic lumbar pain on magnetic resonance imaging with discography correlation

STUDY DESIGN: The correlation between discogenic lumbar pain and disc morphology was investigated by using magnetic resonance imaging and discography. OBJECTIVES: To assess the various pathologic parameters seen on magnetic resonance imaging in patients with discogenic lumbar pain and to correlate them with observations on discography. SUMMARY OF BACKGROUND DATA: Although numerous previous studies on the subject have been performed, the correlations between various pathologic findings on magnetic resonance imaging and pain reproduction by provoked discography have not been explained fully. METHODS: One hundred and one lumbar discs in 39 patients were studied with magnetic resonance imaging and pain provocation discography. When pain reproduction under discography was concordant, various pathologic parameters on magnetic resonance imaging were analyzed by three statistical parameters to determine the associated magnetic resonance imaging findings. RESULTS: Radial tears commonly are demonstrated on magnetic resonance imaging in discs with concordant pain on discography. The presence of these tears is not a reliable predictor of a painful disc on discography. Although a high-intensity zone on T2-weighted images is a relatively reliable predictor of pain, the statistical values were lower than those in previous studies. Massive degeneration and severe disc height loss were rare in this population. These findings were good predictors of pain on disc injection. CONCLUSIONS: Although the lumbar intervertebral discs with posterior combined anular tears are likely to produce pain, the validity of these signs for predicting discogenic lumbar pain is limited.     

Late results of cervical disc surgery

Late results of cervical disc surgery have been reported and statistically studied in 383 cases: 83% were lateral discs, 13% were central spondylosis discs, and 4% central soft discs. Central spondylosis occured at a higher spinal level, and caused cord compression with or without weakness of the hands, but no pain. A posterior approach was used in all lateral discs, and either an anterior or a posterior approach, with or without fusion, for central discs. Preoperative myelography was always done and is recommended postoperatively in central disc surgery to evaluate the results. Our results were good to excellent in 95% of lateral discs, in 64% of central spondylosis discs, and in an unexpected 91% of 11 cases of central soft discs. There were no recurrences and no serious complications, although 20% developed other cervical or lumbar disc herniations.     

A morphometric study of the femoro-patellar joint from lateral x-ray view

PURPOSE OF THE STUDY: The goal of this study was to specify criteria of femoro-patellar joint normality on lateral view. MATERIAL: This study was based on radiological examination of 102 knees in 51 adults (average age 26.1 years). It concerned 29 women and 22 men that had never suffered from their knee and were supposed healthy. METHODS: The radiological protocol was the following: a lateral view at 45 degrees of flexion, two lateral views in extension, with and without quadriceps contraction. The analysis was focused on patellar surface aspect, its height, its depth and covering measurement. RESULTS: We found 83.7 per cent of so-called "normal" patellar surface, and 12.7 per cent of "abnormal" patellar surface (dysplasia) in the absence of pain. DISCUSSION: We have confirmed figures advanced in others series of the literature concerning patellar height and patellar surface, as well as patellar surface depth and covering. We have underlined the interest of lateral views; in extension with quadriceps contracted and relaxed. Finally, we have defined a trochleo-patellar sign that allows to correlate patellar height to patellar surface height (ITP = 0.35 to 0.84). CONCLUSION: This study insists on the interest of radiological lateral views of the knee and determine criteria for normalities.     

