Presence and distribution of antigen-antibody complexes in the herniated nucleus pulposus.

STUDY DESIGN: Herniated tissue was studied by immunohistochemistry in eight patients with lumbar disc herniation. The results were compared with those of control subjects. OBJECTIVE: To assess the presence and distribution of possible antigen-antibody complexes in herniated disc tissue. SUMMARY OF BACKGROUND DATA: It has been suggested that the nucleus pulposus may be recognized as a foreign-body by the immune system and that this will lead to secondary nerve root disturbance. Such immunologic events should be initiated by binding of antibodies to a specific antigen in the disc tissue. However, the presence of antigen-antibody complexes in the herniated disc tissue has not been assessed. METHODS: Amplification of the peroxidase reaction produced in avidin-biotin-peroxidase complex immunostaining by diaminobenzidine was used to visualize antigen-antibody complexes in the herniated tissue. The authors used herniated tissue from eight patients with lumbar disc herniation and nucleus pulposus from five control subjects with nonlumbar disc herniation. Thin paraffin sections, prefixed in 4% paraformaldehyde, were incubated with anti-human IgG antibody to allow visualization of antigen-antibody complexes in the specimens. RESULTS: A brown deposit, indicating antigen-antibody complexes, could be observed in the pericellular capsule in herniated disc tissue but not in control discs or in the residual discs of the herniation patients. CONCLUSION: Antigen-antibody complexes seem to be commonly present in herniated disc tissue, but not in healthy discs. However, the pathophysiologic and clinical significance of this observation has to be elucidated further.     

Lumbar disc herniation regression after successful epidural steroid injection

In some lumbar disc herniation patients, noninvasive measures fail, necessitating more aggressive treatment, such as epidural steroid injections or surgery. This study sought to determine whether improvement in patients who receive epidural steroid injections is related to regression of herniated nucleus pulposus or whether such patients' symptoms decrease because of the steroid effect in the presence of continued herniated nucleus pulposus. Two nonoperatively treated patient cohorts were followed who had follow-up MRI. Specifically, 38 other patients who improved without invasive treatment within 6 weeks after the onset of their symptoms were compared with 20 patients who improved with epidural steroid injections. Results found that both groups had similar initial and follow-up herniated nucleus pulposus size and outcomes. The epidural steroid injection group had fewer sequestered or extruded herniations that resorbed, and most were of lower hydration. In conclusion, epidural steroid injections do not alter ultimate herniated nucleus pulposus regression. Patients in whom the disc herniation has less hydration may have prolonged symptoms, but many improve with epidural steroid injections.     

2000 Volvo Award winner in basic science studies: Exogenous tumor necrosis factor-alpha mimics nucleus pulposus-induced neuropathology. Molecular, histologic, and behavioral comparisons in rats

STUDY DESIGN: This study tested the hypothesis that the 17-kDa form of tumor necrosis factor-alpha is the pathophysiologic agent expressed by herniated nucleus pulposus in vivo that is primarily responsible for the histologic and behavioral manifestations of experimental sciatica associated with herniated lumbar discs. OBJECTIVE: The authors determined the molecular weight and concentration of active tumor necrosis factor-alpha in rat herniated disc and used exogenous tumor necrosis factor-alpha at the same molecular weight to study its neuropathologic effect on rat nerve root and dorsal root ganglion preparations in vivo. SUMMARY OF BACKGROUND DATA: Expressed by herniated nucleus pulposus in culture, tumor necrosis factor-alpha causes neuropathologic injury in nerve roots and neuropathic pain states in which mechanical allodynia is seen in response to peripheral stimuli. METHODS: Western blotting was used to identify the molecular weight of the operative tumor necrosis factor-alpha protein form, and measures of optical density were used for semiquantitative determination of concentration. Plastic-embedded nerve roots and dorsal root ganglion were used for neuropathologic evaluation, and von Frey stimulation was used to quantify mechanical allodynia. RESULTS: The 17-kDa form of tumor necrosis factor-alpha is expressed by herniated nucleus pulposus at a concentration of approximately 0.48 ng per herniated rat lumbar disc. Exogenous tumor necrosis factor-alpha applied in vivo to rat nerve roots produced neuropathologic changes and behavior deficits that mimicked experimental studies with herniated nucleus pulposus applied to nerve roots. CONCLUSIONS: The data reinforce other evidence that tumor necrosis factor-alpha is involved in mechanisms of neuropathic pain.     

