Disc Damage

Protecting the spinal column means treating and preventing herniated discs.

As a child, you were probably told to “stand up straight” when you slouched. The admonishment wasn’t intended to make you uncomfortable, as you might have thought at the time.

The demand for proper posture was actually intended to increase your long-term back comfort. While the phrase is still commonly used from classrooms to clinics, it can be misleading, and it belies the natural curvature of the spine.

The spine is comprised of four curves, divided into four regions: cervical, thoracic, lumbar and sacrum. These gently sloping spinal arcs all play crucial roles in overall comfort and a person’s ability to stand, walk, sit and enjoy a productive quality of life. Spine health shouldn’t be taken lightly.

The curvature of the spine is designed to absorb shock during movement, and the elastic discs that cushion the vertebrae feel the brunt of the burden. It’s no wonder that approximately 70 percent of people have some form of disc pathology, says Matthew Goodemote, MPT, Dip. MDT, founder of Community Physical Therapy & Wellness in upstate New York.

Long-term disc pressure or a sudden increase in pressure can cause the jelly-like disc nucleus to push against the disc casing. When this bulge extrudes into the spinal canal, the result is a herniated disc.

A herniated disc can exert pressure on surrounding nerves, which leads to pain, weakness and reflex changes, says Loren Fishman, MD, founder of Manhattan Physical Medicine & Rehabilitation in New York and author of Sciatica Solutions. If a herniated disc isn’t treated, a rupture can occur, enabling disc fluid to leak out of its casing and into the spinal canal. From there, problems can multiply. In severe cases, untreated or extreme disc damage can lead to loss of bowel and bladder control, numbness and limited movement, says Goodemote.

Assessing Risk Factors

The most common causes of bulging discs and herniations are slumped sitting, forward bending and incorrect lifting, says Tatum McCain, MS, PT, of the Texas Back Institute in Plano.

These risk factors make sense clinically, but a practical example illustrates the impact of repetitive positioning over time. At Goodemote’s clinic, the peak age of his herniated disc patient population doesn’t fit the traditional range of mid-50s, as most research asserts. “It starts in people who are in their 30s, and most of them are in their 40s,” he says.

Goodmote attributes the early incidence of herniated discs among his patients to increased exposure to risk factors. He treats patients who work at a local factory, where employees lift and bend repeatedly all day. The discs in the cervical spine are predisposed to injury from lifting, due to the close proximity to the shoulders. In addition, Goodmote sees truck drivers and nurses with back problems, a result of long days in a sitting position or handling physically demanding tasks.

The discs in the lumbar spine are particularly susceptible to herniation if people spend excessive amounts of time in a fixed position, says Dr. Fishman. Sitting puts 1.5 times the pressure of body weight on discs.1Mundane tasks can also put people at risk for cervical disc problems. “A herniated cervical disc resulting from reading in bed every night with the head propped up is amazingly common,” says Dr. Fishman.

All areas of the spine can be injured from abrupt starting or stopping motions, although disc pathology that’s caused by traffic accidents is more common in the lower spine due to positioning at the time of injury, says Dr. Fishman.

A herniated disc often indicates additional spinal pathology, such as another herniation in the neck. Because spinal regions are interconnected, pathology in one area can easily affect other areas. “Very rarely do I see someone who has just one level of herniation,” says Goodemote.

The Degeneration Factor

Disc pathology can also be linked to degeneration. But whether a herniated disc leads to degeneration, or existing degeneration leads to a herniation, remains unknown. It’s a classic “chicken and the egg, which came first” scenario, says Goodemote. What’s certain is that herniated discs and degenerative disc disease are often linked.

As people age, the chain molecules in discs that attract water, called proteoglycans, become shorter and lose their ability to hold water.1 As a result, a disc’s nucleus becomes dry and stiff, which hinders the ability to absorb shock. In addition, discs receive nutrition through fluid, so decreased water retention leads to a loss of nutrients. These factors create an increased risk of pressure pathologies, such as herniation.1

Aging isn’t the only risk factor for disc degeneration. Smoking can also play a big role in advanced disc changes, says Goodemote. Smoking decreases the amount of oxygen being transported to cells. Just one cigarette cuts the amount of oxygen traveling to discs in half.1

In addition, smoking causes carbon monoxide to flow to the back through red blood cells, instead of oxygen, says Goodemote. “The low back doesn’t have the best blood supply to begin with,” says Goodemote, so smoking compounds this deficiency. As evidence of the impact of smoking, marked changes in discs have been observed in spinal X-rays of young smokers.1

Making a Diagnosis

Pinpointing a herniated disc can be a challenge because many symptoms can stem from a variety of conditions. Common symptoms include back pain, pain in the buttocks and pain radiating down the leg, called sciatica. Three kinds of nerve abnormalities can result from a herniated disc, says Dr. Fishman. Numbness, paresthesias (pins and needles for example), and weakness are the hallmarks of disc pressure on surrounding nerves.