Neuroprotection after spinal cord injury: state of the science

There have been no reports indicating diurnal variations in MRI at different portions of each lumbar disc. Eight asymptomatic healthy volunteers between 22 and 29 years old had MRI of their lumbar spine, twice on the same day (in the morning and evening). Forty lumbar discs were studied and the signal intensity change was measured from three portions of each disc (a total of 120 portions). No visible changes could be detected between scans by blinded observers. However, the calculated signal intensity changes showed an average loss of -20.0% (ant., 5 cases), -19.0% (mid, 2 cases), and -17.5% (post., 1 case). Height loss of the disc showed an average loss of -9.9% (ant., 4 cases), -8.3% (mid., 2 cases), and -10.4% (post., 2 cases). An increase of disc bulge at L4-5 level (18.3%) was pronounced, but L5-S1 level was less than others. Loss of body height averaged a loss of 7 mm (0.39% of body height). There was no correlation between reduced signal intensity and height loss at the ant./post. portion (p = 0.42), but there was a close relation at the mid. portion (p = 0.008). Diurnal change of the disc bulge was not correlated with reduced signal intensity (p = 0.48) or height loss (p = 0.16). Intradiscal fluid change was not necessarily influenced by the disc height loss, and height loss did not necessarily have an effect on disc bulge. But diurnal change showed a trend that was reflected in reduced signal intensity, height loss, and an increase of disc bulge which was more apparent from the ant. portion to the post, portion on moving down to the lower levels. Loss of disc height was one factor in the reduction of body height. These changes occurred randomly throughout 5 lumbar disc levels in each case.     

Soft tissue for allograft reconstruction of the human knee: a survey of the American Association of Tissue Banks

STUDY DESIGN: The reactions to sequestrated disc fragments, which were removed surgically from 35 patients, were examined histologically. OBJECTIVES: To elucidate whether or not there is histologic evidence of absorption of sequestrated discs. SUMMARY OF BACKGROUND DATA: Spontaneous disappearance or diminution of lumbar herniated discs in the spinal canal has been recognized, and this could be a possible explanation for relief of symptoms without surgery. The mechanism of this phenomenon is unclear. METHODS: Sequestrated discs removed surgically from 35 patients were examined histologically. RESULTS: In 30 cases, neovascularization was observed at the periphery of the sequestrated discs. Many foamy cells (macrophages) were present in the vascularized areas. In addition, immunohistochemistry revealed that many spindle-shaped, fibroblast-like cells were positive for CD68, a marker of macrophages. No fibrous scar formation was observed in any region. CONCLUSION: These findings suggest that organization is not a main course for this type of herniated disc and that a kind of "absorption" process occurs predominantly in the healing stage.     

Lumbar disk prolapses and radiological spinal intervention. What do the randomized controlled trials say?

We searched the Medline database and examined 11 randomized controlled trials to evaluate the efficacy of treating lumbar herniated discs by injection with chymopapain or by automated percutaneous discectomy. Our findings show that chemonucleolysis with chymopapain is a documented treatment which is better than placebo, but consistently inferior to surgical discectomy. The two randomized controlled trials to evaluate automated percutaneous discectomy fail to show efficacy that is any better than would be expected from a placebo response. We conclude that surgical discectomy is the best treatment option for a herniated disc when conservative efforts have failed.     

Groin pain associated with lower lumbar disc herniation

STUDY DESIGN: Retrospective clinical and magnetic resonance imaging study of patients with groin pain associated with lower lumbar disc herniation. OBJECTIVES: To demonstrate the clinical features and magnetic resonance imaging findings of these patients. SUMMARY OF BACKGROUND DATA: Patients with lumbar disc herniation sometimes report groin pain. Little mention has been made, however, regarding the clinical features of groin pain stemmed from lower lumbar disc herniation until now, with only Murphey referring to groin pain in disc disease. METHODS: A total of 512 patients were diagnosed with singular lower lumbar disc herniation (L4-L5 and L5-S1) at Kakegawa City General Hospital between July 1990 and December 1993. Of these patients, 21 (4.1%) reported groin pain. The characteristic clinical features and magnetic resonance imaging findings of the 21 patients were investigated and compared with the features and findings of patients with no groin pain. RESULTS: Patients with groin pain had a higher mean age and lower rate of low back pain, and L4-L5 discs were more likely to be involved than L5-S1 discs. In their magnetic resonance images, herniation tended to be more central than in patients with no groin pain. CONCLUSIONS: Elderly patients with L4-L5 protruding herniation of the anulus fibrosus were most likely to experience groin pain. The sinuvertebral nerve that innervates the posterior anulus fibrosus, the posterior longitudinal ligament, and the dura was indicated as the afferent nerve of groin pain.     

