Spinal stenosis is a progressive "wear and tear" or degenerative process. A range of anatomic structures including the facets, ligamentum flavum, and intervertebral discs may contribute to the symptoms. Degenerative stenosis results in narrowing of the spinal canal and lateral recess and foramen. Although degenerative changes are ubiquitous in the aging population, most individuals do not have symptoms despite these radiographic abnormalities.
Symptomatic lumbar stenosis typically occurs in patients in the fifth to seventh decades of life with a reported incidence from 1.7% to 10%, and as the population ages, a greater number of patients will need to be treated for this condition. Although there may be a structural predisposition to stenosis (congenital short pedicles), symptomatic narrowing of the spinal canal almost always is seen in association with osteoarthritic changes of the lumbar spine. Males and females seem to be affected equally with spinal stenosis; however, women are afflicted with associated degenerative spondylolisthesis four times more often than men. The hallmark symptom is neurogenic claudication. Neurogenic claudication refers to pain radiating to the lower extremities that begins and worsens as the patient walks and resolves as the patient bends forward or sits. Also, patients with stenosis complain of mechanical back pain and radiculopathy that may be unilateral or bilateral.
Spinal Stenosis in the Neck
Cervical stenosis is a condition in which the spinal canal is too small for the spinal cord and nerve roots. This can cause damage to the spinal cord, a condition called myelopathy, or pinch nerves as they exit the spinal canal (radiculopathy). Occasionally, damage to the spinal cord and nerve roots may occur, resulting in a condition called myeloradiculopathy. Stenosis is most often caused by a number of factors which combine to cause a critical level of spinal cord compression, at which time symptoms may develop. Factors contributing to the development of cervical stenosis include: congenital short pedicles (the bones which form the sides of the spinal canal), degenerative arthritis causing excessive bone growth, and thickening of the ligamentum flavum. However, it is important to note that cervical stenosis does not always get worse and cause progressive symptoms. Many people have mild stenosis and never become symptomatic, or have mild symptoms which are not bothersome enough to seek treatment. Even if symptoms occur which are severe enough to seek treatment, they can usually be controlled with a combination of medication and physical therapy. If surgery is ultimately necessary, there are two basic surgeries that are performed. Depending on the cause and location of the stenosis, surgery may be performed from the front, known as anterior cervical fusion. Surgery may also be performed from the back of the neck, commonly called a posterior laminectomy or laminoplasty.
Types of Spinal Stenosis