However, “just knowing that a patient has nerve pain doesn’t tell you if it’s piriformis syndrome, a herniated disc or spondylosis,” cautions Dr. Fishman.

But deciphering the clues can alert clinicians to the possibility of a herniated disc. For instance, positive contralateral straight leg is a clear giveaway, says Goodemote. If a patient has radiating pain down the right leg, ask him to lift the left leg. If the patient feels pain in the right leg when the left leg is raised, it’s indicative of a disc change. A typical herniated disc also hurts when a patient coughs or sneezes because it increases abdominal pressure and puts pressure on the spine, he says.

A patient who’s “stuck” or can’t move the back area is likely to be suffering from a disc problem. The spine is the only area that restricts back movement, says Goodemote. Other motion deformities, such as a hunched stance or moving with the hips shifted to the side, are symptomatic of a disc change.

When a physical exam and patient history don’t reveal definitive signs of disc pathology, you may need to use diagnostic tests. Tests such as magnetic resonance imaging (MRI), computed tomography (CT) with myelogram—a radiological technique for viewing the spinal cord—and electromyography (EMG) can help determine the extent of disc herniation and nerve involvement.2

An MRI shows the structure of the spine and identifies a bulging area, says Dr. Fishman. Recent research suggests that a CT is comparable to an MRI for radiological evaluation of herniated discs in the lumbar spine.3However, an MRI produces more reliable results for evaluating lumbar nerve root compression.2 For imaging of the cervical and thoracic spine, MRI is still the best choice.2

As opposed to the structural imaging that an MRI and CT provide, an EMG shows which nerves are functioning poorly, says Dr. Fishman. By measuring the electrical impulses of muscles, an EMG can detect abnormal muscle reactions. And when an EMG is combined with a nerve conduction study, you can detect the location and extent of nerve damage.

Active Treatments

Movement pushes fluid out of the discs, which allows fresh nutrient-filled fluid to be absorbed.1 Flushing discs through movement is a healthy cycle that’s necessary to maintain nutritional well-being. Thus, many treatments for herniated discs are centered on active movement.

If active movement isn’t possible at the beginning of treatment due to pain, “work on finding a position of relief,” says Goodemote. Most patients have a stationary position of relief, whether it’s sitting or standing, he says.

Once you’ve identified a relatively painless position, teach patients to work from that spot to extend mobility. Applying ice and a brief period of bed rest (less than 48 hours) can also contribute to pain relief and prepare the body for movement.2

McKenzie exercises, named after creator Robin McKenzie, PT, can also help patients recover from disc herniations. These exercises are extension-based and “can actually create negative pressure and ‘suck’ the disc back to where it’s supposed to be,” says Dr. Fishman.

McKenzie exercises bring the spine into a position of normal lordosis and produce a force that directs disc material away from nerves and back toward the center of the nucleus.1

Studies show that these extension exercises offer greater pain relief than flexion exercises that have been previously used to treat discs.1 In addition, flexion exercises decrease lumbar lordosis in an attempt to reduce swayback.1 But these positions put extreme force on the posterior longitudinal ligament, which can be vulnerable to disc rupture.1 Many clinicians prefer McKenzie exercises for active treatment.

In order to build strong muscles to support the spine and counteract the loss of water in the disc due to degeneration, encourage patients to begin a whole-body exercise program. Goodemote recommends yoga for its ability to strengthen and mobilize the body. “I’m more concerned with joint mobility than muscle flexibility,” he says. A total-body workout helps patients achieve joint flexibility and flush nutrient-rich fluid in and out of discs.

If active treatments don’t quell pain, a patient may need oral or epidural steroids, says Dr. Fishman. Nonsteroidal anti-inflammatory agents have been successful controlling pain and inflammation in research studies.2

You must address the root of the problem in herniations that are caused by overuse and degeneration. It’s imperative to teach proper techniques to patients who lift objects regularly in order to correct existing problems and prevent future issues.

Patients should keep the back in slight lordosis during lifting, with the load close to the body.1 You should also address posture. Show patients how to maintain proper posture during sitting and standing, especially those who spend many hours a day in fixed positions.