Histology of intervertebral disc protrusion: an experimental study using an aged rat model

STUDY DESIGN: In vitro experimental intervertebral disc ruptures of aged rats were examined histologically. OBJECTIVES: To clarify the mechanism of intervertebral disc herniations by microscopic investigation of ruptured discs. SUMMARY OF BACKGROUND DATA: Clinically, disc herniations have been classified into two types: extrusion and protrusion. However, the pathogenesis of protrusion type herniations has not yet been demonstrated by any studies. To clarify this issue, it is essential to establish an appropriate model producing disc herniations, and to examine the sequential changes in the structure of herniated discs. METHODS: Lumbar discs of 2-year-old rats were examined histologically and compared with human lumbar discs. To examine structural changes in discs subjected to repetitive motion stress, 400 repetitions of a sequence of flexion (30 degrees ) and axial rotation (6 degrees ) were applied in vitro to the lumbar discs of the animals. RESULTS: The microstructure of normal lumbar discs in aged rats was similar in many ways to the human lumbar discs in a 20- to 40-year-old adult. Of 10 discs subjected to repetitive stress, 4 were ruptured at the junction between the posterior anulus fibrosus and the sacral cartilage endplate. One had an extruded nucleus pulposus, and three had a protruded anulus fibrosus, which displayed disorganized structure containing widened and flaccid lamellae. CONCLUSIONS: The results from this study indicate that disc protrusion can be caused by disorganization of the ruptured annular lamellae, not by focal compression of the nucleus pulposus.     

Effect of the transligamentous extension of lumbar disc herniations on their regression and the clinical outcome of sciatica

STUDY DESIGN: Magnetic resonance imaging of symptomatic herniated lumbar discs was investigated longitudinally and prospectively for the presence of tear in the posterior longitudinal ligament (PLL). OBJECTIVES: To clarify the effect of transligamentous extension through the PLL of herniated disc on its regression and to determine the factors contributing to a successful clinical outcome. SUMMARY OF BACKGROUND DATA: Greater regression of the herniated fragment has been noted with larger initial disc herniations. The exposure of herniated disc materials to the epidural vascular supply through the ruptured PLL has been suspected to play a part in the mechanism of disappearance of the herniated nucleus pulposus. However, it had not been shown clinically. METHODS: Clinical outcomes and magnetic resonance images of 36 patients with symptomatic lumbar disc herniations, treated conservatively, were analyzed. Patients were divided into three groups: subligamentous, transligamentous, and sequestered herniations. The size of the herniated disc was measured by herniation ratio, which is defined as the ratio of the area of herniated disc to that of the thecal sac on the axial view. Factors associated with the natural regression of herniated disc and the successful clinical outcome were explored. RESULTS: Of the 36 herniated discs, 25 decreased in size. Ten (56%) of 18 subligamentous herniations, 11 (79%) of 14 transligamentous herniations, and all 4 (100%) sequestered herniations were reduced in size. The average decreases in herniation ratio of the subligamentous, transligamentous, and sequestered disc groups were 17%, 48%, and 82% respectively. The decrease in herniation ratio was related to the presence of transligamentous extension but was not related to the initial size of herniation. Successful outcome correlated with a decrease in herniation of more than 20%. CONCLUSION: Transligamentous extension of herniated disc materials through the ruptured PLL is more important to its reduction in size than is the initial size of the herniated disc. Decrease in herniation ratio of more than 20% seems to correspond to successful clinical outcome.     

