Taking Aim at Sciatica This section is compiled by Frank M. Painter, D.C.
Send all comments or additions to: Frankp@chiro.org
FROM: JACA ~ March 2001
Sciatica is a powerful word. The mere mention of it can send shudders through anyone who has suffered its burning, shooting pain. It's also a big word, despite its economy of letters, referring to a wide range of symptoms and causes. Sciatica is widely recognized as a common variation of low-back pain, with a lifetime incidence estimated between 2 and 40 percent; among patients with low-back pain, 12 percent experience accompanying leg symptoms. [1]
"Sciatica is very relevant for doctors of chiropractic because studies show that between 50 and 75 percent of their patients seek care because of back pain," says Gert Bronfort, DC, PhD, and professor in the Department of Research at Northwestern Health Sciences University. "A substantial proportion of those patients will have sciatica, which is the popular term for pain radiating into the back of the leg, and that is commonly associated with a nerve root irritation in the lower back."
But there are many variations of such leg pain conditions, which is why Dr. Bronfort prefers to categorize them as "back-related leg pain." "Patients can experience pain in the front of the leg, which technically is not a true sciatica," he explains. "Sciatica refers to any pain in the distribution of the sciatic nerve, which means that any nerve root that contributes to the sciatic nerve could produce that pain. The problem can also be due to referred pain from other structures in the low back, such as the disks, the small joints, and the muscles or ligaments."
And such pain does not originate only in the low-back structures. "The term sciatica is a catch-all term representing multiple causes of leg pain that may or may not be due to a problem from the lower back," adds Frederick Carrick, DC, PhD, DACAN, DABCN, DACNB, FACCN. "Leg pain 'sciatica' may be referred from problems elsewhere in the human body, ranging from tumors to vascular diseases."
The definition of sciatica extends further yet, beyond biomechanics to include chemical neuritis. "We see chemical neuritis when the disk has been torn, and some of the degradation products from the tearing, including phospholipase AII and other similar by-products of the injury, are very toxic to the nerve," says John Triano, DC, PhD. "As a result, you can have flaming sciatica, yet the MRI will not show very much. That's because there is an internal disk derangement. This means that the inside of the disk, which may or may not show up as abnormal on the MRI, is torn up and there is a chemical neuritis on the nerve." Dr. Triano practices at the Texas Back Institute in Plano, Texas.
A dull pain or numbness in the buttock, leg, or foot is often the first indication of sciatica. "That's the body's way of saying you better take care of it, or something worse might happen," adds Tim Mick, DC, an associate professor and chair of the Department of Radiology at Northwestern Health Sciences University. "Untreated, sciatica can lead to a loss of muscle strength and muscle size that may be irreversible. Eventually, there can be problems with gait. Patients may trip and stumble, or they may have a foot drop in which muscle weakness related to diminished nerve conduction causes an inability to flex the foot backward. And because the same spinal lesions that commonly produce sciatica may also affect the nerves supplying the sphincter muscles of the bowel and bladder, incontinence (loss of bowel or bladder control) can result."
Diagnosing sciatica can be as complex as defining it. James Cox, DC, DACBR, and author of the textbook Low Back Pain: Mechanism, Diagnosis, and Treatment, [2] has focused much of his 37-year practice on low-back pain and sciatica and considers it one of the greatest challenges in the clinical practice. "We know that back pain is the most expensive ailment treated in the United States in people from age 20 through 50," he says. "It costs billions of dollars to treat every year, and to compound things, 10 percent of those who have back and sciatic pain will take 90 percent of the cost of treatment. This is due to the fact that they are more likely to have disk herniations or spinal stenosis, conditions that commonly result in sciatica and are more difficult to diagnose, and even more difficult to treat. The other 90 percent of people who come in with just back pain, or maybe pain into the buttock or the thigh, usually are not as difficult to diagnose and treat as sciatica patients tend to be." Dr. Cox practices in Fort Wayne, Indiana.
Dr. Cox adds that differential diagnosis of back and sciatic pain is an extensive topic that includes consideration of other less common etiologies than disk herniation and stenosis. These include piriformis syndrome, pregnancy, developmental and acquired stenosis, spinal primary and metastatic tumor, infection, tethered cord, neuropathies, endometriosis, epidural hematomas, and other less common causes. [2]
Because doctors of chiropractic are trained to focus on the whole person, they are well suited to diagnose sciatica. They often take more time, look more closely, and find some of the less common causes.
