One in four Americans will have lower back pain at some point in their lives. Men and women are affected equally, although for different reasons. Men tend to have disk problems and are more likely to receive surgical treatment. Women, on the other hand, have a higher rate of osteoporosis (thinning of the bones) which can result in compression and collapse of vertebrae; as well osteoarthritis which can interfere with the joint motion of the spine.
Lower back pain can be caused by abnormalities in the bones, ligaments, muscles or nerves. Some of these can be seen on X rays, CT or MRI scans, or determined by physical exam. Just as often, however, a person’s lower back pain cannot be explained by physical exam or imaging. This so-called idiopathic, meaning unexplainable, back pain is just as real but frustrating as it is difficult to treat a pain condition which cannot be defined.
Some familiarity with the complex anatomy of the spine is necessary in order to understand back pain. Twenty three interlocking vertebrae with several bony processes attached to them make up the spine. (8 cervical in the neck; 10 thoracic upper back; and 5 lumbar lower back). The lowest lumbar vertebra, L5, articulates with the sacrum, a large triangular bone at the bottom of the spine between the hips. Each vertebra has a solid cylindrical forward portion referred to as the vertebral body, with a bony ring attached to its back, that carries five different bony stubs called processes ( spinous processes, which you can feel or see through the skin, and transverse processes which carry small joints called facet joints whose motion allows bending of the spine. Within this bony ring lives the spinal cord which sends out nerve bundles called spinal ganglions (or nerve roots) through small holes on the side of bony spine, called foramina. These nerve roots fan out into the entire body, somewhat like the branches and twigs of a tree. Intervertebral disks made up of a gelatinous softer material and surround by a fibrous rings called annulus serve as shock- absorbing cushions between the vertebral bones. Strong ligaments as well as a complex arrangement of ligaments and muscles link the vertebrae and disks together and make the spine both stable and flexible.
Pressure or friction to the ganglia can cause pain either near the nerve root (back pain) or along the path of the nerves to organs and limbs, such as arms, legs, hands and feet.This explains, for example why numbness or pain in the foot can come from an injury to the fifth lumbar vertebra or symptoms in the hand can have their origin between the 5th and 6th cervical vertebrae in the neck. Back pain can also be caused by muscles surrounding the vertebral column contracting so forcefully in an effort to protect the spine from injury that it causes spasms = constant uncontrollable contractions.
WHAT TYPE OF INJURIES CAN HAPPEN TO THE SPINE, VERTEBRAL COLUMN AND NERVE ROOTS?
The most common injuries to the spine are sprains, injury to the many ligaments supporting the vertebral column; and strains which are injuries to the muscles and tendons surrounding the spine. These injuries cannot be shown with X rays or even MRI scans which explains why some people have back pain but no diagnosis for the cause of it.
Like any bone in the body, vertebrae and their attached posterior ring structures can break from severe blunt force, such as motor vehicle accidents, falls, or blows. Vertebrae can become unstable or break because of osteoporosis (thin bones) (called compression fractures) or by invasion of infections or tumors. Much more common is irritation of the spinal cord by either malalignment of the vertebral column (called spondylolisthesis),by disk bulging or prolapse, or, most commonly, bydegenerative changes in the bone and joint structures of the vertebral column. In recent years, smoking has been identified as a significant risk factor for disk disease.
Degenerative joint disease (DJD) of the spine is a gradual process and usually starts causing pain inthe second half of life. Prolonged hard physical labor, particularly lifting; extreme sports; poor posture (sitting desk and computer work) as well as familial diseases of the spine (such as rheumatoid arthritis) can cause back and leg pain, referred to as radiculopathy.
Poor muscle tone in the paraspinal muscles as well as the core muscles of the abdomen can contribute to back pain. This type of chronic back pain is usually most severe when a person changes position (from lying to sitting or sitting to standing) when bone grinds on bone between thevertebrae andin the spinal joints and the muscles of the back contract with force in their role of protecting the spine.
Spinal stenosis means narrowing of the spinal canal by either prolapsed disks or bone spurs or other malformations of the vertebral bones which can exert pressure on the nerve roots as well as the spinal cord. One characteristic symptom is leg pain on walking even short distances.
When the spine or the nerve roots get irritated, they respond by swelling (much like a blow to any body part will cause a ‘lump ” (the body producing fluid to cushion the injured area). The swelling increases the rubbing of nerves against bone which produces pain. One of the first line of defense against this cause of pain are so-called NSAIDs (non-steroidal anti-inflammatory drugs) of which Aspirin, Ibuprofen (Advil) and fenoprofen (Aleve) are the most widely used, as they are available without prescription. There are a number of topical creams and patches on the market which contain camphor, eucalyptus and other herbs, which produce a cooling sensation and dull pain, much like ice does. Short courses of steroids are also helpful in reducing the most acute pain from swelling. Other general pain meds (analgesics), such as Acetaminophen (Tylenol) can also help control the pain for a few hours.
Injecting steroid medication directly into the area of joint or nerve root injuries is called epidural block or facet block, typically preceded by an MRI (magnetic resonance imaging) of the spine to define the exact location of the injury responsible for the pain. In very severe cases, part of the nerve root from which the pain originates, can be “burnt” away permanently with an injected alcohol solution (ablation). Muscle relaxant medications also help with back pain, as do TENS (transdermal electrical nerve stimulation) units which are commercially available.
Chiropractic adjustments, massage, acupuncture and acupressure, as well as epidural steroid injections can also alleviate some of the pain. By far the most useful method to prevent and decrease chronic pain is exercise which can be done in physical therapy or at home. Strengthening of the paraspinal musculature as well as abdominal core muscles improve posture, help keep the spine well-aligned and protect against injuries.
Back surgery may be considered if severe lower back pain does not get better after 2-3 month of physical therapy. Most lower back surgery is decompression surgery which means an attempt is made to remove what is pressing on the spinal cord and/or the nerve roots. This can be the prolapsed portion of a disk or bone spurs, which can be removed by discectomyor laminectomy which is the removal of bone or soft tissue pressing on one or multiple nerve roots. Both procedures can be done via a small scope (endoscopy) or during an open procedure, depending on the size of the surgical field.
When symptoms are primarily caused by unstable vertebrae and its components, a fusion is sometimes helpful. This procedure immobilizes two or three contiguous vertebrae in order to prevent the motion which causes the pain.
Multiple studies have compared the outcomes for patients treated with physical therapy alone to patients who had surgery followed by physical therapy and rehabilitation. After one year, both groups fared equally well with respect to pain relief and mobility.
In both groups there were patients who continued to have low level discomfort with intermittent flare-ups of acute intense pain.
Living with chronic pain can be frustrating, even depressing. Most spine centers now have a pain management center where coping techniques such as relaxation, meditation, use of TENS (transcutaneous electrical nerve stimulation), bio feedback, hypnosis and other tools aretaught. There is no one solution for back pain. The best method for everyone is the one which best relieves pain and preserves mobility.