Lyn Lampman, M.R.T.

"My aching back!"  How many physicians have heard this phrase in their practices?

It is estimated that 75% of people of all ages and walks of life experience back pain at some point in their lives and that this problem accounts for 15% of sick leaves.  It is one of the most common complaints heard by today's physicians, affecting rich or poor and working or non-working classes.  Since we live in a society where we tend to sit all day in an office, commute to work by car and have little or no time for exercise, we are easy victims for low back pain.  After spending the past twenty years running a private x-ray clinic for orthopaedic surgeons, I will try in this article to help you understand the different diagnosis and treatments for this problem without going to into a great deal of complicated jargon.
The causes of low back pain are many and varied as are the means of diagnosis and treatment.  Low back pain is a symptom not a disease. Therefore, a certain degree of pessimism and fear often prevents the patients from seeking medical care. Unfortunately, some physicians, confronted with conflicting reports and multiple diagnostic and therapeutic methods, may themselves be pessimistic on how to treat low back pain problems.
With today’s advances in medicine most patients can be diagnosed, treated and with proper care return to normal activities.  The good news is that in the vast majority of these people, probably greater than 90% will recover completely without surgical treatments, only 2-3% of people with back pain will have a herniated disc and about 1% will have compression of a nerve root.
The evaluation of back pain requires a physician experienced in this specialty.  The workup begins with a detailed history and physical examination. The specialist will ask about the quality of the pain, where it radiates, factors that worsen or alleviate the pain and other related questions. The physical examination concentrates on motor and sensory function.  Radiographic evaluation may be indicated, usually starting with a set of plain X-rays.  Over the years, I have x-rayed patients with severe low back pain only to discover a gallbladder full of stones.  Removal of the gallbladder in some of these cases alleviated the pain.  If your physician is suspicious of a structural lesion, based on the history and examination, one or more of the following additional studies may be performed:


The back is a chain of blocks (the vertebrae) stacked one on the other and kept from collapsing by an exact system of muscles and ligaments that act with synergistic (co-operative) and antagonistic (opposing) precision. It completely encloses and protects the spinal column, acts as a flexible support to the trunk and as a central axis of limb movement. Thirty-three spinal vertebrae are held together by multiple ligaments and interposed cartilages: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused into one) and 4 coccygeal (often fused into one). The vertebrae of each group have features that distinguish them from the vertebrae of the other groups.  No two vertebrae are exactly the same and each is modified so that its position in the spine can be recognized. A developing fetus, you have probably noticed, develops with a forward curve (kyphotic) in the womb.  Shortly after birth, the spine develops its normal cervical and lumbar lordoses with compensatory thoracic and sacral kyphoses.
Since low back pain usually stems from problems affecting the lumbar vertebrae and sacrum, this discussion will give primary emphasis to the lumbosacral area.
The lumbar vertebrae are large and massive because of their weight-bearing functions. AP views of the lumbar area show the body, laminae, spinous processes, transverse processes and the intervertebral disc spaces. The lateral view demonstrates the bodies, disc spaces and intervertebral foramina, intervertebral joints and the spinous processes. Oblique views of the lumbosacral junction are sometimes required for the demonstration of the part of the neural arch between the superior and inferior articular processes.

Classification and Different Diagnosis

Mechanical Back Pain

Also known as a "back strain". The diagnosis excludes anatomic sources of origin such as disc herniation, spondylosis, etc. The causes may be multifactoral, including strain of the muscles of along the spine, strain of ligaments of the spine, degenerative facet joint disease (the joints between the bones of the spine) or others. Poor muscle tone is a common cause of muscle strains and ligament sprains. When hip pathology is suspected (e.g.-osteoarthritis or necrosis) hip x-rays can assist the diagnosis. Lumbar scoliosis in adolescence can later cause severe back pain when the patient reaches adulthood.

Degenerative Disorders

Osteoarthritis is a wear and tear problem and is associated with degenerative changes in the articular cartilage. In the vertebral column, the facet joints are involved. Repeat trauma, such as excessive and strenuous exercise pursuits during the teen years, plays a role but doesn't completely explain the disease. Heredity and obesity contribute to the etiology. It is well known that the human spine begins to "squeak & rattle" with increased trauma, obesity and age. The following example shows degeneration of the intervertebral discs with changes at the vertebral margins and osteophyte (spur) formation.  Notice the narrowing of the disc space.

