DiskHerniation-Eng

BASIC STRUCTURE & FUNCTION OF THE SPINEVERTEBRAL COLUMNThe vertebral column or spine is made up of a series of bones called vertebrae. The spine is a strong and flexible column of bones made up of the cervical, thoracic, lumbar, sacral, and coccygeal regions. The cervical or neck region is normally made up of 7 bones, the thoracic or chest region has 12 bones, and the lumbar or low back region is made up of 5 bones. The sacral region consists of 5 fused bones, and the coccygeal region 3 to 5 tiny bones. However variations do occur.The spine is curved and in profile looks like an elongated letter "S" in shape. The cervical and lumbar regions have a forward curve and the thoracic region a backward curve when viewed from the side.It has been suggested that the S shape of the spine:facilitates energy absorption and protects the spinal structures against impact by increasing its strength;helps maintain balance in the upright position; andabsorbs shocks when a person walks.SIDE VIEW OF THE SPINEKEY POINTThe vertebral column or spine is made up of a series of bones called vertebrae. Variation in vertebrae size, shape and detail occur in the different regions of the spine. For example, the lumbar vertebrae are the largest and strongest. In general, however, all vertebrae have the same basic structure.There are three main parts to a vertebra:Vertebral Body (weight bearing structure)Vertebral Arch (protective in function)Vertebral ProcessesVERTEBRAL BODYThe vertebral body is the weight bearing part of a vertebrae.The vertebral body is a thick, disc shaped cylindrical block of bone flattened at the back and with roughened top and bottom surfaces. It is made up of spongy bone on the inside, which enables it to resist compression, and a thin outer covering of compact bone. It is the weight bearing part of a vertebrae.VERTEBRAESide View View From AboveVERTEBRAL ARCHThe vertebral arch surrounds the spinal column and is protective in function.The vertebral arch, or neural arch as it is sometimes called, extends backwards from the vertebral body. It is made up of two short, thick processes called pedicles that stick out backwards from the vertebral body and join the laminae. The laminae are flat and join together to form the back part of the vertebral arch. Together the vertebral arch and vertebral body surround the spinal column. The space occupied by the spinal column is called the vertebral foramen. The vertebral foramen, when stacked on top of each other, forms the vertebral or spinal canal. On each side of the vertebral column there is an opening between each vertebrae called the intervertebral foramen which enables the spinal nerves to pass through.VERTEBRAView From Above Side ViewVERTEBRAL PROCESSESThere are seven different processes that come from the vertebral arch. A transverseprocess extends sideways on each side from the junction of a lamina and pedicle. A single spinous process extends back and downwards from the junction of the laminae. These three processes have spinal muscles attached to them. The other four articular processes form joints with other vertebrae. The two articular processes on top form a joint with the two articular processes on the bottom of the vertebrae above, and the two bottom processes form a joint with the two processes on top of the vertebrae below.VERTEBRAL DISCSAdjacent vertebral bodies are attached to each other by an intervertebral disc. The disc is made up of a central mass of pulpy tissue called the nucleus pulposus and a tough outer covering of fibro-cartilage called the annulous fibrosis. The layers of the annulus are thinner at the back, making this area potentially more prone to damage.INTERVERTEBRAL DISCFront ViewSide ViewView from AboveThe discs are shock absorbers, giving resilience to the spinal column as well as flexibility. When a body is erect, the various parts of the disc are under uniform pressure; but when the spine is flexed, extended or bent to the side, one part of the disc is under increased compression whereas another part is under tension.Vertebral Discs under Various LoadsLIGAMENTSLigaments are strong bands of fibrous tissue that connect structures such as bone to bone. Two long ligaments, one at the front and one at the back (anterior and posterior longitudinal ligament), extend the length of the vertebral column. They are attached to the discs and help prevent excessive movement of the spinal column. An abnormal stress may tear the outer fibres of a disc, causing the jelly like nucleus pulpous to leak out and press on neighbouring spinal nerves.The joints between the vertebral arches are connected by different types of ligamentous tissue:Ligaments are strong bands of fibrous tissue that connect structures such as bone to bone. Articular capsules made up of thin loose ligaments attached to the edges of the articular processes of adjacent vertebrae.Ligamenta flava are elastic sheets connecting