"The diagnosis and treatment of sciatica is not simple," Dr. Carrick adds. "It's not always from the low back or a consequence of pain referral from structures that go into the leg. I believe that DCs are very well trained to embrace the quality of care that is necessary today as a first or primary portal of entry for patients suffering these maladies. "
Dr. Mick agrees. "Often when people think of sciatica, they think about the lumbar spine, or possibly the sacral nerve roots. Because of their whole-body orientation, chiropractors tend to think about possibilities outside a small area of anatomy. They would look at the whole spine and extraspinal anatomy during the examination. On the other hand, medical doctors may order a lumbar spine MRI to rule out sciatica caused by a disk herniation, for example, but if it comes back negative, they stop. Doctors of chiropractic may offer a broader differential diagnosis and consider other explanations, rather than automatically concluding that there is no anatomic cause for the symptoms."
The most reliable diagnostic test for sciatica in the literature, according to Dr. Triano, is the straight-leg raise test. "If the patient has leg pain with straight-leg raise positive and a nerve root pain distribution, you have enough to call it sciatica," he explains. "A lot of people come here who have been misdiagnosed. They were told they had sciatica because they had leg pain. But that isn't necessarily true. Radiating leg pain is necessary, but not sufficient, for a diagnosis of true sciatica. We sometimes find that the patients have nerve damage where there is significant loss of muscle function. That's when you really want to pause and immediately get an MRI to be absolutely sure what is going on anatomically. If there is loss of bowel or bladder control, that is a medical emergency, and the patient should go immediately to the ER."
The MRI has proven to be an effective diagnostic tool for assessing many of the causes of sciatica. Its imagery shows not only the lumbar spine and disk herniations but also any site along the sciatic nerve, including nerve tumors and other less common causes. In addition, MRI and CT scans are effective at diagnosing spinal stenosis, a condition that often eludes x-ray.
There are many approaches to treatment for sciatica. Spinal manipulation can be effective in some cases, though Dr. Triano recommends a wait-and-see attitude.
"The patient who has some leg pain but who has a significant amount of back pain is likely to do best conservatively," he says. "When you manipulate them, they tend to get better. But for patients with only leg pain, which is an important discrimination, if they are not responsive within a couple of treatments, those patients will do best with an epidural steroid injection and/or a selective nerve root block, which is a referral or consultation situation. Sciatica, treated with manipulation, has an eight to nine percent [3] greater rate of recovery than if they go into physical therapy or standard medical care, which is in contrast to what the medical doctors would like their patients to believe."
Dr. Triano stresses that referrals do not mean that chiropractors lose those patients. Rather, the doctor of chiropractic astute enough to do the appropriate diagnostic tests and get the patient referred for the epidural steroid can keep the patient and manage the patient through rehabilitation. "That's where the chiropractic physician role comes in: to be the physician, make the diagnosis, organize the medical resources to get the job done, treat, and rehab the patient," he adds.
There are broader treatment possibilities for those patients with an average nerve canal and a large disk herniation. "Because the nerve gets tweaked, it swells up into the space already partially taken by the disk," Dr. Triano continues. "If I can get an epidural steroid or some anti-inflammatory medication in there to shut that down, I now have more space for the nerve. Then manipulation may help these patients and restore them to their prior function by collaborating in the therapeutic benefits of the epidural steroid or anti-inflammatory medication. Otherwise, many of these patients could not tolerate manipulation because of the swelling. So, again, DCs can preserve these patients for their practice. They can manage these cases by marshaling what we call 'complementary chiropractic procedures,' which are the medical procedures, and rehab them without their ever having to go to surgery."
Dr. Triano adds that research shows that chiropractic has a 50/50 success rate for treating spinal stenosis. [4] He recommends, however, that if the patients do not show improvement within two weeks, they may need an epidural steroid injection or possibly a decompression surgery.
The Cox flexion-distraction procedure, which Dr. Cox developed, has been proven effective in treating sciatica and is the focus of ongoing research. Dr. Cox began developing this procedure after he graduated from National College of Chiropractic in 1963. He soon found that there was much more he needed to learn, especially regarding sciatica.
