Conquer Back and Neck Pain - Walk It Off! (21 page)

A) This side-view MRI scan of the low back shows a 50 percent slippage (spondylolisthesis) of the L5 vertebra on the sacrum. The spinal canal is highly constricted from the slippage, which caused this patient to have a lot of leg pain and difficulty walking. B) Side-view x-ray of the same patient’s low back, one year after a bone graft was used to correct the slippage. The bone graft was held in place with pedicle screws and rods.

One in 20 people in North America have the inherited form of spondylolisthesis. It most commonly occurs between the fifth lumbar vertebra and the sacrum (L5-S1) in your low back, coincidentally the most common level for disc herniation (see
Chapter 5
). It rarely occurs at other levels of the lumbar spine and in the neck. The inherited defect that allows the fifth vertebra to slip forward on the sacrum is in the bony arch that I described to you in
Chapter 6
. The defect occurs in the part that connects the superior articular process to the inferior articular process (pars interarticularis defect, a.k.a. pars defect). This defect, with or without a slippage of the vertebra, first appears in the second decade of life between the ages of 10 and 20 years. It is usually discovered on x-ray when a young person complains of back pain. However, most of the time it is painless and a person does not know they have it.

One of my colleague’s sons was a college football player who was complaining of back pain. I examined him and thought I could feel a step off between the two lowest spinous processes in his low back. An x-ray of his spine confirmed my suspicion that he had spondylolisthesis at L5-S1. I let him continue playing football while wearing a corset, and his back pain eventually went away on its own. He is now in his 40s and rarely complains about his back.

There are all degrees of spondylolisthesis, from just a defect in the pars to total slippage of the fifth vertebra off of the sacrum and into the pelvis (spondyloloptosis — you do not even have to try and say this word), a very difficult condition to treat for the patient as well as the doctor. I have only had to treat two patients with this condition in my career. Most patients have between a 25 and 50 percent slippage. The degree of slippage does not determine whether the condition is painful. Back pain may develop if the slippage makes the spine susceptible to repeated sprains. The most common reason why spondylolisthesis becomes painful is secondary to spinal stenosis, which usually occurs after the age of 40 when the disc at the slipped level degenerates and narrows.

Degenerative spondylolisthesis (acquired) is when the slippage occurs because of disc narrowing as the result of degeneration. There are no inherited bony defects to cause this type of slippage. Degenerative spondylolisthesis occurs most commonly in women over the age of 60 at the L4-5 level of the lumbar spine. It can also occur in the other disc levels of the lumbar spine; in fact, it can occur at several levels at the same time. In the neck it is most commonly seen at the C4-5 level. I have seen only one case of it in the thoracic spine.

Degenerative spondylolisthesis is more commonly associated with spinal stenosis than is inherited spondylolisthesis. To visualize how either type of slippage of the spine contributes to spinal stenosis, superimpose a circle made by apposing your thumb and index finger the size of a quarter on your right hand over the same-sized circle on your left hand. Now slide your right hand over your left hand and notice how the passageway through the circles decreases in size. The same thing happens in the spinal canal, which becomes constricted (stenotic) when one vertebra slips forward on the adjacent one. Superimpose a bulging degenerated disc over a spinal canal that has already been constricted from slippage of adjacent vertebrae and you can see how the two conditions compound one another to make the stenosis worse.

Back and leg pain occurs from degenerative spondylolisthesis because of susceptibility of the spine to repeated sprains and secondarily to constriction of the nerve channels The back pain is mechanical in nature, meaning it is brought on by lifting and bending and is relieved by rest. The leg pain is typical neurogenic claudication seen with spinal stenosis (see
Chapter 6
).

The presence of either type of slippage of the spine implies that the spine is inherently unstable, which makes it susceptible to painful sprains and to worsening of the slippage. Therefore slippage of the spine is the most common reason for a surgical spinal fusion (scan B on page 86), the process of solidly fixing one vertebra to another with metal devices and bone graft (more about spinal fusion on page 93). A fusion is performed for spondylolisthesis to relieve chronic mechanical low-back pain as well as to prevent the slippage from getting worse. When surgery is required to relieve pain from spinal stenosis, a fusion is almost always recommended and necessary for satisfactory long-term relief of back pain (see illustration, page 84).

Instability of the spine, a.k.a. unstable spine or mechanical insufficiency of the spine, means that the spine is unable to function under normal stresses and maintain normal alignment and/or protect the nerves within. Spinal instability can cause neurogenic, arthritic, mechanical, and fatigue pain. The unstable spine is susceptible to repeated sprains and strains, just as someone with an unstable ankle is susceptible to repeated ankle sprains. The unstable spine is also susceptible to slipping or curving more. Instability of the spine can be caused by inherited defects such as spondylolisthesis, disc degeneration, and destructive lesions of bone such as fractures, tumors, and infections.

The diagnosis of spinal instability is made with bending x-rays (stress x-rays), which include a standing side-view x-ray (lateral) while you stand straight, while you bend forward (flexion), and then while you bend backward (extension). The displacement between your vertebrae in these three postures is compared in order to determine change in angulations and slippages. When one vertebra’s position changes more than is normal compared to the adjacent vertebra, then that segment of the spine is considered unstable. You can imagine that the nerves can easily be pinched by abnormal movement if a constricted spine is too loose. Instability of the spine causes spinal stenosis to be more painful. People who suffer from this combination in their low back will frequently complain of pain shifting from one leg to the other and back again for no apparent reason. The reason is that with rotation of the spine the nerve is pinched first on one side then the other.

