Stenosis is usually a degenerative process in which the spinal canal narrows, causing compression of the spinal cord and nerve roots. Through wear and tear with aging, bony ridges (osteophytes) develop on the vertebral bodies adjacent to the areas of motion at the intervertebral discs.
Symptoms: Symptoms and the mechanisms which produce them are similar to those associated with disc herniation; however, the two processes are fundamentally different in that disc herniation is an acute event, while stenosis is a chronic, slowly progressive process, which may be punctuated by episodes of worsening. Patients may have symptoms of radiculopathy; usually manifested as shooting pain into the extremities associated with focal numbness or weakness in the distribution of a particular nerve root. In addition, patients may also present with cervical spondylotic myelopathy. (CSM).
Diagnosis:Plain x-rays of the cervical spine reveal osteophytes at the involved level, loss of disc height, and often a narrow spinal canal. Some degree of spondylotic change is seen in 25-50 percent of the population over the age of 50, and in 75 percent of people over 75. A patient's individual clinical profile must be assessed carefully to determine which symptoms may be caused by spondylosis.
MRI examination gives information about the structure of the cervical spine with respect to the soft tissues. Therefore, it gives good information regarding compression of the spinal cord and nerve roots. Myelogram/CT reveals all of these conditions plus it gives information about the bony anatomy of the region.
Treatment: Unlike patients with cervical disc herniation, most patients with spondylotic myelopathy do not improve with nonoperative treatment, because of the progressive degenerative nature of spondylotic disease. Patients treated nonoperatively must be followed closely for worsening of myelopathy. The surgical options are anterior or posterior decompression. Anterior approaches are similar to those described for herniated cervical disc and may be performed at multiple levels as appropriate.
Alternatively, the entire vertebral body may be removed (corpectomy) between adjacent levels of spondylosis, or several bodies may be removed. A bone graft is placed for fusion. To reinforce long grafts, a plate and screws are usually placed.
Posterior decompression involves a laminectomy at the affected levels, and may or may not require a fusion with metal constructs. Most surgeons today would probably prefer an anterior procedure when feasible.
For more information about spine related conditions and treatments, visit the UCLA Spine Center at at spinecenter.ucla.edu.