Low Back Pain (Overview)
The spine is one of the most important parts of your body. Withoutit, you could not keep yourself upright or even stand up. It givesyour body structure and support. It allows you to move about freelyand to bend with flexibility. The spine is also designed to protectyour spinal cord. The spinal cord is a column of nerves that connectsyour brain with the rest of your body, allowing you to control yourmovements. Without a spinal cord, you could not move any part ofyour body, and your organs could not function. This is why keepingyour spine healthy is vital if you want to live an active life.
The parts of your spine and how they work
What exactly is the spine? Your spine is made up of 24 small bones(vertebrae) that are stacked on top of each other to create thespinal column. Between each vertebra is a soft, gel-like cushioncalled a disc that helps absorb pressure and keeps the bones fromrubbing against each other. Each vertebra is held to the othersby groups of ligaments. Ligaments connect bones to bones; tendonsconnect muscles to bones. There are also tendons that fasten musclesto the vertebrae. The spinal column also has real joints (just likethe knee or elbow or any other joints) called facet joints. Thefacet joints link the vertebrae together and give them the flexibilityto move against each other.
Each vertebra has a hole in the center, so when they stack on topof each other they form a hollow tube that holds and protects theentire spinal cord and its nerve roots. The spinal cord itself isa large collection of nerve tissue that carries messages from yourbrain to the rest of your body. In order for your body to function,you need your nerves. The spine branches off into thirty-one pairsof nerve roots. These roots exit the spine on both sides throughspaces (neural foramina) between each vertebra.
The spine itself has three main segments: the cervical spine, the thoracic spine,and the lumbar spine. Thecervical is the upper part of the spine, made up of Steven vertebrae (bones). The thoracic isthe center portion of thespine, consisting of 12 vertebrae. The lower portion of the spine is called the lumbar spine. It is usuallymade up of five vertebrae, however, some people may have six lumbarvertebrae. Having six vertebrae does not seem to cause a problem.Below the lumbar spine is the sacrum. The sacrum is actually a groupof specialized vertebrae that connects the spine to the pelvis.During development (those nine months before birth), these vertebraegrow together (or fuse) creating one large "specialized"vertebral bone that forms the base of your spine and center of yourpelvis. The nerves that leave the spine in the sacral region controlthe bowel and bladder functions and give sensation (feeling) tothe crotch area.
The normal spine has an "S"-like curve when looking atit from the side. This allows for an even distribution of weight.The "S" curve helps a healthy spine withstand all kindsof stress. The cervical spine curves slightly inward, the thoraciccurves outward, and the lumbar curves inward. Even though the lowerportion of your spine holds most of the body's weight, each segmentrelies upon the strength of the others to function properly.
Now, let' s look at the specific parts that make up your spine:
The individual bones of the spine are the vertebrae.These are the building blocks of the spinal column. The vertebraeprotect and support the spinal cord. They also bear the majorityof the weight put upon your spine. The body of each vertebra isthe large, round portion of bone. The body of each vertebra is attachedto a bony ring. When the vertebrae are stacked one on top of theother, this ring creates a hollow tube where the spinal cord passesthrough.
The bony ring attached tothe vertebral body consists of several parts. First, the laminaeextend from the body to cover the spinal canal, which is the holein the center of the vertebrae. Second, the spinous process is thebony portion opposite the body of the vertebra. You feel this partif you run your hand down a person's back. Then there are two transverseprocesses (little bony bumps), where the back muscles attach tothe vertebrae. Finally, the pedicle is a bony projection that connectsto both sides of the lamina.
The vertebra, like all bones, has an outer shell called corticalbone that is hard and strong. The inside is made of a soft, spongytype of bone called cancellous bone.
The intervertebral discs are flat, round "cushions" thatact as shock absorbers between each vertebra in your spine. Thereis one disc between each vertebra. Each disc has a strong outerring of fibers called the annulus, and a soft, jelly-like centercalled the nucleus pulposus.
The annulus is the disc's outer layer and the strongest area ofthe disc. It also helps keep the disc's center intact. The annulusis actually a strong ligament that connects each vertebra together.
The mushy nucleus of the disc serves as the main shock absorber.The nucleus is made up of tissue that is very moist because it hashigh water content. The water content helps the disc act like a shock absorber - somewhatlike a waterbed mattress.
The facets are the "bony knobs" that meet between eachvertebra to form the facet joints that join your vertebrae together.There are two facet joints between each pair of vertebra, one oneach side. They extend and overlap each other to form a joint betweenthe neighboring vertebra facet joints. Without the facet joints,you would not have flexibility in your spine, and you could onlymove in very straight and stiff motions.
The facet joints are what are known as synovial joints. A synovial joint, such as the knee or elbow, is a structure that allowsmovement between two bones. In a synovial joint, the ends of thebones are covered with a material called articular cartilage. Thismaterial is a slick, spongy material that allows the bones to glideagainst one another without much friction.
Surrounding the facet joint is a watertight sack made of soft tissueand ligaments. This sack creates what is called the "jointcapsule". The ligaments are soft tissue structures that holdthe two sides of the facet joint together. The ligaments aroundthe facet joint combine with the synovium to form the joint capsulethat is filled with fluid (synovial fluid). This fluid lubricatesthe joint to decrease the friction, just like oil lubricates themoving parts of a machine.
The neural foramen is the opening between every two vertebrae wherethe nerve roots exit the spine. The nerve roots travel through theforamen to reach the rest of your body. There are two neural foraminabetween each pair of vertebrae - one on each side. Without the foramen,nerve signals could not travel to and from the brain to the restof your body. Without nerve signals, your body would not be ableto function.