Automated percutaneous lumbar nucleotomy

Surgical Principles The disc space is evacuated with the help of a percutaneously inserted Nucleotome® Probe. The herniated nucleus pulposus material is suctioned through an opening in the probe, cut off with a cutting device and aspirated through the probe. The automated percutaneus nucleotomy can be performed in patients with small or medium sized encapsulated herniated lumbar discs, when conservative treatment failed and prior to considering a lumbar discoidectomy.     

临床症状与髓核突出左右不一致的腰椎间盘突出症的诊治

目的探讨腰椎间盘突出症导致非对称性下肢放射痛的可能原因及术式的选择。方法25例经SCT、MRI检查证实为突出侧与临床症状侧别左右不一致的腰椎间盘突出症患者，均行手术治疗，其中14例行双侧开窗减压探查髓核摘除术，11例仅行突出侧开窗术。结果影像学上髓核突出侧别与术中所见相吻合，但该侧神经根未见到明显压迫或炎性水肿等病理表现；而症状侧无髓核突出，5例神经根未发现异常表现，9例存在不同程度的炎性水肿，其中6例探查发现神经根与对侧髓核不同程度粘连。术后所有患者症状均得到缓解，经过1～5年（平均2．4年）的随访，均无复发。结论SCT结合MRI检查有助于此类腰椎间盘突出症的明确诊断。纤维环无破裂的突出型腰椎间盘突出症，单纯突出侧减压可以获得较好的治疗效果；纤维环破裂的游离型及脱出型腰椎间盘突出症，宜同时行对侧开窗探查。     

Percutaneous laser disc decompression. A new therapeutic modality.

The authors present a new advance in the treatment of herniated disc disease using percutaneous Nd:YAG laser to vaporize a small portion of nucleus pulposus, thereby decompressing the disc. In vitro and in vivo animal data are presented. Three hundred seventy-seven magnetic resonance imaging or computed tomography scan-documented, herniated, nonsequestered lumbar intervertebral discs with corresponding clinical findings in 333 patients were so treated in an outpatient setting. The longest follow-up was 62 months, with a mean of 26 months. According to the Macnab criteria, there was a good to fair response in 261 patients (78.4%), and a poor response in 72 (21.6%); 166 patients experienced relief of pain during the procedure. One-third of repeat magnetic resonance imaging scans at 4-6 months postlaser treatment showed modest to moderate decrease of disc herniation.     

腰椎间盘突出症的免疫病理学研究

目的从免疫组织化学角度研究破碎型和完整型腰椎间盘突出症的病理机制和病理过程，比较其差异，探讨腰椎间盘突出症的不同病理学分型。方法选取40例腰椎间盘突出症患者的椎间盘手术标本，依术中所见分为两组：（1）破碎型腰椎间盘突出组（切开突出病变部浅层后纵韧带及纤维环可见破碎椎间盘组织与椎间盘母体分离，突出病变质软，自行溢出或较易钳出）。（2）完整型腰椎间盘突出组（切开突出病变部浅层后纵韧带及纤维环无破碎椎间盘组织溢出，突出病变质硬，必须以器械切除）。所获得的椎间盘标本均行常规HE染色；以鼠抗人CD43RO、CD20单克隆抗体进行免疫组织化学标记，双盲法半定量计数阳性细胞，Ridit等级分析；以FITC标记的兔抗人IgM、IgG抗体进行免疫荧光标记，双盲法半定量计数荧光量，Ridit等级分析。结果两组形态学有显著差异：（1）HE染色可见破碎组标本边缘灶性炎性细胞浸润，血管化；完整组髓核面积减少，纤维环增厚，软骨基质增生；（2）破碎组标本CD。sRO免疫组织化学阳性反应与完整组比较差异有统计学意义（P〈0．05）；（3）破碎组标本IgG和kM免疫荧光阳性反应与完整组比较差异有统计学意义（P〈0．01）。结论（1）破碎型腰椎间盘突出症标本中有T淋巴细胞浸润和免疫球蛋白IgG、IgM沉积，因而其病理机制可能是在损伤基础上的自免疫炎症反席过程。（2）完整犁腰椎间鼎突出以髓核很蛮、软骨某质及纤维环增牛为丰兽表现．     