the laminae of adjacent vertebrae. Supraspinous ligament: a strong fibrous cord connecting the spinous processes from the seventh cervical vertebrae to the sacrum.Interspinous ligaments are weak bands that connect adjacent spinous processes; and similar bands called intertransverse ligaments are found between transverse processes in the lumbar region.SPINAL LIGAMENTSSpinal Ligaments - Side View Spinal Ligaments - Internal Side ViewMUSCLESThe muscles of the spine are important in maintaining its stability and balance as well as assisting in spinal movement. The superficial back muscles are mainly concerned with movements of the upper limbs. The post-vertebral spinal muscles, or deep back muscles, are numerous and varied in structure and function. Muscles extend from the sacrum to the skull and allow such movements as rotation and extension (backward bending) of the spine.The muscles that are important for the stability of the spine include the:Latissimus Dorsi;Lumbar Paravertebral Muscles; and theMultifidus.The abdominal muscles (found at the front of the spine wrapping around the side of the trunk) form a natural corset with other muscles and play a major role in the maintenance of spinal stability.The abdominal muscles include the:Rectus Abdominus;Internal and External Oblique muscles; and theTransversus Abdominus muscle.SPINAL MUSCLESAbdominal MusclesSuperficial MusclesDeep Back MuclesKEY POINTThe muscles of the spine are important in maintaining its stability and balance as well as assisting in spinal movement.SPINAL CORD & SPINAL NERVESThe spinal cord is cylindrical in shape and starts as an extension of the lower part of the brain stem and finishes at around the second lumbar vertebrae. The cord is made up of some 31 segments that each give rise to a pair of spinal nerves. The spinal cord is protected by the spinal column, the spinal meninges (dense fibrous covering), the cerebrospinal fluid (special fluid surrounding the brain and spine), and the vertebral ligaments. The main function of the spinal cord is to convey motor impulses from the brain to the muscles, and sensory information from the body to the brain.There are 31 pairs of spinal nerves named and numbered according to the level and region of the spine from which they emerge. There are 8 pairs of cervical nerves, 12 pairs of thoracic nerves, 5 pairs of lumbar and sacral nerves, and 1 pair of coccygeal nerves. With the exception of the first pair of cervical nerves, all spinal nerves leave the vertebral column from the intervertebral foramen.SPINAL CORD AND NERVES - BACK VIEWFUNCTION OF THE SPINEThe spine has four main functions:support;mobility;housing and protection; andcontrol.SupportIn human beings, the vertebral or spinal column is the principle supporting structure. The spine bears heavy loads, in particular the cervical and lumbar regions, including the weight of the upper body and any loads being lifted, lowered, carried or held.MobilityThe upper and lower limbs are attached through a series of joints to the spine. Muscles, ligaments and tendons connect parts of the spine to each other as well as to the other limbs and allow a diverse range of movements to occur. The cervical and lumbar spine areas are particularly flexible. Forward bending (flexion) and backward bending (extension) of the lumbar spine produce the greatest range of movement in the spine. Twisting (rotation) and side bending (lateral flexion) are common spinal movements during manual handling.Housing & ProtectionThe spinal column protects the spinal cord and nerves as they pass from the brain to the upper and lower limbs.ControlThe movement of each segment of the spine is controlled, actively by muscles and passively by ligaments. Without muscular support, the spine is unstable. Movement of the human body is initiated and controlled by the contraction of muscles. Ligaments and other soft tissue surround joints and prevent unwanted abnormal movements.BASIC SPINAL BIOMECHANICSFOUR TYPES OF FORCESEach spinal segment is subject to a variety of loads and forces. These include loads from the weight of body segments as well as from the weights being handled. The pattern of injury to the spine is a function of the type and size of forces present at time of injury. It is therefore important to understand these forces and the types of tissue deformations and failures that result.There are four types of forces acting on spinal structures:compression;tension;shear; andtorsional.COMPRESSIONA downward force on the vertebrae compresses the discs and causes them to bulge or shorten and widen. This is called a compressive force. As a compressive force increases so does the disc pressure until damage occurs to the disc structures. The lifting of excessively heavy loads may cause injury due to compressive forces.SPINAL COMPRESSIONSide View Front ViewThe pattern of injury to the spine is a function of the type and size of forces present at time of