Avi J. Bernstein and David Lee Spencer

Goals of Surgical Treatment

To achieve a lumbar laminectomy using a straightforward, efficient, and reproducible technique that provides a safer and more effective exposure of the central spinal canal with easy access to the lateral recess and foramina.

Diagnosis

Lumbar spinal stenosis, lateral recess stenosis, and foraminal stenosis are all diagnosed with advanced radiographic means. The diagnosis may be considered based on clinical symptoms of neurogenic claudication or radiculopathy; the confirmation, however, is based on computed tomography (CT) scanning, CT myelography, or magnetic resonance imaging (MRI) scanning. It is our opinion that even though highly sophisticated, well-performed MRI scans can provide a radiographic diagnosis of spinal stenosis, CT myelography remains the gold standard and is a truer representation of the severity and extent of the underlying pathology. In addition the lateral recesses and foramina are better visualized with postmyelographic CT scans than plain CT or MRI scanning.

Preoperative symptoms of neurogenic claudication, as distinguished from vascular claudication, are pathognomonic for spinal stenosis. Walking distances are diminished, symptoms are aggravated by standing and walking and relieved by sitting or forward flexion of the spine, and symptoms generally radiate from the buttocks into the posterior thighs and into the calves, either bilaterally or unilaterally. The neurologic examination is commonly normal, but some patients are noted to walk in a forward flexed fashion with extension maneuvers aggravating their symptoms. X-rays commonly reveal spondylosis or spondylolisthesis; however, even normal-appearing x-rays with minimal degenerative change may underestimate the degree of spinal stenosis, because stenosis commonly results from secondary soft tissue changes such as disc bulging, disc herniation, facet synovial hypertrophy, and buckling of the ligamentum flavum. Secondary degenerative hypertrophic facet changes and instability including spondylolisthesis suggest subarticular lateral recess stenosis and foraminal stenosis.

In performing lumbar myelography, it is important to obtain weight-bearing anteroposterior (AP), lateral, and oblique views, as they will demonstrate the functional pathology that is symptomatic in the upright position. Absence of these views may completely miss the diagnosis.

Indications for Surgery

1. Symptomatic spinal stenosis, lateral recess stenosis, or radiculopathy unrelievable through symptomatic means.

2. Any indication for routine lumbar laminectomy where access to the central spinal canal, lateral recesses, or foramina are required as part of an open procedure.

3. Laminectomy performed in combination with posterior spinal fusion as a source of additional bone graft and to assist in pedicle evaluation.

Contraindications

1. Prior limited laminectomy or partial laminectomy with secondary scar formation and potential dural adhesions. Under these circumstances extreme caution must be applied to ensure that adhesions do not result in dural laceration.

2. Unidentifiable anatomy.

Advantages

1. Improved procedural time

2. Lower risk and rate of dural laceration

3. Reduction of blood loss

Disadvantage

Iatrogenic instability due to excessive facet resection.

Procedure