"I knew there had to be something else, something better, so I started to study osteopathic techniques in conjunction with chiropractic," Dr. Cox explains. "The osteopaths used distraction manipulation on spines when patients had disk herniations, stenosis, and sciatic pain, so I began to place patients' spines under distraction. Today, through our research, we know that distraction does various positive things to the human spine. Number one, it allows us to increase the intervertebral disk space height. And our research shows that when we do this technique, we increase the height of the intervertebral disk three millimeters at L5/S1, and 1.87 millimeters at the L4/L5 disk level. At the same time that we increase this intervertebral disk space height, we are affecting the pressure inside of the disk. The nucleus pulposus of the disk, which normally has a high positive pressure, is affected under distraction. When we apply this distraction technique, that pressure drops to a negative pressure, as low as a negative 39 to a negative 192 millimeters of pressure. It is this drop in intradiscal pressure that creates the centripetal force that allows the protruding disk to recede. At the same time that we are opening the disk space by dropping the intradiscal pressure, we are also increasing the area of the intervertebral foramen up to 28 percent. This whole procedure allows us to reduce the effect of disk herniation and of spinal stenosis."
Dr. Cox has been working with Ram Gudavalli, Ph.D., principal investigator, associate professor at Palmer Center for Chiropractic Research, and adjunct associate professor at the National University of Health Sciences (NUHS). Dr. Gudavalli received federal research grants to conduct biomechanical and clinical studies on Cox flexion-distraction treatment procedures for low-back pain. In addition, Gregory Cramer, DC, PhD; Jerrilyn Cambron, DC, MPH; and James Jedlicka, DC, have been working with Dr. Gudavalli on these research projects. These studies were conducted at NUHS, and Loyola University researchers Avinash Patwardhan, PhD, and Alexander Ghanayem, MD.
The first project, entitled "Biomechanics of Low-Back Flexion-Distraction Therapy," used unembalmed cadavers to study what happens to disk pressure during the Cox flexion-distraction procedure. The technique was chosen for study for a number of reasons. It is a controlled procedure with few known complications or side effects and no power thrusts, which, compared to the torsion of other techniques, made it biomechancially easier to study. In addition, it is better accepted by the allopathic community. "Orthopedic surgeons and primary care physicians are more familiar with a traction procedure. It is something they are more comfortable referring patients for," Dr. Cambron explains. "Flexion-distraction is a manual traction. Traction is a common procedure for treating disk bulges. But flexion-distraction has the advantage of providing much more precise traction than general traction of the lower back because hand placement is directly above a specific spinal segment, allowing practitioners greater control over which disk space they are working on."
The results of the first study were encouraging. Dr. Gudavalli reports that they were able to demonstrate that the technique can create vertebral motion. "There is a decrease in intradiscal pressure," he says. "That is a very important finding, one that has been hypothesized and has now been demonstrated. For doctors of chiropractic that means that there is an opportunity for the disk protrusions to reduce, to be sucked back in. Also, we noted the increase in the intervertebral foramen space, which means that any pressure on the nerves and dorsal root ganglia can be decreased."
During the third year of this project, a clinical study was conducted on patients to fill in the missing component from the cadaver research, providing information on muscle activity during flexion-distraction.
"We used electromyography (EMG) to test the amount of muscle activity within the subjects' abdominal, obliques, and erector spinae muscles to test for any contraction during the flexion-distraction procedure that would offset the traction we saw in the cadavers," Dr. Cambron explains. "We found that there wasn't a significant amount of EMG activity, which means this traction is most probably occurring in the spine during the flexion-distraction."
Once researchers were satisfied that anatomically the procedure was accomplishing traction, they sought evidence as to whether this procedure helped people feel better. The second study, entitled "Flexion-Distraction vs. Medical Care for Low-Back Pain," focused on patients with chronic low-back pain, which could have included sciatica. They were randomized either to flexion-distraction or to the customary allopathic care, which was physical therapy. Final results of these studies should be available by late summer 2001.
"It was exciting that we worked in a collaborative effort with the medical community for these two studies," Dr. Cambron adds. "And it was exciting that the federal government, through the Health Resources and Services Administration, created this chiropractic demonstration project, which was the first time the government awarded specific money for chiropractic research." These two studies led to a third federally funded research study entitled "Chiropractic vs. Medical Care for Chronic Neck Pain," which was awarded a $1.24 million grant in 2000. Research will continue through 2003. This third grant extends Dr. Gudavalli's research funding to nine uninterrupted years of federal funding, a first for a chiropractic researcher.
In other research, Dr. Bronfort and his team have spent the past four years working on two pilot studies designed to determine the feasibility of conducting a randomized clinical trial on non-operative treatment for sciatica. FCER funded these studies, and plans are underway to apply for federal grants for a full-scale randomized clinical trial.
"We initiated this research because there were only a few controlled clinical trials, and they were of insufficient quality to truly know if spinal manipulation is an effective therapy for sciatica," Dr. Bronfort says. "We also wanted to compare spinal manipulation to other common interventions-primarily medical care and epidural steroid injections. Additionally, we were interested in finding out how much better it is to provide active treatment than just instructing patients on how to manage their own sciatica."
