Evaluation and Treatment of Low Back Pain

The evaluation and treatment of patients who present with low back pain requires an in-depth understanding, not only of the spine but of the degenerative process as well as the mechanism of pain production. 

Low back pain is not a diagnosis. There are over 100 possible causes for low back pain. Possible etiologies may be divided into categories to include congenital, inflammatory, infectious, metabolic, neoplastic, degenerative, traumatic, and physiological. 

The evaluation of patients who present with a worker’s compensation injury, however, usually present with some form of minor trauma, superimposed upon the degenerative process which will be covered.

The scope of low back pain is quite broad. 80-90 percent of people experience low back pain during their lifetime. 20-30 percent of people will have some form of low back pain at any given time. 90 percent of these cases will evolve in 4-6 weeks. 50 percent have recurrent bouts of low back pain. 

Does low back pain represent an injury or illness?
In order to understand why low back injuries seem to be increasing, one must look at history and the present worker’s compensation system. This system allows full treatment for all injuries, which occur on the job. This is a no-fault system. The incidence of back pain does not appear to be increasing but the interpretation and the onset seems to be changing under this scenario. What used to be "oh my aching back" has now become "oh my injured back". 

The full understanding of how the back works will make it easier to understand the present etiology of work related injuries to the low back. The back is a highly specialized organ with the spinal column connected to the pelvis which is supported by very large muscles including the abdominal as well as rectus spinae back muscle groups. Five lumbar vertebra compose the low back region. The back is composed of an anterior column, a posterior column with intervertebral discs between each vertebrae. Each joint is a tri-joint complex with two facet joints posteriorly and the disc joint anteriorly. The disc is composed of a very strong group of fibers around the outer third (the annulus fibrosis.) The inner two thirds are composed of a nucleus pulposis. There are strong reinforcing ligaments, the anterior longitudinal ligament, anteriorly and posteriorly consisting of the posterior longitudinal ligament.

Osteoarthritis is a wear and tear phenomena that is the end-stage result of the degenerative process. The degenerative cascade in the lumbar spine is composed of the process from normal disc early in life to the final stages of advanced osteoarthritis called the stage of stenosis. The stages of the degenerative cascade include the stage of dysfunction, prolapsing stage, instability stage, internal disc disruption and stenosis. The stages of disc injury start from a healthy normal disc, going through the same stages of annular degeneration and annular disruption which leads to several sets of symptoms which may occur in all phases of the degenerative cascade which may lead to the onset of low back pain with apparent superimposed minor trauma. The pain is secondary to a highly rich nerve supply in the outer one-third of the annulus, which may lead to the onset of low back pain and radiating leg pain. 

The onset of low back pain is usually the result of minor trauma. Severe trauma usually results in fractures, dislocations, and even paralysis.

The onset of low back pain requires a complete evaluation and appropriate treatment. There are many forms of treatment, which may be appropriate. A correct diagnosis will lead to the most appropriate treatment and ultimately will be the most cost effective. 

The distinction must be made between acute and chronic pain. Acute pain is usually directly related to the peripheral stimulus and tissue damage. Acute pain, acute disability and acute illness behavior are generally related to physical findings. The treatment for acute pain should be directed to the underlying physical disorder, which is highly effective in relieving acute pain. 

Chronic pain is a clinical syndrome completely different from acute pain. Chronic pain, chronic disability and chronic illness in contrast become increasingly disassociated from the physical problem. There is less and less objective evidence of any remaining stimulus or tissue damage. The appropriate treatment for acute low back pain may include immobilization as well as bed rest for no more than two days. Medications to include non-steroid anti-inflammatories and steroids, which are most effective for, nerve root irritation and radicular pain. Pain pills and muscle relaxants are more effective for acute low back pain. These medications seem to have little benefit for chronic pain. 

Physical therapy in the form of passive modalities such as heat, massage, ultrasound muscle stimulation as well as manipulations may be helpful in the acute phases and seem to make the patients feel better faster. These modalities have little benefit past the acute phase in most instances. The patient should return to light duty if that is available. 

As the patient improves, he should continue with a walking program with the addition of a stretching and strengthening exercise program. Careful review of the back care program with the initiation of the stabilization exercise program and back school training is usually most helpful. Further progression to an aerobic and reconditioning program may be necessary in preparation for returning back to heavy manual labor. Physical fitness has been shown to decrease the incidence of back injuries but is not totally protective. 

Acute becomes chronic when proper exercise is not performed. It is important for the physician to make the correct diagnosis and initiate appropriate treatment. The physician should begin with the end in mind. The patient should progress with improvement through the treatment cycle to prevent the formation of the chronic pain syndrome. The chronic pain syndrome occurs in a very predictable manner beginning with initiation of pain, which leads to muscle guarding. Decreased circulation of the muscle occurs, which decreases the metabolism and restricts the motion. Once restricted motion and pain occurs, the individual stops moving, weakness develops in the muscle, further stiffness occurs and the pain cycle is initiated. These painful syndromes may lead to such diagnoses such as myofacial pain syndrome and fibromyalgia. The best treatment for chronic low back pain is prevention in the acute phase. There is no effective treatment, which will quickly eliminate these painful syndromes once they are fully established. Ultimately the responsibility must be shifted back to the patient for care of his back. Our goal is to minimize the pain and maximize the patient’s function.