Spinal motion in lumbar degenerative disc disease

We have measured the dynamic movement of the lumbar spine in 57 patients with degenerative lumbar disc disease. Each completed a questionnaire which recorded pain and subjective signs and symptoms. From plain lateral radiographs, the subjects were graded using the criteria of Kellgren and Lawrence and those of Lane et al, which are both based on the severity of degenerative changes. Measurements of the height of the disc space and the vertebral height were obtained and expressed as a ratio. We found no relationship between the characteristics of spinal movement and the overall grading of degenerative disc disease with either system. Both were influenced (p < 0.01) by age, walking distance, severity of symptoms, drug intake and frequency of pain. The present systems for grading degenerative disc disease from plain lateral radiographs have limited application.     

Prognostic scores in intensive care

Type X collagen has so far not been reported to occur in human intervertebral discs. The objective of this study was therefore to investigate the occurrence of type X collagen in human lumbar intervertebral discs during ageing and degeneration. Ninety intervertebral discs with adjacent endplates were excised in toto from individuals (0-86 years) without known spinal disease and were processed for routine decalcified histology. Appropriate slices of each disc were processed for immunohistochemistry using a type-specific, monoclonal antibody raised against human type X collagen. Each intervertebral disc was examined for macroscopic and histomorphological features of disc degeneration. Immunohistochemically, a positive specific type X staining was observed in the hypertrophic zone of the growth plate and only in the interstitial matrix of juvenile (<2 years) nucleus pulposus. In adult discs, type X collagen could be localized in conjunction with advanced disc degeneration and first occurred in the disc matrix (i.e., pericellular region) of a 47-year-old specimen. Positive type X staining of the disc matrix was more frequently found in senile (>70 years) discs with end stages of disc degeneration. This study provides the first evidence for the occurrence of type X collagen in human lumbar intervertebral discs and it appears that type X collagen is re-expressed in late stages of disc degeneration.     

不同荷载条件下低孔隙率砂岩巴西劈裂试验的声发射特性

针对巴西圆盘荷载接触条件对巴西劈裂试验影响的问题，采用声发射监测系统开展线/非线荷载接触条件下低孔隙率砂岩巴西劈裂试验。直径为50 mm，厚度为25 mm的标准巴西圆盘按照同一种传感器三维布设方式布置8个Nano30传感器。在相同的荷载速率下，声发射监测Richter8系统对线/非线荷载两种荷载条件下的巴西圆盘进行准静态加载的波形信号连续记录。通过P波自动到时及网格坍塌搜索算法进行定位，在线/非线荷载条件下分别有1131和931个声发射事件被成功定位。圆盘的起裂位置均在圆盘非中心位置，对于非中心起裂的试验值可能低估了巴西抗拉强度。裂纹下半球极点密度投影分析表明，非线荷载条件下破裂面的局部扭曲程度大于线荷载。试样三维损伤演化结果表明，圆盘所受荷载面积大小，显著影响圆盘损伤累计的时间、释放能量的大小和裂纹扩展的稳定性。对有效声发射定位事件进行矩张量分解获取了两种荷载条件下各向同性部分（ISO）、纯双力偶（DC）和补偿线性矢量偶极成分（CLVD）频率百分比，并采用微裂纹破裂类型分类方法来定量分析震源机制，结果表明巴西劈裂对荷载条件并不敏感，两者均可以解释为近似平行于荷载方向上的张拉裂纹的萌生、扩展及贯通。      

