Health

Definition of Terms
Low back pain is a symptom, not a disease. As such, low back pain may lead to several very different diagnoses with very different treatment plans.

What follows is a pathway that may help you understand what your doctor is thinking.

First of all, what is pain? The International Association for the Study of Pain defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” Often the patient and doctor just focus on the physical aspect of pain; clearly, however, using this definition, pain is an emotional experience as well.

The Pain Experience
If you look at pain pathway diagrams in medical textbooks, it will quickly become clear that the physical and emotional experience of pain is a very complex one. For the lay person, it is not important to memorize or understand the whole pathway. What is important is the understanding that there are many pathways that lead to the experience of pain. Thus there are also many ways to treat the experience of pain. This is why so many varied treatments may all be effective in decreasing pain.

Now that we know how we experience pain, what do we do when we have back pain? If it does not go away on its own, we often visit a doctor. In fact, low back pain is one of the leading causes for a consultation with a doctor.

Mechanical and Non-Mechanical Back Pain
Mechanical back pain is caused by abnormalities in the joints, ligaments or muscles. These abnormalities can eventually lead to degeneration or arthritis of joints in the spine or abnormalities in the disc. The first thing that a doctor often does is to make sure that the pain is indeed mechanical back pain and not due to something else like cancer, infection or pain from an abdominal organ. Red flags or danger signs that may lead one to think of these other diagnoses are sudden and severe low back pain, numbness in the groin area, severe and progressive symptoms such as increasing weakness, bowel or bladder incontinence or lack of control, muscle weakness or previous surgery associated with persistent pain. These symptoms should lead your physician to be more suspicious of other more dangerous diagnoses. Aggressive testing may be necessary. Non-mechanical spine diagnoses should also be considered, such as neurologic (brain or spinal cord), vascular (blood vessel), gynecologic (female reproductive system), genitourinary (urinary tract), cervical (neck) or thoracic (back at the level of the chest) problems, hip and leg disorders and abdominal organ disease.

If none of these findings are present, then mechanical back pain may be the cause.

The pathway for the treatment of mechanical back pain that follows is adapted from the the North American Spine Society (NASS) Guidelines and the work of Robin McKenzie and Stanley Herring.

Types of Mechanical Back Pain
One way of thinking of mechanical back pain is to organize them into three groups as proposed by Robin McKenzie:  postural, dysfunction and derangement.

All three arise from mechanical deformation of soft tissue such as muscles, nerves or ligaments. The cause for the deformation is where the three differ.

Postural problems arise from poor posture or the way one carries his or her body. Since it is due to postural stresses, it comes and goes based on one’s body position. Certain positions should make it worse, and other positions should make it better.

In dysfunction, the cause is shortened structures such as a muscle. This leads to loss of movement in certain directions. It is characterized by intermittent or on-and-off pain with loss of movement. Diagnoses that fall in this category include low back strain (injury to ligaments) and myofascial pain (injury or knots in muscles).

Finally, derangements are due to abnormalities in structures inside joints. These include osteoarthritis, herniated disc, spinal stenosis, spondylolisthesis, spondylolysis and instability.

Primary Level of Care

Non-Surgical Treatment Options
Once a diagnosis of mechanical back pain (as previously defined) is made, the patient may be started on a course of non-surgical treatment that would consist of activity modification, medications, self-applied thermal modalities and physical therapy.

Activity modification means adjusting activity so that structures are not further stressed. This may be achieved by joint conservation (protecting the joint) or energy conservation (increasing efficiency of how an activity is done) techniques.

Medications include analgesics like acetaminophen, Non-steroidal anti-inflammatory drugs (NSAID) like ibuprofen, steroids like prednisone and opiates like morphine. NSAIDs and steroids decrease inflammation or swelling. Analgesics and opiates relieve pain without necessarily affecting the cause of the pain. Depending on what the doctors are trying to achieve, they may use none, one or a combination of the medications mentioned.

Thermal modalities include the use of heat or cold. Some examples are hot or cold packs, ice massages or ultrasound.

Physical therapy consists of exercises that try to balance muscles through stretching and strengthening. There are many styles of exercise; none are proven to be more effective than others.

Framework for Non-Surgical Treatment Options
One can combine the non-surgical treatment options above in many ways; there is no one way proven to be the most effective. There are certain similarities to these approaches, however, and one way of thinking of these methods is using a framework proposed by Stanley Herring.

