腰痛和腰椎间盘突出症(英文)_【ppt课件】

单击此处编辑母版标题样式 单击此处编辑母版副标题样式 *1 LOWER BACK PAIN AND HERNIA OF INTERVERTE BRAL DISC 腰痛和腰椎 间盘突出症 lStructural support and balance for upright posture Functions of the Spine lProtection Spinal cord and nerve roots Functions of the Spine Internal organs lFlexibility of motion in six degrees of freedom Functions of the Spine Left and Right Side Bending Flexion and Extension Left and Right Rotation lCranial - the head or towards the head lCaudal - the tail or towards the tail lAnterior - the front section or towards the front lPosterior - the back section or towards the back lVentral - the front or anterior surface lDorsal - the back or posterior surface Basic Terminology Cranial Caudal Anterior Posterior Dorsal Ventral Vertebral Structures lPedicle notches Slight Notch Deep Notch Intervertebral Foramen lIntervertebral foramen lNerve roots exit Vertebral Structures Body Pedicle Lamina Superior Articular Process Spinous Process Transverse Process Vertebral Foramen Lumbar Vertebrae lBody - L1 to L5 progressive increase in mass lPedicles - longer and wider than thoracic; oval shaped lSpinous processes - horizontal, square shaped lTransverse processes - smaller than in thoracic region lSpinal foramen- large to allow for cauda equina and nerve roots lIntervertebral foramen - large, but with increased incidence of nerve root compression lIntervertebral Disc Vertebral Structures lEnd Plate lApophyseal Ring Cartilaginous Bony lThe FUNCTIONAL UNIT of the spine lComprised of: Two adjacent vertebrae Intervertebral disc Connecting ligaments Two facet joints and capsules The Motion Segment lFibrocartilaginous joint of the motion segment lMakes up the length of the spinal column lPresent at levels C2-C3 to L5-S1 lAllows compressive, tensile, and rotational motion lLargest avascular structures in the body Intervertebral Disc Intervertebral Disc lAnnulus Fibrosus Outer portion of the disc Lamellae lGreat tensile strength Made up of lamellae Annulus Fibrosus Layers of collagen fibers lArranged obliquely 30 lReversed contiguous layers Intervertebral Disc lNucleus Pulposus Nucleus Pulposus Inner structure Gelatinous High water content Resists axial forces Intervertebral Disc lLargest avascular structure lBlood supply by diffusion through end plates lDamage to the blood supply leads to degradation of the disc Anatomy and Degenerative Change The Vertebral Body (VB) Key Roles Carry 80% of the axial loads through VB and disc Endplates enable nutrition to diffuse to disc Intervertebral Disc The Intervertebral Disc Has two roles Shock absorber of axial forces Pivot point in motion segment Intervertebral Disc Ligaments Ligamentu m flavum Posterior longitudinal ligament Anterior longitudin al ligament Spinal Ligaments lBands or sheets of tough, fibrous tissue that connect bones, cartilage, or other structures lBecome active when stressed to maximum range of motion lProtect the joints from being hyperflexed The Intervertebral