Congenital Disorders

Minor anomalies of the vertebrae are so common that a variation from "the norm" is not always considered the cause of back pain. A change in the number of vertebrae in the lumbar spine is the most significant congenital anomaly that can cause low back pain. Lumbarization of the first sacral vertebral gives the patient individual six lumbar vertebrae and causes a greater stress on the lumbosacral joint. Sacralization of the fifth lumbar vertebra, which results in four lumbar vertebrae, is unlikely to cause symptoms when the entire vertebra is incorporated into the sacrum. The most common form of sacralization is for one of the transverse processes of the fifth to be enlarged and joined to the sacrum. This may cause strain on the side opposite the sacralization.


This is described as pain radiating into the buttock, back of the thigh and often into the calf and foot. It is usually caused by irritation of a sciatic nerve root, often from compression by a disc or degenerative disease.

Herniated Disc

Also known as herniated nucleus pulposus, disc rupture or disc prolapse. Ruptured discs are among the most common and painful of all back ailments. The intervertebral discs are cartilaginous plates, surrounded by a fibrous ring, that lie between the vertebral bodies and serve to cushion them. Through degeneration, wear and tear or trauma the fibrous tissue (annulus fibrosus) constraining the soft disc material (nucleus pulposus) may tear. This results in protrusion of the disc or even extrusion of disc material into the spinal canal or neural foramen. In addition, the motor fibers of the affected root are also compressed and this situation leads to atrophy and weakness in the appropriate muscles. This is known as a herniated, ruptured or prolapsed disc. The most common complaint in patients with a herniated disc is that of severe low back pain developing immediately or within a few hours after an injury. Often the patient (usually between the ages of thirty and fifty years) tells of heavy lifting or a twisting motion while moving a heavy object. The pain, accentuated by forward bending, sneezing or straining, is associated with severe muscle spasm. There is flattening of the lumbar area from loss of the normal lumbar lordosis.

The disc herniation may become significant if a nerve root is compressed. Irritation of the nerve root produces pain in the distribution of that nerve.  Different levels of nerve root compression cause different symptoms.  Compression of the nerve root at L4&5 causes pain over the sacroiliac joint and the lateral thigh and leg with difficulty walking on heels. Whereas a compression of the nerve root at L5S1 causes pain over the sacroiliac joint, hip, back and lateral side of leg down to the heel with difficulty walking on toes. For this reason, a herniated lumbar disc normally produces sciatica but not the back pain per se. If sensory function of the impinged nerve root is impaired, numbness will result, the exact area determined by the particular root.

The actual amount of disability from a disc depends on several mechanical factors:

For example, some patients have a very narrow canal so even a small herniation will cause severe symptoms whereas others may have a large canal so a small herniation will have little effect.
Diagnosis should be suspected from the history and physical examination. Radiographic studies should be done to make a define diagnoses and define its location. It is impossible to diagnose disc protrusion by simple X-rays. Generally an MRI provides excellent detail. A CT scan, while inferior to MRI in soft tissue detail, is superior in bony detail and faster and less expensive. A good quality CT is often sufficient in an uncomplicated herniated lumbar disc. A myelogram with a CT gives excellent definition of the spaces around the nerve roots but its disadvantage is the injection of contrast dye through a lumbar puncture.
The mainstay of therapy for a herniated lumbar disc is conservative treatment, that is, nonsurgical. In the majority of patients the symptoms resolve or subside to a level allowing normal activity within two to three weeks. If rest with limited activities fails, surgery may be considered.
Surgery for removal of a herniated lumbar disc has been one of the most commonly performed procedures. Up until the past 5 years or so, the procedure has been fairly standard. An incision is made vertically along the midline of the back, usually about 2 inches long. Some of the muscles overlying the bone (lamina) that forms the back of the spinal canal are separated off the bone. A small window is drilled in the laminae overlying the herniation. The nerve root is identified and gently retracted away to expose the offending herniation. The disc material is then removed and the wound is closed in a way that restores the normal anatomic layers.
Postoperative recovery is relatively short. Patients are walking the same night or the next morning and discharged home in three or four days. The recovery period is about six to eight weeks. The vast majority of patients experience permanent relief of pain. Recovery of motor function is variable.
Nowadays, a new endoscopic procedure referred to as MicroEndoscopic Discectomy (MED) significantly reduces hospital stays and recovery time for many people suffering from herniated discs. The objective is to decompress the nerve root. Approximately 75% of patients with herniated discs are candidates for this procedure. The surgery can be performed on an outpatient basis. The MED procedure uses microsurgical and endoscopic techniques with advanced optical systems. Instruments are inserted into the back through a tube slightly larger than a fountain pen. Doctors perform the surgery while viewing a video monitor. The procedure is less painful, requires only a half inch incision and patients are back at work within seven to ten days. The success rate: 93% excellent, 7% good. The only drawback is not that many hospitals are equipped with the MED system.