Severe primary HIV-1 infection among black persons in Barbados

The purpose of this long-term follow-up was (1) to investigate disc changes in the olisthetic segment in patients treated conservatively, (2) to compare disc changes above the slipped vertebra in conservatively treated patients with those in operatively treated patients, and (3) to establish possible relations of disc changes to the degree of the slip and to subjective back pain symptoms of the patients. The subjects were 227 patients with isthmic L5 olisthesis diagnosed under 20 years of age (mean 13.8 years) with a mean follow-up of 15.4 (range 5-30) years. Of these, 145 patients had been treated with segmental fusion and 82 had been treated conservatively. At follow-up, standing anteroposterior and lateral radiographs as well as flexion/extension views of the lumbar spine were taken. Disc degeneration was graded semiquantitatively: 0 = normal disc height, 1 = decrease of disc height < 50%, 2 = decrease > or = 50%, and 3 = obliteration of the disc. In the conservatively treated patients degeneration of the olisthetic disc was distributed by grade as follows: O: n = 38, 1: n = 24, 2: n = 14, 3: n = 6. No motion at all was observed in the olisthetic segment in 40 patients (48%) with a mean slip of 30%, segmental motion of 4 degrees-18 degrees was found in 42 patients with a mean slip of 14%. There was a statistically significant association of the degree of slip to the severity of disc degeneration and non-mobility of the segment. Grade 1 degeneration of the L4/5 disc occurred in 25.6% of the conservatively treated patients and in 32% of 48 patients treated with L5-S1 fusion. This correlated with the severity of the slip, but not with pain symptoms or pathologic segmental mobility at the time of follow-up. Out of 84 patients with L4-S1 fusion, in 17% grade 1 degeneration of the L3/4 disc was observed, and 3 out of 13 patients (23%) with L3-S1 fusion had grade 1 degeneration of the disc above the fusion. The disc changes had no correlation with subjective pain symptoms. It is concluded that the natural course of isthmic spondylolisthesis is associated with disc degeneration and spontaneous stabilization of the olisthetic segment. Fusion operations do not significantly increase the rate of disc degeneration in the adjacent disc above the fusion after a mean postoperative follow-up of 13.8 years. No correlation between the number of degenerated discs or the degree of degeneration and subjective low back pain symptoms was found.     

A paramedian tangential approach to lumbosacral extraforaminal disc herniations

OBJECTIVE: Extraforaminal disc herniations today are operated on via the so-called lateral approach. Clinical experience has shown that in contrast to levels L2/3-L4/5, this approach may become extremely difficult at the L5-S1 level. According to new microanatomic studies, the previous lateral approaches at this level often do not allow access to the neuroforamen without partial or total destruction of the L5-S1 facet joint. Postoperatively, this may lead to joint irritation with consecutive low back and pseudoradicular pain. To preserve the facet joint, a new approach was developed based on an anatomic study. METHODS: The approach was first considered with the help of bone specimens including ilium, vertebra 5, and sacrum. Thereafter, lumbar maceration specimens were prepared leaving ligaments, intervertebral discs, and joints intact. From these specimens, bony and ligamentous landmarks were deduced. Finally, the approach was tested on seven cadavers. Subsequently, the approach was performed on 13 patients and the intraoperative findings, the clinical feasibility, and the postoperative results were analyzed. APPROACH: After a transverse skin incision above the dorsal curvature of the ilium, the paravertebral muscles are dissected from the ilium medially toward the spinous process. Lateral from the apophyseal joint, a canal is drilled through the spongiosa of the sacrum. Primarily, a thin layer of inner cortex is spared to protect the content of the neuroforamen. Subsequently, it can easily be removed with the dissector to enter the extraforaminal space. In the depth of the drilled canal, the nerve root is found, because it is fixed at the sacrum near the disc space by the anterior lumbosacral ligaments. Riding on the nerve root, the intertransverse ligament and muscle can be removed with the punch. It is then possible to see the neuroforamen and extraforaminal space in front of the joint. Free fragments and contained discs can then easily be found and removed. CONCLUSION: Using this new approach, the L5-S1 joint remains intact. Space for instrumental manipulations is created in areas not essential for joint function. For this procedure, newly defined anatomic landmarks, such as the ileolumbar ligament, upper edge of the sacrum, lateral rim of the apophyseal joint, and para-articular notch, guide the operative route. In accordance with the preliminary anatomic studies, this approach was successfully used in 13 patients, and we think that it is a promising alternative that helps to preserve joint function and dorsal root ganglion integrity.     