Disc and Degenerative Change Two major components of IVD Annulus fibrosis: thick, fibrous “radial tire” Lamellae Nucleus pulposus: ball-like gel The Intervertebral Disc (IVD) and Degenerative Change By age 50, 95% of people show lumbar disc degeneration lNot all have symptoms lSignificant changes to IVD are: Water and proteoglycan content decreases Collagen fibers of AF become distorted Tears may occur in the lamellae lResults in: Disc loses height and volume Loses resistance to loading forces lNo longer acts as a shock absorber Overview - cont. lThe motion segment is the functional unit of the spine and consists of Muscle (activators) Ligaments (passive restraints) Adjacent vertebral bodies A 3-joint complex of two facet joints and a disc (pivots) lDegeneration can begin in one or more of these joints, but ultimately all three will be affected Degenerative Conditions Provide an overview of degenerative conditions Degenerative Disease Spinal Stenosis Herniated Disc Degenerative Disease - Overview lLoss of normal tissue structure and function due to aging process lChanges are usually gradual, trauma sometimes accelerates lDegenerative changes do not always lead to clinical symptoms lWhen changes cause symptoms (often pain), the process is referred to as osteoarthritis lSpondylosis is degenerative changes in the spine Anatomy and Degenerative Change The Vertebral Body (VB) Degenerative Changes Sclerosis: Increased bone formation adjacent to endplates Reduces nutrition diffusing to disc Stiffens endplate, and reduces ability to absorb loads Osteophytes: Formation of small bony spurs Can project into neuro structures Facet Joints and Degenerative Change Key Roles Carry 20% of compressive loads Help stabilize spine lDegenerative Changes Cartilage lining loses water content Cartilage wears away Facets override each other Leads to abnormal function of motion segment Anatomy and Degenerative Change Ligaments and Muscles lLigaments attach bone to bone Provide stability, enable normal motion lDegenerative Changes Partial ruptures, necrosis and calcifications Negatively impact function of motion segment Degenerative Disc Disease lChanges include: Disc loses height and volume Compressive loads transfer away from nucleus to margins Sclerosis of endplate reduces disc nutrition Facet joints wear away cartilage, begin to override Motion segment becomes hypermobile Osteophytes develop to attempt to stabilize motion segment Osteophytes may encroach on neuro structures Spinal Stenosis Narrowing of the spinal canal and/or lateral foramen through which the nerves travel Three types: Central stenosis: in central spinal canal where cord or cauda equina are located Lateral recess stenosis: in the tract where nerve roots exit canal Acquired: in lateral foramen where nerve roots exit to body Most frequent in lower cervical and lower lumbar spine Herniated Disc lOften called “ruptured disc” lVery common pathology lL3-4, L4-5, L5-S1 common