In the pilot study, the investigators looked at patients who had had their sciatica for a relatively short period of time-three months or less. This proved to be too limiting, and they were unable to recruit and study a sufficient number of eligible patients to conclude that a large study would be feasible. However, the investigators identified that there were a substantial number of patients who had sciatica for much longer than three months. In the second pilot, which was a three-group, parallel-design, randomized observer-blinded study comparing spinal manipulation with epidural injections and self-care, they expanded their criteria to include patients of a more chronic nature. The second pilot study showed that a full-scale study was feasible.
In the pilot study, chiropractic care was limited to spinal manipulation, with light soft- tissue massage and/or flexion-distraction technique. Medical care was limited to prescription NSAIDs, acetaminophen, and mild narcotic medication. Up to three epidural steroid injections were provided to the third group during the 12 weeks of the study. All patients received two 45-minute sessions of self-care instructions, and modifications of activity were prescribed as needed. Outcomes were measured by self-report questionnaires administered at the beginning of the study, at three weeks, and at the end of the study. Outcome measures included the Roland Morris Disability Questionnaire, with 23 items designed to quantitatively measure the degree to which the patients' low-back pain/leg pain restricts their daily activities. All three groups showed substantial improvements at the end of the study, with the mean estimated direct cost per patient for 12 weeks of treatment ranging from $1,700 for those who received injection, $800 for medical care, and $550 for chiropractic care [1].
"These are feasibility studies. They are too small to make any conclusion regarding the effectiveness of the treatments," Dr. Bronfort adds. "But based on the research that has been done so far, I think we can say that spinal manipulation looks promising. Based on the results of the second pilot study, we plan to apply for federal funds for the larger study by the middle of this year. There are certainly many good reasons to further examine the effect of spinal manipulation and other commonly used treatments for back-related leg pain."
For all the research and treatment options, though, the human body's intrinsic ability to heal remains key. "Some people get better very nicely without any treatment within about six weeks," Dr. Triano explains. "Others will recover usually between 6 and 18 weeks, certainly by 6 months, while some may opt for very casual treatment-a little physical therapy and reduced activity. So the purpose of treatment often is to speed the rate of recovery. It's not an if/then statement. It's not 'if you don't get treatment, you're not going to get better.' The question is whether you want to be off work or suffer for that long. One of the most important things is to get people back to doing as much of their activities of daily living as rapidly as possible. You do not want to take people who can be active and make them inactive; it makes matters worse. For some reason, it is difficult to get some doctors of all varieties to understand that, but it is a very important issue."
That's not to say that people with sciatica who don't seek treatment will always get better. Some may have serious complications. The disk herniation or stenosis may get progressively worse, with the net results of bowel and bladder functional loss, loss of motor control in the leg, or severe limitations in their lives because of their chronic low-back/leg pain. And not every patient with sciatica will respond favorably to chiropractic management. In such cases, Dr. Mick notes that DCs understand the importance of making prompt and appropriate referrals. "Chiropractic education and improved inter-professional relations and communication, as well as increased access to advanced diagnostic imaging and specialized neurologic testing, have increased the possibility of timely, effective referrals in such instances." Dr. Triano adds that if the patient is not significantly improving in a reasonable period of time-say, two to four weeks-therapy should cease and diagnostic evaluation should be obtained. "Get the MRI, get the CT, do the electro-diagnostic or nerve conduction studies. Find out why they aren't improving," he says. "I'm going to offer a specific clinical example of a very pleasant older gentleman who was referred to me by a chiropractic colleague. The patient had been under treatment for severe back pain for a month. At the end of the month, he started having leg pain, which progressively got worse. They treated him another month, still with no improvement. When the patient was referred to my office, we took our own set of x-rays and compared them with the initial doctor's x-rays, and something didn't look right. We immediately got an MRI and found we were dealing with terminal-stage cancer. The reason the patient had leg pain was that his L5 vertebra was totally eaten out by the cancer, which had crossed right over the nerve and eaten through the ileac crest. So when he pointed to his back, and said, 'This is where I hurt,' he was pointing to a tumor. And the reason his leg hurt is that the tumor had incarcerated the nerve going down to his leg. The doctor had missed it completely and continued to treat the patient for two months. That's what gets you in trouble."
