Spinal Stenosis

Overview

Stenosis means narrowing, and when referenced to the spine means narrowing or constriction of the spinal canal, which contains the spinal cord and nerves. Although the lumbar spine region is more accommodating and forgiving (than the cervical or thoracic regions) of neurologic compression, it is also the most common location of its occurrence. Spinal stenosis is generally sequelae of aging and degenerative arthritis of the spine. As the degenerative process occurs, the ligamentum flavum becomes hypertropic (overgrown) and the facet joints enlarge and develop osteophytes (bone spurs) that encroach into the spinal canal. As the nerve compression worsens, patients often develop pain, numbness, weakness, and/or difficulty walking (neurogenic claudication). Spinal stenosis is increasingly being recognized as a major cause of pain and dysfunction in our society, particularly since the elderly population is growing exponentially. It is expected that by 2030, 20% of the population will be 65 years or older.

Diagnosis

The condition of spinal stenosis is extremely common and usually easily diagnosed. It can be complicated when the symptoms or physical findings are atypical. Some patients will complain of isolated "hip pain" or "knee pain," and be evaluated and treated for this rather than a back problem. It is important for the clinician to conduct a thorough history and clinical examination prior to formulating a diagnosis so as not to misdiagnosis this condition. Imaging studies (and occasionally laboratory tests) must be used to clarify the diagnosis.

Treatment Options

The treatment of lumbar spinal stenosis often depends on the severity of a patient's symptoms and the severity of neurologic compression. Patients with mild or moderate stenosis may respond very well to conservative treatments. Conservative treatments may consist of oral anti-inflammatory medications and pain medications. Muscle relaxant medications should be used for severe pain and muscle spasms, and only for short duration in elderly patients. Complications secondary to medications are more common in the elderly, and all medications should be closely monitored by the prescribing physician. Physical therapy, manipulation, and modalities may also be utilized, primarily to improve a patient's strength, endurance, and level of function. Epidural steroid injections may provide dramatic improvement of pain symptoms, but only 25% have long-term relief according to a study authored by Surin.

When a patient has severe spinal stenosis and symptomatology, or a patient with mild or moderate stenosis has failed conservative modalities, surgical intervention is considered. Patients noted to have multiple spinal levels involved are indicated for a laminectomy. If a patient only has one or two levels of involvement, then minimally invasive procedures such as a microscopic laminectomy or intra-laminar decompression may be considered. The goals of surgery are to improve a patient's pain and level of function, as well as prevent further deterioration of function and worsening pain. Patients who demonstrate instability or mal-alignment of the spine may also require spinal fusion (mending the spine bones together) in addition to a decompression procedure. There is a high rate of success for patients treated surgically, yet there is a notable increase in morbidity and mortality in elderly patients over 80 years-old, especially those with significant medical problems. A careful preoperative evaluation and delicate perioperative and postoperative management is particularly important in this setting.

 



Selected Bibliography

Amundsen T, et al.: Lumbar spinal stenosis: conservative or surgical management? : a prospective 10-year study. Spine 2000;25(11):1424.

Atlas SJ, et al.: Long-term outcomes of surgical and nonsurgical management of lumbar spinal stenosis: 8 to 10 year results from the Maine Lumbar Spine Study. Spine 2005;30(8):936.

Basmajian JV: Acute back pain and spasm: a controlled multi-center trial of combined analgesics and anti-spasm agents. Spine 1989;14:438.

Fischgrund JS, et al.: Degenerative lumbar spondylolisthesis with spinal stenosis: a prospective randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation. Spine 1997;22:2807.

Galiano K, et al.: Long-term outcome of laminectomy for spinal stenosis in octogenarians. Spine 2005;30(3):332.

Herkowitz HN, Kurz LT: Degenerative lumbar spinal listhesis with spinal stenosis; a prospective randomized study comparing decompression with decompression and intertransverse process arthrodesis. J Bone Joint Surg Am 1991;73:802.

Katz J, et al.: Predictors of surgical outcome in degenerative lumbar spinal stenosis. Spine 1999;24(21):2229.

Lee CK, Rauschning W, Glenn W: Lateral lumbar spinal canal stenosis: classification, pathologic anatomy and surgical decompression. Spine 1980;13:313.

Liebergall M, et al.: The role of epidural steroid injection in the management of lumbar radiculopathy due to disc disease or spinal stenosis. Pain Clin 1986;1:35.

Rosen CD, Kahanovitz N, Berstein R: A retrospective analysis of the efficacy of epidural steroid injections. Clin Orthop 1988;228:270.

Surin V, Hedelin E, Smith L: Degenerative lumbar spinal stenosis. Acta Orthop Scand 1982;53:79.