locations lThought to be a culmination of acute traumatic events to the disc Herniated Disc: 4 degrees Nuclear herniation: nucleus ruptures. No disruption of outer annular fibers Disc protrusion: ruptured nucleus causes outer fibers to bulge Nuclear extrusion: Complete split in annulus. Material leaks but remains attached to nucleus Sequestered nucleus: Leaked substance no longer attached to nucleus INTRODUCTION lThe back and leg pain since - Greeks recognized it. lIn the fifth century AD Aurelianus clearly described the symptoms of sciatica. lThe sciatica arose from either hidden causes or observable causes- a fall, a violent blow, pulling, or straining. 单击此处编辑母版标题样式 单击此处编辑母版副标题样式 *39 lThe most notable of these is the Lasgue sign, or straight-leg raising test, described by Forst in 1881 but attributed to Lasgue, his teacher. This test was devised to distinguish hip disease from sciatica. Biomechanics of the lumbar spine Biomechanics of the lumbar spine Biomechanics of the lumbar spine Biomechanics of the lumbar spine Biomechanics of the lumbar spine Biomechanics of the lumbar spine INTRODUCTION lMixter and Barr in their classic paper published in 1934 again attributed sciatica to lumbar disc herniation. Definition lRuptured discs are among the most common and painful of all back ailments. lThe condition occurs when the outer cover of a disc is torn and the soft inner tissue extrudes. The extrusion often puts pressure on the spinal nerves, causing back and leg pain which can be severe. l腰椎间盘突出症是因椎间盘变性，纤维环破裂，髓核 突出刺激或压迫神经根、马尾神经所表现的一种综合 征。 Prolapsed intervertebral disc lIt usually occurs in the L4/5 or L5/S1 intervertebral disc regions and is most often seen on only one side but may be bilateral. lIt may occur in other regions, especially at the L3/4 level, and occasionally disc protrusion may occur at more than one level simultaneously. lIt is often due to degeneration of the disc and therefore occurs most commonly in middle or old age. lDegeneration of the annulus fibrosus allows the nucleus pulposus to herniate through 压迫对神经根的作用 l压迫改变神经根的传导、营养状态，通过 影响局部血运和脑脊液的营养， l机械直接损伤神经内部，神经根受压变形 ，有张力，压迫神经根可引传导性损伤， 功能改变。 l同周围神经一样，单纯压迫不引起根痛， 没有炎症和刺激因素压迫只产生感觉缺失 ，运动无力，反射异常，但无痛。如有化 学炎症和代谢因素产生炎性反应存在 压迫对神经根的作用 l压力从1013.33kPa引起了神经传导功能的逐 渐减弱。其中，传入神经传导功能的减弱更加 明显，而去压迫后，运动神经能更加容易和迅 速地恢复到几乎正常的CMAP水平。 l压迫在26.67kPa时，引起了神经传导功能的迅 速减弱，而且去压迫后传入神经几乎没有恢复 ，传出神经仍有30%40%的恢复。将压迫时 间从2h延长到4h，对神经恢复能力的影响更加 明显3。 产生腰痛的组织 -背根节 lHowe发现背根节对中度压迫极 度敏感，当压力解除后感觉神 经释放的信号可持续25分钟。 l从神经生理学角度背根节是特 有的、“捣鬼”的疼痛源，突出 椎间盘能挤压它 l对于周围神经来说，当刺激解 除后，神经冲动马上停止. 产生腰痛的组织-背根节 实验结果背根节在尼龙线牵拉产生60秒的发电， 而玻璃棒压迫会产生4分钟的冲动 产生腰痛的组织-背根节 l背根节的神经细胞与突触相交 处的细胞膜上有高密度的钠通 道，使其对机械压力特别敏感 。 l这种高密度的钠通道可能是导 致神经冲动持续，在背根节受 压时产生生骨神经痛. 产生腰痛的组织-神经根 lOlmarker等应用不同的化学标记物来 研究压力的大小和压迫发生的速度与 水肿形成和营养障碍的关系。 l结果提示，压迫产生越迅速，神经根 水肿的形成和营养供给障碍越明显。 产生腰痛的组织-脊神经背根 l与DRG不同，背根对机械压力不是始终有 反应，除非神经根有炎性或处可易惹状态 。 lHowe在被铬肠线结扎神经根后可以引出多 次发电的情况，单一压迫刺激即可引A、 、d神经纤维放电5-30秒。 l被刺激的神经根是有鞘神位由可能含有神 经末梢。Jang发现了猫的S1背根中有点状 直接受刺激区 产生腰痛的组织-脊神经背根 l最有效的机械刺激是轻度牵拉 ，与临床情况相吻合。 