injury. Lifting excessively heavy loads may result in damage to the disc structures.TENSIONTensions pull apart the structures being loaded. In the spine it is the ligaments that are usually under tension, causing lengthening and narrrowing. Overstretching of the ligaments may result in tears to parts of or all of a ligament. Low back pain is usually experienced with these types of sprain injuries.TENSIONSide View Front ViewKEY POINTOverstretching may result in tearing of ligaments and consequently low back pain. SHEARShear forces involve the application of a load parallel to the vertebral surface. On forward bending of the spine there is a tendency for a vertebra to slide forwards on the one below it. Shear forces are most commonly experienced in the lumbo-sacral region and are an important mechanism in disc prolapse or herniation.SHEAR FORCES ACTINGON A VERTEBRAShear forces, as a consequence of forward bending of the spine, may result in disc prolapse or herniation.TORSIONALTwisting movements of the spine cause soft tissue strain through the generation of large muscle forces and loads on the intervertebral discs. These types of movements cause the soft tissues to be exposed to a combination of compression, shear and tension forces. TORSIONAL FORCES ACTINGON A VERTEBRATwisting movements of the spine may cause soft tissue damage.During manual handling a combination of compression, torsional, tension and shear forces occur throughout the activity.Degenerative Diseases of the Spine: Lecture on the Cervical Spine (Clinical Presentation) The cervical spine is particularly susceptible to the degenerative process, in part because of its large range of motion and the five–joint complex making up each spinal motion unit.These five joints are:the intervertebral disc,the two zygoapophyseal joints, andthe two uncovertebral joints.The degenerative process may begin in any of these joints but with time will cause secondary changes in the others. For example, the intervertebral disc may be primarily affected. As the disc narrows, the normal kinematics of that segment is altered, and the other four joints are subjected to abnormal forces leading to degenerative arthritis.Neck pain as a result of spondylosis is common. The pain usually radiates into the shoulder blade or arm. Patients may have an arm complaint, not as the result of nerve root compression. Dysphagia (rarely) can result from large anterior osteophytes.Physical examination may show a spasm of the paravertebral, trapezium, or sternomastoid muscles. This may be secondary to pain. In association with the degenerative process, this can result in a decreased range of motion. Movement of the cervical spine may precipitate or exacerbate symptoms.A thorough neurologic examination must always be done to rule out a deficit. A shoulder examination should also be done to ensure that the symptoms are indeed originating from the neck.Diagnostic Evaluation: X–RAYPlain radiographs of the cervical spine may show narrowing of the intervertebral disc space height, anterior osteophytes, arthrosis of the facet joints, and osteophytes from the uncovertebral joints (see figures below). The most commonly affected level is C5–C6, followed by the C6–C7 level.Diagnostic Evaluation: Computed TomographyComputed tomography (CT) provides good demonstration of the bony changes associated with degenerative spondylosis. Osteophytes can be evaluated both on axial and sagittal cuts. However, CT does not allow optimal evaluation of disc pathology. It can be used to show disc herniations, but these may not always be present, even with advanced degenerative changes.Diagnostic Evaluation: Magnetic Resonance ImagingMagnetic resonance imaging (MRI) is a powerful tool in the assessment of patients with symptomatic cervical spondylosis. Decreased signal intensity on T2–weighted images results from disc desiccation. T1–weighted images can show osteophytes and joint arthrosis. Because MRI is a sensitive imaging modality, pathology may be demonstrable in more than 40% of asymptomatic people over age 40 (see figure).MRI remains a morphometric test, and the clinician must correlate MRI findings with symptoms.Diagnostic Evaluation: DiscographyAs in the lumbar and thoracic spine, cervical discography (see figure) remains controversial. Although the discogram may add to the clinician's knowledge, it should not be used by itself to predicate treatment.Diagnostic Evaluation: Facet BlocksFacet blocks in the cervical spine are subject to the same criticisms as facet blocks used elsewhere. There is little scientific documentation to validate their use. Repeating the test and comparing results at different levels probably gives much more useful information than carrying out facet blocks at one or more levels at one point in time.Treatment: NonoperativeNonoperative treatment of cervical degenerative disease provides good to excellent results in over 75% of patients. A