Low Back Pain and Herniated Disk

Definition

Discomfort, aching or stiffness concentrated in the lower back, resulting in the impairment of physical activity.

Description

At least once in their lives, about 80 percent of all Americans will experience low back pain that can range from a dull, annoying ache to absolute agony. On any given day, over 6.5 million Americans are under some sort of treatment for low back pain.

Low back pain is one of the most common ailments in the U.S., and it is preceded only by colds and the flu for time lost from work. Low back pain has been described as a 20th century epidemic, the nemesis of medicine and an albatross of industry. When all the costs connected with it are added up - job absenteeism, medical and legal fees, social security disability payments, workmen's compensation and long-term disability insurance - the bill to business, industry and the government has been estimated to total over 16 billion dollars each year.

Those most often affected are young adults in their most productive years, between the ages of 17 and 45.

Causes and Risk Factors

It is believed that many cases of low back pain are due to stresses on the muscles and ligaments that support the spine. Our sedentary jobs and lifestyle make us vulnerable to this type of damage. Too much time in front of the TV, not enough exercise, poor posture and poor sleeping habits (including sleeping on the stomach) weaken muscles.

Weak muscles, especially abdominal muscles, cannot support the spine properly. Obesity, which afflicts over 35 million Americans, is another factor - it increases both the weight on the spine and the pressure on disks.

When the body is in poor shape, it does not take much to overstretch (strain) a muscle or put a small tear (sprain) in a ligament. The medical word for backaches arising from either of these conditions is lumbosacral strain (or sprain).

Sometimes, a sudden twist or fall can bring on muscle spasms - sudden, involuntary contractions that can be excruciatingly painful. A spasm immobilizes the muscles over the injured area, possibly acting as a kind of splint to protect muscles or joints from further damage.

Jobs that involve bending, twisting or lifting heavy objects repeatedly, especially when the loads are beyond a worker's strength, are no better for the back than sedentary jobs.

Certain occupations, such as truck driving or nursing, are particularly hard on the back. The truck driver must contend with sitting for long periods of time (worse for the back than standing), the vibration of the vehicle and lifting and straining at the end of the day, when muscles are fatigued and more susceptible to damage. Football, gymnastics and other strenuous sports can also damage the lower back.

Symptoms

Slipped Disks

Because many people are familiar with the term "slipped" disk, this problem is mistakenly believed to be the chief cause of most low back pain, but in fact, slipped disks are responsible for only 5 to 10 percent of the cases. Actually, the term itself is inaccurate, because the disk does not slip at all; it bulges (herniates out) between two vertebrae.

In some cases, the tough tissues that contain the disk are weakened by injuries that allow the soft gel-like center to protrude. If the protrusion presses on a nerve root, pinching it against the bone, the result is pain in the area of the body served by that nerve. Doctors can tell which disk in the lower back is causing the problem from the part of the body that is affected, usually the legs.

The protruded part of the disk does not slip back into place. Scar tissue forms around the protrusion and walls it in. If the outer tissues continue to be stressed, they will weaken further. In time, the slightest activity - a sneeze or a cough - may cause the disk to burst through its capsule (or rupture). Pain can be severe.

To make matters worse, if a nerve root is irritated in any one place, it tends to become irritable along the entire length of the nerve. A ruptured disk that presses on nerve roots in the low back (lower lumbar or high sacral areas) causes sciatica, a condition in which sharp, shooting pains begin in the buttock and run down the back of the thigh, on to the inside of the leg and down to the foot. Tingling, numbness and weakness may follow. If the pressure on the nerve root is not relieved, the leg muscles will eventually waste away, or atrophy.

Diagnosis

In addition to a complete medical history and physical exam, your physician may order blood tests or x-rays.

Treatment

For the majority of cases, localized back pain comes from the straining of muscles and ligaments. Relatively limited protrusion of a disk that impinges on nerve roots is a much less frequent cause, though not rare.

In either case, the first things to do are:

• Lie down on a bed or couch in any comfortable position or positions.

• Use anti-inflammatory medication (aspirin, ibuprofen or prescription drugs).

• Apply heat or cold, whichever feels better.

This is called "conservative" therapy - no surgical procedure is performed.

Conservative therapy is not merely symptomatic; these measures have specific benefits. First, lying on one's side or back with the hips and knees somewhat flexed relieves forces that a vertical position, or even sitting, imposes on the disks, ligaments and muscles of the spine.