l有病间盘水平的神经根比邻近 正常的神经根更敏感 lKuslich在局麻下椎间盘手术中 ，对有炎症或压迫的神经根压 迫特别敏感，压迫它再现坐骨 神经痛 lSmyth用尼龙线绕过受累神经 根，轻拉即再现坐骨神经痛的 神经源的化学介质 损伤和炎症的组织释放的化学介质 使神经末梢致敏。 l这些神经致敏物质包括由C纤维释 放出的P物质、11氨基酸神经肽。 lP物质导致血管扩张，血浆外渗， 肥大细胞释放组胺。 l这些炎性介质的持续释放引起了疼 痛。 神经源的化学介质 l虽然原因还不清楚，P物质可能直 接作用神经末梢或间接通过血管扩 张，释放组胺、血浆外渗起作用。 lP物质在神经致敏中起重要作用， 这有重临床意义， l脊柱的运动正常是无痛的，但在炎 症条件下引起疼痛 腰痛症状持续的原因 非神经源的化学介质 l在组织损伤中产生的可以激活和致敏神经末梢 的化学介质包括：缓激肽、血清素(5-HT)、组 织胺、钾离子、前列腺素。 l已在椎小关节及邻近组织中发现了P物质， l使用10-g即能同时兴奋低痛阈和高痛阈神经 纤维， l30分钟后这些神经对机械刺激的痛阈明显降低 非神经源的化学介质 l当将角叉菱胶或陶土注入关节后， 神经纤维致敏兴奋性增加，1-2mm 的各方关节活动即可导致关节支配 神经的持续释放冲动电位。 l最近的研究表现在神经感受器对机 械压力敏感的部位，注入角叉菱胶 ，会导致神经元放电达3小时 非神经源的化学介质 l这些研究的临床意义：如果 关节囊、韧带、肌肉受牵拉 ，例如脊柱滑脱和椎间盘突 出症，引起组织损伤会导致 持久的伤害性刺激， l并可以导致一种循环状态， 肌肉痉挛，痛觉过敏，以致 持续性疼痛 椎间盘及神经根周围的炎症 l有关椎间盘的神经生理学 研究是有限的。 lCavanaugh报告了椎间盘 受机械刺激时只偶有少量 冲动，只有腹侧硬膜受牵 拉才有持续冲动。 l只有电刺激椎间盘和后纵 韧带引起A-d纤维冲动， 同椎管内注入致痛物质， 像组胺作用一样 椎间盘及神经根周围的炎症 lYamashita报告了椎间盘对机械压力大部分情况是 没有反应。椎间盘内只有静止伤害感受器，它只 对损伤或炎症产生的致痛电学物质有反应。 lMcCarron向狗硬膜外腔注入自体的髓核，表现出 它的致炎作用。 lOlmarker 发现身体髓核在神经 l组织中产生炎性和退行性改变 免疫和炎症反应 l腰腿痛当中，原因很复杂，椎间盘突出 l的大小与疼痛程度不一， l生化和机械因素交互作用。 l有很多证据表明髓核有致免疫原性， l自体髓核与血液接触，对髓核自身抗体已发现，虽然很多证 据表明介导免疫炎性，绝大多数以前的研究都注意到椎间盘 退变和疼痛的产生中的免疫现象标志物。 lSaal证明突出间盘边缘有免疫细胞，发现了T淋巴细胞IL-1、 2，据细胞。浸润的不同程度分级与症状相关。反应程度与术 前症状时间相关 l但病人没有全身的自身免疫性疾病表现, 疼痛直接原因不清。 磷脂酶A2 -PLA2 l在风湿性关节炎、急性胰腺炎、血清单阴 性关节炎、脓毒症表现出明显的炎症作用 。它在体内的源性： l表1 PLA2 activiyu l PMN3,2 l Platelet1.4 l Plasma0.006 l Sperm28.0 l inflammatory synovial fluid 12.1 l herniated lumbar disc1212.0 l正常椎间盘内PLA2就有致水肿作用 PLA2的神经毒性 lSteroid局部应用非常有效，在没有免疫反应的生化炎症， 作为疼痛发生机制的另一个原因 l髓核有介导炎性的能力，含有高浓度的PLA2。 lSaal在有腰痛病人病变节段的椎间盘组织内会有不正常高 浓度的磷酸激酶A2-PLA2。髓核、PLA2及别的致炎物质 作用到椎间盘的伤害感觉受器，它激活痛感纤维的作用比 单纯压力更大 lPLA2进入神经根后神经水肿，髓鞘轴突损伤，同注射 蛇毒 PLA2，但作用程度轻，支持了PLA2的神经毒性 l硬腰外使用自体髓核，发生传导阻滞，神经周围组织炎症 。 Leakage of nucleus pulposus material to nerve roots, is a pathophysiologic mechanism in LBP and sciatica lIncision of the anulus fibrosus induces nerve root morphologic, vascular, and functional changes. An experimental study. lKayama -Japan: Spine 1996 lThe nerve conduction velocity was significantly lower in the incision group (13 14 m/sec) compared with the nonincision group (73 5 m/sec). lThe obvious signs of capillary stasis with an increased number and diameter of the intraneural capillaries in the incision group. Cultured, autologous nucleus pulposus cells induce functional changes in spinal nerve roots lKayama -Sweden : Spine 1998 lNucleus pulposus cells and fibroblasts were cultured for 3 weeks, and various preparations were applied to the cauda equina in 29 pigs. After 1 week, nerve conduction velocity was determined by local electrical stimulation. lApplication of nucleus pulposus cells reproduced the previously seen reduction in nerve conduction velocity induced. 腰痛症状持续的原因 椎间盘及神经根周围的炎症 lKuslich在144例椎间盘手术中，在病变椎间盘外侧检查刺激 或电刺激产生中度疼痛占70%，重度占30%。 l突出椎间盘或狭窄的椎间只对DRG或突炎神经根的机械压迫 是持续的，就能导致持续性疼痛，或DRG或炎性神经根内压 增加这种持续性疼痛就会变为进行性加重。 lCavanaugh将自体髓核注入DRG引起1-3分钟的神经释放 PLA2致痛原因 l致炎因素；直接作用伤害感受器；磷脂酶本 身的直接造成神经损伤。炎症介定导致源发性神经 根坏死， l体外证实PLA2直接刺激纤维环伤害感受器。 