Spinal Cord and Nerve Roots
The spinal cord is a columnof millions of nerve fibers that run through your spinal canal.It extends from the brain to the area between the end of your firstlumbar vertebra and top of your second lumbar vertebra. At the secondlumbar vertebra, the spinal cord divides into several differentgroups of fibers that form the nerves that will go to the lowerhalf of the body. For a small distance, the nerves actually travelthrough the spinal canal before exiting out the neural foramen.This collection of nerves is called the cauda equina while it isstill inside the spinal canal.
A protective membrane called the dura mater covers the spinal cord. The dura mater forms a watertightsack around the spinal cord and the spinal nerves. Inside this sack,the spinal cord is surrounded by spinal fluid.
The nerve fibers in your spinal cord branch off to form pairs ofnerve roots that travel through the small openings (foramina) betweenyour vertebrae. The nerves in each area of the spinal cord connectto specific parts of your body. This is why damage to the spinalcord can cause paralysis in certain areas and not others -- it dependson which spinal nerves are affected. The nerves of the cervicalspine go to the upper chest and arms. The nerves in your thoracicspine go to your chest and abdomen. The nerves of the lumbar spinethen reach to your legs, bowel, and bladder. These nerves coordinateand control all the body's organs and parts, and let you controlyour muscles.
The nerves also carry electricalsignals back to the brain that allow you to feel sensations. Ifyour body is being hurt in some way, your nerves signal the brainthat you have been hurt. Damage to the nerves themselves can causepain, tingling, or numbness in the area where the nerve travels.
The paraspinal muscles referto the muscles next to the spine. They support the spine and arethe motor for movement of the spine. Your joints allow flexibilityand your muscles allow mobility. There are many small muscles inthe back - each controlling some part of the total movement betweenall the vertebrae and the rest of the skeleton. These muscles canbe injured directly, such as when you have a pulled muscle or musclestrain of the back muscles. The muscles can also cause problemsindirectly, such as when the muscles are in spasm after injury toother parts of the spine.
When you experience a muscle spasm, it is because your muscle tightensup and will not relax. These spasms usually occur as a reflex -meaning that you cannot control the contraction of the muscles.When any part of the spine is injured, including: a disc, ligaments,bones, or muscles, the muscles automatically go into spasm to reducethe motion around the area. This protective mechanism is designedto protect the injured area.
When muscles are in spasm they produce too much of the chemical,lactic acid. Lactic acid is a waste product produced by the chemicalreaction inside muscle cells that must occur to allow the muscleto contract. If the muscle cell cannot relax, too much lactic acidbuilds up inside the muscles. The buildup of lactic acid causesa painful burning sensation.
The main reason that lactic acid builds up inside the muscle cellsis that when the muscles contract, the small blood vessels travelingthrough the muscles are pinched off (just like a tube pinched betweenyour thumb and finger). When the muscle relaxes, the lactic acidis eventually washed away by fresh blood flowing into the muscleas the blood vessels open up.
Back specialists sometimes look at a spinal segment to understand and explain how the whole spine works.A spinal segment is made up of two vertebrae attached together byligaments, with a soft disc separating them. The facet joints fitbetween the two vertebrae, allowing for movement, and the neuralforamen between the vertebrae allow space for the nerve roots totravel freely from the spinal cord to the body.
The spinal segment allows us to focus on the repeating parts ofthe spinal column to better understand what can go wrong with thevarious parts of the spine. Sometimes problems in the spine involveonly one spinal segment, while other times the problems involvemultiple segments.
Each spinal segment is like a well-tuned part of a machine. Allof the parts should work together to allow weight bearing, movement,and support. When all the parts are functioning properly, all spinalsegments join to make up a remarkably strong structure called thespinal column. When one segment deteriorates to the point of instability,it can lead to problems at that segment causing pain and other difficulties.
Now that you know the parts of the spine, let's look at the spineitself, which has three main segments - the lumbar, thoracic, andcervical spines.
The lowest part of the spine is called the lumbar spine. This area has five vertebrae. However, sometimes peopleare born with a sixth vertebra in the lumbar region. The base ofyour spine (sacrum) is a fusion of many bones, and when one of themforms as a vertebra rather than part of the sacrum, it is calleda transitional (or sixth) vertebra. This occurrence is not dangerousand does not appear to have any serious side effects.
The lumbar spine's shape has what is called a lordotic curve. Thelordotic shape is like a backwards "C". If you think ofthe spine as having an "S"-like shape, the lumbar regionwould be the bottom of the "S". The vertebrae in the lumbarspine area are the largest of the entire spine, so the lumbar spinalcanal is larger than in the cervical or thoracic parts of the spine.Because of its size, the lumbar spine has more space for the nervesto move about.
Low back pain is a very common complaint for a simple reason. Sincethe lumbar spine is connected to your pelvis, this is where mostof your weight bearing and body movement takes place. Typically,this is where people tend to place too much pressure, such as: liftingup a heavy box, twisting to move a heavy load, or carrying a heavyobject. Such repetitive injuries can lead to damage to the partsof the lumbar spine.
The thoracic spine is madeup of the middle 12 vertebra of the spine. These vertebrae connectto your ribs and form part of the back wall of the thorax (the ribcagearea between the neck and the diaphragm). This part of the spinehas very narrow, thin intervertebral discs, so there is much lessmovement allowed between vertebrae than in the lumbar or cervicalparts of the spine. It also has less space in the spinal canal forthe nerves. The thoracic spine's curve is called kyphotic becauseof its shape, which is a regular "C"-shaped curve withthe opening of the "C" in the front.