When one develops mechanical back pain, five things need to be addressed:

1.  Clinical symptoms refer to the pain and movement limitations that one experiences.
2.  Tissue injury refers to the actual body part that is injured.
3.  Tissue overload refers to the other body parts that are overloaded to make up for the problems caused by the initial injured body part.
4.  Functional biomechanical deficits refer to tightness or weakness that results when tissues are injured or overloaded.
5.  Finally, the patient presents with substitution patterns to make up for the injury.

As an example, a patient may have a disc herniation from bending forward too quickly while carrying a heavy load. The clinical symptom is pain in the back. The tissue injury is the herniated disc. This leads to spasms in the back muscles, leading to tissue overload. This may then lead to tightness in the back muscles and weakening of the abdominal muscles, leading to functional biomechanical deficits. In order to continue to move without causing increased low back pain, the patient may move his neck or hips in a different manner, which in turn could lead to problems in these new areas due to these substitution patterns.

The goals of treatment are to decrease symptoms, restore lost function and avoid recurrence of symptoms.

We can divide the non-surgical treatment process into three phases:  acute, recovery and functional.

In the acute phase, the goal is adequate tissue healing. At this point, the areas affected should have relative rest. Total rest is not advocated since it can lead to deconditioning, a problem in itself. Medications and thermal therapeutic methods may be used. Initial exercise and physical therapy may be initiated. This period usually lasts for a few days.

The recovery phase starts 1-2 weeks after an injury, usually lasting several weeks. The goal is complete tissue healing which in most cases, given a good environment for healing, occurs in 4-6 weeks. During this time, the focus should be more aggressive physical therapy. Increased flexibility or suppleness of muscles is important. Regaining increased control over movement (neuromuscular retraining) and proprioceptive training (knowing where a joint is in space to improve control of movement) needs to be achieved. Strength is increased through progressive exercise.

Finally in the functional phase, the goal is good overall fitness and body mechanics (movement). Power (explosive strength) and endurance are important. Training in specific movements or skills is carried out during this phase to help patients get back to their previous level of activity.

If the problems are resolved using the non-surgical means discussed here, then the patient can return to regular activity with a home exercise program to maintain functional gains.

Secondary Level of Care

Re-evaluation
If it is unresolved after 4-6 weeks, the patient should be examined again and the signs and symptoms reviewed by the physician. At this point, plain lumbar spine x-rays should probably be taken. If the x-rays are normal, physical therapy should again be initiated and new medications may be tried.

If abnormalities are found in either the physical examination or the tests, referral to a back specialist should be considered.

The specialist will then again review the patient’s recounting of how the symptoms started (history) and do another physical examination. The plain x-ray should be reviewed. At this point, additional views – flexion, extension and oblique – should be considered. These views enhance the detection of specific disorders.

The specialist may consider repeating the same treatment. Non-mechanical spine diagnoses should again be considered such as neurologic, vascular, gynecologic, genitourinary, cervical or thoracic problems, hip and leg disorders and abdominal organ disease. If the diagnosis is truly arising from the lower back, the most likely diagnoses are herniated disc, spondylosis or spondylolisthesis, spinal stenosis and low back instability

Common Diagnoses

Herniated Disc
A herniated disc, a protruded vertebral disc, can cause pinching of the spinal cord or nerves. It commonly affects 20-50 year old adults. Pain predominantly affects the legs and buttocks. There may or may not be neurologic deficits (nerve damage usually manifested as weakness or numbness). There may also be pain with movement that stretches nerves such as when the doctor elevates the straightened leg of the patient while the latter lays on the examining table.

If the symptoms are mild to moderate, non-operative treatment described above may again be done.

If the problem is more severe as manifested by neurologic deficits (weakness, numbness or changes in reflexes), disabling leg pain, or as decided by the patient, then confirmatory studies may be considered. This would consist of MRI, CT scan, CT myelogram or electrodiagnostic testing. At this point surgical options would be discectomy or decompression. These surgeries will be discussed under Surgical Treatment Options.

Spinal Stenosis
Spinal Stenosis, or tightness of the spinal canal, also leads to pinching of the spinal cord or nerves. It usually presents in patients over 50 years old since it is usually due to osteoarthritis. Back and leg pain usually worsen with standing or walking since these positions lead to an increased tightness in the spinal canal because of the way the ligaments are positioned. There may or may not be neurologic findings.

For mild to moderate symptoms, non-operative treatment previously described may be tried again. In addition, corticosteroid injections may be tried. Corticosteroids or steroids relieve inflammation or swelling of body structures. In the case of spinal stenosis, the covering of the nerves may get swollen from constant hitting against the tight walls of the spinal canal. With this swelling, the canal gets even tighter leading to more difficult nerve gliding and, therefore, more pain. By injecting steroids into the canal, the swelling of the nerve covering is decreased, leading to more space and less pain. A series of three injections is often done.

