- Discussion:
- central stenosis produces compression of the thecal sac in contrast to
lateral stenosis which
involves compression of individual nerve roots;
- may be congenital (idiopathic or developmental in
achondroplastic dwarfs) or acquired;
-
acquired stenosis:
- due to degenerative hypertrophic facets w/ medial encroachment (inferior facets most commonly involved);
- can be secondary to
spondylolisthesis, post traumatic, post surgical, Paget's disease, ect;
- soft tissue (ligamentum flavum and disc) may contribute as much as 40% to dural sac compression;
- central stenosis is more common in males because their spinal canal is smaller at the L3-L5 level;
- Clinical Findings:
- neurogenic claudication;
- CT Scan:
- compression of thecal sac to less than 100 mm squ or < 10 mm of
AP diameter as seen on CT cross section;
- Treatment:
- lumbar epidural steroids may be helpful for short term relief;
- surgery is indicated in patients with positive studies and persistent symptoms;
-
decompression:
- laminectomy;
- partial faceteotomy of the
lateral recess;
- can be done w/o destabilizing, thus avoiding fusion;
-
fusion:
- indicated in patients with surgical instability (bilateral facet joint removal);
- neural arch defects with
disc disease;
- symptomatic radiographic instability ( > 4-6 mm horizonatal translation or reversal of the intervertebral angle);
-
degenerative spondylolisthesis;
- degenerative
Scoliosis;