The cervical spine is madeup of the first Steven vertebrae in the spine. It starts just belowthe skull and ends just above the thoracic spine. The cervical spinehas a lordotic curve (a backward "C"-shape) - just likethe lumbar spine. The cervical spine is much more mobile than bothof the other spinal regions - think about all the directions andangles you can turn your neck.
Unlike the rest of the spine, there are special openings in each vertebra in the cervical spine for the arteries (blood vessels that carry blood away from the heart), as well as the spinal canal that carries the spinal cord. The arteries that run through these openings bring blood to the brain.
Two vertebrae in the cervical spine, the atlas and the axis, differ from the other vertebrae because they are designed specifically for rotation. These two vertebrae are what allow your neck to rotate in so many directions, including looking to the side.
The atlas is the first cervical vertebra - the one that sits between the skull and the rest of spine. The atlas does not have a vertebral body, but does have a thick forward (anterior) arch and a thin back (posterior) arch, with two prominent sideways masses.
The atlas sits on top of the second cervical vertebra - the axis. The axis has a bony knob called the odontoid process that sticks up through the hole in the atlas. It is this special arrangement that allows the head to turn from side to side as far as it can. Special ligaments between these two vertebrae allow a great deal of rotation to occur between the two bones.
Though the cervical spine is very flexible, it is also very much at risk for injury from strong, sudden movements, such as whiplash-type injuries. This high risk of harm is due to the limited muscle support that exists in the cervical area, and because this part of the spine has to support the weight of the head. This is a lot of weight for a small, thin set of bones and soft tissues to bear. Therefore, sudden, strong head movement can cause damage.
Pathological Concepts of the Spine
Back pain can be caused by a number of spinal conditions, and beloware descriptions of various causes of discomfort:
Mechanical versus Compressive pain
Sometimes it is useful for back specialists to understand backproblems by dividing the problems into different categories. Oneway to look at back pain is to divide problems into two large categories-- mechanical back pain and compressive back pain.
Mechanical pain is oftencalled back strain because is linked with the movement, or "themechanics" of the spine. This type of pain occurs when injuryto the spine's discs, facet joints, ligaments, or muscles resultsin inflammation. It is called mechanical pain because it relatesto the mechanics of your spine. The more you use the back, the moreit hurts. This pain can be caused by many conditions in the spine.These conditions include: fractures of the vertebra, muscle strainsin the paraspinal muscles, ligament injures in the spine, and wearand tear of the spine's joints and discs.
Compressive pain is a resultof pressure or irritation on the spinal cord, or nerves that leavethe spine. For example, if an intervertebral disc herniates (usuallycalled a ruptured disc) and pushes into the spinal canal, it cancause problems with the nerve. Usually this pressure or irritationcauses pain, numbness, and muscle weakness where the nerve travels.
Each part of the spine can cause pain. It can be helpful to understandwhich part of the spine is causing your back pain and whether thepain is from a compressive or mechanical type problem.
The term arthritis means inflammation of the joints. Arthritisof the spine usually refers to a condition where there is inflammation of the facet joints between the vertebrae. The pain that resultsfrom arthritis is usually the mechanical type of back pain. If bonespurs develop due to the arthritis and begin rubbing on the spinalnerves, there can also be compressive type pain produced as well.There are two types of arthritis: systemic inflammatory arthritis,and wear-and-tear arthritis. A systemic type of arthritis is actuallya disease process that affects all the joints of the body - suchas rheumatoid arthritis. Many arthritis type diseases affect theconnective tissues of the body. All of these diseases cause inflammationof the joint tissues and destruction of the joints. The joints ofthe spine may be involved in systemic types of arthritis becausethe facet joints are made up of the same tissues as any other joint.Therefore, diseases that attack joint tissues also attack the facetjoints.
Wear-and-tear arthritis, or osteoarthritis, can result from manythings. It can come from a single injury that damages the joint.It can also result from a lifetime of overuse of different jointsthat damage the joint a little bit at a time. Doctors are now beginningto realize that osteoarthritis also runs in families. Somethingabout the genetic makeup of different individuals makes them moreprone to develop osteoarthritis of various joints.
Osteoarthritis is caused by a permanent breakdown of the articularcartilage inside the affected joint. Articular cartilage is thematerial inside the joint that cushions the bones of the jointsfrom impact and allows smooth, gliding motions. Because damagedcartilage cannot repair itself, it begins to fray, making it lessflexible and more prone to injury. Over time, the cartilage canwear away completely, causing the bony surfaces of the joint torub directly against each other. Eventually the joint becomes wornaway and bone spurs develop around the joint.
Facet Joint Syndrome
Sometimes the facet joints are the main cause of back pain. Inmany cases, the facet joints are at least part of what is causingyour back pain. When your doctor thinks the facet joints are a majorsource of your pain, he may use the term "facet joint syndrome".Facet joint degeneration, or osteoarthritis, can be caused by acombination of aging, pressure overload of the facet joints, andinjury.
Pressure overload on the facet joints is probably caused by degenerationof the intervertebral disc. As the discs degenerate, they wear downand begin to collapse. This narrows the space between each vertebra.This narrowing of the space between each vertebra affects the waythe facet joints line up. When this occurs, it places too much pressureon the articular cartilage surface of the facet joint. The excessivepressure leads to damage of the articular surface and eventuallythe cartilage begins to wear away.
When facet joint arthritis gets bad enough, the cartilage and fluidthat lubricate the facet joints are eventually destroyed as well,leaving bone rubbing on bone. Bone spurs begin to form around thefacet joints. When bone spurs develop, they can take up space inthe foramen (the opening between vertebrae where nerve roots exitthe spine) and press into nerve roots. As the bone spurs begin togrow larger, they can eventually extend into the spinal canal itself.This leads to narrowing of the spinal canal (spinal stenosis).