multidisciplinary approach includes:immobilization (can be achieved using a collar or braces; most beneficial during acute exacerbations of pain by reducing motion at the symptomatic levels),physical therapy, (can be useful in decreasing the secondary muscle spasm that can contribute to symptoms; this is where heat, electrical stimulation, and exercise have their maximum benefit), andmedications (include analgesics, nonsteroidal anti–inflammatories, and muscle relaxants, patients must be informed of possible complications and side effects).Patients should be reassured that nonoperative treatment can provide good long–term results.Treatment: OperativeThe surgical procedure proposed for these patients is usually fusion. In almost all instances, the preferred approach is an anterior interbody fusion. Using the anterior approach, a complete discectomy can be done, and with careful sculpting of the graft, normal intervertebral disc space height and normal lordosis can be restored. An Anterior metal plate may be utilized to help restore stability.Until diagnostic testing improves to the point where we can show irrefutably that a specific cervical spinal motion unit is giving rise to symptoms, surgery for neck pain without neurologic involvement should be discouraged.Lumbar Endoscopic Discectomy (LED)The procedure takes about one hour with the patient under local anesthesia. With the help of x-ray guidance, a smallneedle is inserted into the disc. A specially designed dilatorand cannula is inserted through the skin of the back intothe herniated disc space. The disc is visualized with anendoscope. The herniated disc is removed using mechanical instruments, including graspers and forceps. Thermalheat is applied to the disc with a Holmium yag laser andEllman's radiofrequency probe to shrink the disc further and seal it. The rest of the disc is left intact. The incision in the skin is closed with a Band-Aid®.POSTOPERATIVE COURSEMost patients feel reasonable relief of their symptoms following the procedure. Walking is permitted the same day, and the patient is discharged within three hours following the surgery. Following discharge, a physical therapy program is recommended. Postoperative pain medications are prescribed. Normal activity can usually be resumed within one to six weeks following the procedure, depending on the type of job the patient does.ADV ANTAGES OF LEDThe advantage of lumbar endoscopic discectomy is that there is no interference with muscles, joints or manipulations of the nerves in the low back area. Since the insertion of the probe into the muscle is the only wound, there is no scarring in or around the nerves. Because the procedure is performed under local anesthesia, it is much safer for the patient than procedures performed under general anesthesia. Most of the complications that may occur with open surgery are eliminated with the LED procedure.CONCLUSIONAbout 80% of all patients worldwide have experienced relief of pain with this procedure. The patients who do not obtain relief within six months of the surgery might be candidates for other surgical procedures. The advantages of LED are:Excellent success rate.Structure of the disc is still maintained.Serious complications are very rare.No hospitalization.Faster return to work and normal activities.Significant cost savings.Back & SpineThe back is the structure that supports your upper trunk, houses and protects the spinal cord, and helps you move. A healthy back is strong and pain free. The low back area bears the most stress of movement and, therefore is usually the site of most problems. The low back is made up of four parts:The discs are the cushiony material between the vertebrae. The center of the disc isjellylike, and the outer part is made up of slightly elastic woven bands. They act as shock absorbers and permit movement between the vertebrae.The vertebrae are the bony segments of the spine. The vertebrae are stacked one upon another, forming three large curves. The low back area curves forward or inward. This is called lumbar lordosis. The purpose of the vertebrae is to house and protect the spinal cord and its nerve roots and give support to the body.The sacrum is the large triangular-shaped bone at the base of the spine.The coccyx is the small bone at the end of the spine. It is also called the tailbone. Though humans are born with 33 separate vertebrae, by adulthood most only have 24. Physicians use a code to identify the vertebrae. The seven in the neck, the cervical vertebrae that support and provide movement for the head, are called C1 to C7. The thoracic vertebrae numbered T1 to T12, join with and are supported by the ribs, which protect the heart and lungs. Because they are fairly rigid, thoracic vertebrae don't permit much movement and consequently, aren't injured as often as the other vertebrae. The lumbar vertebrae, below the thoracic vertebrae and above the sacrum, are most frequently