腰椎间盘突出症突出髓核中抗原抗体复合物测定的临床意义

目的：探讨抗原体复合物在突出髓核中的分布及临床意义。方法：应用免疫酶组织化学染色的方法，对31例腰椎间盘突出症患的突出髓核中抗原抗体复合物进行检测，与20例正常椎间盘作对照并结合临床资料分析其意义。结果：在突出髓核的标本中可在髓核细胞膜周围观察到显示阳性的棕色沉淀物存在，而在正常椎间盘对照组中却未见阳性显示。突出型及脱垂游离型髓核中68．42％显示为强阳性，31．58％显示为阳性，膨隆型髓核中58．33％显示为阳性，41．67％显示为阴性。两组之间P＜0．05，有统计差异。结论：在突出髓核组织普遍存在抗原体复合物，而健康椎间盘中却不含有此免疫复合物。抗原体复合物阳性与强阳性表达与髓核暴露于机体免疫系统的程度相关，临床疼痛症状的程度与自身免疫反应的程度相关。髓核突出后引起的自身免疫反应是导致神经根慢性炎症的重要原因。     

Neovascularization of the outermost area of herniated lumbar intervertebral discs

In 64 surgically treated herniated lumbar intervertebral discs, we performed histopathological studies of neovascularization in the outermost layer of the herniated mass in various types of hernia. We obtained specimens separately from the capsule tissue covering the herniated mass and the inner tip tissue of the herniated mass for comparison. Histologically, in most cases, the capsule tissue was the outermost layer of the annulus fibrosus or posterior longitudinal ligament, and the inner tip tissue was the nucleus pulposus. In the capsule tissue, newly formed small blood vessels were present in 73.4% of the total cases examined, regardless of the hernia type. However, the frequency and degree of such vessels in the tip tissue were significantly higher in hernias that perforated the posterior longitudinal ligament than in those that did not. When the intervertebral disc herniates, new blood vessels proliferate in the capsule of the hernial tissue. At the stage when the hernial capsule tissue is still present, these vessels were observed to have difficulty reaching the inner tip portion. These findings suggest that when the nucleus pulposus portion of the herniated mass perforates the posterior longitudinal ligament, it may be subject to a stronger neovascularization reaction. Received for publication on May 18, 1998; accepted on Jan. 19, 1999     

Role of leukocytes in radicular pain secondary to herniated nucleus pulposus

Some studies have assessed inflammatory cells such as macrophages, lymphocytes, and neutrophils in herniated lumbar disc tissues using histologic analysis. However, there is no consensus regarding the relationships between clinical symptoms, including radicular pain and the presence of inflammatory cells. It has been shown that autologous nucleus pulposus relocated on the lumbar nerve root in rats produces time dependent and reversible mechanical hyperalgesia, which is thought to be a pain related behavior in peripheral neuropathic pain models. The purpose of this study was to determine whether leukocytes play a role in the mechanical hyperalgesia induced by the nucleus pulposus and to characterize the role of leukocytes in radicular pain attributable to lumbar disc herniation. Nitrogen mustard was used to induce and evaluate leukocytopenia in rats. Sensitivity to mechanical noxious stimuli was measured quantitatively, and inflammatory cells in granulation tissue around the nerve root were examined histologically. The nucleus pulposus produced neither mechanical hyperalgesia nor abundant inflammatory cells in rats with nitrogen mustard induced leukocytopenia. Neuropathic pain produced by the nucleus pulposus, when placed on the nerve root, may be related to inflammatory cell infiltration induced by relocation of the nucleus pulposus, rather than the nucleus pulposus itself.     