Encourage the use of a lumbar support for office workers and frequent drivers. Even a rolled up towel can work as a lumbar support if it’s placed between the back of chair and the lower back, says Goodemote. Sitting in a forward position for extended periods of time, which causes spine flexion, is terrible for the back, says Goodemote. People who sit for lengthy periods should take breaks to stretch and move around to relieve pressure on the discs.

Surgical Interventions

While a majority of herniated discs heal without surgery, some injuries are too severe to heal on their own. Surgery may be indicated when a bulge or herniated disc puts extreme pressure on nerves in the spine and leads to intense pain, weakness and progressive loss of sensation, says McCain. The cauda equina syndrome, which involves multiple nerve roots and results in saddle anesthesia and urinary retention, is considered a surgical emergency.2

Surgical interventions include the “classic” discectomy, in which a surgeon works through a 2- to 3-inch incision in the midline of the back to remove the lamina (the bony projection off the vertebrae) and remove disc material that’s pressing on the nerve, says McCain.

Microdiscectomy and percutaneous discectomy use operating microscopes and X-ray pictures and video. These procedures use smaller incisions and create less damage to bone and surrounding tissue, says McCain. Fusion may be used when an entire disc needs to be removed in order to correct the resulting instability.

Regardless of the surgical procedure that’s used, you need to be honest with patients about what to expect afterwards, says Goodemote. “Sometimes patients will panic after the operation if they still feel pain. But pain is normal, even up to 6 months post-surgery,” he says.

Clinicians also need to communicate clearly to patients about what they can and can’t do after surgery. Surgeons usually set post-surgical weight lifting restrictions. Goodemote helps patients understand restrictions in practical terms by comparing the weight of a gallon of milk versus a bag of garbage, so people know what they can lift safely.

Above all, patients need to move after surgery. Prolonged periods of bed rest hinder recovery. But controlled, early movement usually leads to better success, says Goodemote. To start, have patients practice proper posture. “After surgery, posture is always acceptable,” he says.

Many treatments for herniated discs are also the best prevention against future herniation and degeneration. Exercise, refraining from smoking, proper posture and correct lifting techniques top the list of preventive measures that you should discuss with patients, even if they aren’t exhibiting any disc pathologies.

If you take disc health seriously, your patients will follow suit.

References

1. Foster, M.R. (2001). Backache: Putting it behind you. Danbury, CT: Rutledge Books.

2. Hanley Jr., E.N., & Wetzel, F.T. (2002). Spine surgery: A practical atlas. New York: McGraw-Hill.

3. Van Rijn, J.C., et al. (2006). Observer variation in the evaluation of lumbar herniated discs and root compression: Spiral CT compared with MRI. The British Journal of Radiology, 79(941), 372-377.

Diana Olsen is assistant editor of ADVANCE. She can be reached at dolsen@merion.com

Examining Options

Traction can factor into treating certain spinal conditions. Spinal decompression applied in constant or intermittent phases can isolate mechanical impairment in the neck or back. Barring spinal instability, traction is a gentle approach to treat common spinal dysfunctions or address nonfused, post-surgical discomfort. Traditional diagnoses of disc pathology, such as prolapse, herniation and stenosis, respond to spinal traction. In more severe conditions, traction combined with manual treatment and pharmacology is more likely to lead to resolution.

During traction there’s an unweighting of soft tissue and a separation of vertebrae. A vacuum is created by decreasing intervertebral pressure, which reduces the protrusion. Backward bending is thought to lessen posterior annular strain and reduce extruded nuclear material. However, forces acting posterior don’t correspond to a reduction in nuclear material. Although narrowed in the lower lumbar area, tensioning the posterior longitudinal ligament through traction offers support to posterior structures and facilitates anterior migration of the protrusion. Traction forces also offer relief from tissues under stress from impingement in the presence of an osteophyte, pain without range limitations and gradual onset of lower back or radicular pain. Mechanical traction accomplishes the goal of centralizing and reducing the frequency and intensity of pain. Mobilizations should precede traction interventions. Innovations in traction equipment provide a more comfortable environment for joint and myofascial mobilization so patients can make quicker transitions to stabilization exercises.

Paul Hoffman, MD, is the medical director at Siskin Hospital for Physical Rehabilitation in Chattanooga, Tenn. H John Kelly, MPT, is an outpatient therapist at Siskin Hospital for Physical Rehabilitation in Chattanooga.