Second, aspirin and its relatives are anti-inflammatory drugs. Not only do they relieve pain - thus reduce one of the triggers of reflex muscle spasm - they also reduce inflammation in injured tissues. To get the anti-inflammatory effect requires more than the usual painkilling dose; at least two tablets every four hours (but not during the hours of sleep) is typically required.

Finally, cold applied immediately after an injury helps to prevent swelling and pain. Later, heat appears to reduce swelling and promote recovery.

Surgery

The vast majority of people with low-back pain, even those with disk disease, will not need surgery. In general, surgery is only useful for problems in the four broad categories: (1) disk displacement (a protruded or "slipped" disk), (2) painful (and abnormal) motion of one vertebra in relation to another, (3) narrowing of the spinal canal from overgrowth of bone (spinal stenosis), or (4) some cases in which misalignment of one vertebra on another leads to chronic and/or severe pain.

If there is clear evidence in the physical examination that function of a nerve root is impaired, and if one of the diagnostic imaging techniques confirms an anatomical abnormality accounting for pressure on that root, surgery is worth considering.

If there are signs of rapidly progressive nerve damage - increasing weakness in a leg, loss of bladder or bowel function - surgery moves high on the list of options. It also must be considered when pain is unremitting or getting worse.

Both criteria for surgery should be met; neurological abnormalities and pressure on the implicated nerve root (as shown by an appropriate imaging technique). Bear in mind that diagnostic images often show evidence of spinal abnormalities in people without symptoms. Unless there are signs of nerve compression, it is quite possible that the pain is coming from another source.

Evidence of nerve compression is not an automatic reason to operate. Signs of compression often subside after a period of controlled activity. As a rule, all non-surgical approaches should be exhausted first, providing that delaying surgery does not jeopardize the patient's health. Decisions about surgery must take into account the individual's situation and preferences.

Types of Operations

The type of operation a surgeon performs depends on the nature of a patient's back problem, but most procedures involve a laminectomy, which may require the partial removal of the vertebral arch to gain access to the cause of the low back pain.

If a disk has ruptured, a surgeon will perform a partial laminectomy to investigate the vertebral canal, identify the ruptured disk and remove a good portion of the degenerated disk material, especially those fragments that press on nerve roots.

The surgeon may consider a second procedure - a spinal fusion - if he or she feels that stabilization of the spine is necessary. A spinal fusion is performed by fusing the vertebrae together with bone grafts (sometimes combined with metal pins).

Recovery After Surgery

Recovering after back surgery varies with the type of operation performed. Following ordinary disk removal, most patients are able to get out of bed and move in three or four days. They may be released from the hospital in five days.

Patients who have undergone a spinal fusion or an operation for stenosis take longer to become mobile. These patients may remain in the hospital for about 10 days after the operation. After discharge from the hospital, most back surgery patients will need some time to recuperate before returning to their usual activities.

The types of activities the patient can safely resume should be outlined by the operating surgeon and followed carefully by the patient. The period of recuperation varies, but it may range from several weeks to three months.

Prevention

Prevention of back pain can be accomplished in the following ways:

• Keep weight under control and lose excess weight, if possible.

• Regular exercise, including exercises that strengthen the abdominal muscles.

• Careful attention to posture when sitting for long periods of time while working or driving.

• Common sense when stooping, bending, lifting or carrying objects - use of the legs for lifting rather than the back is the key.

Questions to Ask Your Doctor

If tests haven't been performed - What tests might be used to diagnose a herniated disk? Are there any risks or side effects?

For conservative treatment - What do you recommend? If rest is recommended, how much rest is required and exactly what kind of rest is required? If bedrest is required, what body position is best? What over-the-counter medications do you recommend and how much?

If conservative measures fail, what about a direct injection of cortisone into the area around the cord? What are the risks or side effects?

If surgery is necessary, what procedure would be performed? How is the surgery performed? What can be expected after the surgery? What are the possible complications? How long is the hospital stay? How long will it take to return to normal daily activities or work?

Is there a specialist you recommend for these procedures or a second opinion?

At any time while this condition exists, are there any alarming signs which may indicate the need to call a doctor immediately?

What back-strengthening exercise program is recommended? When should it be started?