Clinical evaluation of lumbar CT assisted discography in comparison with human cadaver

In order to estimate the clinical value of lumbar CT assisted discography (CTD), results obtained by this method were compared with histological findings of the cross section of the spine in fresh human cadavera. Based on these findings, preoperative CTD of lumbar disc herniation was investigated. In the discs of human cadavera, the contrast medium mainly invaded the fissures of nucleus pulposus and the ruptures of annulus fibrosus and then diffused to the surrounding tissues. These ruptures were classified into two categories: radial and circumferential. This identification was possible only in CTD and was obscure in the usual discogram. Not all the ruptures could be dyed in a severe degenerative disc, and a rupture which was not communicated with nucleus pulposus was not dyed in a mild degenerative disc. In the preoperative CTD of lumbar disc herniation, the posterior radial ruptures representing the route of herniated nuclei were characteristic and the circumferential ruptures were found complicated.     

The effect of age on inflammatory responses and nerve root injuries after lumbar disc herniation: an experimental study in a canine model

STUDY DESIGN: An experimental investigation on the effect of age on pathologic events surrounding the herniated disc and at the adjacent nerve root. OBJECTIVES: To investigate the role of age on the inflammatory responses and nerve root damage surrounding a sequestered lumbar disc fragment using a dog model. SUMMARY OF BACKGROUND DATA: Lumbar disc herniation is manifested in patients by variable clinical findings, natural history, and resorption phenomena in which the variability is particularly noted among patients with different ages. There are no previous reports on the effect of age on pathologic events induced by the herniated disc. METHODS: Six beagle dogs, including two animals of each age group of 6, 12, and 24 months (human equivalent ages of 10, 15, and 24 years), were used in this study. The dogs underwent L4-L5, L5-L6, and L6-L7 laminotomy and discectomy under general anesthesia. An autologous intervertebral disc from the tail was divided into anulus fibrosus and nucleus pulposus fragments. The anulus fibrosus and nucleus pulposus fragments were placed in the anterolateral epidural space of L5-L6 and L6-L7, respectively. The L4-L5 discectomy site served as a control. Dogs were killed at 12 weeks after surgery. The lumbar spine was removed en bloc, and histologic sections were prepared consecutively and examined. RESULTS: In the nucleus pulposus group at L6-L7, neovascularity, and intensive infiltration of lymphocytes, macrophages, and fibroblasts were observed surrounding the nucleus pulposus fragment in the 24-month-old group only. Degenerative changes of the nerve root fibers were observed in the 24-month-old group only. In the control and anulus fibrosus groups at L4-L5 and L5-L6, there were no marked inflammatory reactions in all age groups. The nerve root fibers around the anulus fibrosus were normal in all age groups. CONCLUSIONS: There is an effect of age on the inflammatory response and nerve root injury caused by the herniated disc. The apparent neuroprotective mechanism in the young animal, and the apparent inflammatory and resorption changes of the nucleus pulposus fragment in the older animal are quite intriguing.     

前列腺素E2在突出腰椎间盘中的表达及其与坐骨神经痛的关系

目的探讨前列腺素(PG)E2在突出腰椎间盘组织中的表达及其在坐骨神经痛发病机制中的作用。方法 42个突出椎间盘标本取自42例腰椎间盘突出并有坐骨神经放射性疼痛症状的手术治疗患者,其中膨隆型12例,破裂型15例,游离型15例,取材部位为紧贴神经根突入椎管的椎间盘组织(A部位)和椎间隙内残存的椎间盘组织(B部位)。术前采用视觉模拟评分(VAS)对所有患者坐骨神经痛严重程度进行评分。应用酶联免疫吸附试验(ELISA)检测PGE2含量。结果 A部位PGE2含量自膨隆型、破裂型至游离型逐渐升高,差异有显著性(P<0.01);A部位PGE2含量高于B部位(P<0.01);PGE2含量与患者坐骨神经痛VAS评分存在明显相关性(r=0.848,P<0.01)。结论 PGE2参与了腰椎间盘退变、突出的发病机制,PGE2含量与坐骨神经痛程度呈正相关性。     

Sequential dynamics of monocyte chemotactic protein-1 expression in herniated nucleus pulposus resorption