Sensory nerve fibres from lumbar intervertebral discs pass through rami communicantes. A possible pathway for discogenic low back pain

It has been thought that lumbar intervertebral discs were innervated segmentally. We have previously shown that the L5-L6 intervertebral disc in the rat is innervated bilaterally from the L1 and L2 dorsal root ganglia through the paravertebral sympathetic trunks, but the pathways between the disc and the paravertebral sympathetic trunks were unknown. We have now studied the spines of 17 rats to elucidate the exact pathways. We examined serial sections of the lumbar spine using immunohistochemistry for calcitonin gene-related peptide, a sensory nerve marker. We showed that these nerve fibres from the intervertebral disc ran through the sinuvertebral nerve into the rami communicantes, not into the corresponding segmental spinal nerve. In the rat, sensory information from the lumbar intervertebral discs is conducted through rami communicantes. If this innervation pattern applies to man, simple decompression of the corresponding nerve root will not relieve discogenic pain. Anterior interbody fusion, with the denervation of rami communicantes, may be effective for such low back pain.     

The topographical characteristics of the blood vessels of the human spine

Methods of roentgen angiography, injections of India ink-gelatin mass, morphometry, microscopy and others were used in an experiment carried out on non-fixed corpses of children and adults for studying functional topography of arteries and veins of the vertebral column. Posterior intercostal and lumbar arteries were established to give off 3-4 anterior and 3-5 lateral branches from each side which penetrate into paradiscal segments of the vertebral body. In 92% one lateral branch runs downwards to the intervertebral disc and lower vertebra. Great number of vertical branches of various diameters come off from intraorganic arteries of horizontal orientation of paradiscal segments to intervertebral discs. The medial segment contains distinct basivertebral, anterior and lateral veins falling into venous plexuses surrounding the vertebrae. The diameter of these veins depends on specific properties of angiotopography, sizes and shape of the vertebra. The regular trends in question aid to explain the question of pathogenesis of hematogenic lesions of the vertebrae and to choose the methods of osteoplastic operations.     

Intragenic polymorphisms of the vitamin D receptor gene associated with intervertebral disc degeneration

STUDY DESIGN: A study in genetic epidemiology of disc degeneration, based on lifetime exposure data, findings on magnetic resonance imaging, and genotyping of intragenic markers. OBJECTIVES: To pursue the potential correlation between common allelic variations in the vitamin D receptor locus and degeneration of the intervertebral disc. SUMMARY OF BACKGROUND DATA: Familial aggregation has been observed in intervertebral disc degeneration, but the relative significance of the genetic component and shared environmental influences is unknown. The identification of relevant candidate genes associated with disc degeneration would specify a genetic component and increase our understanding of the etiopathogenesis of disc degeneration. METHODS: From the population-based Finnish Twin cohort, 85 pairs of male monozygotic twins were selected based on exposure to suspected risk factors for disc degeneration. Interview data were gathered on relevant lifetime exposures, and thoracic and lumbar disc degeneration was determined through quantitative and qualitative assessments of signal intensity on magnetic resonance imaging, and qualitative assessments of disc bulging and disc height narrowing. Possible associations were examined between disc degeneration measures and two polymorphisms of the coding region of the vitamin D receptor locus. RESULTS: Two intragenic polymorphisms of the vitamin D receptor gene revealed an association with disc degeneration. Quantitatively assessed signal intensities of thoracic and lumbar (T6-S1) discs were 12.9% worse in men with the Taql tt genotype and 4.5% worse in men with the Tt genotype, compared with signal intensity in men with the TT genotype (age adjusted P = 0.003). A similar pattern was found between disc signal intensity and Fokl genotypes; men with the ff and Ff genotypes had mean signal intensities that were 9.3% and 4.3% lower, respectively, than those in men with FF genotypes (age-adjusted P = 0.006). The summary scores of qualitatively assessed signal intensity, bulging, and disc height were 4.0% and 6.9% worse in men with Ff and ff genotypes, respectively, when compared with those in men with the FF genotype (age-adjusted P = 0.029). CONCLUSION: Specific vitamin D receptor alleles were associated with intervertebral disc degeneration as measured by T2-weighted signal intensity, demonstrating for the first time, the existence of genetic susceptibility to this progressive, age-related degenerative process.     

