BACK PAIN

The back is a remarkable combination of anatomical structures that are designed to function with a great deal of flexibility and strength and provide structure. When something goes wrong, back pain can take over our lives.

Muscle strain is the most common form of back pain, but other cause are also common, such as a herniated disc, degenerated disc, osteoarthritis, and spinal stenosis, among others. Back pain can occur suddenly or develop slowly over time. It can be centered in one area of the back or travel to the arms, legs and other extremities.

Treatments vary considerably and many forms of back pain treatment may work well for one person, but not another. Trial and error is often employed to select the most effective back pain management course.

ARTHRITIS AND OSTEOARTHRITIS

Arthritis is a general term that describes many different diseases that cause tenderness, pain, swelling and stiffness of the joints, as well as abnormalities of various soft tissues of the body. Some of the most common forms of arthritis include rheumatoid arthritis, osteoarthritis, fibromyalgia and (less common) ankylosing spondylosis.

With osteoarthritis, the cartilage around the joint wears out and causes the two halves of the joint to rub against each other, creating inflammation with pain. In the spine, osteoarthritis causes the small joints in the back of the spine column (facet joints) to wear out, reducing flexibility and causing back pain. Over time, bone spurs (osteophytes ) typically form and may irritate or press in the nerves, causing back pain or spinal stenosis and sciatica symptoms.

SPONDYLOSIS

Spondylosis (spinal osteoarthritis) is a degenerative disorder that may cause loss of normal spinal structure and function. Although aging is the primary cause, the location and rate of degeneration is individual. The degenerative process of Spondylosis may affect the cervical (neck), thoracic (mid-back), or lumbar (low back) regions of the spine.

Spondylosis often affects the following spinal elements

Intervertebral Discs as people age, certain biochemical changes occur affecting tissue found throughout the body. In the spine, the structure of the intervertebral discs (annulus fibrosis, lamellae, nucleus pulposus) may be compromised. The annulus fibrosis (eg- tire-like) is composed of 60 or more concentric bands of collagen fiber termed lamellae. The nucleus pulposus is a gel-like substance inside the intervertebral disc encased by the annulus fibrosis. Collagen fibers form the nucleus along with water and proteoglycans. The degenerative effects of aging can weaken the annulus fibrosis structure, causing the 'tire tread' to wear or tear. The water content of the nucleus decreases with age affecting its ability to rebound following compression (e.g. shock absorbing quality). The structural alterations from degeneration may decrease disc height and increase the risk for disc herniation.

Facet Joints (or Zygapophyseal Joints) The facet joints are also termed zygapophyseal joints. Each vertebral body has four facet joints that work like hinges. These are the articulating (moving) joints of the spine that enable extension, flexion, and rotation. Like other joints, the bony articulating surfaces are coated with cartilage. Cartilage is a special type of connective tissue that provides a self-lubricating and low-friction gliding surface. Facet joint degeneration causes loss of cartilage and formation of osteophytes (eg, bone spurs). These changes may cause hypertrophy or osteoarthritis, also known as degenerative joint disease.

HERNIATED DISC

As a disc degenerates, the soft inner gel in the disc can leak back into the spinal canal. This is known as disc herniation, or herniated disc. Once inside the spinal canal, the herniated disc material then puts pressure on the nerve, causing pain to radiate down the nerve leading to sciatica or leg pain (from a herniated disc in the lumbar or lower back) or arm pain (from a herniated disc in the neck).

Progression of Herniated Disc
There are four stages to the formation of a herniated disc, as shown here

1. Disc Degeneration: During the first stage, the nucleus pulposus weakens due to chemical changes in the disc associated with age. At this state no bulging (herniation) occurs.
2. Prolapse: During prolapse, the form or position of the disc changes. A slight bulge or protrusion begins to form, which might begin to crowd the spinal cord.
3. Extrusion: During extrusion, the gel-like nucleus pulposus breaks through the tire-like wall of the annulus fibrosis but still remains within the disc.
4. Sequestration: During the last stage the nucleus pulposus breaks through the annulus fibrosis and even moves outside the disc in the spinal canal.
   

LUMBAR RADICULOPATHY

Approximately 80% of the population is plagued at one time or another by back pain. Associated leg pain occurs less frequently. Pain can be bothersome and debilitating, limiting daily activities. Leg and back pain can be caused by a variety of reasons, not all of which originate from your spine.

For the purpose of this article, we will focus on lumbar radiculopathy, which refers to pain in the lower extremities in a dermatomal pattern. A dermatome is a specific area in the lower extremity innervated by a specific lumbar nerve. This pain is caused by compression of the roots of the spinal nerves in the lumbar region of the spine. Diagnosing leg and back pain begins with a detailed patient history and examination.

Medical History
Your medical history helps the physician understand the problem. It is important to be specific when answering medical questions related to pain onset but remembering every detail is often not critical. Keeping records of your medical history, including medical problems, medications you are taking and surgeries you have had in the past is helpful.

Regarding your leg and back pain, it may be helpful to keep a journal of your activities, documenting when the pain began, the activities that aggravate your pain and those that relieve your symptoms. It is also important to determine whether your back pain is more bothersome than your leg pain or vice versa. You may be asked if you are experiencing any numbness or weakness in your legs or any difficulty walking. Remember, understanding the cause of your problem is based on the information you provide.

Most people describe radicular pain as a sharp or burning pain that shoots down the leg. This is what some people call sciatica. This pain may or may not begin in the low back. Leg pain caused by compressed nerve roots generally has specific patterns. These patterns of pain depend on the level of the nerve being compressed. After reviewing your history, your physician will perform a physical examination. This will help the physician determine if your symptoms are due to a problem that is caused by spinal nerve root compression. To help you understand, the exam performed by your physician lets pause for a quick anatomy lesson.

Anatomy
The spine is comprised of 33 vertebrae (bones stacked on top of each other in a "building-block" fashion) that have 4 distinct regions: Cervical, Thoracic, Lumbar, and Sacral. Discs, cushion-like tissues separate most vertebrae and act as the spine's shock absorbing system. The disc has a tough outer ring of fibers called the Annulus Fibrosis and a soft gel-like center called the Nucleus Pulposus.