Pinched Nerve (Radiculopathy)
Radiculopathy is the medicalterm used to describe a "pinched nerve" in the spine.A radiculopathy occurs when a nerve is irritated by something thatis either rubbing on the nerve or pressing on the nerve. In somecases, such as a herniated (or ruptured) disc, there may also bea chemical reaction irritating the nerve. Chemicals released fromthe inside of the disc seem to irritate nerve tissue, causing painand inflammation of the nerve.
Abnormal pressure or irritation on a particular nerve causes severalproblems. First, there is numbness in the area where the nerve usuallyprovides sensation, or feeling. For example, if the nerve usuallyends in the side of the foot and supplies sensation to that area,it will have decreased feeling, and often pain.
The key to understanding a radiculopathy is understanding thatyour brain cannot tell where the problem really is. While the irritationor pressure on the nerve may be in your back, your brain thinksthe pain is coming from your foot. In addition, the muscles thatthe nerve usually controls will not work right. You will usuallyhave weakness in the muscles, and the reflexes controlled by themuscles will not work. This is why doctors always check reflexes.The body has a pretty standard wiring diagram. By determining whichreflexes are not working, the doctor can usually tell which nerveis involved with the problem.
Things that can cause a radiculopathy include: herniated discs,bone spurs, tumors that are growing into the nerves, and fracturesthat put pressure on the nerves.
The term sciatica refers to a certain type of radiculopathy thatoccurs in the leg. It is called sciatica because it describes theradiculopathy that occurs when one or more of the nerves that makeup the large sciatic nerve are irritated or pinched. Therefore,sciatica is not any different than a pinched nerve anywhere elsein the spine. It simply has its own name because it is fairly common.It also occurs in the lumbar spine, the most common site of spinalnerve irritation.
Sciatica is used to describe the pain that travels from the sciatic nerve in the lumbar region intoyour buttocks, back of the thighs, and sometimes calf and foot.The pain is typically caused by irritation of the nerve roots thatjoin outside the spine to make up the sciatic nerve. Conditionsthat can cause sciatica are: herniated discs, bone spurs, canceroustumors that are growing into the nerves, and fractures that putpressure on the nerves.
Spinal Cord Pressure
We have seen how individual nerve roots are affected by pressureand irritation -- but what about the spinal cord itself? Pressure on the spinal cord typically results from a condition calledstenosis. Stenosis means narrowing of an opening or tube - in thiscase the spinal canal.
Spinal stenosis is a termcommonly used to describe a narrowing of a portion of the spinalcanal. Stenosis can occur in all areas of the spine, but it is mostcommon in the cervical and lumbar spine. There can often be narrowingof most of the lumbar spinal canal and of several segments of thecervical spine. Each behaves somewhat differently.
Although there is some space between the spinal cord and the edgesof the spinal canal, this space can be reduced by many conditions.Bone and tough ligaments surround the spinal canal. This tube cannotexpand if the spinal cord or nerves require more space. If anythingbegins to narrow the spinal canal, the risk of irritation and injuryof the spinal cord or nerves increases. Some conditions that canlead to narrowing of the spinal canal include: infection, tumors,trauma, herniated disc, arthritis, thickening of ligaments, growthof bone spurs, and disc degeneration.
Spinal stenosis usually occurs in older people after years of wearand tear or degeneration of the spine. This wear and tear resultsin changes in the structures around the spinal canal, such as thickeningof the large ligaments that connect the vertebra together, bonespurs around the facet joints and disc space, and bulging of thediscs themselves. All of these changes push into the spinal canal,making the tube of the spinal canal smaller. Eventually, there isnot enough space in the spinal canal for the nerve to comfortablyfit without causing too much pressure. Stenosis can also developbecause of injuries, infections, or tumors. Some people even havea narrow spinal canal from birth, and this abnormality leads tosymptoms of stenosis.
The narrowing of the spinal canal can lead to irritation of thenerves of the spine. This can cause pain and problems with the nervesnot working right. The lack of space can also cause the supply ofblood and oxygen to the spinal cord to be reduced. When the spineneeds more blood flow during increased activity, the blood vesselsmay not be able to swell to get more blood to the spine. This canlead to numbness and pain in the affected nerves. The nerves alsolose some of their mobility when the space available to them isreduced. This leads to irritation and inflammation of the nerves.
Other symptoms of spinal stenosis include: a sensation of heaviness,weakness, and pain when walking or standing for a long period. Withrest, these symptoms often disappear. These symptoms occur becausethe nerve roots are being tampered with, upsetting the normal signalsthat travel from the brain to the body. Irritation of the nervesin the spinal canal is worse when with standing or walking becauseof the mechanical compression and stretching of the nerves.
Segmental Spinal Stenosis
Segmental spinal stenosis is a narrowing of the spinal canal in a segmented, or specific,area. Sometimes the stenosis only occurs in a small area of thespine, such as an area where there is a combination of bone spursfrom the facet joints in the back of the spinal canal and a bulgingdisc in the front of the spinal canal. This results in narrowingof that one area of the spine.
Segmental stenosis can occur in both older and younger people.The symptoms of segmental spinal stenosis are similar to other conditionsof the spine. Segmental spinal stenosis can affect the nerve rootsthat leave the spine at the area where the segmental stenosis occurs.These nerves can become irritated, causing pain, numbness, and weaknessin the area the nerve travels. There can also be pressure on therest of the spinal nerves that must travel through the narrowedarea of the spinal canal.