If severe, as manifested by neurologic symptoms, disabling pain or decided by the patient, confirmatory studies such as MRI, CT, CT myelogram or electrodiagnostic testing may be done. At this point, surgical options would be posterior decompression with or without fusion or instrumentation. These surgeries will be discussed under Surgical Treatment Options.

Spondylolysis and Spondylolisthesis
Spondylolysis is a defect in the pars interarticularis of a vertebra. This is a portion of the bone between the superior and inferior articular facets. Spondylolisthesis is fracture of a vertebra followed by dislocation or movement away from another vertebra. This manifests as back pain with or without leg pain. Pain is increased by activity. The patient may or may not have neurologic deficits. To confirm or exclude this diagnosis, the following tests may be done:  (X-ray), MRI, CT, CT myelogram, Bone Scan, Discography, Facet/Lysis injection, Psychiatric Evaluation, Functional Capacity Evaluation. If non-operative management as previously outlined does not work, surgical interventions may include decompression, fusion or instrumentation. These surgeries will be discussed under Surgical Treatment Options.

Instability
Finally, the pain may be due to instability of the spine. The manifestation is predominantly back pain with or without leg pain. Muscle guarding or spasms may be found as well as decreased range of motion. To confirm or exclude this diagnosis, the following tests may be done: MRI, CT, CT myelogram, Bone Scan, Discography, Facet/Lysis injection, Psychiatric Evaluation or Functional Capacity Evaluation. If non-operative management as outlined above does not work, surgical treatment may be done with fusion of the vertebrae. These surgeries will be discussed under Surgical Treatment Options.

Surgical Treatment Options
Following is a description of surgical interventions. The two main goals of surgery are decompression and stabilization. Decompression leads to an increase in the space for the spinal cord or nerves allowing them to function. Stabilization leads to decreased movement of the spinal joints.

Discectomy
Discectomy leads to decompression. It removes a part of or the whole disc. When a disc herniates, it can pinch the spinal cord or a nerve, leading to neurologic problems and pain. Removing a part of or the entire disc relieves the pressure on the spinal cord or nerves, allowing them to function normally.

Laminoplasty or Laminectomy
Decompression of the spine may also be achieved through laminoplasty or laminectomy. The back of the vertebra is called the lamina. Removal of this part of the vertebra allows the structures inside, specifically the spinal cord or nerves, to have more space so they can function normally. Laminoplasty is removal of part of the lamina. Laminectomy is the removal of the whole lamina.

Fusion
Fusion is the merging together of vertebrae after a disc is removed. This is achieved by using bone grafts from the hip with or without fusion cages (metal cages placed between the vertebrae and filled with bone grafts encouraging bone ingrowth).

Instrumentation
Instrumentation is used to enhance fusion. It uses screws attached to plates or rods to help stabilize fused vertebrae.

Tertiary Level of Care
If pain persists after surgery, this could be due to non-operative, operative or structural issues.

Non-operative issues may include biomechanical dysfunction, systemic disease, psychosocial issues or deconditioning.

Biomechanical dysfunction is a problem arising from abnormal body structures leading to faulty body movement and therefore pain.

Systemic disease includes such things as rheumatoid arthritis, which leads to problems of muscles and bones as well as other organs.

Psychosocial issues include problems such as poor job satisfaction, poor family support and mental illness.

Deconditioning refers to loss of flexibility, strength, endurance and cardiovascular fitness from disuse, which often occurs due to decreased activity because of pain.

If these issues are the source of the problem, then referral to a non-operative back specialist may be needed. Focusing on activities of daily living despite symptoms is an option. Palliative care, focusing on relief of symptoms rather than cure, may be another. If questions of compensation or litigation are involved, then the patient may be labeled as having reached Maximum Medical Improvement (MMI) which means that the patient has achieved the best level of function that may be expected after maximizing medical treatment of the disease.

Operative issues are often associated with spinal stenosis, spondylolysis, spondylolisthesis or instability. It could be due to incomplete diagnosis; incomplete treatment; or complications such as infection, hardware failure, pseudoarthrosis or fracture.

Failed improvement after herniated disc surgery is often due to structural or soft tissue issues. This may be because of recurrent herniation, stenosis or instability.

Further surgery or multi-interdisciplinary assessment may need to be done.