involved in back pain because they carry most of the body's stress. They are known as L1 to L5.Sandwiched between each pair of adjacent vertebrae is a spinal disc, 23 discs in all. discs are flat, round structures-about one-quarter of an inch thick-of tough outer rings of tissue that contain a soft, white jelly center. Each disc is connected to the vertebrae above and below it by flat, circular plates of cartilage. The discs not only keep the vertebrae apart, but act as shock absorbers. They compress when weight is put on them, and spring back when the weight is removed.The spinal cord, an extension of the brain, extends as far as L1, where it ends in a sheaf of nerves. Throughout the length of the spine, 31 pairs of nerves branch off from the spinal cord and serve all parts of the body, transmitting sensory messages to the brain, and messages from the brain to the muscles.The 33 vertebrae, 23 discs, 31 pairs of spinal nerves, 140 muscles that hook on to the vertebrae, plus ligaments, tendons, cartilage are all very complicated and are potential sources of back trouble.Common Spine and Disc ProblemsTorn AnnulusA sudden movement may cause a tiny tear in the tough outer ring of your disc. Nearby ligaments may also stretch. Since the annulus and ligaments contain pain fibers, a tear may cause pain.Bulging DiscRepeated movement may cause a disc to dry out and degenerate earlier than normal. As the disc wears out, the inner jelly like center begins to bulge, pressuring the outer ring causing pain.Ruptured DiscAs a disc bulges, its center (nucleus) moves closer to the outer ring (annulus). Sometimesa sudden movement will cause the annulus to rupture and the nucleus squeezes out and irritates the nerve, causing pain.ArthritisBone spurs can form at the joint between your vertebrae as discs wear out over time. Poor posture can contribute to the degeneration of your discs earlier than usual. These problems may cause a narrowing of the space where your nerve runs and cause pain. InstabilityAs a disc stretches and flattens, the vertebrae can slip back and forth, creating an unstable spine which puts pressure on the annulus causing pain.TreatmentsEvery patient is an individual who will be treated in a variety of ways. In general, conservative treatments such as medications, changes in lifestyle, and a physical therapy regimen will be tried before more invasive treatments such as injections or surgery would be considered.Ruptured Disc diseaseClassificationDemographicsClinical SymptomsMedical EvaluationTreatment optionsBack Pain Flow ChartClassificationA herniated disc may be referred to by many adjectives that can be confusing. A rupture, slip, bulge, herniation, or a fragment of the disc material( all meaning the same thing), that separates the vertebrae is displaced. Based upon the pressure this disc is placing on nerves, specific symptoms will occur such as a sharp, severe pain down the entire leg and into the foot. The inner disc nucleus breaks free of the surrounding annulus ( tough ligament surrounding the spongier nucleus) into the spinal canal.Disc anatomy with innersoft nucleus and outertough annulusThe spinal canal has limited space which is inadequate for the spinal nerve and thedisplaced herniated disc fragment. The nerves exiting the confines of the bony spine aswell as the spinal cord maybe affected.With age, injury, poor posture ordiseases such as arthritis there can bedamage to the bone or joints of thespine. As the discs in the neck and lowback wear out sudden movement orinjury such as whiplash may cause thedisc to slip or herniate.Both the lumbar and cervical spine are susceptible to this repetitivedegeneration. Vigorous activity or years of severe strain to these structures predisposes someone to a herniation.MRI scan showing acervical herniated discpushing on the spinalcordDemographicsRuptured discs occur at all ages under various circumstances. The most common years are in the 30 - 50 mage category when initial disc deterioration begins. A person who has sustained one disc herniation is statistically at increased risk for experiencing another. This may have a genetic basis and relate to the ligament strength in thespine. Re-rupture at a disc site occurs 5% of the time following removal of the first herniated fragment.Lifestyles predisposing to repetitive wear and tear on the discs as well as normal aging phenomenon make the soft disc material predisposed to rupture from with the annulus tissue. Factors involved may be related to an individuals level of physical conditioning, work or behavioral habits.Clinical SymptomsCervical herniated discs:Acute herniated or slipped disc in the neck generally causes neck pain and pain with weakness radiating down the arm. The disc causes referred pain in-between the scapula in the upper middle of the back. Headache originating at the base of the neck is common. Pressure on a nerve may cause numbness and burning or weakness