Discogenic Pain is a termback specialists use when referring to pain caused by a damagedintervertebral disc. A degenerating disc may cause pain of the mechanicaltype. As the disc begins to degenerate, there is some evidence thatthe disc itself becomes painful. Movements that place stress onthe disc can result in back pain that appears to come from the disc.This is similar to any other body part that is injured, such asa broken bone, or even a cut in the skin. When these types of injuriesare held still, there is no pain. However, if you move a brokenbone, or the skin around a cut, it causes pain.
Discogenic pain usually causes pain felt in the lower back. Itmay also feel like the pain is coming from your buttock areas andeven down into the upper thighs. The experience of feeling painin an area away from the real spot causing the pain is common inmany areas of the body, not just the spine. Examples include: aperson who has gallstones may feel the pain in their shoulder; ora person experiencing a heart attack may feel pain in the left arm.This is called radiation of the pain. It is very common for painproduced by spine problems, such as disc problems, to be felt indifferent areas of the body, including the back itself.
Bulging discs are fairlycommon in both young adults and older people. They are not causefor panic. In fact, abnormalities that show up on MRIs, such asbulging or protruding discs, are seen at high rates in patientsboth with and without back pain. Most likely, some discs begin tobulge as a part of the aging process, and the degeneration processof the intervertebral disc. A bulging disc is not necessarily asign that anything serious is happening to your spine.
A bulging disc becomes important when it bulges enough to causenarrowing of the spinal canal. If there are bone spurs present onthe facet joints behind the bulging disc, the combination may causenarrowing of the spinal canal in that area. This is sometimes referredto as segmental spinal stenosis.
Click here to view animation.A herniated disc occurswhen the intervertebral disc's outer fibers (the annulus) are damagedand the soft inner material of the nucleus pulposus ruptures outof its normal space. If the annulus tears near the spinal canal,the nucleus pulposus material can push into the spinal canal. Thiscan cause too much pressure on the spinal cord and nerve roots.There is also some evidence that the nucleus pulposus material causesa chemical irritation of the nerve roots. Both the pressure on thenerve root and the chemical irritation can lead to problems withhow the nerve root works. The combination of the two can cause pain,weakness, and/or numbness in the area of the body to which the nervetravels. For this reason, a herniated disc usually causes pain ofthe compressive type. Sometimes a herniated disc is referred toas "slipped disc", though the disc does not actually slip.
Herniated discs are common in the lumbar spine because of all thepressure it supports. A herniated lumbar disc often produces sciatica.This is a condition where the lower back pain and numbness radiatesdown the back of the leg, side of the calf, and possibly into theside of the foot. You may not necessarily have much back pain. Theexact area where you will feel numbness depends on the nerve rootthat is affected; the numbness could be in the inner ankle, bigtoe, heel, outer ankle, outer leg, or a combination of them. Yourdoctor can use this information to get an idea which nerve is affected.
Pressure on the nerve root can cause the parts of the nerve thatcontrol the muscles not to work properly. This can result in weaknessof some muscles and may change the reflexes in certain areas. Again,your doctor can use this information to try to determine which nerveis involved.
The same is true for the neck. A problem stemming from the neckmay result in pain that is perceived in the arm or hand. However,a herniated disc is much less common in the thoracic spine. Thisis likely because the discs are much thinner and there is less materialin the nucleus pulposus to rupture into the spinal canal. HOWEVER,if a herniated disc does occur in the thoracic spine, it can bemuch more serious than in the lumbar spine. The thoracic spine hasvery little extra room in the spinal canal. In addition, a herniateddisc in the thoracic spine puts pressure on the spinal cord - notjust a few nerve roots. Too much pressure on the spinal cord froma herniated thoracic disc can lead to total paralysis from the waistdown.
Just because a disc has herniated does not necessarily mean thatyou will need to undergo surgery. In most cases, a herniated disccan be treated without surgery. The treatment of a herniated discdepends on the symptoms. It also depends on whether the symptomsare getting steadily worse -- or whether they are getting better.If the symptoms are getting steadily worse, your doctor may be morelikely to suggest surgery. If the symptoms are getting better, yourdoctor may suggest watching and waiting to see if the symptoms goaway. In many cases, the initial problems due to a herniated disccompletely resolve over several weeks to months.
In rare cases, a herniated disc in the lumbar spine area can beso large that it fills the entire spinal canal in the area whereit ruptures. When the spinal canal fills with disc material, itmay place a great amount of pressure on the nerves. If this occursin the lower spine, it can lead to a condition called "caudaequina syndrome". This problem can lead to permanent paralysisof the muscles that control your bowels and bladder. If you losecontrol over your bladder or bowels, you should contact your healthcare provider immediately. These symptoms require immediate medicalattention.
Degeneration of the Intervertebral Disc
The process of degeneration of the intervertebral disc causes many problems in the spine.Everything you do during the day - once you stand upright - beginsto test the spine's ability to support your body weight. Over time,these repeated daily stresses and minor injuries can add up andbegin to affect the discs in your spine. Minor injuries to a discmay occur and not cause pain at the time. However, as they add up,the disc eventually begins to suffer from the wear and tear - itbegins to degenerate.
There is an intervertebral disc between each of your vertebra.The intervertebral discs are designed to absorb pressure and keepthe spine flexible by acting as cushions during body movement. Thediscs work similarly to shock absorbers. They are like cushionsin running shoes; without them, a jogger would feel every poundon the pavement, and the feet would soon tire out. Without the cushioneffect of the discs, the vertebrae in your spine would probablyfracture or break. Bones cannot sustain high stress repeatedly withoutbeing cushioned.