High- and low-bar squatting techniques during weight-training

STUDY DESIGN: Tissues in the area of herniated lumbar discs were examined for inflammatory cytokines to elucidate the causes of sciatic pain in lumbar disc herniation. OBJECTIVES: To determine the role of inflammatory cytokines in the stimulation of sciatic pain in lumbar disc herniation. SUMMARY OF BACKGROUND DATA: It is postulated that in addition to mechanical compression of lumbar nerve roots and sensory root ganglia by herniated discs, there is a chemical stimulus to the production of sciatic leg pain. The exact mechanisms of chemical stimulation are not clearly defined. METHODS: During surgery, cases of lumbar disc herniation in 77 patients were classified macroscopically into protrusion, extrusion, and sequestration types. Tissues adjacent to nerve roots at the herniation were excised and analyzed biochemically and immunohistochemically for the presence of inflammatory cytokines and for the production of these cytokines and prostaglandin E2 in vitro. RESULTS: The homogenates of samples were analyzed for interleukin-1 alpha, interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, and granulocyte-macrophage colony stimulating factor, which were detectable. Most of the cytokine-producing cells were histiocytes, fibroblasts, or endothelial cells in extrusion and sequestration types, and chondrocytes in protrusion type. The secretion of these cytokines and prostaglandin E2 was decreased by the addition of betamethasone. The prostaglandin E2 production was dramatically enhanced by additional interleukin-1 alpha, but decreased by the addition of tumor necrosis factor-alpha. CONCLUSION: The results demonstrate that at the site of lumbar disc herniation, inflammatory cytokines such as interleukin-1 alpha are produced, which increases prostaglandin E2 production. Further studies are required to elucidate the role of inflammatory cytokines in causing sciatic pain.     

Adenovirus-mediated gene transfer to nucleus pulposus cells. Implications for the treatment of intervertebral disc degeneration

STUDY DESIGN: In vitro and in vivo studies using a rabbit model were performed to determine the feasibility of adenovirus-mediated gene transfer to the intervertebral disc. OBJECTIVES: This study was conducted to determine whether it is possible to transfer genes to cells within the intervertebral disc by direct injection of an adenovirus and to determine the duration of gene expression obtained by this method. SUMMARY OF BACKGROUND DATA: Although growth factors have the potential to stimulate the regeneration of nucleus pulposus, sustained delivery of growth factors to a degenerated disc is clinically unfeasible with present technology. Novel approaches such as gene transfer should be investigated as possible solutions to this problem. METHODS: The lacZ marker gene was used to evaluate gene delivery to cells within intervertebral discs. For the in vitro study, cell cultures were established from the nucleus pulposus tissue of New Zealand white rabbits and infected with an adenovirus encoding the lacZ gene (Ad-lacZ). For the in vivo study, the anterior aspects of lumbar intervertebral discs were surgically exposed, and Ad-lacZ in saline solution was directly injected into the nucleus pulposus. An equal volume of saline only was injected into control discs. Expression of the transferred gene was detected by staining with 5-bromo-4-chloro-3-indolyl-beta-galactosidase (X-Gal). RESULTS: The in vitro experiments confirmed that nucleus pulposus cells were efficiently transduced by an adenoviral vector carrying the lacZ gene. In vivo injection of Ad-lacZ into the nucleus pulposus resulted in the transduction of a considerable number of cells. Marker gene expression in vivo persisted at an apparently undiminished level for at least 12 weeks. No staining was noted in control discs. CONCLUSIONS: The results show the feasibility of adenovirus-mediated gene transfer to the intervertebral disc. Expression of the marker gene persisted at least 12 weeks in vivo. This successful demonstration of exogenous gene transfer to the disc and sustained, long-term expression suggests that the adenoviral vector may be suitable for delivery of appropriate genes to the disc for the treatment of spinal disorders.     