We previously demonstrated that the granulation tissues of herniated nucleus pulposus are composed of a marked infiltration of macrophages that strongly express monocyte chemotactic protein-1. Monocyte chemotactic protein-1 is a chemotactic cytokine that contributes to the activation and recruitment of macrophages. Relatively little is known about its role in the resorption process of herniated nucleus pulposus. To clarify the sequential dynamics of expression of monocyte chemotactic protein-1 in the granulation tissues of herniated nucleus pulposus, we introduced a rat autologous transplantation model of nuclear materials onto its lumbar dura mater and performed immunohistological analysis and competitive polymerase chain reaction assay using the grafted samples. Immunohistological analysis demonstrated that the majority of infiltrating mononuclear cells expressed monocyte chemotactic protein-1. Monocyte chemotactic protein-1 mRNA was expressed in the first 3 weeks after the procedure and was significantly and maximally upregulated at 1 week. To determine whether human recombinant monocyte chemotactic protein-1 facilitates the resorption process of herniated nucleus pulposus, we introduced another model of autologous transplantation, wherein the nuclear materials were grafted to the abdominal subcutaneous tissues and recombinant monocyte chemotactic protein-1 was subsequently applied to these materials. When monocyte chemotactic protein-1 was injected into the murine nucleus pulposus tissues, they reduced in size more rapidly than in the control group. These findings suggest that monocyte chemotactic protein-1 plays an important role in the recruitment of macrophages in the early phase of the resorption process of herniated nucleus pulposus and that its application may physiologically facilitate the resorption process of the nucleus pulposus.     

Metaplastic proliferative fibrocartilage as an alternative concept to herniated intervertebral disc

It is hypothesized on the basis of experimental intervertebral disc degeneration that herniated disc is actually newly synthesized proliferative metaplastic fibrocartilage and not herniation of pre-existing disc tissue, particularly that of the nucleus pulposus. Human material in selected surgical tissues was examined to test this concept. Histology revealed evidence for proliferative fronts of fibroblastic cells in herniated discs with hypocellular interiors. Hydroxypyridinium cross-link assay was used to determine the maturity of the collagen. Results indicated, with statistical significance, that herniated disc is a younger tissue than in situ annulus fibrosis, and that herniated disc is not from the nucleus pulposus, thus supporting the hypothesis.     

Ultrasonic level diagnosis of lumbar disc herniation

Although the use of diagnostic ultrasound to measure the spinal canal has been proposed, the value of ultrasound for lumbar disc herniation has not been yet fully assessed. The purpose of this investigation was to evaluate the effectiveness of ultrasound in the level diagnosis of herniated nucleus pulposus. Prospective ultrasound examinations were performed on 80 consecutive patients with clinically suspected lumbar disc herniation. In 41 discs of those 40 patients with surgically confirmed lumbar disc herniation, there were 32 discs (78%) with true-positive ultrasound diagnoses, 37 discs (90%) with true-positive myelographic diagnoses, and 20 patients (50%) with true-positive neurologic diagnoses. Conversely, ultrasound diagnoses showed positive echogram in 24 (60%) of 40 nonoperative patients. These results suggest that ultrasound is of value as an aid for diagnosing the level of lumbar disc herniation.     

磷脂酶A2在腰椎间盘突出症髓核中的表达及相关临床研究

目的：探讨磷脂酶A2（PLA2）在腰椎间盘突出症中的作用机制。方法：1．在术前和术中收集35例因腰椎间盘突出而手术的病人的疼痛程度、直腿抬高试验度数、突出病理征象等临床资料，采集突出组和对照组（8例）的血清和髓核标本。2、应用微孔比色法测定PLA2的活性。3．将获得的数据和临床资料进行统计学分析。结果：突出组髓核中的PLA2活性高于对照组，血清中两组无差异。髓核PLA2活性在破裂型或游离型中同在凸起型中的表达有差异（P＜0．05），与直腿抬高试验度数呈负相关（r=-0.344)，与疼痛存在相关性（P＜0．05）。结论：腰椎间盘出症髓核的PLA2活性高于正常腰椎间盘，化学性炎症机制在腰椎间盘突出症根性疼痛中发挥着可能比机械压迫更重要、更直接的作用，PLA2抑制剂有望成为治疗腰椎间盘突出症新一类药物。