A spinal injury usually refers to an accident that damages the vertebral column and may likewise injure the spinal cord and/or spinal nerves. When a spinal injury affects the spinal cord or the spinal nerves, it is because of the proximate anatomical relationship between the vertebral column and spinal cord with its emerging spinal nerves.
There are four main types of spinal injury – dislocation, fracture, sprain, and herniated intervertebral disk. Of the four, herniated intervertebral disk is considered the most common type.
The intervertebral disks are tough, elastic disks that are interposed between the centra of adjoining vertebrae to provide for cushioning as well as to allow for a certain amount of flexibility. There are a total of twenty-three intervertebral disks in the spine. Each of these is composed of a softer central part (nucleus pulposus) and a surrounding ring of dense tissue (anulus fibrosus).
Once a disk is injured, the nucleus pulposus often protrudes through the damaged part of the anulus fibrosus. This brings pressure against an adjacent nerve root and causes discomfort and often some loss of function. The most common site in which a herniated intervertebral disk occurs is the lumbar region of the lower back. This is followed by the lower part of the neck.
Lifting a heavy object while in a twisted or stooping position is the usual cause of damage to an intervertebral disk in the lumbar region. At the time of the initial injury, the victim will usually experience pain for a few days, a back muscle pull or a neck muscle spasm. Some time later, the nucleus pulposus actually squeezes out and causes pressure upon the adjacent nerve root. This, in turn, causes pain that radiates along the nerve thus compressed.
Pain from a herniated intervertebral disk in the lower back often affects the buttock and the side and back of the leg and thigh. Numbness and tingling is usually felt in the same area. Sneezing or coughing or straining at stool aggravates the pain. Stooping or twisting or lifting can worsen the condition.
Pain from a herniated intervertebral disk in the lower part of the neck affects the shoulder, arm, and forearm. When pain extends to the hand, it can either be on the little finger side or the thumb side. Numbness and tingling will be felt in these areas. Also, the triceps muscle is enfeebled.
Conservative treatment for cases of herniated intervertebral disk consists of bed rest for a few weeks to get rid of the mechanical pressure which caused the intervertebral disk to break down and jut out. On the other hand, surgical treatment involves eliminating the nucleus pulposus squeezing against the nerve root. The surgeon may, in some cases, find it necessary to insert a bone graft to firm up the vertebral column at the site of difficulty.