l这些化学物质可直接刺激纤维环和周围神细胞中的 细小的无髓纤维C或Adeltal。致病物质作用后，伤害 感受器的痛域下降。 l（对机械刺激）正常的生理活动就可以导致腰痛、 障碍痛、根性痛（在纤维环外1/3后纵韧带）. 第二部分：腰痛症状持续的原因 椎间盘及神经根周围的炎症 l临床、组织化学、生理化学、神经组织学研究，髓核含有化 学性致炎、神经退变，急性期有神经兴奋的作用。 l同样化学物质有氢离子、PLA2免疫球蛋白G等，在椎间盘性 疼痛中，增加炎性神经根的敏感性起重要作用 Phospholipase A2 sensitivity of the dorsal root and dorsal root ganglion lOzaktay USA ：Spine 1998 Jun lPhospholipase A2 appeared to be neurotoxic when doses ranging from 100 to 400 U were applied on the mechanically sensitive segments of the dorsal root ganglia. lPLA2 doses comparable to serum concentrations in human rheumatoid arthritis when applied to dorsal root ganglia. lThese results suggest that dorsal roots and dorsal root ganglion may be impaired by phospholipase A2, leading to sciatica and low back pain. 脊髓水平 l中枢致敏 l组织损伤可能导致连续的神经冲动至脊髓，这使后 角神经元致敏 l致敏的神经元痛阈下降， l对传入冲动的反应增强， l对重复刺激的反应也增强， l接受刺激的阈值变宽。 l恶性刺激导致中枢致敏时，有明确证据后角释放了 兴奋性胺基酸和神经肽 脊髓水平-中枢致敏 l在中枢致敏状态下， l机械刺激的致痛阈值已下降，使很低 的机械刺激就可以让后角发出疼痛信 号。 l变宽的接受阈能把损伤处及附近正常 组织的传入信号变为疼痛信号向上传 递， l这就解释了腰疼痛位不清和持久、及 牵涉痛的原因 脊髓水平-中枢致敏 lGilleffe发现了后角单个神经 元可接受从各种脊柱组织传入 的信号，呈一种高度会聚接收 状态。 l脊髓后角的神经元可以由压迫 皮肤、椎小关节、韧带、及肌 肉而兴奋，这种高度会聚功能 也是腰痛不易定位的原因 Chronic Compression of Dorsal Root Ganglion Produced by Intervertebral Foramen Stenosis lHu SJ- Xian, PR China Pain 1998 Jul lAn experimental model in the rat. lA small stainless steel rod (0.5-0.8 mm in diameter) was inserted into the L5 intervertebral foramen lThese neurons had a greatly enhanced sensitivity to mechanical stimulation of the injured DRG and a prolonged after discharge. la persistent heat hyperalgesia 5-35 days lThe excitatory responses were evoked in the injured, but not the uninjured, DRG neurons. EPIDEMIOLOGY-risk factors lMultiple factors affect the development of back pain. lsmoking, pro-longed daily driving of motor vehicles, jobs requiring frequent repetitive lifting of heavy objects and twisting, the use of jackhammers and machine tools, and the operation of motor vehicles episodes of anxiety and depression. lIt is more common in males than females and has a maximal incidence in the third and fourth decades of life. LUMBAR DlSC HERNlATION lBack pain may be caused by stimulation of the pain fibers in the outer layers of the annulus fibrosus. lAlternatively, distortion of the posterior longitudinal ligament, which is richly innervated by pain fibers, may result in back pain. lLeg pain can result from compression of a nerve root by an HNP l腰痛可以起自于椎间盘、椎小关节、肌肉的 神经末梢。 l化学炎性介质释放，使正常无痛的运动变为 疼痛性的。 l髓核是强列的神经根和神经末梢致炎和刺激 物质 l椎间盘与神经根的位置、 DRG的特殊神经生 理特点、神经根和DRG易被压迫而出现坐骨 种经痛。 