- spinal stensosis is a narrowing of the lumbar spinal canal and/or neural foramina;
- results in compression of the cauda equina and lumbar nerve roots, producing neural root ischemia and neurogenic claudication;
- compression of neural structures also compresses vascular supply of nerves so that symptoms are predominately those of neural ischemia;
- because both neural canal and the neural foramen are narrowed w/ spine in extension & opened in flexion, neural compression is most often temporary;
- pain induces patients to change position and relieve nerve pressure before permanent neurologic damage is done;
- although degenerative spondylolisthesis is common cause of stenosis, 10% of adults > 65 yrs may have this finding & many are asymptomatic;
- central stenosis:
- refers to narrowing and compression at the entrance and within the neural foramen formed by the cephalad and caudal pedicles,
facet joints dorsally and vertebral body and discs ventrally.
- The natural course of lumbar spinal stenosis.
rest and standing;
- radicular symptoms may be unilateral or bilateral with or without back pain
- pain occurs when the patient is upright and particularly when walking;
- standing and walking up inclines increase pain;
- sitting and lying on side with the hips and knees flexed relieve pain as does leaning over a shopping cart.
- patient seeks relief by sitting, leaning forward to "relieve pressure" putting his foot on a raised rest, or lying down;
- common denominator is changing the position of the spine from extension to flexion;
- dx of spinal stenosis is made by eliciting h/o of pseudoclaudocation, positive spinal Phalen test, and imaging confirming stenosis;
- patients may present with bizarre neurologic complaints
- EMG is helpful in evaluation the nerve roots affected and in ruling out other causes of neuropathy;
- this test attempts to reproduce symptoms of leg pain, weakness, or numbness by causing neural ischemia;
- w/ pt upright, bend the patient into extension for a full minute;
- this should accentuate the spinal stenosis;
- positive test will produce a crescendo of leg symptoms followed by rapid relief of these symptoms when the patient flexes forward,
places his hands on examination table, and places one foot on stool;
- AP and lateral radiographs including flexion and extension laterals are helpful.
- disk space narrowing is a poor predictor of symptoms;
- normal anterior and posterior translation from L1 to L5 is about 8% of length of vertebral body or about 4 mm;
- note that the typical degenerative changes of osteophyte formation, decrease in disc height, and ligament calcification will serve to limit motion;
- myelogram with the patient in extension may offer the best information on location of stenotic areas;
- CT scan:
- coronal and sagittal CT reconstructions are quite helpful
- evaluate for lateral stenosis & central stenosis;
- cross-sectional dural areas of < 100 mm2 denote stenosis;
- clinical syndrome of lumbar stenosis correlates more closely w/ anteroposterior diameter of the dural sac;
- dural sac w/ AP diameter of < ten millimeters is consistent w/ clinical syndrome of lumbar stenosis;
- MRI delineates very accurately the compressive elements of LSS
- Role of computed tomography and myelography in the diagnosis of central spinal stenosis.
- Radiologic diagnosis of degenerative lumbar spinal instability.
- Non Operative Treatment:
- high percentage of patients will have little change in their symptoms without treatment;
- physical therapy and aquatic exercises which avoid extension may be helpful.
- image guided intralaminal epidural and transforaminal nerve root steroid injections may provide relief for variable periods of time.
- Operative Treatment:
- decompression by laminectomy and partial facetectomy is effective.
- indications for fusion:
- fusion with instrumentation in addition to decompression may be necessary in patients with degenerative spondylolisthesis,
degenerative scoliosis, post laminectomy, and those with adjacent segment stenosis following a fusion;
- w/ no segmental instability, arthrodesis may not be required, (assumming that posterior elements have not been destabilized);
- degenerative spondylolisthesis;
- be particularly certain that there is no pressure on abdomen which would compress the vertebral venous plexus;
- laminae are minimally trimmed for exposure;
- includes widening of lateral recess;
- removal of medial rim of facets;
- postero-lateral fusion:
- see: fusion of the spine
- Treatment of cervical spondylotic myelopathy by enlargement of the spinal canal anteriorly, followed by arthrodesis.
- Bone regrowth after surgical decompression for lumbar spinal stenosis.
- Lumbar foraminal stenosis: critical heights of the intervertebral discs and foramina. A cryomicrotome study in cadavera.
- Increase of motion between lumbar vertebrae after excision of the capsule and cartilage of the facets. A cadaver study.
- Laminectomy with and without spinal fusion.
- Postdecompression lumbar instability.
- Morbidity and mortality in association with operations on the lumbar spine. The influence of age, diagnosis, and procedure.
- Neurologic complications and lumbar laminectomy. A standardized approach to the multiply-operated lumbar spine.
- Repeat decompression of lumbar nerve roots. A prospective two-year evaluation.
- Degenerative lumbar spinal stenosis. Decompression with and without arthrodesis.
- The outcome of decompressive laminectomy for degenerative lumbar stenosis.
- A Comprehensive Study of Patients with Surgically Treated Lumbar Spinal Stenosis with Neurogenic Claudication.
- Perioperative Complications of Posterior Lumbar Decompression and Arthrodesis in Older Adults.
1997 Volvo Award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: a prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation.
Original Text by Clifford R. Wheeless, III, MD.
Last updated by Data Trace Staff on Thursday, April 12, 2012 4:10 pm