in the arm and hand. Pressure on the spinal cord in the neck causing symptoms of weakness in the legs, electric shocks down the spine, numbness or poor coordination and is very concerning indicating spinal cord injury is developing. These symptoms require an urgent call to your physician, or the nurse coordinators with Northern Rockies Brain and Spine Center.Further progression of these symptoms may lead to severe impairment or even paralysis.Lumbar Herniated Discs:Typically low back pain or a long history of intermittent episodes of low back pain is associated with degeneration of the lumbar spinal discs. This predisposes to an actual herniation that compresses the spinal nerve resulting in worsened back pain with severe pain radiating down the leg. The pain may also radiated around into the groin. Sciatica is sharp pain which radiates from the low back area down through the leg, into the foot in a characteristic pattern, depending upon which of the lumbar spinal nerve affected. This pain often is described as sharp, electric shock-like, severe with and movement and worse with sitting. Often, by lying down or utilizing a lumbar support pillow, the pain is somewhat relieved. The direct compression of the nerve may produce weakness in the leg or foot resulting in stumbling and foot drop.With time much of the back pain improves but the radiating leg numbness, weakness and burning sensation persists. This may wax and wane but usually worsens with coughing, sneezing or exertion.Medical EvaluationYour doctor or chiropractor should be able to perform a detailed neurological evaluation on you if your symptoms cause you enough distress you seek out medical attention. Your provider should have expertise in spinal evaluations to assess and document your symptoms and the physical signs. This examination must include assessment of sensation, strength and reflexes in various parts of your body. Not only will this pinpoint which nerves or what parts of your spinal cord are affected, but with abnormality identified, trigger a referral to NRBS. A comprehensive flow chart allows treating providers a guideline as to the evaluation and indications when to refer to NRBS.Your doctor may order a number of studies to image and electrically diagnose the ruptured disc.X rays: A simple x-ray demonstrates bony alignment and may indicated excessive motion of two adjacent bony elements or show areas of spinal arthritis, however thex-rays do not show the disc fragment compressing a nerve. A more sophisticated x-ray such as CAT scan or MRI is needed. X-rays of the spine also rules out other causes of pain such as i.e. tumors, infections, or fractures.Computed Tomography/ Myelogram (CT Myelogram): The myelogram is an x-ray taken after a dye is injected into the spine that outlines the spinal cord and nerves. This dye provides excellent contrast during a CAT scan that will demonstrate and better define the relationship of the disc or bone spurs to the spinal cord and nerves. Herniated disc fragments or bone spurs compressing the nerves will be well visualized.Magnetic Resonance Imaging (MRI): The MRI uses a powerful magnetic field rather than x-rays to produce a detailed anatomical picture of the spine, the spinal cord, the nerve roots and the disc material. The study is noninvasive (no needles) however claustrophobic patients may have some trouble with this study.Electromyogram and Nerve Conduction Studies (EMG/NCS): These tests primarily study how the nerve and muscles are actually working together and weather a nerve compressed is physiologically not working properly. For instance the electrical flow of information might be affected and the muscle the nerve is going to may be weakened. This information allows the specialist to determine how severely the nerves are compressed.UPTreatment optionsThe initial treatment for a herniated disc is based upon the severity of thesymptoms. Studies have shown that prolonged nerve compression by a disc fragment will result in scarring of the nerve. This may result in permanent pain, numbness or weakness in the nerves muscular distribution. Many acute disc ruptures with bulging fragments seen on MRI scan may be managed without surgery. Resting the low back area, maintaining a comfortable posture and a painless level of work or recreational activities for a few days to a few weeks in combination with anti-inflammatory and muscle relaxant medication maybe very effective. As the spinal nerve inflammation quiets down, many symptoms will resolve.More potent cortisone medication maybe attempted either orally or via a spinal injection to decrease the inflammation. There are certain risks with steroid medication that you should speak to your doctor about, however short courses of these drugs is usually quite safe.Physical therapy and chiropractic manipulation also may be beneficial. under the direction of a physical therapist. Successful physical therapy treatment。