The stiffness of lumbar spinal motion segments with a high-intensity zone in the anulus fibrosus

STUDY DESIGN: Biomechanical and anatomic study of human cadaveric spinal motion segments. OBJECTIVES: To measure the stiffness of spinal motion segments by disc type and by load type (flexion, extension, axial rotation, or lateral bending). To compare stiffness in motion segments with and without a high-intensity zone or radial tear in the anulus fibrosus. SUMMARY OF BACKGROUND DATA: The high-intensity zone, that is a linear zone of high-intensity on T2-weighted magnetic resonance images corresponding to a radial tear in the anulus fibrosus, is a marker for a painful disc at discography. The high-intensity zone is hypothetically associated with diminished stiffness of the motion segment. METHODS: Human cadaveric lumbar spinal motion segments with normal disc morphology or a high-intensity zone of the anulus fibrosus were selected on the basis of magnetic resonance imaging. The motion segments were subjected to incremental flexion, extension, rotation, and lateral bending torques. Rotation was measured with a kinematic system. Torque-rotation curves and stiffness were calculated for each motion segment and for each torque. The motion segments were sectioned on a cryomicrotome to verify the disc morphology as normal or as that of a radial tear. RESULTS: In four motion segments with normal discs, stiffness was greater in axial rotation (8.4 Nm/degree) than in lateral bending (2.3 Nm/degree), flexion (1.8 Nm/degree), or extension (2.6 Nm/degree). In 16 motion segments with a high-intensity zone, stiffness was 2.4 Nm/degree in axial rotation, and less severely reduced in lateral bending, flexion, and extension. Stiffness in motion segments with a high-intensity zone was significantly less with smaller than with larger axial rotation loads. CONCLUSIONS: The presence of a high-intensity zone in the intervertebral disc is associated with reduced stiffness of motion segments. The reduction is greater in axial rotation than in other torques. The reduction is more in smaller than in larger axial torques.     

Relation between the level of E. coli gene expression and the structure of translation initiation region (TIR). III. Sites of complementary interaction of TIR with 16S rRNA

The addition of vertebral disc degeneration to the job-related disease register raises the question of vertebral disc degeneration patterns according to loading strain. The readings of the lumbar vertebra of construction workers and nurses were compared with those of a group without workload. In the groups examined, aged 35 to 50, monosegmental damage was found in only 17% of the patients with high workload, as opposed to 29% of those with no workload, mostly with monosegmental damage at level L5/S1. Damage to the upper segments of the lumbar spine with intact discs in between was found exclusively in patients with high workload. Multiple segment damage in the age range examined was found in subjects with activities that add to the load of the spinal column. The value of MRI in assessing and evaluating illness originating from the vertebral discs is currently being discussed.     

A case report on surgery for chylothorax after anterior spinal fusion: usefulness and effectiveness of intraoperative milk administration and postoperative OK-432 administration]

After having reported preliminary results of soft system stabilization according to Graf in a series of 27 patients with degenerative disc disease of the lumbar spine in early 1995 the authors report long term clinical and radiological results of this patient series (n = 25). At a mean period of postoperative observation of 50 months excellent, good, satisfactory, moderate and poor results were obtained in 62, 9%, 11, 1% and 11, 1%, 7, 4% and 7, 4% of the patients, respectively. The well-known phenomenon of loss of disc height at the level of posterolateral fusion and instrumentation as well as overcharge of adjacent segments were not observed after soft system stabilization. Regional as well as global lumbar lordosis were maintained and, although statistically not significant, an increase of intervertebral distance was observed in adjacent segments in flexion of the lumbar spine. These phenomena might represent pressurization of instrumented as well as adjacent discs after the insertion of ligament prostheses. It is the impression of the authors, that the Graf technique leads to good surgical results in degenerative disc disease with destabilization of lumbar motion segment(s) if the following criteria are strictly respected: 1. No or only mild arthrotic changes of the facet joints 2. Preferably minor disc degeneration/only mild loss of intervertebral distance. 3. Well trained low back muscles and 4. A clear-cut, repeatedly demonstrated pain-relief on trial anaesthesia of the corresponding articular nerves and while wearing a probatory jacket.