A healthy intervertebral disc has a great deal of water in thenucleus pulposus - the center portion of the disc. The water contentgives the nucleus a spongy quality and allows it to absorb spinalstress. Excessive pressure or injuries to the disc can cause theinjury to the annulus - the outer ring of tough ligament materialthat holds the vertebrae together. Generally, the annulus is thefirst portion of the disc that seems to be injured. Small tearsshow up as in the ligament material of the annulus. These tearsheal by scar tissue. The scar tissue is not as strong as normalligament tissue. Over time as more scar tissue forms, the annulusbecomes weaker. Eventually this can lead to damage of the nucleuspulposus. The nucleus begins to lose its water content due to thedamage - it begins to dry up.
Because of water loss, the discs lose some of their ability toact as a cushion. This can lead to even more stress on the annulusand still more tears as the cycle repeats itself. As the nucleusloses its water content it collapses, allowing the two vertebraeabove and below to move closer to one another. This results in anarrowing of the disc space between the two vertebrae. As this shiftoccurs, the facet joints located at the back of the spine have toshift. This shift changes the way the facet joints work togetherand can cause problems in the facet joints as well.
Bone spurs, sometimes called osteophytes, may also form aroundthe disc space. These bones spurs can also form around the facetjoints. This is thought to be due to the body's response to tryto stop the excess motion at the spinal segment. The bone spurscan become a problem if they begin to grow into the spinal canaland press into your spinal cord and nerves. This condition is calledspinal stenosis.
Segmental Instability of the Spine
Each spinal segment is like a well-tuned part of a machine. Allof the parts should work together to allow weight bearing, movement,and support. A spinal segment is composed of two vertebrae attachedtogether by ligaments, with a soft disc separating them. The facetjoints fit between the two vertebrae, allowing for movement, andthe foramen between the vertebrae allows space for the nerve rootsto travel freely from the spinal cord to the body. When all theparts are functioning properly, the spinal segments join to makeup a remarkably strong structure called the spine. When one segmentdeteriorates to the point of instability, it can lead to localizedpain and difficulties.
Segmental instability occurswhen there is too much movement between two vertebrae. The excessmovement of the vertebrae can cause pinching or irritation of nerveroots. It can also cause too much pressure on the facet joints,leading to inflammation of facet joints. It also may cause musclespasms as the paraspinal muscles try to stop the spinal segmentfrom moving too much. The instability eventually results in fasterdegeneration of the spine in this area.
It is hard to determine which problem comes first in segmentalinstability. In some cases, degeneration of the disc begins theprocess. Once the disc is no longer able to function normally, thedegeneration process of ALL parts of the spinal segment begins.As the disc continues to degenerate, the facet joints become arthritic,bone spurs form around the joints, and the segmental instabilitygets worse. This cycle continues.
Before a health care professional can diagnose your condition anddesign a treatment plan, a complete history and physical examinationare necessary. There are so many possible internal causes of pain;it is important to determine what is and is not causing the problem.After the physician has a better idea of what is attributing toyour discomfort, diagnostic tests of some sort may be recommended.
First, you will be asked for a complete physical history of yourcondition. This may begin by filling out a written form that asksyou a number of questions relating to your pain. The more informationyou share with the provider, the easier your problem will be todiagnose. Your physical history is important because it helps yourdoctor understand: when the pain began, anything that could havecaused an injury, your lifestyle, physical factors that might becausing the pain, and your family history of similar problems. Afterreading through your written history, your physician will ask morequestions that relate to the information you have given. Some typicalquestions include:
- When did the pain begin?
- Was there an injury that could be related to the pain?
- Where do you feel the pain? What is the intensity?
- Does the pain radiate to other parts of the body?
- What factors make the pain feel better or worse?
- Have you had problems with your bladder or bowels?
- Is there a history of osteoporosis in your family?
After taking your history, the physician will give you a physicalexamination. This allows the doctor to rule out possible causesof pain and try to determine the source of your problem. The areasof your body that will be examined depend upon where you are experiencingpain - neck, lower back, arms, legs, etc. The following are someof the things that are checked in a typical exam:
- Motion of Spine and Neck - Is there pain when you twist, bend, or move? If so, where? Have you lost some flexibility?
- Weakness - Your muscles will be tested for strength. You might be asked to try to push or lift your arm, hand, or leg when light resistance is put against them
- Pain - The doctor may try to determine if you have tenderness of certain areas
- Sensory Changes - Can you feel certain sensations in specific areas of the feet or hands?
- Reflex Changes - Your tendon reflexes might be tested, such as under the kneecap and under the Achilles tendon on your ankle
- Motor Skills - You might be asked to do a toe or heel walk
- Special Signs - The physician will also check for any "red flags" that could indicate something other than spinal/vertebrae problems. Some signs of other problems include tenderness in certain areas, a fever, an abnormal pulse, chronic steroid use (leads to loss of bone mass), or rapid weight loss
You may be asked to take a variety of diagnostic tests. The testsare chosen based upon what your physician suspects is the causeof your pain. These are the most common diagnostic tests:
An X-ray is a painless process that uses radioactive materialsto take pictures of bone. If your doctor suspects vertebral degeneration,X-rays can be used to verify: a decrease in the height of spacebetween discs, bone spurs, nerve bundle sclerosis (hardening), facethypertrophy (enlargement), and instability during flexion or extensionof limbs. X-rays show bones, but not much soft tissue, so they willdefinitely be used if fractures, infections, or tumors are suspected.
During X-rays, you will be asked to lie very still on a table andhold certain positions while photographs are taken of your spine.