Lumbar Stenosis (Spondylosis)

The term lumbar stenosis refers to any narrowing of the spinal canal. The most common cause is degenerative, occurring with aging in essentially the entire population. The degenerative narrowing is referred to as spondylosis. This is a complex problem requiring an individualized approach for each patient, by an experienced specialist. Another cause of stenosis is the slippage of one vertebra on another with disalignment and causing narrowing of the canal. This slippage is called spondylolisthesis that will be dealt with at a later point.
Several factors contribute to the narrowing of the spinal canal with degenerative changes. Arthritis often causes spondylosis so it is often seen in older patients. First, wear and tear causes the joints (facets) to hypertrophy. This may be analogous to degeneration and swelling of other joints in the body. Second, the major ligament of the spinal canal undergoes hypertrophy and buckling. Third, the intervertebral disc may bulge or herniate. Fourth, as mention previously, the vertebrae may slip forward. Finally these changes may be superimposed on a congenitally narrow canal.

Spondylolysis & Spondylolisthesis

Spondylolysis is a defect in the isthmus (pars inarticularis) that is the supporting structure of the vertebra. This can have many causes including degeneration, trauma and congenital defects. Spondylolisthesis is a defect in both sides of the vertebra through the pars, with anterior slipping of the vertebral body. The slippage is classified from grade I to IV. A grade I spondylolisthesis means displacement up to 25% and a grade IV slip means a complete forward displacement of the affected vertebral body. The fifth lumbar vertebra is most commonly affected followed in frequency by the fourth vertebra. Symptoms usually come from the spinal nerves that may be pinched as the vertebra slips forward. While both spondylolysis and spondylolisthesis can be congenital most cases are acquired and repeated stress is considered to be the cause.

Oblique x-rays of the lumbosacral spine demonstrate pictures characteristic of each condition. For example, on an oblique x-ray, a normal vertebra gives the appearance of a "Scotty dog". If the "Scotty dog" is wearing a collar, there is a defect in the pars interarticularis and the patient has spondylolysis. If the head of the "Scotty dog" is separated from the neck, the patient has spondylolisthesis.

Posterior oblique view demonstrating formation of radiographic "Scotty dog". On left side from top to bottom:

In simple spondylolysis, on the left, the dog appears to be wearing a collar. In spondylolisthesis, on the right, the dog appears decapitated.

Trauma is the most frequent cause of back pain. Every day people injure their backs because of foolish lifting practices, a fall, an athletic injury or a possible MVA. The main reason for the majority of these injuries is that so many people are in poor physical condition. Most muscle strains and back pain could be avoided by proper weight control and daily exercise to keep trim and retain good muscle tone. Most people, as they pass thirty years of age, become physically sluggish, gain weight and exercise sporadically, if at all. When they do, "common sense" is not very common and exercise is often a strenuous workout at a strenuous sport. Low back pain is also very common in pregnant women with excessive weight gain who fail to recondition themselves after delivery. They develop poor muscle tone, obesity, and spinal decompensation leading to chronic pain.

Compression fractures usually result from a fall and generally affect the lower thoracic and upper lumbar area. They are easily diagnosed on an x-ray by their wedge-shaped appearance and seem to respond well to bed rest. However, if the patient is osteoporotic the trauma needed to fracture a vertebra is sometimes very trivial-a minor slip or fall, etc. Therefore, middle-aged and upward patients, women being more prevalent, account for a great majority of compression fractures.

Fracture dislocation


In this article I have briefly touched upon the various mechanisms and causes of low back pain in the hope that the information I have related to you will be easy to understand and beneficial to family, friends and technicians in the approach to the patient with low back pain. There are, of course, more serious problems, a lot more complicated that what my article has dealt with. You have probably in your own practice seen the insertion of certain types of hardware because of the major advances in back surgery over the past five to ten years. The reasoning behind this type of surgery is more appropriately dealt with by the specialists in order that there is no misinterpretation. As mentioned previously, with modern diagnostic methods and the skills of today's physicians and surgeons, a great number of these people can be effectively treated to lead relatively normal lives.

Illustrations thanks to Dr. Frank H. Netter. M.D.

This site was lasted updated April 25/09

Sign My Guest bookGuestbook by GuestWorldView My Guest book

Comments Welcome