Like spondylolisthesis, scoliosis — or curvature of the spine — comes in two major varieties: inherited and acquired (degenerative). Curvature of the spine can also cause muscular fatigue as well as neurogenic pain. When your body is thrown off of balance by a curvature (your head is not directly located over your pelvis), your muscles continually work to straighten up your back. They become fatigued and painful in the process. When scoliosis produces pain in adolescents it is usually the result of muscle fatigue, whereas pain from spinal curvature in adults is usually the result of nerve pressure from spinal stenosis, mechanical pain (instability of the spine and susceptibility to sprains), and muscle fatigue. Spinal fusion with metal fixation devices is performed for painful scoliosis to correct the deformity and to maintain that correction, as well as to prevent future worsening of the curvature.

This front-view low-back x-ray shows curvature of the spine; note how the disc is now on the concave side of the curve.

Some older adults have a combination of constriction (spinal stenosis), slippage (spondylolisthesis), curvature (scoliosis), and instability of the spine at the same time! These four conditions can also produce nerve, mechanical, and muscle fatigue pain at the same time. When all three conditions are present, it is almost always necessary to perform a surgical decompression of the constricted spinal canal and spinal fusion with metal screws and rods, as well as bone grafting in order to obtain long-lasting relief of pain. The combination of these painful disorders of the spine and the necessity for a major (certainly not micro!) operation to obtain relief is difficult to explain to a person in their 80s. I have seen patients who have tried to get by with smaller, less-invasive “micro” operations for these conditions, but they received little pain relief from the procedure and were after that almost impossible to help. If your doctor tells you that your pain is coming from any one or any combination of these conditions and that you can be treated with micro-surgery, I advise you to obtain a second opinion from a qualified spinal surgeon (see
Chapter 4
).

Inherited curvature of the spine comes in several varieties. The most common curvature under the age of 18 is idiopathic adolescent scoliosis (curvature of the spine in adolescence, the cause of which is unknown). The term idiopathic is old terminology when it comes to adolescent scoliosis because we now know that this type of curvature is inherited. These curves are not present at birth but begin to form at the beginning of the growth spurt, age nine to 14 in girls and 11 to 15 in boys. They are usually detected in school scoliosis screening programs. If you get notice from the school that your growing daughter or son has scoliosis, do not panic; the majority of these cases require no treatment. However, you should have your pediatrician follow the progress of the curve to determine if it needs to be treated. Your pediatrician will refer you to a children’s scoliosis specialist (pediatric orthopaedic spine specialist) if it is necessary for the scoliosis to be followed or treated with a brace or surgery.

Two myths that must be dispelled are that exercise will correct or keep a curvature of the spine from getting worse, and that the curvature occurs because of bad posture. The truth is that curvature of the spine and the degree to which an adolescent curvature advances are determined by genetic factors (similar to adolescent disc degeneration — see
Chapter 1
). Therefore, all the good posture and exercise in the world will not prevent or correct curvature of the spine in adolescents. Blaming the curvature on poor posture or insisting that your daughter or son exercise to correct a scoliosis is futile and wrong. The presence and progression of the curvature is genetically programmed. A better approach is to explain to your young person that maintaining good health will help them obtain a better result from treatment of their scoliosis, be it a brace or surgery.

The other two types of inherited scoliosis are congenital scoliosis (an inherited type of curvature of the spine that is present from birth and detected before the age of two) and infantile scoliosis (occurs between two and nine years of age). These forms of scoliosis should be managed by a pediatric orthopaedic specialist in a children’s hospital setting. Most of these curves require sophisticated surgical correction at an early age, and there should be no delay in finding appropriate care for the child or infant with scoliosis.

Infants and young children do not complain of pain from scoliosis. Adolescents complain of aching and fatigue when the curvature reaches a certain severity and/or causes them to be out of balance. When a young person of any age complains of spine pain, particularly if it causes sleep disturbance, it could indicate a more serious problem and they should be seen by their pediatrician for evaluation as soon as possible. If a young person is sick and has a fever or a stiff neck along with neck, chest, or back pain, they should be taken for emergency care immediately.

There is a certain peculiar painful condition of the spine that occurs in adolescents and can cause muscle spasm and scoliosis. This condition, called osteoid osteoma, is a small bone reaction about the size of a pea that can be located anywhere in the spine and causes severe night pain, which is dramatically relieved by aspirin. It is not a tumor, but it is so painful that it causes the spine to lean over like the Leaning Tower of Pisa. The diagnosis is made by finding a dense circle of bone on an x-ray near where the patient complains of pain. A test called a bone scan shows a very dark spot over the skeleton. I once took care of a 14-year-old young man with this condition who was dramatically cured of his pain and curvature by removing the pea-sized lesion with a large biopsy needle using fluoroscopy, a moving x-ray imaging system. He no longer had to take aspirin to be able to sleep, and his spinal curvature went away.

A common cause of deformity and spine pain is osteoporosis, or softening of the bones. Osteoporosis is most commonly seen in small, post-menopausal women, particularly those who have a history of smoking. When the bone becomes soft, the vertebrae can collapse from minor trauma, such as riding over a speed bump, and cause kyphosis (excessive rounding of the spine).

If you look at the spine from the side, there are normal curves that balance each other so that the head is centered over the pelvis. In the neck and low back the curve is forward (lordosis), and in the thoracic spine and sacrum (that part that attaches to your pelvis) the spine curves backward (kyphosis). With osteoporotic compression fractures of the vertebrae the spine becomes more rounded, with accentuated kyphosis in the thoracic spine, usually seen in older osteoporotic women. When this occurs in the lumbar spine there is a loss of the normal swayback appearance (loss of lordosis), called flat back. Incidentally, a flat back can also occur as the result of degenerative disc narrowing. Rounding of the spine, be it in the thoracic or lumbar spine, throws the body off balance (tilting it forward) and results in pain from muscle fatigue.