l系列恶性冲动使后角感觉神经元致敏，导致 的慢性疼痛状态 CIinicaI Presentation lThe following are risk factors for herniated disc disease in the lumbar spine: lsmoking, pro-longed daily driving of motor vehicles, and frequent repetitive lifting of heavy objects and twisting. lIt is more common in males than females and has a maximal incidence in the third and fourth decades of life. lThe clinician must rule out a compressive lesion of the sciatic nerve peripherally before ascribing the pain to a herniated disc. lThere may be a history of a previous injury. CIinicaI Presentation lA symptom- HNP. Sciatica is pain along the course of the sciatic nerve. lThe classic symptom is low back pain with radiation of severe pain down the back of the leg to the ankle and foot. lIt may be associated with neurological signs such as motor and sensory loss and occasionally bladder involvement. The levels of lumbar HNP The most common levels - L4-L5 and L5-Sl. For this reason, radicular symptoms almost always refer to symptoms below the level of the knee, in the L5 or S1 dermatome. Leg symptoms can vary from numbness to dysesthesia to true pain. lThe herniation of the L4-L5 disc can compress the S5 and lThe lumbosacral disc causes compression of the S1 nerve root. Symptoms and signs of the lumbar spine lThere is often associated spasm of the spinal muscles with tenderness over the lower lumbar spine on the side of the lesion. lThe muscular spasm may produce a scoliosis. Limitation of lateral flexion of the lumbar spine to the same side will be most marked with a protrusion lateral to the nerve root, lwhile limitation of lateral flexion to the opposite side will be most marked with a protrusion medial to the nerve root. Focal signs lFocal signs are dependent on the distribution of the affected nerve root. lWith L4 compression there is weakness of quadriceps and tibialis anterior, with sensory change over the medial aspect of the shin and depression of the knee jerk. lL5 root compression may solely declare itself by weakness of extensor hallucis longus. Any sensory change is found over the medial aspect of the dorsum of the foot and the lateral shin. lIn an Sl root syndrome weakness can occur in the buttock muscles, the hamstrings or the calf muscles. The ankle jerk is likely to be depressed or absent. Sensory change particularly occurs over the lateral aspect of the foot and the calf. Protrusion of the L4/5 disc lIt may cause L5 root pressure with pain radiating down the leg to the dorsum of the foot. lThere may be numbness on the outer side of the calf and medial two-thirds of the dorsum of the foot lwith weakness of dorsiflexion, particularly of the foot and toes. Protrusion of the L4/5 disc lProtrusions at the L4/5 level will thus compress the L5 root, while protrusions at the L5/S1 level will compress the first sacral root. Protrusion of the L5/S1 disc lIt will press on the S1 nerve root and may lead to pain and numbness on the outer side of the foot and under side of the heel. Protrusion of the L5/S1 disc lThere may be weakness of both eversion and plantarflexion of the foot with a diminished or labsent ankle jerk. Protrusion of the L3/4 disc lIt may cause pressure on the L4 nerve root lmay lead to numbness over the front of the knee and leg lwith diminution of the knee jerk land weakness of the knee extensors. Protrusion of the L3/4 disc lFemoral nerve traction test Cen