MRI Scan (Magnetic Resonance Imaging)
The MRI scan is a fairly new test that does not use radiation.By using magnetic and radio waves, the MRI creates computer-generatedimages. The MRI is able to cut through multiple layers of the spineand show any abnormality of soft tissues, such as nerves and ligaments.The test also can be used to verify: loss of water in a disc, facetjoint hypertrophy (enlargement), stenosis (narrowing of spinal canal),or a herniated disc (protrusion or rupture of the intervertebraldisc).
During an MRI test, you lie on a table that slides into a machinewith a large, round tunnel. The machine's scanner then takes manypictures that are watched and monitored by a technician. Some newerMRI machines, called Open MRIs, are likely to be more comfortablefor patients who experience claustrophobia. The procedure takes30-60 minutes.
CAT Scans (Computer Assisted Tomography)
The CAT scan is an X-ray test that is similar to both the MRI anda regular X-ray, because it can show both bones and soft tissues.CAT scans are also able to produce X-ray "slices" takenof the spine, allowing each section to be examined separately. Thescan forms a set of cross-sectional images that can show disc problemsand degeneration of bones, such as bone spur formation or facethypertrophy (enlargement). CAT scan images are not as clear as eitherX-rays or an MRI. To make the soft tissues easier to see, the CATscan is often combined with a myelogram.
Like an MRI, with a CAT scan you will lie on a table that slidesinto a scanner. The scanner is essentially an X-ray tube that rotatesin a circle taking many pictures. The procedure takes 30-60 minutes.
A myelogram is an older test that is used to examine the spinalcanal and spinal cord. During this test, a special X-ray dye isplaced into the spinal sac. This will require a spinal tap to beperformed by your doctor. This procedure is performed by insertinga small needle in the lower back and into the spinal canal. Throughthe needle, dye is injected which mixes with the spinal fluid.
The dye shows up on X-rays. Therefore, when the X-ray is taken,the dye outlines the spinal cord and nerve roots so that disc andbone spur problems can be seen.
To conduct the myelogram, the patient lies on a tilting table.As the table tilts, the movement of the dye shows the outline ofthe spinal sac. X-rays are taken as the patient is titled to showthe flow of the dye through the spinal region, helping doctors determineif there is any unusual indentation or an abnormal shape. This indentationcould be from a herniated or bulging disc, lesions, tumors, or injuryto the spinal nerve roots. The myelogram is often combined witha CAT scan to get a better view of the spine in cross section.
In many cases, the MRI has replaced both the myelogram and theCAT scan. Sometimes the myelogram still shows the problem betterthan the MRI, but today it is used less frequently than the MRI.
A bone scan can be used to locate any problem areas of the spine.The bone scan works by injecting a radioactive chemical, sometimescalled a "tracer", into the bloodstream through an IV.The chemical will attach itself to areas of bone that are undergoingrapid changes. Over a period of several hours, a lot of the traceraccumulates in the problem area(s).
A special camera is then used to take pictures of the skeleton.The chemical tracer is radioactive, and therefore sends out radiationthat can be captured by the camera. Specific problem areas showup on the film as dark spots or "hotspots".
A bone scan is very useful when it is unclear exactly where theproblem is in the skeleton. The ability to take a picture that lightsup the area where the problem seems to be coming from allows thedoctor to pinpoint where to look next. After locating the problemareas, other tests can be done to show more aspects of those specificspots. The bone scan can identify problem areas such as bone tumorsand compression fractures. A bone scan can also be used to determinebone density and the bone-thinning condition of osteoporosis.
EMG/SSP (Electrodiagnostic Study)
An electromyogram (EMG) is a test that looks at the function ofthe nerve roots leaving the spine. The test is done by insertingtiny electrodes into the muscles of the lower extremity. By lookingfor abnormal electrical signals in the muscles, the EMG can showif a nerve is being irritated or pinched as it leaves the spine.Think of how you test the wiring on a lamp. If you place a workingbulb into the lamp, and the bulb lights up, you assume that thewiring is okay. However, what if the bulb does not light up? Youcan safely assume that something is probably wrong with the wiring,like the lamp is unplugged, or a short circuit has occurred. Byusing the muscles like the light bulb in the lamp, the EMG is ableto determine the condition of the nerves that supply those muscles,just like the wiring on the lamp. If the EMG machine finds thatthe muscles (the light bulb) are not working properly, the doctorcan assume that the nerves (the wiring) must be getting pinchedsomewhere.
Facet Joint Block
Like any joint in the body, facet joints can cause pain if theyare irritated or inflamed. The facet joint block is a procedurewhere a local anesthetic medication (such as lidocaine or Novocain)is injected into the facet joint. This same type of medication isused by a dentist to numb your jaw, or a doctor to sew up a laceration.The lidocaine actually numbs the area around the facet joint. Ifall your pain goes away, the doctor can assume that the facet jointis a problem.
Further lab tests may be done to check for problems that are notrelated to deterioration of the spine. Other testing can help determinethe presence of serious problems such as: an infection, arthritis,cancer, or an aortic aneurysm. The most frequent lab test is bloodsampling.
A spinal tap is done inorder to get a sample of the cerebrospinal fluid that surroundsthe spinal cord. The fluid is usually very clear. It contains proteins,sugar, and other substances that can be found in blood. It typicallydoes not contain red blood cells or many white blood cells. A spinaltap checks the pressure and content of the fluid. Signals that theremay be problems include: evidence of bleeding, an increase in whiteblood cells (infection fighting cells, dead cells are "pus"),an increase in protein level, or inflammation. This could mean infection,tumors, or a hemorrhage around the brain or spinal cord. To obtainthe fluid sample, a needle will be inserted into the spinal canalin the lumbar region.