For years, surgery was widely prescribed for sciatica with mixed results. Dr. Carrick believes there is still an excessive amount of surgery-some successful, some not-for individuals with sciatica. "But I think that now the patient is a more educated patient than he or she was some 20 years ago when I started practicing. People are aware of alternatives, and also surgeons are aware of alternatives. And no one likes to have bad outcomes," he says. "So I see a change. Individuals will see doctors of chiropractic, acupuncturists, and other health care practitioners before they will resort to something as final as surgery. People have had positive experiences over a period of time with chiropractic, and that draws them to the DC as a primary source with these types of conditions. The treatment of these disorders by doctors of chiropractic has been promoted to the point that for many people, the first thing that pops into the mind when they hurt their back or their leg hurts is a visit to the DC. I think that has also contributed to a decrease in surgical intervention, although some cases do go on to surgery because no other treatments work for them."
Dr. Triano finds that some patients with sciatica, especially those with a lot of leg pain and no back pain, may need surgery if they are not responsive to epidural steroid injections. In these cases, he considers surgery a realistic last resort to resolve the suffering of the patient.
Recurrence of sciatica is a common problem. People with disk herniations, for example, tend to become asymptomatic but not necessarily permanently "cured." Dr. Mick says, "The sciatica goes away, but they still may have the disk herniation or other abnormality. Six months from now or even years down the road, if they're lifting or twisting improperly and not watching their back, the problem may recur and may be even worse than the first episode. So, sciatica definitely tends to be a recurrent problem. And some contributing problems, such as tight or imbalanced muscles, might need to be treated. But if the patient resumes bad habits or simply 'overdoes it,' the problem returns, and so does the patient."
Sciatica presents a challenge to the doctor of chiropractic. It requires an investment of time, knowledge, and continuing research to discern the causes and the best solutions. "Over the years, I have found that people who have disk herniations and sciatica take more time and more visits to get well," Dr. Cox says. "A clinical trial of 1,000 patients treated at 30 different chiropractic clinics in the United States and Canada proved that disk herniation cases required more days and visits than other back conditions to reach maximum chiropractic improvement. This illustrates to me that sciatic patients are more difficult cases to treat, requiring more of the doctors' knowledge, expertise, and treatment ability. It is the most demanding condition that we treat, but through our research and ongoing studies, chiropractic can make an important contribution to sciatica treatment and to relieving the suffering it causes."
Sciatica: Can It Be Prevented?
Strengthen back and abdomen muscles. Dr. Mick shares a personal example to explain how patients can take better care of themselves. "I'm a runner, and I have twinges of problems down my leg on occasion. I find that if my abdominal muscles are strong and supportive of my lumbar spine, I tend not to have the problem. I can run and everything's fine. But as soon as my abdomen is a little weak, then I may experience some numbness. Often that's how full-blown sciatica starts-as a little numbness or a little uncomfortable sensation in the leg or heel. Strong and properly balanced abdominal and pelvic muscles may help substantially. There are different kinds of exercises that doctors of chiropractic commonly prescribe for the low back, such as the Williams program (emphasizing flexion) and the McKenzie program (emphasizing extension). The one prescribed may depend on which one the patient best responds to, which muscle groups are weak or imbalanced, and the exact location and nature of the lesion producing the sciatica."
Even when lifting light objects, hold the object close to the body and lift with the back straight, rising up by using muscles in the hips and legs.
Occupational therapy or job retraining may be necessary if working conditions such as heavy lifting, long-distance driving, and long periods at a desk continue to aggravate the condition.
Avoid sitting for long periods of time. Take frequent breaks and walk around or do a short exercise routine. Make sure the ergonomics of the workstation support good habits.
References:
Bronfort G, Evans RL, Anderson AV, Schellhas KP, Garvey TA, Marks RA, et al.
Nonoperative Treatments for Sciatica: A Pilot Study for a Randomized Clinical Trial
J Manipulative Physiol Ther. 2000 (Oct); 23 (8): 536–544Cox, James M.
Low Back Pain: Mechanism, diagnosis, and treatment.
Lippincott Williams & Wilkins, Sixth edition, 1998Shekelle PG, Adams AH, Chassin MR, Hurwitz EL, and Brook RH.
Spinal manipulation for low-back pain.
Ann Intern Med 1992;117:590-8Cassidy JD, Kirkaldy-Willis WH, McGregor M.
Spinal manipulation for the treatment of chronic low-back and leg pain: An observational study.
In: Buerger AA, Greenman PE, eds.
Empirical approaches to the validation of spinal manipulation.
Springfield, Il: Charles C. Thomas, 1985
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