A discogram is an X-rayexamination of the intervertebral discs. This test is used to determinewhich disc(s) are damaged and if surgery is necessary. The testis performed by injecting dye into the center of the injured disc(s).The dye makes the disc clearly visible on X-ray film and a fluoroscopescreen. This test is better than an X-ray or myelogram for determiningif there is a disc problem. The dye helps the physician make anaccurate diagnosis. A simple X-ray shows only the vertebrae, anda myelogram is best for assessing the spinal canal.
With a discogram, you will be given medication to help you relax,then a local anesthetic. The procedure usually lasts about 40 minutes.
On your first visit to a back specialist, the initial decisionthat must be made is exactly how serious the problem is. Some problemsneed immediate attention - possibly even surgery. However, the vastmajority of back problems do not require surgery. Once the mostlikely cause of your problem has been determined (your diagnosishas been made), you and your health care provider can decide on atreatment plan.
A variety of treatment options exist for different types of backpain, and in most cases, simple therapies such as mild pain medicationsand rest, are effective in relieving the immediate pain. The overallgoal of treatment is: to make you comfortable as quickly as possible,to design a program to reduce further degeneration, and to get youback to normal activity as soon as possible. The more you know abouthow your back works and what you can do to prevent further injury,the more effective your program will be. Below are descriptionsof the most common forms of treatment, along with a brief explanationof what each is designed to do.
Back specialists often use the term "conservative treatment"to describe any treatment option that does not involve surgery.Therefore, you may hear, or read in your records, that your provideris recommending a course of conservative treatment for your backproblem. Treatment for your back problem may be as simple as reassuringyou that it is not a serious problem and doing nothing but watchingand waiting. However, usually anyone who has a back problem thatbecomes symptomatic should consider some preventive measures. Thisusually means that you should learn more about how to protect yourback and consider beginning exercises to strengthen your back. Theseexercises can be quick and easy to do, do not require any specialequipment, and can help prevent problems later.
A variety of treatment options exist for back pain that is theresult of degeneration (wear and tear) on the parts of the spine.In most cases, simple therapies such as mild pain medications andrest are effective. The goal of treatment is to make you feel comfortable,reduce further degeneration, and get you back to normal activityas quickly as possible. As a last resort, and only if all otherconservative treatments fail, surgery might be considered.
Immediately after a back injury, rest is often all your back needsto feel better. Rest is used to take the pressure off your spineand the muscles around your spine. You should rest in a comfortableposition on a firm mattress. Placing a pillow under your knees canalso help relieve pain. Do not stay in bed for several days! Bedrest for more than two or three days can weaken the back muscles,making the problem worse instead of better. Even though you maystill feel some pain, a gradual return to normal activities is goodfor your muscles. In most cases of sudden back pain, the sooneryou start moving again, the sooner your back pain will resolve.If you are sent to see a physical therapist, the first few daysmay be spent educating you on ways to take stress off the back whileremaining as active as possible. Short periods of rest combinedwith brief exercises designed to reduce your pain may be suggested.
Mild pain medications can reduce inflammation and pain when takenproperly. Medications will not stop degeneration, but they willhelp with pain control.
Aspirin compounds are over-the-counter pain relievers that canhelp relieve minor pain and back ache. The main potential side effectof aspirin is the development of stomach problems, particularlyulcers with or without bleeding. You should not take aspirin ifyou are pregnant. In fact, you should not take any medication unlessyou have discussed the medication with your obstetrician.
NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)
NSAIDs include over-the-counter pain relievers such as ibuprofenor naproxen. These medications once were only available by prescription.NSAIDs are very effective in relieving the pain associated withmuscle strain and inflammation. They block the inflammatory responsein joints. However, be aware that NSAIDs can decrease renal functionif you are an older patient. Excessive use can lead to kidney problems.Again, do not take them if you are pregnant.
Non-narcotic Prescription Pain Medication
Non-narcotic analgesics (the term analgesics means "pain relievers")address pain at the point of injury. Analgesics are ideal in thetreatment of mild to moderate chronic pain. Tylenol and aspirinare the most widely used over-the-counter analgesics. Medicationsthat are analgesics and require a prescription from the doctor includeNSAIDs such as: carprofen, fenoprofen, ketoprofen, and sulindac.To reduce any side effects: do not lie down for 15 to 30 minutesafter taking medication, avoid direct sunlight, wear protectiveclothing, and sun block. Avoid using these medications if you arepregnant, have recurrent ulcers, or liver problems.
Narcotic Pain Medications
If you experience severe pain, your health provider might prescribea narcotic pain medication such as codeine or morphine. Narcoticsrelieve pain by acting as a numbing anesthetic to the central nervoussystem. The strength and length of pain relief differs for eachdrug. Narcotics can cause related side effects such as nausea, vomiting,constipation, and sedation or drowsiness. These side effects arepredictable and can often be prevented. Common preventative measuresinclude: not taking sleeping aids or antidepressants in conjunctionwith narcotics, avoiding alcohol, increasing fluid intake, eatinga high fiber diet, and using a fiber laxative or stool softenerto treat constipation. Remember that narcotics can be addictiveif used excessively or improperly.
If you are having muscle spasms, muscle relaxants can help relievepain, but they are only shown to be marginally effective. They alsohave a significant risk of drowsiness and depression. Long-termuse is not suggested; only three to four days is typically recommended.
Back pain is actually a common symptom of depression and couldbe an indicator of its presence. Antidepressants can relieve emotionalstress that leads to symptoms of back pain. An important fact tonote - it seems that the same chemical reactions in the nerve cellsthat trigger depression also control the pain pathways in the brain.Some Antidepressant medications seem to reduce pain, probably becausethey affect this chemical reaction in the nerve cells. Some types of antidepressants also make rather good sleep.